Detrital zircons record rigid continents after 2.5 Ga Quantifying gas

Transcription

Goldschmidt Conference Abstracts
Detrital zircons record rigid
continents after 2.5 Ga
Quantifying gas composition and
yield from the 946 CE Millennium
Eruption of Paektu volcano,
DPRK/China
LINDA M. IACCHERI1* AND ANTHONY I.S. KEMP1
1
School of Earth and Environment, The University of Western
Australia, 35 Stirling Highway, Crawley 6009 WA
(*correspondence: [email protected])
The Neoarchean-Paleoproterozoic boundary represents a
milestone in Earth’s history and is marked by fundamental
changes in mantle, crust and atmosphere-hydrosphere
compositions [1]. These transitions show that the evolution of
Earth’s deep interior and its exterior are linked, but the
processes that lie behind the transitions are still cryptic.
The composition of the crust depends on magmatic
processes and/or on the nature of the magma source(s), which
can be revealed by the isotopic fingerprints locked in zircons.
Monitoring how the composition of the magma sources
change with time can help to unravel crustal evolution.
Here we present new oxygen and Hf isotope compositions
of detrital zircons from 1.8 Ga turbidites from the North
Australian Craton. The detrital zircons have local provenances
and record a crustal source section for three subsequent
magmatic events: 2.7 Ga, 2.5 Ga and 1.9 Ga. These ages
straddle the Neoarchean-Paleoproterozoic boundary and
correlate with the major peaks in the global zircon record [2].
The results portray complex reworking of crustal
components with limited growth. At 2.7 Ga, bimodal εHf (+6
to +4, 0 to -7) and mantle-like δ18O values indicate both
crustal growth and the reworking of infracrustal components.
At 2.5 Ga a wide range in εHf (+7 to -12) and δ18O from 5 to
7‰ reflect limited crustal growth and the reworking of
variably old infracrustal and supracrustal components. At 1.9
Ga the εHf array contracts markedly (from +3 to -8) and is
coupled with heavy oxygen (δ18O from 7 to 9.5‰), reflecting
partial melting of supracrustal sources.
The lack of a linear correlation between zircon εHf and
δ18O at 1.9 Ga implies that the array does not reflect the
simple mixing of contrasting magmas. The isotopic array at
1.9 Ga may instead represent the partial melting of
sedimentary rocks derived from heterogenous 2.5 Ga crust that
was blended by weathering and erosional processes.
This finding suggests more rigid behaviour of the crust
after 2.5 Ga, allowing mountain building, uplift, mechanical
erosion, transport and deposition.
[1] Barley et al. (2005) EPSL 238, 156-171. [2] Condie (1998)
EPSL 163, 97-108.
K. IACOVINO1*, J.S. KIM2, T. SISSON1, J. LOWENSTERN1,
K.H. RI3, J.N. JANG2, K.H. SONG2, H.H. HAM2, C.
OPPENHEIMER4, J.O.S. HAMMOND5, A. DONOVAN6, K.
WEBER-LIU7, K.R. RYU8
1
US Geological Survey, Menlo Park, CA 94025
*correspondence: [email protected]
2
Earthquake Administration, Pyongyang, DPRK
3
State Scientific Academy, Pyongyang, DPRK
4
Dept. of Geography, University of Cambridge, UK
5
Department of Earth and Planetary Sciences, Birkbeck,
University of London, UK
6
Dept. of Geography, King’s College London, UK
7
Environmental Education Media Project, Beijing, China
8
Pyongyang International Information Centre of New
Technology and Economy, Pyongyang, DPRK
Magmatic volatiles such as H2O, CO2, sulfur, and
halogens (e.g. F, Cl) are injected into the atmosphere during
explosive volcanic eruptions and can drive globally significant
climate change. Accurate quantification of volatile yield and
composition is critical in assessing the impact of an eruption
but is elusive, particularly for pre-historic or unmonitored
eruptions. We utilize a geochemical technique to calculate CO-H-S-F-Cl gas composition and mass yield from silica-rich
explosive volcanoes by examining trends in incompatible trace
and volatile element concentrations in crystal-hosted melt
inclusions. We apply this technique to one of the largest
volcanic eruptions in recorded human history, the 946 CE
Millennium Eruption (ME) of Paektu (Changbaishan) volcano,
which produced comenditic tephra and a caldera that straddles
the border between the Democratic People’s Republic of
Korea (DPRK) and China. We calculate a sulfur yield of up to
45 Tg S from the ME. An estimated column height of 29 km
indicates injection of much of this S into the stratosphere. This
sulfur yield is 1.5 times that released during the eruption of
Tambora in 1815, which resulted in significant global cooling
in 1816. We suggest that the minimal climate perturbations
after the Millennium Eruption as inferred from polar ice cores
was due to the high latitude and season of the eruption and is
not reflective of the significant S output. The total gas yield is
calculated to be 3517 Tg, made up of 88.7 wt% H2O, 1.3 wt%
S, 1.6 wt% F, 0.6 wt% Cl, and 7.8 wt% CO2. Our work places
the Millennium Eruption among the top ranking volcanic
volatile emitters in recorded human history.
Physisorption Analysis And
Interpretation Of Earthy Materials
Applied Topically As Cosmetics In
Some Selected African Countries
IBEH OS, AZIKE NI, POPOOLA EO
123
1
[email protected]
[email protected]
3
[email protected]
2
Earthy materials are those indigenous substances which
various communities apply for beautification, sunscreening,
cleansing and against UV light, this is common to African
communities. They are useful for both industrial and
indigenous practices. The study focused on using the
physisorption data to interpret and classify them according to
their adsorption isotherm (Type I-IV). 22 samples was
collected from Botswana (BTS), Cameroon (CMR),
Democratic Republic of Congo (DRC), Nigeria (NG), South
Africa (SCC) and Swaziland (SWL) respectively.
Micromeritics BET, Tristar II 3020 instrument and N2 (g), a
standard laboratory method was used to determine the various
classifications, porosity and surface area. BTS 1 and BTS 2,
CMR 1 and CMR 2, NG 1 and NG 2, SCC 4, SCC 5, SCC 8,
SCC 9, SCC 11 and SCC 12 and SWL 1 and SWL 2 fell
within Type II adsorption isotherm, whereas samples SCC 2,
SCC 3, SCC 6, SCC 7 and SCC 7 are Type III isotherm. The
study revealed that the shape (Type) of the pore and the
surface chemistry of an earthy materials enhances its
usefulness for topical application.
Partitioning of Fission Products (Cs,
Sr and I) into Salt Phases
J. ICENHOWER1*, L. KIRKES1, C. MARRS1, J. KNOX1, J.
DEAN1, R. GRANT2, AND J. OHLHAUSEN2
1
Sandia National Laboratories, 4100 National Parks Highway,
Carlsbad, New Mexico 88220, USA (*correspondence:
[email protected]; [email protected];
[email protected]; [email protected];
[email protected])
2
Sandia National Laboratories, 1414 Eubank, Albuquerque,
New Mexico 87123, USA ([email protected];
[email protected])
The Waste Isolation Pilot Project (WIPP) is a
nuclear waste repository located in SE New Mexico, USA.
The repository is hosting TRU waste and future disposal in
similar sites may accept waste containing fission products
(FPs). Should groundwater intrude such a repository and
mobilize FPs, the transport of Cs, Sr and I may be limited by
partitioning into salt phases, such as carnallite
[KMgCl3·6H2O],
langbeinite
[K2Mg2(SO4)3],
leonite
[K2Mg(SO4)2·4H2O], polyhalite [K2Ca2Mg(SO4)4·2H2O],
gypsum [CaSO4·2H2O], and sylvite [KCl]. We report
experimentally determined partitioning of non-radioactive
isotopes of Cs, Sr and I between salt phases and solution as a
function of temperature and concentration of target elements.
Experiments were carried out at temperatures from 28 to
90°C. Saturated solutions were evaporated to induce mineral
growth. Concentrations of Cs, Sr and I were added to solution
between 100 to 1,000 ppm, except for sylvite experiments, in
which concentrations of 1,000 and 5,000 ppm were required.
Concentrations (ppm) of major, minor and trace elements were
determined by ICP-MS, -AES and IC (SO42- and I-).
Concentrations of Cs, Sr and I (ppm) in crystals were
determined by electron microprobe analysis (EMPA) and the
distribution of these elements in solids imaged by time-offlight secondary ion mass spectrometry (ToF-SIMS).
Previous investigations [1, 2] quantified partitioning
of Cs into carnallite and sylvite. Our results are consistent with
previous work with distribution coefficients for Cs between
carnallite and solution between 0.5 and 1.5. The distribution of
I between carnallite and solution correlates inversely with
temperature with values between 0.05 and 0.3. Partioning of
Cs and I between sylvite and solution is ≤ 0.05 and ~0.20,
respectively. The distribution of Cs between leonite and
solution is ~1.0.
[1] Schock & Puchelt (1971) Geochim. Cosmochim. Acta 35, 307317. [2] Schock (1966) Contrib. Min. Petrol. 13, 161-180. This
research is funded by WIPP programs administered by the
Office of Environmental Management (EM) of the U.S
Department of Energy. Sandia National Laboratories is a
multi-program laboratory managed and operated by Sandia
Corporation, a wholly owned subsidiary of Lockheed Martin
Corporation, for the U.S. Department of Energy’s National
Nuclear Security Administration under contract DE-AC0494AL85000. This research was supported by the Salt R&D
Programs administrated by the Office of Nuclear Energy, U.S.
Department of Energy.
The Equation of State of Liquid Pure
Fe and Fe-light Elements Alloys by
Ab Initio Molecular Dynamics
Simulations to confine the outer core
composition
HIROKI ICHIKAWA1,2*, TAKU TSUCHIYA1,2, AND
MASANAO OHSUMI1
1
Geodynamics Research Center, Ehime University, 2-5,
Bunkyocho, Matsuyama, Ehime, 790-8577, Japan
2
Earth-Life Science Institute, Tokyo Institute of Technology,
Ookayama 2-12-1, Megro Tokyo, 152-8551, Japan
The equation of state (EoS) of pure Fe and Fe-light
elements alloy liquids were calculated by means of ab initio
molecular dynamics (AIMD) simulations at the outer core P-T
conditions. In the outer core, many light elements, such as
carbon, nitrogen, oxygen, hydrogen, sulfur, and silicon, have
been proposed as possible constituents. The concentrations of
these elements have been strongly debated for years.
The density and the adiabatic bulk and shear modulus of
iron and iron-light element alloys are essential to interpreting
seismological observations and to constructing a mineralogical
model of the core. On this subject, AIMD simulations have
successfully clarified density and bulk sound velocity at the
outer core conditions for various Fe-light elements systems
[e.g. 1, 2]. However, the data points are limited at several P, T
conditions. Meanwhile, several studies have been performed
throughout the whole outer core P-T conditions for pure Fe [3,
4], Fe-S [5], and Fe-H [6]. In these studies, Grüneisen
parameter, whose value is required for the calculation of bulk
sound velocity, is obtained as a consequence of the evaluation
of the equation of state. However, different formulations of
Grüneisen parameter are employed in all the studies.
In this study, we investigated energy (E)-pressure (P)volume (V)-temperature (T) relationships of liquid Fe-light
elements systems in the Earth’s core condition by AIMD
simulations and proposed a new P-V-T EoS under the whole
outer core conditions. We also confined plausible outer core
compositions, which reproduce seismological values
reasonably throughout the whole outer core conditions.
[1] Pozzo et al. (2013) PRB 87, 014110. [2] Badro et al.
(2014) PNAS 111, 7542-7545. [3] Vočadlo et al. (2003) PEPI
140, 101-125. [4] Ichikawa et al. (2014) JGR 119, 240-252.
[5] Umemoto et al. (2014) GRL 41, 6712-6717. [6] Umemoto
& Hirose (2015) GRL 42, 7513-7520.
Molecular simulation of pressure
dependent boron isotope equilibrium
between boron hydrates
H. ICHIKAWA1a, M. MUSASHI2b*, M. MIKAMI3c,
S. TSUZUKI3, T. OI1
1
Sophia Univ., Tokyo 102-8554 Japan ([email protected])
2
Tokyo Metropol. Univ., Tokyo 192-0397 Japan.
3
AIST, Tsukuba 305-8565 Japan ([email protected])
Present addresses: aAsahi Dia. Industrial Co., Tokyo 102-0094
Japan ([email protected]); bShibaura Inst. Technol.,
Saitama 337-8570 Japan; cKeio Univ., Yokohama 223-8522
Japan ([email protected])
Boric acid, B(OH)3, is partially dissociated in solution as
borate anion, B(OH)4-. Boron, B, isotope exchange
equilibrium between the two molecules has been important
tool to study geochemical problems related to a circulation of
volatile elements at subduction related environment. However,
since chemical equilibrium depends on several factors, careful
discussion on B isotopic fractionation in nature is necessary.
Recent result on molecular orbital, MO, calculation showed
that reduced partition function ratio, RPFR, of B hydrate
depended on the hydration number, n. A pressure made it
progress dehydration of hydrates adsorbed onto solid phase,
implying that B isotope effect might be influenced by
pressure.
In this study, we perform the molecular dynamics, MD,
simulation to evaluate the pressure dependence of dehydration
of B hydrates in bulk solution, and employ the MPDyn
program. The geometrical parameters and force fields of
molecules are calculated by the ab initio MO method, and the
systems are simulated as a B(OH)3 molecule with 2502
molecules of H2O and a B(OH)4- molecule with a H3O+
molecule and 2500 molecules of H2O. The MD simulations
are performed for 10 ps at 100MPa, and for 100 ps at 0.1, 50,
and 100MPa. A radial distribution function, RDF, and an
angle distribution are simulated for 1.2 ns.
Results of the RDF of either between a B of B(OH)3 and a
H2O molecule or between a B of B(OH)4- and a H2O molecule
show that the hydration numbers in the first hydration sphere,
n1, are invariant up to 100MPa. In both cases, any obvious
difference on neither RDF nor the n1 is found at this condition,
implying that pressure would less influence on the B isotope
effect caused by dehydration of the boron hydrates in bulk
solution. However, by a study of MO computation, RPFR of
B(OH)4- increases with decreasing the n1 of B(OH)4- hydrate
adsorbed on to solid phase. This suggests that dehydration of
B hydrate adsorbed into solid phase from bulk solution could
reduce its RPFR. Enhancement of the dehydration by pressure
could be a cause of the gain of the RPFR.
Petrogenesis of plutonic rocks in the
Mineoka-Setogawa Belts: Toward
understanding of deep crustal rocks
in the IBM Arc
Y. ICHIYAMA1*, H. ITO2, N. HOKANISHI3, A. TAMURA4
4
AND S. ARAI
1
Chiba University, 1-33 Yayoi, Inage, Chiba, 263-8522 Japan
2
Central Research Institute of Erectric Power Institute
3
University of Tokyo
4
Kanazawa University
The Mineoka-Setogawa Belts are Paleogene accretionary
complexes distributed around the Izu Peninsula. These belts
contain the various sizes of ophiolitic fragments of
serpentinized mantle peridotites, plutonic rocks and volcanic
rocks. We performed the zircon U-Pb dating for the gabbros,
diorites and tonalites from the Mineoka-Setogawa Belts, and
obtained approximately 35 Ma that is coeval with the Eocene
to Oligocene arc magmatism in the IBM Arc.
The major-element chemistry of the plutonic rocks from
the Mineoka-Setogawa Belts shows linear trends in several
elements against SiO2 content. The REE patterns of the
gabbros and the diorites and tonalites are similar to those of
tholeiitic and calc-alkaline volcanics in the Eocene to
Oligocene IBM Arc, respectively. The chemistry of the
tonalites are also similar to the crust-origin rhyolites in the
IBM Arc [1]. The plagioclase An content in the diorites
indicates that the diorites were formed by the mixing between
mafic and felsic magmas. Tatsumi and Suzuki [2] proposed
that andesitic plutonic rocks in the middle crust in the IBM
Arc were produced by the mixing of tholeiitic basaltic magma
with the crust-origin rhyolitic magma. The petrological
characteristics of the Mineoka-Setogawa plutonic rocks are
highly consistent with the current petrogenetic model for the
deep IBM crust.
[1] Tamura et al. (2009) J. Petrol., 50, 685-723. [2] Tatsumi
and Suzuki (2009) J. Petrol., 50, 1575-1603.
Time scale evalutation of transitions
of chemical weathering reactions in
Kirishima volcanic area, Japan
K. IDE1, T. HOSONO2, S. HOSSAIN1 AND J. SHIMADA1
1
Graduate School of Science and Technology, Kumamoto
University, 2-39-1 Kurokami, 860-8555, Kumamoto,
Japan (*correspondence: [email protected])
2
Priority Organization for Innovation and Excellence,
Kumamoto University, 2-39-1 Kurokami, 860-8555,
Kumamoto, Japan ([email protected])
The Kyushu Island in southern Japan is located within
very high potential area of the chemical weathering and
suggested as an area showing the highest discharge potential
of dissolved silicates and some cations within the Japanese
Island arc. Based on dissolved ion concentrations information,
many studies have reported that geochemically evolved (old)
and un-evolved (young) groundwater have different chemical
weathering stages. However, the knowledge of water-rock
interaction time scale that requires for the transition of each
secondary mineral is not sufficiently known in natural systems
due to the lack of groundwater age information together with
chemical weathering index.
The objective of this work was to investigate the time
scale of transitions of chemical weathering reactions in natural
groundwater systems. In total of 197 spring water samples
were collected during 2007-13 around Kirishima volcanic
area, southern Kyushu Island (1700 m in altitude, average
annual precipitation of 2600 mm/yr). These samples were
analyzed for groundwater residence time and geochemistry to
be compared.
The geochemical features of spring water samples with
geological information of this area suggested that dominant
reactant minerals are pyroxene and plagioclase. Precipitation
minerals were also estimated using Geochemist’s workbench
software. Then, kaolinite and smectite were deduced as major
secondary minerals precipitating from the system. In order to
verify the water-rock interaction occured in the system,
stoichiometry calculation was attempted on measured
dissolved ions. Estimated concentration from weathering
equation was plotted against measured concentrations of
dissolved ions and found, the samples which are indicating of
smectite precipitation has longer residence time compare to
those samples indicating of kaolinite precipitation.
Our observation suggest that at least 20 years of
interaction is needed for the alteration of precipitation reaction
from kaolinite to the smectite .
Possible Fe(II) Fueled Microbial
Ecosystem at the Carbonate Rich Hot
Spring Okuoku-hachikuro Onsen, a
Possible Early Ocean Analog Site
Salinity Dependence of Apparent
Diffusion Coefficients of Selenite,
Selenate, Molybdate and Iodate in
Compacted Bentnite
A.IDEI1*, T.KAKEGAWA2, SE. MCGLYNN1,3
K. IDEMITSU, R. HAMADA, Y. OGAWA, N.
OKUBO, Y. INAGAKI, T. ARIMA
1
Department of Biological Sciences, Tokyo Metropolitan
University, Tokyo, Japan (*[email protected])
2
Department of Earth Science, Tohoku University, Sendai,
Japan
3
Earth-Life Science Institute (WPI-ELSI), Tokyo Institute of
Technology, Tokyo, Japan
The Okuoku-hachikuro (OHK) hot spiring in Akita
Prefecture, northeastern Japan has iron and carbonate rich
water and sediments. At the spring, iron and carbonate
deposits exhibit sub-millimeter lamination textures resembling
banded iron formations [1]. Iron-rich deposits are commonly
thought to be formed by microbial activity in various marine
and fresh water environments [2, 3, 4]. In this study, we report
our preliminary data about biomass distributions different sites
along the hot spring fluid flow. Surprisingly, the majority of
cells are at depth, implying redox or nutritional gradients drive
specific niches (Fig. 1) and almost all microbes are observed
on the mineral particles. In the hot spring, we hypothesize
there is a ferrous iron fueled ecosystem at depth which cannot
exist on the surface because ferrous iron is depleted by
microbial oxidation and also with O2.
Kyushu Univ., Fukuoka 819-0395 Japan
The apparent diffusion coefficients of oxyanions such as
selenite, selenate, molybdeate and iodate in Japanese
bentonites were investigated in various salinity, because the
waste including a great deal of salinity occurred by Fukushima
dai-ichi accident.
The apparent diffusion coefficients of oxyanions tended to
decrease with increase of dry density and content of
montmorillonite of bentonite and be increased by the salinity.
This is explained by a change in porosity as diffusion path.
Furthermore, effective porosity for diffusion becomes small
by anion exclusion of the negatively charged montmorillonite.
Anion accessible porosity was calculated by left out the
interlayer porosity [1]. The apparent diffusion coefficients of
oxyanions are plotted as a function of anion accesible porosity
in figure below. The apparent diffusion coefficient would be
explained by Archie’s law [2] and is proportional to
exponentiation of anion accesible porosity. Selenite has larger
apparent diffusion coefficient than those of other anions
becouse the stokes radius of selenite is larger than others.
10
10
-10
>0.5 M <0.1 M
▼
▼ : IO3
■
■:
◆
◆:
●
●:
2-
SeO4
2MoO4
2SeO3
-11
a
2
D (m /s)
10
-9
Fig. 1. The number of cells from different sites along the hot
spring fluid flow. Place 1 is the hot spring source. Place 2 is
the surface at the edge of source pool. Place 3 is the surface in
low flow and Place 4 is flowing site. Place 5 is a terminal
small pool.
[1] TAKASHIMA, C., OKUMURA, T., NISHIDA, S.,
KOIKE, H. and KANO, A. (2011), Island Arc, 20: 294–304.
[2] Widdel F., Schnell S., Heising S., Ehrenreich A., Assmus
B. & Schink B. 1993. Nature 362, 834–6. [3] Kennedy C. B.,
Scott S. D. & Ferris F. G. 2003. Geomicrobiology Journal 20,
199–214. [4] Kappler A. & Newman D. K. 2004. Geochimica
et Cosmochimica Acta 68, 1217–26.
10
-12
10
-13
0.01
0.1
Anion accesible porosity (-)
1
Figure 1: Apparent diffusion coefficients of oxyanions as
a function of anion accesible porosity.
[1] Idemitsu et al. (2015) Progress in Nuclear Energy
doi:10.1016. [2] Archie (1942) Trans. Am. Mech. Eng. 146,
54-67. [4]
Mullitization from sillimanite by
synchrotron X-ray diffraction
experiment and TEM observation
Are biological aerosols involved in
resuspension processes of Fukushima
radioCs?: Preliminary observations
YOHEI IGAMI1*, SHUGO OHI2, AND AKIRA MIYAKE1
YASUHITO IGARASHI1*, TERUYA MAKI2, KAZUYUKI
KITA3, CHISATO TAKENAKA4, TAKESHI KINASE3
1
Department of Geology and Mineralogy, Kyoto University,
Kitashirakawa-oiwakecho, Sakyo, Kyoto, 606-6502, Japan
2
Faculty of Education, Shiga University, Hiratsu, Otsu, Shiga,
520-0862, Japan
The polymorphs of Al2SiO5 including sillimanite is very
important for geologists as indicators of the pressure and the
temperature in metamorphic rocks. Moreover, it is well known
that sillimanite heated at high temperature transform to mullite
Al2 [Al2+2x Si2-2x] O10-x (x = 0.17 – 0.59) [1,2], but the
transformation to mullite (which is called as mullitization)
from sillimanite has not been well revealed in detail and the
mullitization temperature Tc is even not well determined. The
main experimental problem is that it is difficult to distinguish
sillimanite and mullite by X-ray diffraction (XRD) experiment
because each unit cell parameters are very similar. Therefore,
we carried out high resolution synchrotron XRD experiment
(BL-4B2 in PF, KEK) and transmission electron microscope
(TEM, JEOL JEM-2100F) observation for annealed
sillimanite, to reveal the behaviour of mullitization.
As the result, the texture like anti-phase boundary (APB)
with sub-micro order SiO2-rich glass, similar to the texture
shown in previous study [3], were observed from the samples
heated at various experimental conditions. The high resolution
XRD pattern of these samples clearly showed mullite peaks.
So, we interpreted that APB-like texture and glass inclusions
are the texture of the early stage of mullitization. We made
Time-Temperature-Transformation diagram of mullitization
by XRD patterns, and estimated the mullitization temperature
Tc as about 1013˚C
[1] Gyepesova & Durovic (1977) Silikaty, 2, 147-149
[2] Tomba et al. (1999) Ceramic International, 25, 245-252.
[3] Holland & Carpenter (1986) Nature, 320, 151-153.
Meteorological Research Institute,1-1 Nagamine, Tsukuba
305-0052, Japan; [email protected]
2
Kanazawa University, Kakuma, Kanazawa 920-1192, Japan;
[email protected]
3
Ibaraki University, Bunkyo, Mito 310-8512, Japan;
[email protected]
4
Nagoya University, Furo-cho, Nagoya 464-8601, Japan;
[email protected]
1
The present authors have carried out field observations for
atmospheric re-suspension of the radioactive cesium (Cs)
originated from the Fukushima Dai-ichi Nuclear Power Plant
(FDNPP) accident in contaminated area in Fukushima
prefecture (Namie) by the accident to assess the atmospheric
effects.
After ceasing the surge of the primary emission from the
FDNPP site by the accident, so-called resuspension has
continued from the contaminated area. As a result of the
observation it was known that 1) during summer Cs
concentration increases in such typical Japanese villagevicinity mountain area and that 2) radioactive particles in
summer seem to be dust from its appearance and their optical
micrograph with a sort of our preconception. Whereace we
realized, in the course of the research, that most of the
particles collected on the filter were of biological origin from
electron-microscopic analysis. Considering the known fact
that true fungi concentrate Cs due to misidentifying Cs as
potassium, we hypothesize that the fungal spore could be the
major contributing host particle for Cs resuspension.
So, we have carried out preliminary observations at the
Namie site during summer and winter for the possible
bioaerosol detections by using the fluoresence microscopy and
DNA analysis. In this presentation, we will show the results
for the bioaerosol number concentrations by fluoresence
microscopic counting and predominant species by the DNA
analysis.
The Cs resuspension through the terrestrial ecosystemic
cycle could be possible, for instance, in the case of cedar
pollen. However, bio-resuspension related to the fungal spore
or related bioaerosol emission is a quite novle hypothesis. The
hypothesis is under tests by observations as well as model
simulations through budget analysis, etc., which could
contribute better understanding of anthropogenic Cs behavior
in the terrestrial environment.
Estimation of evaporation rate and
temperature for water using
hydrogen and oxygen stable isotopic
ratios
HIROYUKI II1 AND MASAHIRO YAMASHITA 2
1,2
Concise method for isotope analysis
of oxygen in phosphate: A new
inorganic biomarker
H. IIDA1, K.E. YAMAGUCHI1,2, AND X. WANG3
1
Department of Chemistry, Toho Univerisity
NASA Astrobiology Institute
3
Anti-Doping Research Lab., Japan Chemical Analysis Ctr
2
930 Sakaedani, Wakayama city, Wakayama prefecture,
Japn, [email protected]
Both evaporation rate and temperature were estimated
from δD and δ18O values of water before and after
evaporation in laboratory evaporation test under uniform
temperature condition. Temperature during evaporation
process was calculated by the following equation.
(δDae – δDbe – 51.3) / (δ18Oae - δ18Obe -7.52)
= -0.064×temperature + 7.45
δDae: δD value of water after evaporation, δDbe: δD
value of water before evaporation, δ18Oae: δ18O value of
water after evaporation, δ18Obe: δ18O value of water before
evaporation.
The relation between evaporation rate and hydrogen or
oxygen stable isotopic ratio changed with temperature during
evaporation process. Then, under each temperature condition,
evaporation rate was calculated from hydrogen or oxygen
stable isotopic ratio by the following equations.
20℃：Evaporation rate = 1.32(δDae – δDbe) + 10.96
Evaporation rate =9.90 (δ18Oae - δ18Obe) – 16.36
25℃：Evaporation rate = 0.60(δDae – δDbe) +15.19
Evaporation rate = 3.66(δ18Oae - δ18Obe) + 10.63
35℃：Evaporation rate =1.16(δDae – δDbe) + 3.15
However, these relations were stable under low humid
condition but unstable under high humid condition because
isotope effect for evaporation process is influenced by isotopic
ratio of vapor and then under high humidity condition, the
effect of vapor is eager to be strong.
Oxygen isotope compositions of phosphate (δ18OP) have
been recently used as inorganic biomarker, paleothermometer,
or tracer of phosphate in the environment. Various studies
have applied this tool to analyses of natural samples. Previous
studies used several precipitation steps (MAGIC: Mg-induced
coprecipitation, APM: NH4 phosphomolybdate, MAP: Mg
ammonium phosphate, or CePO4) followed by ion exchange to
isolate phosphate. However, there exist serious analytical
problems; (1) time-consuming phosphate-isolating steps, (2)
unknown removal efficiency of interfering elements and (3)
degree of isotope fractionation during separating procedures.
This study overcame these problems by simplifying the
conventional procedure to just 3 steps; MAGIC, cation and
anion exchange, and by investigating phosphate recovery,
removal efficiency of interfering elements, and isotope
fractionation on each step to quantitatively assure a newly
developed separating method. Phosphate was finally
precipitated as Ag3PO4 for δ18OP analysis by TC/EA-irMS.
Recovery and removal were almost 100%. Isotope
fractionations were small during MAGIC and Ag3PO4
precipitation (max. 3.99‰ and 1.62‰, respectively).
However, large fractionations occur during anion exchange
(13.95‰), which are best explained by Rayleigh distillationlike, irreversible anion exchange reaction by column
chromatography. The 13.95‰ fractionation was the largest in
non-biological reactions ever published, and comparable to
that during biological reactions. These results further
underscore, for precise oxygen isotope analysis of phosphate,
the importance of perfect phosphate recovery (ensured in this
study) especially during anion exchange. Further studies of
δ18OP analysis of natural samples are expected with this newly
developed method.
Fluid path in the lower crust
estimated by S-wave reflection
analysis
Y. IIO
1
1
Disaster Prevention Research Institute, Kyoto Univ.,
Gokasho, Uji, Kyoto 611-0011, Japan
([email protected])
The Role of geofluids on geodynamics and earthquake
generation has long been investigated. It is well known that
high pore pressure can reduce the strength of seismogenic
faults, and that strain rates increase with high water contents
within ductile faults below the seismogenic layer.
Furthermore, it is thought that these phenomena are originally
related to geofluids upwelling from subducting oceanic plates.
The physical and/or chemical processes concerning these
phenomena are clear, however, direct evidence about them in
the real crust has been rarely obtained until now. For example,
high pore pressures have not been measured directly in the
fault zone, and low velocity or low resistivity anomalies of a
fault width scale have not estimated in the lower crust.
In this study, in order to clarify geofluid paths from mantle
to seismogenic faults and its role on earthquake generation, we
estimated detailed crustal structures mainly by an S-wave
reflection analysis using waveforms of natural earthquakes.
Since we used the data from the dense seismic network
operated by the “manten” project, we estimated relative
reflection strengths with a very fine scale of 1.5km in the
lower crust.
It is found that near the Moho discontinuity, regions of high
reflection strengths are limited at several sites in a region of
about 50km x 50km in the central to northern Kinki district in
Japan. Further, it is found that low frequency earthquakes
(LFE) occur near most of those regions near the Moho
discontinuity, and that high reflectivity regions extend from
those locations of LFE to the seismogenic fault. These results
suggest that fluid paths are limited from mantle to crust and
that low frequency earthquakes can be an index of these fluid
paths.
Modeling silicate melt
TOSHIAKI IITAKA1
1
Computational Astrophysics Laboratory, RIKEN, Japan
Silicate melt is a complex network liquid composed of
SiOn (n=4-6) polyhedra with other elements such as silicon,
oxygen, aluminum, alkalis, magnesium, iron etc. Knowing its
physical properties is of great importance in understanding
geophysical processes in history of Earth, Moon and other
terrestrial planets. Therefore its physical properties at low
pressure have been theoretically studied with some success by
using molecular dynamics simulation with empirical force
fields. However, empirical force fields often fail to describe
the behavior of silicate melts at high pressure, where only few
experimental data are available for fitting potential
parameters. First principle molecular dynamics simulation is
expected to play an important role in studying silicate melts,
such as magma ocean[1], in a wide range of temperature and
pressure condition.
It is well known that diffusivity and viscosity of silicate
melts calculated with empirical force fields much more
strongly depend on the size of the simulation cell than those of
liquid water[2-4]. Only model silicate melt with simple
stoichiometry in a small simulation cell can be investigated
with first principles simulation due to its huge computational
cost. Then questions arise: How large simulation cell and how
long simulation time are needed for the convergent results of
the transport properties? How is it possible to extrapolate the
results for a small cell to obtain the results for an infinite cell?
What is the physics behind the size dependence? How large
simulation cell and how long simulation time can be achieved
with conventional and order-N first principles simulations?
How can we construct empirical force fields from first
principle simulation data? I will discuss these questions.
[1] B.B. Karki et al. (2010) Science 328, 740.
[2] Y. Zhang et al. (2004) J. Phys. Condens. Matter 16, 9127.
[3] J. Horbach et al. (2006) Phys. Rev. E 54, R5897.
[4] I.C. Yeh et al. (2004) J. Phys. Chem. B 108, 15873.
U–Pb isotope systematics of eucrites:
A record of the thermal history
Past antholopogenic aerozols
preserved in ice core of south-east
dome, Greenland
T. IIZUKA1*, A. YAMAGUCHI2, P. KOEFOED3, Y. HIBIYA1,
Y. AMELIN3
YOSHINORI IIUKA1, HIROSHI OHNO2, SUMITO
MATOBA3
1
The University of Tokyo, Japan ([email protected])
National Institute of Polar Research, Japan
3
The Australian National University, Australia
2
Eucrites represent basaltic crust that underwent a complex
thermal history involving magmatism, metamorphism and
metasomatism, probably on Vesta. To set chronological
constraints on these thermal events, we have conducted U–Pb
dating for pyroxene as well as plagioclase of four eucrites:
Agoult, an unbrecciated granulitic eucrite [1]; Camel Donga, a
brecciated eucrite [2]; DAG 380, a weakly shocked eucrite;
NWA 049, a metasomatized eucrite [3]. We are still in the
process of analysis for plagioclase of Camel Donga, DAG 380
and NWA 049.
The model 207Pb/206Pb ages of the analyzed fractions range
from 4532 to 4435 Ma, in general agreement with the results
of previous eucrite U–Pb dating [4,5]. The oldest model ages
were obtained from pyroxene fractions of Agoult and DAG
380 and plagioclase fractions of Agoult. The Agoult
plagioclase fractions yielded a consistent isochron 207Pb/206Pb
age of 4532.4 ± 0.9 Ma, while pyroxene fractions of all
studied eucrites do not define precise isochrons. The isochron
and model 207Pb/206Pb ages are distinctly younger than a
207
Pb/206Pb age of 4554.5 ± 2.0 Ma for Agoult zircon which
was interpreted as the timing of prolonged high-T
metamorphism [6]. Considering that Agoult underwent an
rapid heating event subsequent to high-T metamorphism [1],
we intepret the placioclase and pyroxene ages as reflecting
that rapid heating event. Notably, an identical 207Pb/206Pb age
of 4531 ± 10 Ma was reported for Camel Donga zircon [7],
whereas Camel Donga pyroxene and plagioclase yielded
model 207Pb/206Pb ages of ca. 4510 Ma. This implies that the
4532 Ma heating event caused zircon U–Pb age resetting only
in brecciated eucrites and that a thermal event at ca. 4511 Ma
further led to Pb isotope disturbance in their pyroxene and
plagioclase. The youngest model ages of ~4435 Ma were
obtained from pyroxene fractions of NWA 049. Since this
meteorite exhibits evidence of metasomatism [3], the ages
would appoximate the timing of fluid-rock interactions on
Vesta.
[1] Yamaguchi et al. (2009) GCA 73, 7162. [2] Palme et al.
(1988) Meteoritics 23, 49. [3] Barrat et al. (2011) GCA 75,
3839. [4] Manhes et al. (1984) GCA 48, 2247. [5] Tera et al.
(1997) GCA 61, 1713. [6] Iizuka et al. (2015) EPSL 409, 182.
[7] Zhou et al. (2013) GCA 110, 152.
1
Institute of Low Temperature Science, Hokkaido University,
Sapporo, Japan; [email protected]
2
Kitami Institute of Technology, Kitami, Japan;
[email protected]
3
Institute of Low Temperature Science, Hokkaido University,
Sapporo, Japan; [email protected]
We conducted ice core drilling on the southeastern
Greenland Ice Sheet on May 2015 to reconstruct
concentrations and compositions of anthropogenic aerosols
after the industrial revolution. We obtained a 90m long ice
core with an electrical mechanical drill developed by the
Institute of Low Temperature Science, Hokkaido University.
The ice cores were packed in plastic bags and stored in
insulation boxes, and transported at frozen condition to the
Institute.
The core has unique characteristics that; 1) The drilling
position is N67˚11́, W36 ˚22́, and 3170 m asl, where is one of
the highest domes on Greenlandic ice sheet; 2) very high
accumulation region (ca. 1.0 m/y in water equivalent), and the
depth at 90 m is corresponding to about AD 1950-1960; 3)
close-off depth from firn to ice is about 86 m, which means we
obtained ice not but firn including antholopogenic aerosols in
spite of a Greenlandic dome more than 3000 m asl.; 4)
weather is controlled by Icelandic Low with high winter
accumulation, and the ice core preserved anthropogenic
materials mainly from Europe.
For the unique characteristics 3), we can measure
directory the compositions of past aerosols in ice by Raman
spectroscopy, and also we can measure concentrations and
compositions of many past soluble arosols by using the
sublimation method, which is developed by authors. We will
present the concentrations and compositions of anthropogenic
aerosols in the ice core.
Origin of biogenic methane in the
Nankai submarine mud volcano
based on methane stable
isotopologues
Understory CO2, sensible heat, and
latent heat fluxes in a black spruce
forest in interior Alaska
HIROKI IKAWAA, F, TARO NAKAIA, B, ROBERT C. BUSEYA,
YONGWON KIMA, HIDEKI KOBAYASHIC, SHIN NAGAIC,
MASAHITO UEYAMAD, KAZUYUKI SAITOE, HIROHIKO
NAGANOA, RIKIE SUZUKIC, LARRY HINZMANA
AKIRA IJIRI1,2*, DAVID T. WANG3, SHUHEI ONO3, AND
FUMIO INAGAKI1,2
1
Kochi Institute for Core Sample Research, Japan Agency for
Marine-Earth Science and Technology (JAMSTEC),
Nankoku, Kochi 783-8502, JAPAN (*correspondence:
[email protected])
2
Research and Development Center for Submarine Resources,
JAMSTEC, Yokosuka, Kanagwa 237-0061, JAPAN
3
Department of Earth, Atmospheric and Planetary Sciences,
Massachusetts Institute of Technology, Cambridge,
Massachusetts 02139, USA
Submarine mud volcanoes act as “natural pipelines” that
transport deep hydrocarbons, including methane, to the
overlying hydrosphere and atmosphere. In 2012, we explored
one of the active submarine mud-volcanoes in the Kumano
forearc basin of the Nankai Trough, off the Kii Peninsula of
Japan using the deep-sea drilling vessel Chikyu (33˚67.581N,
136˚56.8085E, 1986.7 m in water depth). Gas samples were
recovred from sediment core samples drilled down to 200 m
below the summit using a hydraulic piston-coring system and
a gas-tight hybrid-pressure coring system (Hybrid-PCS).
Relatively high C1/C2 ratios (670±390) in the headspace
gas suggest the contribution of biologically produced methane.
The average δ13C value of methane (–34.3±2.3‰) is within
the typical range of thermogenic methane. In contrast, the
hydrogen isotopic compositions of methane (–181±2‰) as
well as the magnitude of 13C-isotopic difference between DIC
and methane (73.9±3.5‰) are fully consistent with substantial
contribution
of
methane
from
hydrogenotrophic
methanogenesis. The abundance of 13CH3D, a multiply
substituted “clumped” isotopologue, in two Hybrid-PCS
samples obtained from 6.5 m and 61.5 m below seafloor,
indicates apparent equilibrium temperatures (Δ13CH3D
temperatures) of ca. 29˚C and 31˚C, respectively. Assuming
two endmember mixing of biogenic and thermogenic methane,
we estimated that as much as 90% of methane was microbially
produced at 17–30˚C. Combining these constraints with the insitu temperature profile (29˚C km–1), we estimate the depth of
mud pools from which methane was sourced to be around
400–1,000 m below seafloor. Our results indicate that
microbial activity in the deep mud-volcano biosphere strongly
impacts on the biogeochemical carbon cycle in the Nankai
accretionary complex.
a
International Arctic Research Center, University of Alaska
Hydrospheric Atmospheric Research Center, Nagoya
University
c
Department of Environmental Geochemical Cycle Research,
Japan Agency for Marine-Earth Science and Technology
d
Graduate School of Life and Environmental Sciences, Osaka
Prefecture University,
e
Department of Integrated Climate Change Projection
Research, Japan Agency for Marine-Earth Science and
Technology,
f
Agro-Meteorology Division, National Institute for AgroEnvironmental Sciences,
HirokiIkawa ([email protected])
At this conference, we would like to introduce our recent
publication, Ikawa et al., 2015 Agricultural and Forest
Meteorology conducted at the flux site (US-Prr) located in
interiorAlaska:http://audioslides.elsevier.com//ViewerSmall.as
px?source=1&doi=10.1016/j.agrformet.2015.08.247. An open
black spruce forest, the most common ecosystem in interior
Alaska, is characterized by patchy canopy gaps where the
forest understory is exposed. This study measured CO2,
sensible heat, and latent heat fluxes with eddy covariance (EC)
in one of those large canopy gaps, and estimated understory
fluxes in a black spruce forest in 2011 – 2014. Then
understory fluxes and ecosystem fluxes were compared. The
understory fluxes during the snow-free seasons were
determined by two approaches. The first approach determined
understory fluxes as the fluxes from the canopy gap, assuming
that fluxes under the canopy crown also had the same
magnitude as the canopy gap fluxes. The second approach
determined the understory fluxes by scaling canopy gap fluxes
with a canopy gap fraction, assuming that only canopy gaps,
which mostly constitutes the forest floor, contribute to fluxes.
The true understory fluxes would be in between these two
estimates. Overall, the understory accounted for 53 (39 – 66)
%, 61 (45 – 77) %, 63 (45 – 80) %, 73 (56 – 90) %, and 79 (59
– 98) % of the total net ecosystem productivity (NEP), gross
primary productivity (GPP), ecosystem respiration (RE),
sensible heat flux (H), and latent heat flux (LE), respectively.
The ratio of understory NEP (NEPU) to the ecosystem NEP
(NEPE) and similarly calculated LEU/LEE during the daytime
increased with vapor pressure deficit (VPD) at low VPD
conditions (~ 2000 Pa) at half-hourly temporal scale. At high
VPD conditions, however, NEPU/NEPE decreased with VPD,
whereas LEU/LEE was maintained at the high level even at
high VPD conditions. Despite large ranges of the estimates for
the understory contributions, we conclude that the understory
plays an important role in the carbon and energy balances of
the black spruce ecosystem, and their contribution highly
depends on the level of VPD.
b
Nickel behavior toward biogenic
mackinawite during laboratory
experiments aimed at mimicting
mangrove sediments
Investigations of several inhibitors
for silica scale control in Sumikawa
geothermal brine, Japan
RISA IKEDA1, AKIRA UEDA1, TAKEHIKO ISHIDUKA2
3
AND KAZUO ISHIMI
1
Enviromental Biology and Chemistry, Graduate School of
Science and Engineering for Education, University of
Toyama, 3190 Gofuku, Toyama 930-8555, Japan,
([email protected], [email protected])
2
BWA JAPAN CO. LTD., Tobutateno Bldg. 8F, 2-10-27
Kitasaiwai, Nisi-ku, Yokohama, Kanagawa 220-0004,
Japan, ([email protected])
3
Techno Office, Isutokoa Hikibune Nibankan No.2808, 1-1-2
Kyojima, Sumidaku, Tokyo 131-0046, Japan, ([email protected])
In geothermal power plants, silica in brines precipitates as
scale in pipes and injection wells and decreases the amount of
injecting brine. A pH adjustment method has been applied to
prevent the silica scaling so far, but this method can not
completely prohibit the scaling. There is a problem that added
sulfate for the pH adjustment promotes anhydrite (CaSO4)
precipitation in production wells.
The purpose of this study is to develop a new method to
prevent silica scale with chemical reagents. We examined nine
organic inhibitors by passing brine with the reagent through
columns. The brine used in this study is taken from well SC-4
under an atmospheric pressure (pH:6.48, Cl:1,100mg/L,
SiO2:980 mg/L) at Sumikawa geothermal power plant
(50MW), Akita, Japan. The intermal diameter and length of
the column in our experiments are 15mm and 40cm,
respectively. A teflon pipes is set in the column and filled with
glass beads with a diameter of 1mm. The mixed geothermal
brine (1L/min) and inhibitor solution (2, 10, and 25mg/L)
were passed through the column for 4 days. The flow rates ,
pH and EC were monitored.
The flow rates of brines in all columns decreased with
time, whereas those of the brine without addition of any
inhibitors quickly decreased up to 0 L/min within 3 days. The
results indicate that the cationic inhibitors showed an
aggregation effect of silica in brines and the inhibitor
concentration is critical to control the silica precipitation. The
best concentration for the prohibition of silica scaling in this
study is 2mg/L. This inhibitor can reduce by 10 to 20% of the
silica precipitation rates compared to no addition test into the
brine. Therefore, we concluded that the effective inhibitor
condition is 1) anionic inhibitor and 2) the low concentration.
MAYA IKOGOU1, GEORGES ONA-NGUEMA1,
FARID JUILLOT1, 2, NICOLAS RICHEUX1,
PIERRE LE PAPE1, JEAN-MICHEL GUIGNER1,
VINCENT NOËL1, JESSICA BREST1, GUILLAUME MORIN 1
1
IMPMC, UMR CNRS 7590, UPMC, IRD, MNHN, France
2
IRD, UR 206, Noumea, New Caledonia
The growing need for nickel (Ni) in industry implies
increasing mining and subsequent release in surrounding
environments. In tropical areas, Ni mining mainly concerns
lateritic ores that are often connected with coastal ecosystems
such as mangroves. In the anoxic sediments of these
mangroves, Fe-(hydr)oxides are dissolved by iron-reducing
bacteria (IRB) while sulfates/thiosulfates are reduced by
sulfate/thiosulfate-reducing bacteria (SRB), leading to
aqueous Fe(II) and H2S that further react to precipitate Fesulfides (Canfield et al., 1992; Rickard & Luther, 2007; Otero
et al., 2009). Since these Fe-sulfides can have a strong affinity
for a large set of trace metals (Jong & Parry, 2004; Kwon et
al., 2015), evaluating their actual role in the biogeochgemistry
of Ni in mangrove sediments that receive increasing inputs
from mining activitiy is an important issue.
In the present study, we investigated the behavior of Ni
upon Fe-sulfides formation during laboratory experiments
performed with Desulfovibrio capillatus, a thiosulfatereducing strain, in the presence of soluble Fe(III)-citrate and
thiosulfates. XRD and Fe K-edge EXAFS results indicate that
biogenic mackinawite (FeS1-x) is the end-product mineral and
Ni K-edge EXAFS results show that Ni is structurally
incorporated in this biogenic mackinawite through substitution
with Fe. In addition, comparison between Ni and Ni-free
experiments indicates that the growth kinetic of mackinawite
particles is significantly accelerated when Ni occurs in the
starting solution. Regarding the large amounts of Ni
incorporated in mackinawite (i.e. up to 98% of initial Ni),
these results emphasize the strong sequestering capacity of
this biogenic Fe-sulfide toward Ni in mangrove sediments.
Finally, they also indicate that this sequestering capacity can
be driven by thiosulfate-reducing bacteria activity.
Canfield et al. (1992) Am. J. Sci., 292, 659-683; Otero et al.
(2009) Geoderma, 148, 318-335; Rickard & Luther (2007)
Chem. Rev., 107, 514-562; Jong & Parry (2004) JCIS, 275,
61-71; Kwon et al. (2015) Am. Min., 100, 1509-1517.
Tracing euxinia by molybdenum
concentrations in Holocene marine
sediments along the Eastern Adriatic
coast
NIKOLINA ILIJANIC1, SLOBODAN MIKO2, OZREN HASAN3,
4
5
DEA BRUNOVIC , IVAN RAZUM
1234
Croatian Geological Survey, Sachsova 2, 10 000 Zagreb,
Croatia ([email protected], [email protected],
3
[email protected], [email protected])
5
Natural History Musem, Demetrova 1, 10 000 Zagreb,
Croatia ([email protected])
Elevated Mo contents in marine sediments are indicative
of deposition from an anoxic and sulfide-rich (euxinic) watercolumn and sediments deposited under these conditions
constitute major sinks for a range of transition metals
(including molybdenum), both in modern and ancient oceans
[1]. This can be used for tracing past euxinic conditions in
marine sedimentary archives. Molybdenum content was
analysed in Holocene marine sediment cores (1 to 10 m) of
shallow Adriatic Shelf along the Eastern Adriatic coast. Mo
enrichment and hence euxinic depositional conditions appear
in karst depressions during flooding of brackish marsh/lake
enviroments by sea water. The Mo accumulation occurs
during early phases of flooding when restricted circulation and
anaerobic conditions prevail. In submerged depressions, Jaz
and Sonte on the Island of Cres, high values of Mo (>30
mg/kg) appear at different depths depending on the timinig of
the sea flooding. Pirovac and Morinje Bay in central Adriatic
show higher values (12 and 21 mg/kg) at 300 and 60 cm, after
the sea level rise and Holocene transgression in the bay. In the
southern Adriatic, on the Island of Mljet, the core from Stupa
depression represents sediment sequence from lake to marine
sediments where the highest Mo peak appear (120 mg/kg). In
contrast, Caska Bay on the Island of Pag, Novigrad and Karin
Sea and Modric Bay have low Mo concentrations in the whole
marine sediment core (~1 to 4 mg/kg). The accumulation of
these Holocene marine sediments occured in shelves.
Molybdenum enrichment in investigated Holocene marine
sediments occured in isolated or silled basins during initial sea
flooding, while oxigenated shelves deposited considerably less
Mo.
[1] Calvet, S.E. & Pederson, T.F. (1993) Marine Geology
113, 67-88.
The role of pesticides in stabilization
of TiO2 nanoparticles in aquatic
environments
S. M. ILINA1, P. OLLIVIER1, N. BARAN1, D. SLOMBERG2,3,
N. DEVAU1, A. PARIAT2,3, N. SANI-KAST4, M.
SCHERINGER4,5, J. LABILLE2,3
1
BRGM (French Geological Survey), 3 av. C. Guillemin, BP
6009, 45060 Orleans Cedex 2, France
2
CNRS, Aix-Marseille University, CEREGE UM34, UMR
7330, 13545 Aix-en-Provence, France
3
International Consortium for the Environmental Implications
of Nanotechnology iCEINT, Aix-en-Provence, France
4
Institute for Chemical and Bioengineering, ETH Zürich, CH8093 Zürich, Switzerland
5
RECETOX, Masaryk University, 625 00 Brno, Czech
Republic
The
influence
of
pesticides
(glyphosate,
aminomethylphosphonic acid (AMPA) and 2.4-D) on the
surface charge and aggregation of pure TiO2 nanoparticles
(NP; 5-30 nm; anatase and rutile) have been investigated in
modeled water solutions. The dependence of the surface
charge and the size distribution at upon the various factors
(including surface chemistry of NP and pesticides, presence of
mono- (Na+) and bi-valent (Ca2+) cations, pH value, and ionic
strength (IS) of an aqueous solution) has been studied.
The presence of glyphosate (5µg/L) affects rutile TiO2 NP
(5 mg/L) stabilization in NaCl solution of IS=10-4M - 10-3M
(>CCC) and in CaCl2 solution of IS =10-4M (>CCC) with
pH=5 near the pH point of zero charge (PZC) (pHPZC=4.5).
With adding of the glyphosate no changes in NP aggregation
were observed in very high (IS= 10-1M) ionic strength
solutions for rutile NP and in all studied conditions for anatase
NP. No significant changes in NP aggregation were observed
in the presence of AMPA and 2.4-D. Compared to monovalent cations, bi-valent cations favored an increase in zeta
potential at pH8 and no changes at pH5. These results show
new evidences of the role of pesticides on the NP mobility in
aquatic environments.
The platinum group elements (PGE)
distribution in the minerals from the
peridotites of the Udachnaya pipe
(Yakutia)
Mineralogical Characteristics of
volcanic glass in Ulleung Island,
Korea and its implications for
Quaternary volcanic activity
O.V. ILYINA1*, L.N. POKHILENKO 1, A.M. AGASHEV1
JI HYEON IM1 AND CHANG OH CHOO2
1
1Sobolev Institute Geology and Mineralogy, Novosibirsk
630090, Russia (*[email protected])
The olivines and silphides in the deformed perodotites (the
most enrichment rocks) and olivines in the dunites (the most
depleted rocks) from the Udachnaya pipe have been analyzed
for PGE by isotope dilution. Olivines from dunites and
deformed peridotite show high PGE concentrations as well as
ones from the depleted harzburgites of the Lherz massif (Fig.
1). But the PGE distribution of these two rock types is
different. While PGE concentration in pure olivine megakryst
from kimberlite four-five order lower than in rocks above and
the pattern shape have another character.
Figure 1: The PGE distribution in minerals from
peridotites.
We assume that the silphides are the main host mineral of
PGE in our rocks [2]. Chondrite normalized PGE
concentrations in the sulphides are three orders higher than
that in the deformed peridotites whole-rock (Fig. 1). But the
pattern shape is similar. We propose that these sulphides are
probably the result of submicron sulphide phases skimping in
the interstices of mantle rocks on the last stage the deformed
peridotites evolution. Because olivine PGE concentration and
the sulphide ones are approximately the same it is thought to
be that olivines had micro-inclusions of the sulphides (Fig. 1).
[1] Luguet et al (2007) Geoch. et. Cosmoch. Acta 71,
3082-3097. [2] Alard et al (2000) Nature 407, 891-894.
1
Korea Institute of Geoscience and Mineral Resources,
Daejeon, 305-350, South Korea ([email protected])
2
Department of Geology, Kyungpook National University,
Daegu, 702-701, Korea ([email protected])
Ulleung Island is the largest volcanic island located in the
northern part of the Ulleung Basin of the East Sea, Korea. The
volcanic activity of subaerial Ulleung Island took place during
the period ranging from late Pliocene to Holocene [1, 2]. The
black glass locally occurs at the southwestern part of Ulleung
Island, belonging to the upper trachytic rock with trace
agglomerate of Seonginbong Group, the upper strata of
Ulleung volcano [3]. The mineralogical and morphological
characteristics including chemical composition and microtexture of glass were examined by optical microscope, XRD,
XRF, FT-IR, EPMA and thermal (DSC-TG) analyses.
The fracture patterns of glass that formed by the rapid
cooling of trachytic lava show subrounded and oval,
bounded by cooling joints to form globule or lump. It
contains some phenocrysts such as sanidine, plagioclase,
diopside, biotite, chlorite and Fe-Ti oxides, etc. The glass
cluster have fiamme-like texture and preferred orientation
with mafic phenocrysts. The glass samples are mostly
amorphous and the major element compositions of bulk
samples are in the range of 61.85-62.30 wt % for SiO2,
17.70-17.86 wt % for Al2O3, 0.30-0.36 wt % for MgO,
13.00-13.28 wt % for Na2O+K2O, and 0.11-0.12 wt % for
P2O5, belonging to trachytic composition. SiO2 and Al2O3
contents of pure glasses based on EPMA are higher than
those of bulk samples, whereas Na2O+K2O and P2O5
contents are less than those of bulk samples. FT-IR and
thermal analysis show relatively small hydration degree. Its
mineralogical and petrological results show intermediate
characteristic between obsidian and tachylite.
Analytical results of black glass materials will lead to a
better understanding of cooling process of trachytic lava
under subaqueous conditions (at least saturated with
seawater).
[1] Kim et al (1999) Geochemical Journal 33, 317-341. [2]
Kim et al (2014) Bulletin of Volcanology 76(4), 1-26. [3]
Hwang et al (2012) KIGAM. Report, 84p.
Pressure- and temperature-induced
transformation of natrolite to
sequester Cs and Pb
Identifying 2 km-deep methanogenic
community members using a longterm bioreactor cultivation
J. IM,1 D. SEOUNG2, Y. LEE1, S. Y. LEE3, D. A. BLOM4, T.
VOGT4, C.-C. KAO2 AND Y. LEE1*
H. IMACHI1*, E. TASUMI1, T.-H. TU1, A. IJIRI2, Y.
MORONO2, S. ISHII2, B. A. METHÉ3, K. TAKAI1 AND F.
INAGAKI2
1
Department of Earth System Sciences, Yonsei University,
Seoul 03722, Korea (*correspondence:
[email protected])
2
Stanford Synchrotron Radiaition Lightsource, SLAC National
Accelerator, Menlo Park, CA 94025, USA
3
Division of Radwaste Disposal Research, Korea Atomic
Energy Research Institute, Daejeon 34057, Korea
4
NanoCenter & Department of Chemistry and Biochemistry,
University of South Carolina, Columbia, SC 29208, USA
We report here a pressure- and temperature-driven
transformation to sequester environmentally toxic cations such
as Cesium (Cs+) and Lead (Pb2+). Ag-exchanged natrolite and
Pb-exchanged natrolite are pressurized in an aqueous CsI
solution and pure water as a pressure-transmitting medium
(PTM), respectively. Ag-NAT with CsI solution PTM results
in the exchange of Ag+ by Cs+ in the natrolite framework
forming Cs-NAT-I and, above 0.5 GPa, its high-pressure
polymorph (Cs-NAT-II). During the initial cation exchage, the
precipitation of AgI Occurs. Additional pressure and heat at 2
GPa and 160 °C transforms Cs-NAT-II to a pollucite-related,
highly dense, and water-free triclinic phase. At ambient
temperature after pressure release, the Cs remains sequestered
in a monoclinic pollucite phase at close to 40 wt% and
favorably low Cs leaching rate under back-exchange
conditions [1]. In the case of Pb-NAT in pure water PTM, four
high-pressure polymorphs of natrolite (Pb-NAT-I, II, II′ , III)
and one reconstructive transformation are through the
pressure-induced hydration (PIH). Heating at 200 °C and 4.5
GPa, leads to a denser lawsonite phase with orhorhombic
space group which is recovered after pressure release. The
recovered lawsonite phase has much stable Pb coordination
environment in the natolite channel compared to that in the
original Pb-NAT and its high-pressure polymorphs [2]. The
structures of the recovered Cs- and Pb-sequestered phases are
confirmed by HAADF-STEM real spacing imaging.
[1] Im et al. (2015) Environ. Sci, Technol 49, 513-519. [2] Im
et al. (2016) Dalton Trans 45, 1622-1630
1
Department of Subsurface Geobiological Analysis and
Research, Japan Agency for Marine-Earth Science and
Technology (JAMSTEC), Yokosuka, Kanagwa 237-0061,
JAPAN (*correspondence: [email protected])
2
Kochi Institute for Core Sample Reseacrh, JAMSTEC,
Nankoku, Kochi 783-8502, JAPAN
3
Department of Environmental Genomics, J. Craig Venter
Institute, Rockville, MD 20850, USA
During the Integrated Ocean Drilling Program (IODP)
Expedition 337, we successfully enriched a methanogenic
microbial community from 2 km-deep lignite coalbed samples
using a down-flow hanging sponge (DHS) reactor [1, 2].
During the DHS reactor operation for 932 days at near the insitu temperature of 40°C, we observed a continuous methane
production since the 7th day, even without adding any organic
substrates in the seawater-based medium after 721 days. The
carbon isotopic composition of methane gradually decreased
with the operational time from -42.9‰ to -94.0‰, suggesting
the significant contribution of microbial methanogenesis.
Interestingly, the effluent contained acetate (up to 0.6 mM),
which is most likely a major end-product of the heterotrophic
microbial activity. Electron microscopic observation of the
lignite particles showed that remarkably abundant and
morphologically diverse microbial cells tightly attached to the
particles. 16S rRNA gene-tag sequence analysis revealed that
archaeal community was consisted mainly of a
hydrogenotrophic CO2-reducing methanogen related to
Methanobacterium, whereas no aceticlastic methanogens were
detected. Bacterial community was predominated by the
members within Firmicutes and Gammaproteobacteria. These
data suggest that the enriched microbial community represents
a heterotrophic microbial ecosystem that largely relies on
coaly organic matter, and its activity produces both acetate
and methane via the degradation of lignite. On-going efforts
on metagenomic and metatranscriptomic analyses will reveal
genetic and functional networks of the 2 km-deep microbial
community, as well as the comparative genomics of isolates
obtained from the methanogenic community.
[1] Imachi et al. (2011) ISME J., 5, 1913-1925. [2] Inagaki et
al. (2015) Science, 349, 420-424.
Diversity of methanogenic and
methanotrophic archaea beneath
bacteria mats in shallow gas hydrate
bearing deep subsurface sediments
Numerical modelling of magma
plumbing system interactions at
Torfajökull, Iceland: an insight from
the crystal cargo
TAKUMI IMAJO1, JUNPEI HASHIGUCHI1, TAKESHI
KOBAYASHI1*, CHIAKI IMADA1, TAKESHI TERAHARA1
AND MATSUMOTO RYO2
CAMILLA L. IMARISIO1, CHRISTINA J. MANNING1, DAVE
WALTHAM1, PETER BURGESS1,2
1
The graduate school of marine science and technology,
TUMSAT, 4-5-7, Konan, Minato-ku, Tokyo, Japan
(*correspondence: [email protected] )
2
Meiji University, Tokyo, Japan
Methane hydrate is ice like lattice composing huge amount
of methane. Methane hydrate in Japan sea are known as
shallow gas (methane) hydrate. From the isotopic fractionation
effect, it is possible to define methane as biogenically
(microbially) produced or thermogenically produced. The
methanogenic archaea are said to be responsible for the
methane production in the deep subsurface sediments. But it is
still unclear how strong they are contributing to the
production. On the other hands, it is also known that those
hydrate bearing areas has specific structures on the subsurface
sediments, such as bacteria mats. The formation of bacteria
mats in the methane rich area has relationship with
methanotrophic archaea (ANMEs), and also reported that
these mats has specific community structure of ANMEs.
In order to know the relationship between methane hydrate or
specific structures of subseafloor and methanogenic or
methanotrophic archaea, we need to isolate or to analyze
community structure of these archaea. In this study, we used
samples from environment assessment cruise. We sampled the
sediments by MBARI push corers, where we observed specific
structures. We also collected the reference sediments, where
no specific structures were observed, for the comparison. The
cultivation and community analysis were carried out using the
samples previously described. We succesufully isolated
methanogenic archaea from the sediment. The results of
community analysis showed that the sediment beneath bacteria
mat has diverse community from the reference sediment.
This study was conducted as a part of the shallow methane
hydrate exploration project of METI.
1
Royal Holloway University of London, Department of Earth
Sciences, TW20 0EX, Egham, Surrey, United Kingdom.
*correspondence: [email protected]
2
University of Liverpool, Department of Earth Sciences
Torfajökull is the largest silicic centre in Iceland. Situated
in the south east, it intersects the southern tip of the Veiðivötn
fissure swarm[1]. Previous whole rock studies have identified
mixing between rhyolitic and basaltic products[2]. This could
represent interaction between hot basaltic melt and solid
rhyolite or intrusion of basaltic melt into a rhyolitic magma
chamber. If it is the latter it could have major implications for
eruption trigger mechanisms at Torfajökull.
We have undertaken textural, CSD and chemical analysis
on crystals hosted in lavas ranging from tholeiite to rhyolite.
All samples show a range of microtextures observed in both
plagioclase and clinopyroxene crystals which, alongside CSD
analyses that indicate at least two different plagioclase
populations, suggests evolution through open system
processes. LA-ICP-MS of clinopyroxene and plagioclase
crystals from a single lava show clinopyroxene compositions
to vary within a narrow range (Mg#~72-82) whilst plagioclase
shows significant variation in core An% (38-80), indicating
multiple populations, and exhibits both reverse and normal
zoning. P-T conditions calculated using the equations of
Putirka[3] and an estimated equilibrium melt composition show
that different populations crystallised at different conditions.
δ18O crystal data will be used as additional evidence for
distinguishing between melt mixing and crystal contamination.
This insitu data is being used to test a simple numerical
forward model that combines published equations for
calculating crystal growth rates and compositions with
methods for assessing the effects of various petrogenetic
processes on the host melt[3,4,5]. The model outputs a thin
section style image that allows comparison with insitu
chemical data and textural analysis.
[1]Zellmer(2008)Earth Planet. Sci. Lett.269,388-398
[2]McGarvie(1990)J. Petrol. 31,461-481
[3]Putirka(2008)Rev. Mineral. Geoche.69,61-120
[4]DePaolo(1981)Earth Planet. Sci. Lett. 53,189-202
[5]Toramaru(1991)Contrib. Mineral. Petrol.108,106-117
Metamorphic history of the
Paleoproterozoic Salma eclogite in
the Kola Peninsula, Russia
Cesium-rich micro-particles unveil
the explosive events in the Fukushima
Daiichi Nuclear Power Plant
T. IMAYAMA1*, C. W. OH 1, S. K. BALTYBAEV2, C. S.
PARK3, K. YI3, H. JUNG4
JUNPEI IMOTO 1, GENKI FURUKI 1, ASUMI OCHIAI 1,
SHINYA YAMASAKI 2, KENJI NANBA 3, TOSHIHIKO
OHNUKI 4, BERND GRAMBOW 5, RODNEY C. EWING 6,
1
AND SATOSHI UTSUNOMIYA
1
Department of Earth and Environmental Sciences, Chonbuk
National University, Jeonju, South Korea
2
Institute of Precambrian geology and geochronology,
Russian Academy of Sciences, Russia
3
Korea Basic Science Institute, Jeonju Center, South Korea
4
Division of Earth and Environmental Science,, Korea Basic
Science Institute, South Korea
The Precambrian Salma eclogite in Kola Peninsula, Russia
is one of the oldest eclogites of the world, but there has been
much debate about the timing of eclogite-facies
metamorphism: Archean (2.72–2.70 Ga) or Paleoproterozoic
(1.91–1.88 Ga). Microstructural observations, P-T analyses,
zircon inclusion analyses, and U-Pb zircon dating in this study
support the Paleoproterozoic eclogite facies metamorphism
under the P–T condition of 16–18 kbar and 740–770 °C at
1.89–1.88 Ga. The 1.89–1.88 Ga sector, patched, and cloudy
zoned zircons with pale grey CL include inclusions of garnet +
omphacite + diopside + amphibole + quartz + rutile ± biotite,
and they have the flat pattern of HREE due to the amounts of
abundant garnet during the eclogite facies metamorphism. In
contrast, the Archean metamorphic zircons (2.73–2.72 Ga) are
unzoned grains with dark CL that contain inclusions of garnet
+ amphibole + plagioclase + quartz + rutile ± biotite, and they
are relatively enriched in HREE, indicating a first amphibolite
facies metamorphic event at 2.73–2.72 Ga. In the
Paleoproterozoic period, the Salma eclogites may also
undergo epidote–amphibolite or amphibolite facies prograde
metamorphism. After the peak eclogite facies metamorphism,
granulite
facies
metamorphism
occurred
during
decompression stage from 18 kbar to 9–12 kbar, followed by
amphibolite facies overprint of 8–10 kbar and 590–610 °C
during cooling. Whole rock chemistry indicates that the Salma
eclogite was originally tholeiitic basalt formed at the midocean ridge. The 1.89–1.88 Ga eclogite facies metamorphism
implies that the continent–continent collision between the
Kola and Karelian continents occurred during the
Paleoproterozoic, rather than the Archean. This and previous
studies imply that the deep subduction to form eclogite may
have begun in the Paleoproterozoic.
1
Department of Chemistry, Kyushu University, Motooka 774,
Nishi-ku, Fukuoka 819-0395, Japan
2
University of Tsukuba, Ibaraki 305-8577 Japan
3
Fukushima University, Fukushima, 960-1296 Japan
4
Japan Atomic Energy Agency, Ibaraki 319-1195, Japan
5
University of Nantes, Nantes 44307, France
6
Stanford University, Stanford, CA 94305-2115 USA
Cesium-rich micro-particles (CsMPs) retain novel
information on the molten core-concrete interaction (MCCI)
that happened inside the Fukushima Daiichi Nuclear Power
Plant (FDNPP). In order to elucidate the micron-scale
processes of radionuclides release during the explosion,
systematic micro-analyses were completed on the CsMP using
a variety of electron microscopy techniques.
CsMPs specimens were discovered from paddy soils in
Okuma town and in atmospheric particulates collected at
Suginami, Tokyo, by using autoradiography and SEM.
Subsequent to gamma radioactivity measurement The CsMP
was thinned by using a focused ion beam system. STEM was
employed for nano-scale analysis.
The size, 134Cs and 137Cs radioactivities were determined to
be 0.58-5.3 μm, 0.273-145 Bq, 0.207-134 Bq, respectively.
All CsMPs were mainly composed of Si oxide associated with
Fe, Cs, Zn, Sn, Rb, K, Mn, Cl and Pb. The Cs concentration
ranges from 0.81-36 wt% as Cs2O. The electron diffraction
pattern revealed diffused diffraction maxima, indicating the
amorphous structure. Various nanoparticles were identified at
the size of 2-40 nm; crystalline Ag2Se0.5S0.5, silver telluride
and Sn metal nanoparticles, indicating that a part of volatile
fission products such as Te and Se associated with Ag to form
airborne nanoparticles. Numerous pores were present in the
center, which is the evidence of entrapped CO2 and H2O
sparged during MCCI. Surface and interior of the CsMPs
exhibited unique texture of nanoparticles aggregation. Hence,
condensation of SiO(g) proceeded by the immediate
incorporation of soluble Cs already present as vapors and
entrapment of airborne nanoparticles liberated from the debris
as the particle grew. Still, the CsMP is another important route
of dispersion of the low-volatile radionuclides to the
surrounding environment.
Cadmium mass and stable isotope
budget of three Swiss wheat cropping
sites
M. IMSENG*1, M. BIGALKE1, M. WIGGENHAUSER2, E.
FROSSARD2, M. MÜLLER3, A. KELLER3, M. REHKÄMPER4,
K. KREISSIG4, K. MURPHY4, W. WILCKE5
1
Geographic Institute, University of Bern, Hallerstrasse 12,
CH-3012 Bern (*corresp.: [email protected],
[email protected])
2
Institut für Agrarwissenschaften, ETHZ, Eschikon 33, CH8315 Lindau ([email protected],
[email protected])
3
Agroscope, Reckenholzstrasse 191, CH-8046 Zürich
([email protected],
[email protected])
4
Department of Earth Science & Engineering, Imperial
College, London SW7 2AZ, UK
([email protected], [email protected],
[email protected])
5
Institut für Geographie und Geoökologie, KIT, Kaiserstr. 12,
D-76131 Karlsruhe ([email protected])
Mineral phosphate fertilizers contain up to 600 mg Cd kgP and its application might result in Cd accumulation in the
fertilized soils. Cd incorporation into the food chain might
finally affect human health. We sampled soil in different
depths and all inputs and outputs of three wheat cropping sites
for one hydrological year. The Cd concentrations and stable
isotope ratios of soils, soil parent material, mineral phosphate
fertilizers, bulk deposition, wheat plants (roots, straw and
grains) and soil water were analyzed. After matrix separation,
Cd isotope compositions were determined by double-spike
MC-ICPMS. The main Cd input (>75%) was via mineral
phosphate fertilizers, the main output was with the harvest.
Inputs exceeded outputs so that Cd accumulated in the soils.
The soils showed no vertical variations in δ114/110Cd values.
Only one soil, originating from limestone, was fractionated
compared to the parent material with Δ114/110Cdparent-soil =
0.27‰). The main inputs from mineral phosphate fertilizers
(δ114/110Cd = 0.13 to 0.26‰) and precipitation (-0.15 to
0.15‰) showed limited variation in Cd isotope ratios. In
contrast, the main outputs to wheat harvest (0.43 to 0.78‰)
and seepage water (0.39 to 0.79‰) showed positive
fractionation. The bedrock-soil, soil-soil solution and soilplant induced isotope fractionation are discussed to investigate
biogeochemical processes of Cd in terrestrial systems. Cd
isotope budgets are used for source tracing to improve the
understanding of Cd fluxes in agricultural systems.
1
Fractionation of zirconium-hafnium
in ferromanganese crusts
J. INAGAKI1*, A. SAKAGUCHI 2, M. INOUE3, A.
USUI4, H. HABA5, T. KASHIWABARA6, S.
YAMASAKI2, K. SUEKI2, Y. TAKAHASHI7
1
Univ. of Tsukuba, Tsukuba, Ibaraki, 305-8577, Japan
([email protected])
2
CRiED, Univ. of Tsukuba, Tsukuba, Ibaraki, 305-8577,
Japan
3
Hiroshima Univ. Hiroshima, 739-8526, Japan
4
Kochi Univ. Kochi, 780-8520, Japan
5
RIKEN, Saitama, 351-0198, Japan
6
JAMSTEC, Kanagawa, 237-0061, Japan
7
The Univ. of Tokyo, Tokyo, 113-0033, Japan
The zirconium(Zr)-hafnium(Hf) pair is known as a
“geochemical twin”, and Zr/Hf ratios in various systems are
theoretically the same as that of the chondrite meteorite.
However, significant fractionation of the two elements
between seawater and ferromanganese crusts (FMCs) has been
reported (Bau, 1996). In this study, we have attempted to
clarify the accumulation mechanisms of Zr and Hf in FMCs
by performing sequential extraction and desferrioxamine
(DFO) complexed radio-Zr and radio-Hf (DFO-Zr and DFOHf) adsorption experiments with X-ray absorption fine
structure analysis for synthesised and natural samples obtained
from the Ryusei and Takuyou seamounts. The Zr and Hf
partition coefficient KD between natural FMCs and seawater
were around 108, and their ratios were fractionated compared
to that of seawater (Firdaus et al., 2011). The observed Zr
chemical states in FMCs resembled that for coprecipitation
with ferrihydrite, coprecipitation with δ-MnO2 and a basaltlike composition, aithough the results of sequential extraction
showed that Zr and Hf were found predominantly in the Fe
fraction. In the case of the adsorption experiments for DFO-Zr
and DFO-Hf to ferrihydrite and δ-MnO2, it was found that the
Hf-DFO had larger KD values for both minerals than Zr-DFO.
In this case, the observed bond length of Hf-O was slightly
shorter than that of Zr-O in the synthesized minerals.
Dissolution Kinetics of a Simplified
Nuclear Waste Glass, ISG, in MgCl2
solution
Geochemistry of REE in hyperacid
and hypersaline waters in
hydrothermal systems
Y. INAGAKI, R. MATSUMOTO, K. IDEMITSU, T. ARIMA
INGUAGGIATO C.1, 2, 3, CENSI P.1 , D’ALESSANDRO W.3,
ZUDDAS P.2
Dept. of Applied Quantum Physics & Nuclear Engineering,
Kyushu Univ., Fukuoka 819-0395, Japan
Experimental
ISG (International Simple Glass) is a six-component
alumino-borosilicate glass developed as a reference benchmark glass for six nations collaborating study on high-level
nuclear waste glass dissolution kinetics [1]. In order to
evaluate effects of environmental Mg on the dissolution
kinetics of ISG, aqueous dissolution tests were performed at
90°C with MgCl2 solution at a constant pH (8.2) as a function
of MgCl2 concentration by using Micro-Channel FlowThrough (MCFT) method [1]. The dissolution rate was
measured for each glass constituent element as a function of
reaction time, and the reacted glass surface was analysed by
use of SEM/EDX and XRD.
Results and Discussion
Normalized dissolution rate, NRi, is shown in Fig.1 for
each element in the test with 10-3M MgCl2 solution. NRi
decreased with reaction time for all elements, indicating the
glass dissolution is supressed by interactions with Mg. The
reacted glass surface analysis by SEM/EDX and XRD
confirmed formation of hydrotalcite (Mg6Al2CO3(OH)16 4H2O)
as a major secondary phase covering the surface. The results
suggest that hydrotalcite forms as the secondary phase rather
than Mg-silicates under the present conditions ([Mg2+] =103
M, [H4SiO40]<10-4M, pH8.2, 90°C) to become and/or cause a
protective layer against the glass dissolution.
3
NRi [g/m2/day]!
[MgCl2] = 10-3M!
pH 8.2, 90℃!
2
B
1
Na
Si
Al
0
0
10
20
30
Reaction time [day]!
Fig.1. Normalized dissolution rate, NRi, of Si, B, Na, Al as a
function of reaction time in MCFT test with 10-3M MgCl2
solution with pH8.2 at 90°C.
[1] Inagaki, et al.(2013) IJAGS, 4[4], 317-327.
1
DiSTeM, Università degli Studi di Palermo, Via Archirafi,
22 - 90123 Palermo, Italy.
2
UPMC-Sorbonne Universités, Institut des Sciences de la
Terre de Paris, 4 place Jussieu, F75005 Paris, France.
3
INGV-Palermo, Via La Malfa, 153, 90146 Palermo, Italy.
The REE (Rare Earth Elements; lanthanides and yttrium)
are economically important resources. Here, recent progresses
concerning the study of the REE geochemistry in natural
systems are presented. Specifically, the REE behaviour was
studied in hyperacid and hypersaline waters with variable
redox conditions.
The important role of the pH (from 1 to 8.8) and the
chemical composition of the water on the distribution of REE
was investigated in the Nevado del Ruiz volcanohydrothermal system. The ΣREE (from 0.8 to 6722 nmol l-1) is
inversely correlated to pH values. The pH rules the
precipitation of Fe-, Al-bearing minerals inducing changes in
REE abundances and a strong cerium anomaly. The REE
patterns normalized to average local rock show significant
LREE (Light REE) depletion in acidic sulphate waters from
which alunite and jarosite precipitate [1].
The key role of the Eh values (from -400 to 256 mV) and
water composition on the distribution of REE was evaluated in
waters along the Dead Sea Fault with TDS values ranging
from 0.3 to 193.5 g l-1. The ΣREE ranges from 0.02 to 2.98
nmol l-1. PAAS-normalized patterns show MREE (Middle
REE) enrichments in waters with relative higher Ca and SO4
contents deriving from gypsum dissolution. The redox
conditions influence the amplitude of Ce and Eu anomalies.
Oxidized waters show negative Ce anomalies related to the
oxidative Ce scavenging [2], while positive Eu anomalies are
found only in waters characterized by Eh values < -100 mV,
consistently with the Eu occurrence as dissolved Eu2+. This
reducing conditions enhances the Eu2+ stability in the
dissolved phase relatively to its trivalent neighbours along the
REE series.
A very interesting point is that the ion speciation of REE
in solution is not always sufficient to explain the distribution
of these elements. The processes of precipitation and
dissolution of solid phases are responsible of the changes in
the REE distribution in waters.
[1] Inguaggiato et al (2015). Chem. Geol. 417, 125-133.
[2] Seto and Akagi (2008). Geoch. Journ. 42, 371-38.
The Evolution of Geochemical
monitoring on active volcanoes: Case
Studies from the Aeolian Islands
Molecular-level insight into the
effects of amino acids on
biomineralisation
SALVATORE INGUAGGIATO
R. INNOCENTI MALINI1, A. R. FINNEY1, P. M. RODGER2,
C. L. FREEMAN1, J. H. HARDING1*
Istituto Nazionale di Geofisica e Vulcanologia, Palermo, Italy
([email protected])
The geochemical surveillance of an active volcano aims at
recognizing possible signals related to changes of volcanic
activity. In fact, as a consequence of magma rising inside the
plumbing system and/or refilling of new batches, volatiles
dissolved into it are progressively released as a function of
their relative solubility. Approaching the surface, these fluids,
discharged during magma degassing, may interact with
shallow aquifers and/or may be released along the main
volcano-tectonic structures.
The first step in the framework of the geochemical
investigation of a volcanic system aimed at a surveillance
activity is the chemical and isotopic characterization of fluids
and for then putting forward a geochemical model; inside of
this geochemical model it is possible to interpret the observed
changes in any single investigated parameter. The
geochemical approach is to identify the following topics:
i) The main End-Members involved in the studied system;
ii)Possible type and degree of interaction processes, WaterRock and Gas-Water; iv)Mixing among the individuate EndMembers; v)Chemical and isotopic characterization of a
possible hydrothermal system; vi)Formulation of a
geochemical model; vii)Choice of sites and useful
geochemical parameters able to give us information about
changes of volcanic activity. Then, we can start the continuous
and discontinuous geochemical monitoring program.
The Aeolian Archipelago (Italy) is characterized by the
presence of several active volcanoes with different volcanic
activity: a)Vulcano Island with solphataric activity, last
eruption occurred in 1888; b)Stromboli Island, with
strombolian activity, last eruptions occurred in 2002-2003,
2007 and in 2014; c)Panarea Island, undersea degassing, last
massive submarine gas output occurred in November 2002.
The Aeolian active volcanoes represents a real unique and
natural laboratory where the geochemical scientists worked for
more of twenty years producing a lot of geochemical data.
Moreover, advanced geochemical continuous monitoring
systems was installed in the active volcanoes (like Vulcano
and Stromboli Islands) to measure extensive parameters (Soil
CO2 and Plume SO2 fluxes) and intensive parameters like
High-Temperatures fumaroles and characteristic chemical
species ratios (like C/S).
Here, we present a review of aquired geochemical data,
interpretative models and installed monitoring networks.
1
Department of Materials Science and Engineering, University
of Sheffield, Sheffield S1 3JD, UK
2
Centre for Scientific Computing and Department of
Chemistry, University of Warwick, Coventry CV4 7AL,
UK.
The incorporation of organic molecules into mineralised
tissues lends these materials special mechanical properties.
Furthermore, proteins directly influence the growth of mineral
phases, controlling both the crystal structure and assemblyof
biominerals.
Calcium carbonate (CaCO3) is often employed as a model
system to investigate biomineralisation. In recent years, a
number of nucleation and growth mechanisms have been
proposed, which include the formation of stable clusters
before nucleation [1], and the emergence of dense liquids,
which are stabilised in the presence of polyASP [2,3]. An
amorphous phase is known to preceed crystalline CaCO3
phases and it was shown that glycine-rich proteins stabilise
this phase [4]. Picker et al. conducted an in depth study of the
effect of all 20 amino acids on crystallization, identifying
multiple effects on the stages of CaCO3 crystallization [5]. The
molecular level detail of this control remains obscure.
Here, we investigate the effect of three amino acids—
ASP, ARG and GLY—on various stages of CaCO3 growth
using molecular dynamics with the Demichelis et al. force
field [6]. Starting from dispersed ions in solution at 20 mM
and pH 10, we investigated the effect of molecules on ionic
speciation. We also simulated liquid-liquid phase separation in
the presence of the amino acids, as well as the effect of
surface-adsorbed molecules on the stability of amorphous
CaCO3. Our results suggest that amino acids can indeed
regulate many aspects of biominerlization, with evident
changes to the stability of crystal precursor phases. Combined
with experimental data, these new results offer important
design principles for molecular additives to control mineral
growth.
[1] D. Gebauer et al. (2008), Science, 322, 1819. [2] M. A.
Bewernitz et al. (2012), Farad. Discuss., 159, 291. [3] L. B.
Gower and D. J. Odom (2000), J. Cryst. Growth, 210, 719. [4]
J. Aizenberg et al. (1996), Adv. Mater., 8, 222. [5] A. Picker et
al. (2012), Z. Kristallogr. 227, 744. [6] R. Demichelis et al.
(2011), Nat. Comms., 2, 590.
Co-occurrence and Metabolic
Consequences of Candidate Bacterial
Phyla and Anaerobic Methane
Oxidizing Archaea in the Deep
Crustal Biosphere
KOHEI INO1, ALEX W. HERNSDORF2, UTA KONNO3,
MARIKO KOUDUKA1, MICHINARI SUNAMURA1, AKINARI
HIROTA3, YOKO S. TOGO3, KAZUMASA ITO3, AKARI
FUKUDA3, 4, TERUKI IWATSUKI4, TAKASHI MIZUNO4,
DAISUKE KOMATSU5, URUMU TSUNOGAI5, KATSUNORI
YANAGAWA6, TOYOHO ISHIMURA7, YUKI AMANO4,
BRIAN C. THOMAS2, JILLIAN F. BANFIELD2AND YOHEY
SUZUKI1*
1
University of Tokyo, Tokyo 113-0033, Japan
(*correspondence: yohey-suzuki@ eps.s.u-tokyo.ac.jp)
2
University of California, Berkeley, CA 94720, USA.
3
Geological Survey of Japan, Ibaraki 305-8567, Japan
4
Japan Atomic Energy Agency, Gifu 509-6132 or Ibaraki 3191184, Japan
5
Nagoya University, Aichi 464-8601, Japan
6
Kyushu University, Fukuoka 812-8581, Japan
7
Natl. Inst. of Tech., Ibaraki College, Ibaraki 312-8508, Japan
The deep terrestrial subsurface is known to harbor microbial
life that is energetically dependent on organic matter and/or
H2. Recent studies have provided indications that anaerobic
oxidation of methane (AOM) is microbiologically mediated in
these environments as well as in the deep oceanic crust. As
methane and sulfate are abundant in deep terrestrial aquifers, a
substantial portion of subsurface microbial biomass may
harvest energy from AOM. In this study, groundwater was
collected from two adjacent boreholes drilled into highly and
sparsely fractured domains at a 300-m depth stage of the
Mizunami underground research laboratory in central Japan.
The highly fractured domain was associated with groundwater
dominantly colonized by Archaea implicated in AOM and
bacteria of the candidate phyla OD1 and OP3, none of which
were detected in the sparsely fractured domain where
groundwater is enriched in H2 (~10-100 nM) and depleted in
sulfate (<5 μM). We detected 13C-enriched dissolved inorganic
carbon from microbial cells incubated with 13CH4 in
groundwater with and without the molybdate inhibition of
dissimilatory sulfate reduction, indicating trace oxidation of
methane (TOM) by methanogens and AOM, respectively.
Although a syntrophic partnership among methanotrophs and
the bacteria needs further investigation, our results
demonstrate that deep methanotrophy is coupled to sulfate
reduction in one of the largest microbial habitats on Earth.
Temporal and spatial variation of
transboundary transported
anthropogenic sulfur deposition in
Japan by using sulfur isotopic ratio
Y. INOMATA1*, T. SAITO1, N. YAMASHITA1,2, M.
MOROHASHI1, H.SASE1, T.OHIZUMI1,3, K.
TAKAHASHI4 AND K. NAKAGOMI5
1
[Asia Center for Air Pollution Research, Niigta, 950-2144,
Japan, *corresponding author: [email protected],
[email protected], [email protected], [email protected]]
2
[Foresttry and Forest Products Research Institute, Ibaraki,
305-8687, Japan,[email protected]]
3
[Niigata Prefectural Institute of Public Health and
Environmental
Sciences,
Niigata,
950-2144,
Japan
[email protected]]
4
[ Japan Environmental Sanitation Center, Kanagawa, 2100828, Japan, [email protected]]
5
[Nagano Environmental Conservation Research Institute,
Nagano, 380-0944, Japan, [email protected]].
Estimate of anthropopgenic sulfur deposition in Japan
The spatial and temporal distribution of anthropogenic
sulfur deposition were evaluated the contribution from
transboundary transport from the Asian continent to Japan at
the Japanese EANET monitoring sites. In the coast of the Sea
of Japan, temporal variations of nss-sulfur isotopic ratio
(δ34Snss) were characterized by seasonal variation with high in
winter and low in summer (e.g. at Kajikawa in Niigata, +2+4.9‰). Similar seasonal variations were also found at Tokyo
and Ijira, which were located in the Pacific coast. The δ34Snss
was lower with smaller seasonal variation compared with
those at the coastal site of the Sea of Japan (e.g. Tokyo, -0.73+4.0‰). At Happo (1850 m asl), δ34Snss were almost constant
value (4.7±1.2‰). This suggests that sulfate in precipitation
was mainly derived from transboundary transport from the
Asian continent. Relative contributions of anthropogenic
sulfur have been evaluated with mass balance model. It was
clear that the transboundary transported sulfur deposition in
the coastal site of the Sea of Japan (e.g. at Kajikawa, 1.1-20
mg m-2 day-1) was two-three times larger than those in the
Pacific coast (e.g. at Tokyo, 0.03-6.7 mg m-2 day-1).
Assessing the roles of coral-algal
symbiosis in coral calcification based
on culture experiments using
symbiont and aposymbiont primary
polyps
M. INOUE*1, N. GUSSONE2, T. NAKAMURA3 Y.
YOKOYAMA4, A. SUZUKI5, K. SAKAI6, H. KAWAHATA4
1
Okayama Univ. 3-1-1 Tsushima-naka, Okayama, 700-8530,
2
Universität Münster, Corrensst. 24, D-48149 Münster,
Germany
3
Univ of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
4
AORI, Univ of Tokyo, Kshiwa 277-8564, Japan
5
GSJ, AIST, Tsukuba 305-8567, Japan
6
Sesoko Station, Univ. of the Ryukyus, Okinawa 905-0227
Scleractinian corals are well known for their vigorous
calcification, enabled by their symbiotic relationship with
photosynthesizing zooxanthellae. However, there is little
evidence of a direct link between the presence of symbionts
and the enhancement of calcification. In this study, we reared
symbiotic and aposymbiotic primary polyps from the same
coral colony (Acropora digitifera) in order to examine the role
of symbionts for coral calcification. We cultured the polyps
for 10 days at four temperatures (27, 29, 31 and 33˚C) and five
salinities (34, 32, 30, 28, 26). Then U/Ca, Mg/Ca and δ44Ca
were analyzed in polyp skeletons as a proxy for pH, organic
matrix (OM) and activity of Ca2+ channel.
In our experiment, we observed a clear decrease of
skeletal U/Ca, but not Mg/Ca, in symbiotic compared with
aposymbiotic polyps in both the culture expetiments. These
results suggest that OM secretion, the precursor step to CaCO3
precipitation, is controlled mainly by the coral host, without
any contribution from zooxanthellae. In contrast, our results
imply a higher pH of the calcifying fluid in symbiotic versus
aposymbiotic polyps. Isotope fractionations of Ca showed no
systematic differences between symbiotic and aposymbiotic
polyps and environmental settings, suggesting activities of
Ca2+ channel is not mainly controlled by the presense of
zooxanthellae. Thus, our results demonstrate that the role of
coral-algal symbiosis on coral calcification is predominantly
to enhance the pH of the calcifying fluid rather than to
promote OM secretion and/or activate Ca2+ channel.
Hydrous bridgmanite: possible water
reservior in the lower mantle
T. INOUE1*, S. KAKIZAWA1, K. FUJINO1, T.
KURIBAYASHI2, T. NAGASE2, S. GREAUX1, Y. HIGO3, N.
SAKAMOTO4, H. YURIMOTO4, T. HATTORI5, A. SANO5
1
Geodynamics Research Center, Ehime University, Matsuaya
790-8577, Japan (*correspondence: [email protected] Tohoku Univerisity, Sendai 980-8578, Japan
3
JASRI, Hyogo 679-5198, Japan
4
Hokkaido University, Sapporo 060-0810, Japan
5
JAEA, Ibaraki 319-1184, Japan
Recently hydrous ringwoodite was found in a natural
diamond inclusion [1], which includes ~1.5 wt% H2O. In
addition, the experimental studies show that wadsleyite and
ringwoodite, which are the most abundant minerals in the
mantle transition zone, can contain water up to 2.2–2.7 wt%
[e.g. 2, 3]. These results show that the mantle transition zone
is a strong water reservoir in the Earth’s interior, and at least
locally, hydrous. On the other hand, the water storage capacity
in the lower mantle is a matter of debate.
In the last Goldschmidt conference, we presented that Albearing bridgmanite (Mg-silicate perovskite) can contain
significant amount of water [4,5]. The possible H substitution
mechanism can be proposed by means of chemical
compositional relationship between Mg, Si, Al and H. In
addition, we clarified the possible H position in the
bridgmanite by means of the powder neutron diffraction
analysis in J-PARC, together with the single crystal X-ray
structural analysis in PF. This shows that the significant
amount of H (water) can be stored in the Earth’s lower mantle.
We have also conducted the equation of state and the
ultrasonic wave velocity measurements of hydrous
bridgmanite in BL04B1, SPring-8 to determine the elastic
wave velocities and the elastic properties under high pressure
and temperature condition. In this talk, we will introduce
about the recent progress of our “hydrous bridgmanite”
project.
[1] Pearson et al. (2014) Nature 507, 221-224. [2] Inoue et al.
(1995) Geophys Res Lett 22, 117-120. [3] Kohlstedt et al.
(1996) Contrib Mineral Petrol 207, 345-357. [4] Inoue et al.
(2015) Goldschmidt2015. [5] Kakizawa et al. (2015)
Goldschmidt2015.
Are cratonic roots forever? Erosion
and renewal of Siberian cratonic
mantle
DMITRI A. IONOV1*, A.V. GOLOVIN2, O.B. OLEINIKOV3
1
Geosciences Montpellier, Université de Montpellier &
CNRS UMR 5243, 34095 Montpellier, France
(correspondence: [email protected])
2
Sobolev Inst. Geol. Miner., Siberian Branch, Russian Acad.
Sci. & Novosibirsk Univ., Novosibirsk 630090, Russia
3
Diamond & Precious Metal Geology Institute, Siberian
Branch, Russian Acad. Sci, 677007 Yakutsk, Russia
The stability and longevity of cratonic lithosphere is often
attributed to the strength and buoyancy of its refractory keels,
which are assumed to have formed in the Archean, i.e. be
roughly coeval with the oldest overlying crust. This might be
the case for some cratons, but does not appear to be consistent
with recent data on the age and composition of the Siberian
cratonic mantle (and lower crust). Peridotite xenoliths
appropriate for petro-geochemical studies in the areas with
exposed or presumed Archean crust on the Siberian craton are
available in two kimberlite pipes, Udachnaya in its center and
Obnazhennaya in its NE part as well as in the Tok basaltic
field in its SE corner. Re-Os dating of refractory, meltdepleted peridotites yield TRD ages of ~2.8 Ga and ~2 Ga for
Obnazhennaya [1] and ≤2.0-2.2 Ga for Udachnaya and Tok
[2,3], the latter are younger than the oldest crust in each area.
We argue that a significant part of the lithospheric mantle
beneath the NE craton and nearly all mantle lithosphere in the
central and SE craton were eroded and replaced with new
melting residues at ~2 Ga. Further, the cratonic keel beneath
the Tok area was delaminated and the remaining spinel facies
mantle re-worked in the Phanerozoic by percolating basaltic
melts [4], like in the North China craton [5]. We present new
data on metasomatism, in particular by carbonate-rich melts in
the Siberian peridotites. Melt-reacted peridotites with
relatively low Mg# and/or high CaO and incompatible minor
elements appear to be more common than pristine refractory
peridotites [1-4, 6]. Overall, erosion and renewal of cratonic
roots is widespread in cratonic mantle worldwide.
[1] Ionov et al. (2015a) EPSL 428, 108-119. [2] Ionov et
al. (2015b) GCA 165, 466-483. [3] Ionov et al. (2006a) EPSL,
241, 47-64. [4] Ionov et al. (2006b) GCA, 70, 1231-1269. [5]
Gao et al. (2002) EPSL, 198, 307-322. [6] Ionov et al. (2010)
J.Petrol. 51, 2177-2210.
Protosolar jets and their implications
for processing in the solar nebula
T.R. IRELAND 1,*, R. SALMERON 2 AND M. WARDLE 3
1
Research School of Earth Sciences, The Australian National
University, Canberra, Australia (*correspondence:
[email protected])
2
Mathematical Sciences Institute, The Australian National
University, Canberra, Australia
3
Dept. of Physics & Astronomy, Macquarie University,
Sydney, Australia
The meteoritic record indicates that the early solar nebula
was characterised by transient, high temperature episodes.
Evidence for this includes the high temperatures required to
melt, evaporate, and condense the elements comprising CAIs
and chondrules, and the often rapid cooling rates suggested by
preservation of glass, for example, in chondrules.
Many thermal models invoke high-temperature processing
close to the proto-Sun because that is where high temperatures
are readily available. But it is not clear that if thermal
processing occurred in this vicinity whether rapid cooling can
be achieved as well.
Protostellar winds provide an astrophysical scenario for
rapid changes in both temperature and thermal gradient. They
are commonly observed in star-forming regions and and are
thought to be an integral part of the star-forming process.
Magneto-centrifugally accelerated disk winds offer the
prospect of thermal processing well in to the accretion disk [1,
2].
In this scenario, solid clumps may be entrained in the disk
wind and effectively levitate relative to a highly accelerated
disk wind. The less refractory elements evaporate from the
clumps causing refractory residues. The ambient gas in the
accretion disk will also be affected by this process. Initially a
gas of solar oxygen isotope composition will be apparent
because the local mix of CO and nebula water will maintain
solar abundances [3,4]. But as the temperature increases and
evaporation of lithophile elements occurs, the oxygen
composition of the solids will be favoured and it will be closer
to planetary composition.
The episodic nature of jets and winds can quickly change
both the thermal regime, but also the oxygen isotope
composition of the nebula gas.
[1] Salmeron & Ireland (2012a) Earth Planet. Sci. Letts. 327328, 61. [2] Salmeron & Ireland (2012b) Meteoritics & Planet.
Sci. 47, 1922. [3] Yurimoto and Kuramoto (2004) Science
305, 1763. [4] Ireland (2012) Austr. J. Earth Sci. 59, 225.
Duration of sediment supply from
various source rocks deduced from
mineral composition of the sediment
from the Beppu Bay, southwetern
Japan
1
2
3
TOMOHISA IRINO , KEN IKEHARA , MICHINOBU KUWAE ,
KEIJI TAKEMURA4, AND MASANOBU YAMAMOTO1
1
1Hokkaido University, Japan (*correspondence:
[email protected])
2
Gelogical Survey of Japan, National Institute of Advanced
Industrial Science and Technology, Japan ([email protected])
3
Ehime University, Japan ([email protected])
4
Kyoto University, Japan ([email protected])
The Beppu Bay located in the northeast Kyushu Island, the
southwestern Japan receives detrital materials mainly from
two drainage systems, the Ohno River and the Oita River.
Surface geology of the Ohno River drainage area is roughly
divided into two as intermediate to felsic volcanic area
covered with andosol in the southwestern headwater region
and Paleozoic to Mesozoic sedimentary rocks covered with
brown forest soil to the southeast. The drainage basin of the
Oita River is located in the north of the Ohno River drainage,
which is characterized by mafic volcanic rocks in the
headwater region as well as interediate to acidic volcanics
along the river path.
Since the Beppu Bay receives the materials from such
geologically contrasted drainage systems, the temporal
changes in the provenance for the sediment can be utilized to
seek for the erosion and sediment supply from hinterland
basin. For this purpose, we examined the mineral
compositions of BP09 and BP15 sediment cores, covering the
last 7,000 yrs, collected from the center of Beppu Bay as well
as sediment from surface soils and river beds using X-ray
powder diffraction.
Beppu Bay sediments mainly consist of laminated
hemipelagic clay with frequent intercalation of feldspathic
sand layers. Feldspar compostion (anorthite (An) / albite (Ab)
ratio) of the sediment was within the range of surface soils in
the drainage of Ohno and Oita Rivers. Feldspars in fine
hemipelagic sediments and sand layers in lower sequence
showed more An-rich composition while sand layers in upper
sequence are more Ab-rich, suggesting that the source rocks
supplying sand grains had changed from time to time while
the source of fine grained materials have been maintained
consistently during these 7,000 years.
Geochemical study on geothermal
resources in Oku-Hida Hot Spring
area, Gifu Japan
REONA ISAJI1 AND AKIRA UEDA1
1 Enviromental Biology and Chemistry, Graduate School of
Science and Engineering for Education, University of
Toyama, 3190, Gofuku, Toyama, 930-8555, Japan
([email protected], [email protected])
There are many high-temperature hot springs with > 90 ℃
in the vicinity of Yakidake volcano across the border of Gifu
and Nagano Prefectures. Koji et al. (2012) reported the
chemical and isotopic (δD and δ18O) compositions of 30 hot
spring waters and 5 river waters in this area. Most hot springs
were of meteoric origin and of Na+-Cl－・HCO3－ and Na+HCO3－ types with low salinity (less than 30 meq/L). The
estimated underground temperatures by geothermometers are
150 to 200℃ at the depth of ca. 1km. The total geothermal
resources in the study area are estimated to be ca. 400 MWe
for producing the electricity.
Recently, geothermal well was drilled in the study area
(1,200 m in depth). The Sr concentration and isotopic ratios of
both hot springs and rocks are analyzed. The purpose of this
study is to estimate the depth of the reservoirs which issue the
hot spring waters by using Sr concentration and its isotopic
composition (87Sr/86Sr) in hot spring waters and rocks
obtained from a newly drilled well. In this preliminary report,
the Sr concentrations of the hot spring waters collected by
Koji et al (2012) were analyzed.
The results show that the hot spring waters in the southern
part of the study area have slightly higher Sr concentration
than those in the northern part. The Sr concentration increases
with increasing of Ca concentration in the southern area,
whereas those in the Northern part show an almost constant
value. These results show that Sr concentration in hot spring
waters reflect those of reservoir rocks.
Effects of increasing salinity on
the biogeochemical cycle of the
hypersaline biomat: Insights from the
isotopic composition of pigments
Y. ISAJI1*, H. KAWAHATA1, J. KURODA2, T.
YOSHIMURA1, N. O. OGAWA2, A. SUZUKI3, T. SHIBUYA2,
F. J. JIMÉNEZ-ESPEJO2, S. LUGLI4, V. MANZI5, M.
ROVERI5, AND N. OHKOUCHI2
1
Atmosphere and Ocean Research Institute, University of
Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564,
2
Japan Agency for Marine-Earth Science and Technology
3
National Institute of Advanced Industrial Science and
Technology
4
Università degli Studi di Modena e Reggio Emilia, Italy
5
Università di Parma, Italy
In shallow hypersaline environment, benthic microbial
mat is often formed. It is densely inhabited by microorganisms
such as cyanobacteria, sulfur oxidizing bacteria, sulfate
reducing bacteria, and others [1]. Hypersaline microbial mat is
characterized by extremely high primary production, which
results from efficient recycling of nutrients inside the mat [2].
This study aims to understand the biogeochemical processes
occurring in this unique ecosysytem, as well as their changes
with increasing salinity.
Brine water and sediments on the bottom were collected
from the solar saltern in Trapani, Italy (9 samples, salinity
range 38-276). Carbon isotopic composition of dissolved
inorganic carbon (δ13CDIC) was highly variable, with lower
values (-5.1~-10.6‰) recorded in the ponds where microbial
mat is formed, and the highest value (~7.2‰) where salinity
was high (>270) with no microbial mat developing. While
high δ13CDIC may be attributed to degassing of CO2 from the
brine due to evaporation [3], remineralization of organic
carbon or penetration of CO2 from the atmosphere may be
responsible for low δ13CDIC [4]. To investigate the
biogeochemical cycle in the mat, we conducted compoundspecific isotope analysis on pigments extracted from different
layers of the mat (yellow, green, and pink, and black layers
from the top to the bottom). Discussion based on δ13C and
δ15N of chlorophyll a originating from cyanobacteria and
bacteriochlorophyll a from purple sulfur bacteria will be
presented, as well as their variations with different salinity.
[1] Ollivier et al. (1994) Microbiol. Mol. Biol. Rev. 58, 27-38.
[2] Canfield & Des Marais (1993) Geochim. Cosmochim. Acta
57, 3971-3984. [3] Stiller et al. (1985) Nature 316, 434-435.
[4] Lazar et al. (1990) Geology 18, 1191-1194.
Data assimilation for terrestrial
ecosystem models: a case study with
the particle filter
TAKESHI ISE1*
1
Field Science Education and Research Center, Kyoto
University, Kyoto, Japan
(*correspondence:[email protected])
Data assimilation is a promissing, but currently
underutilized numerical technique to optimize terrestrial
ecosystem models. Differing from atmospheric or oceanic
models, terrestrial ecosystem models generally have nonlinear
or abrupt behaviors that are not appropriate for widely-used
data assimilation methods such as emsemble Kalman filter.
However, the particle filter, one of the data assimilation
methods, is supposed to have enough flexibility to optimize
terrestrial ecosystem models at the expense of large
computational burden.
In this study, several parameters of the terrestrial
ecosystem model SSSEM are simultaneously optimized by the
particle filter in order to reproduce phenological patterns of a
deciduous forest stand near Fairbanks, Alaska. The satellitebased observation of leaf area index (LAI) is used to fit the
model. After the data assimilation, the seasonal pattern of
LAI is successfully reproduced. The timings of leaf onset and
offset, and the maximum LAI of summer are appropriately
estimated (Figure 1).
Figure 1: SSSEM simulations: default and optimized results.
Moreover, the parameter set (e.g., light use efficiency,
photosynthate allocation to leaf, stem, and root) of the model
are successfully optimized by the particle filter. The variance
of each estimated parameter is reduced, implying that the
probable ranges of parameter estimates are found in this
experiment.
This case study showed that nonlinear behaviors of
terrestrial ecosystem such as leaf onset and offset can
successfully be optimized using data assimilation.
Are seafloor massive sulfides a
modern analogue for VMS deposits ?
JUN-ICHIRO ISHIBASHI1
1
Dept. Earth Planet. Sci., Faculty of Science, Kyushu Univ.;
E-mail: [email protected]
Seafloor massive sulfides recognized in hydrothermal
fields in arc-backarc settings in the western Pacific are
commonly represented by coexisting occurrence of zinc- and
lead-enriched polymetallic sulfides and abundant sulfate
minerals. The mineralogy and geochemical signatures present
has led researchers to suggest these areas may be a modern
analogue for the formation of ancient Kuroko-type
volcanogenic massive sulfide (VMS) deposits. Seafloor
drilling during IODP (Integrated Ocean Drilling Program)
Expedition 331 documented the subseafloor hydrothermal
system at the Iheya North Knoll in the Okinawa Trough.
Mineral textures and assemblages present in the drilled cores
obtained from a hydrothermal mound in the proximal area
were consistent with those recognized in ancient Kuroko-type
mineralization. Moreover, stratabound occurrences of basemetal mineralization and widespread hydrothermal alteration
were recognized across an area of over 500 m extent, which
are comparable to ancient Kuroko-type deposits. On the other
hand, geochemical studies of hydrothermal fluid venting from
the seafloor and pore fluid within the sediment demonstrated
diverse range of sulfide and sulfate mineralization could be
related to subseafloor geochemical processes and fluid flows.
Geochemical studies on present seafloor hydrothermal
activities would provide a rare window into the dynamic
processes for formation of VMS deposits.
Practical class "Water geochemistry"
composed of fieldwork, analysis and
lecture
JUN-ICHIRO ISHIBASHI1* AND TOMOHARU MIYAMOTO1
1
Dept. Earth Planet. Sci, Faculty of Science, Kyushu Univ.
*E-mail: [email protected]
A practical class "Water geochemistry" is composed of
pre-training (6 hours), fieldwork to collect water samples and
observe rocks (one day), analysis of the collected water
samples (6 hours), classroom lecture on chemical equilibrium
of water-rock interactions (12 hours), and report writing
(students' own effort). Sampling stations are located along
streams around a karst tableland called Hirao-dai (Fig.1). The
streams are selected from different geologic bodies (limestone
region, granite body, metamorphic rocks), so that students
easily recognize diversity of chemical compositions among the
collected waters and ruminate factors controlling water
chemistry (Fig. 2). Experiences through the class should be
valuable for the third grade undergraduates as good training to
switch their mind from passive lecture-based learning to active
thesis studies.
Fig. 1 Geological map of the fieldwork area
1
2
5
4
3
1.0
2.0
+
6
7
+
Na + K
Ca2+
Mg2+
meq/kg
2.0
1.0
-
Cl
HCO3
SO42-
Fig. 2 Stiff diagrams of the stream waters
Generation of Carbon Compounds by
“Low” Velocity Impacts
K. ISHIBASHI1*, K. KUROSAWA1, T. OKAMOTO1 AND
T. MATSUI1
1
Planetary Exploration Research Center, Chiba Institute of
Technology, Narashino, Chiba, Japan (*correspondence:
[email protected])
Impacts are common phenomena through the history of
the solar system. Some evidence shows that there was a period
of extremely high impact flux that is called late heavy
bombardment occurred approximately 3.8-4.1 Ga [e.g., 2]. In
this period impacts might have affected the surface
environment of planets significantly. Asteroids and comets,
which are survivors of planetesimals in the early solar system,
include a large amount of carbon. The redox state of carbonbearing gas species released after impacts is important for
early Earth and early Mars. For example, precursors of life on
early Earth (and early Mars) must have preferred a reductive
environment to an oxidative one.
Simulated impact vaporization experiments that used laser
irradiation to vaporize meteorites and/or meterorite analogue
have shown that the impact-generated gas has oxidative
composition because of oxygen released from silicates
included in the samples [3, 4].
In this study we focused on relatively "low" velocity
impacts. In general the required velocity for incipient
vaporization of silicates is ~10 km/s and for complete
vaporization a few tens of km/s [5]. Impacts with the velocity
where silicates does not evaporate or partially evaporate might
generate reductive chemical species.
We conducted impact experiments using a two-stage
hydrogen gun to investigate the composition of the impactgenerated gas. The target samples were mixture of SiO2
powder and polyethylene powder, which were used as
simplified carbonaceous chondrite analogue. The impact
velocities were ~5-7 km/s. The generated gas was measured
with a quadrupole mass spectrometer. The preliminary
analysis shows that a large amount of CH4 and little CO2 was
produced, which suggests that the composition of the impactgenerated gas under the condition that silicates do not vaporize
is reductive. More detailed results will be presented at the
conference.
[1] Chyba et al. (1990) Science 249, 366-373. [2] Morbidelli
et al. (2012) Earth Planet. Sci. Lett. 355-356, 144-151. [3]
Gerasimov et al. (1998) Earth Moon Planets 80, 209-259. [4]
Ishibashi et al. (2013) Earth Planets Space 65, 811-822. [5]
Ahrens and O’Keefe (1972) The Moon 4, 214-249.
Cesium-137 concentrations in
freshwater fishes collected in Lake
Inba
N. ISHII1*, M. KAGAMI 2, T. FUROTA2, K. TAGAMI1 AND S.
UCHIDA 1
1
National Institute of Radiological Sciences, Anagawa 4-9-1,
Inage-ku, Chiba 263-8555, Japan (*correspondence:
[email protected])
2
Toho University, Miyama 2-1-1, Funabashi, Chiba 275-8510,
Japan
A large amount of Cs-137 was released into the
environments following the Fukushima Daiichi nuclear
accident in 2011. Concequently, freshwater environments
have also been contaminated with Cs-137. Most of Cs-137 is
storongly assosicated with suspended matter in freshwater
systems, and thus, it is easy to accumulate on the bottom of
rivers and lakes. Aquatic organisms may accumulate Cs-137
into their bodies. We especially foucused on fish because the
trophic level of fish is relatively high, and fish consume a
large amount of foods contaminated with Cs-137. In addition,
from the viewpoint of radiation dose for human, consumption
of freshwater fish is one of pathways of internal dose. In this
study, we determined the concentrations of Cs-137 in various
parts of freshwater fishes in a lake to clarify major factors
affect to Cs-137 concentration in fish.
We collected four fish species from Lake Inba (north
basin) in 2015: Channa argus (n=1), Ictalurus punctatus
(n=2), Cyprinus carpio (n=5), and Carassius sp. (n=3). Fish
samples were separated into muscle, bone, and internal organs
parts after the measurements of body length and fresh weight.
Each separated part was freeze-dried and powdered, then the
activity concentration of Cs-137 was measured with a Ge
detector. The age of fish was detemined using otoliths.
From their age, all the collected fishe individuals had
already been born when the nuclear accident was occurred.
Therefore, exposing time should be the same for all samples.
Among the fish body parts, the highest concentration was
found in muscle for all species. Cs-137 concentrations in
internal organs and born samples were less than 1/100 of the
muscle. These results suggest that Cs-137 was highly
accumulatied in muscle. The concentrations of Cs-137 in fish
werehigher in the following order: C. argus > I. punctatus >
Cyprinus carpio ≈ Carassius sp. C. argus and I. punctatus are
carnivorous, and Cyprinus carpio and Carassius sp. are
omnivorous. Such feeding habitat may be the majour factor of
the Cs-137 differeces in freshwater fish species.
T. ISHII1*, N. MIYAJIMA1, S. PETITGIRARD1, C.
MCCAMMON1, T. KATSURA1
1
Univ. Bayreuth, Bayreuth, D-95440, Germany
Water is thought to be transported as hydrous minerals
through subduction of slabs at least to depths reaching the
transition zone. Nominally anhydrous lower mantle minerals
(e.g. bridgmanite (Brm)) can incorporate a limited amount of
water. Therefore, water could be hosted by hydrous minerals
such as phase D (phD) in the lower mantle. Brm contains
significant amounts of Fe3+ (Fe3+/ΣFe > 0.1) even when
coexisting with metallic iron. The Fe3+ content increases with
increasing Al2O3 in Brm, and exceeds 0.5 relative to total iron
in lower-mantle Brm. Therefore, the formation of Brm could
extract oxygen from hydrous minerals (reduction of OH to H2)
through the deposition of Fe metal. In this study, we
demonstrated this reduction reaction using phD with a Kawaitype multianvil press.
The starting materials were sintered Al-free and aluminous
phD (Al-phD) pre-synthesized at 27 GPa and 1100 K, a
natural olivine single crystal (Olv) and pyroxene as
(Mg0.9Fe0.1)(Si0.9Al0.1)O3 (FeAl-En) synthesized at 1300 K at
controlled oxygen fugacity (PO2≈IW). Sintered Al-free phD
and Al-phD were combined with Olv or sintered FeAl-En in
Au capsules. The samples were pressurized to 27 GPa and
heated at 1100 K for 1 hour.
No reaction between Al-free phD and Brm + ferropericlase
aggregate formed from Olv according to SEM data. In
contrast, a 4 µm fine-grained layer consisting of SiO2 and an
amorphous phase was found with TEM on the boundary
between Al-phD and Brm aggregate formed from FeAl-En.
The present results strongly indicate that the decomposition of
phD is accompanied by the formation of Fe-bearing aluminous
Brm. It is suggested that phD decomposes by reduction at
depths to 720 km and that no water is transported into the
deeper part of the lower mantle.
Changes in the concentrations of
radioactive cesium outflowed from
the steep moutainious forest of
Abukuma Mountains, released by
Fukushima Daiichi Nuclear Power
Plant Accident.
Y. ISHII*, T. WATANABE, T. OHYAMA, Y. SASAKI,
H. ABE, K. MITACHI, T. NIIZATO
Japan Atomic Energy Agency, Miharu, Fukushima 963-7707,
JAPAN (*correspondence : [email protected])
Mountainous forest is currently one of the most important
sources of radioactive cesium released from the Fukushima
Daiichi Nuclear Power Plant accident in Fukushima
prefecture, which was coverd approximately 70% of the land
area by the forest. This study reports the changes in
concentrations of radioactive cesium in sediments outflowed
from the steep mountanious forest of the Abukuma Mountains,
Fukushima, during September 2013 – December 2015.
The sediment samples of 0-5 cm layer were obtained from
the soil-saving dam installed at outlet of the steep river-valley
in the mountanious forest of Fukushima, Japan. The The
catchment area is 2.1 ha and total amount of the sediments
measured by 3D laser sccaning method during the period were
2.4 m3 in this dam [1]. 9 – 17 samples were collected each
year at the position of 1 – 3 m upstream side from the dam
body. Figure 1 shows the radioactive cesium concentration in
the sedimented soils. The Cs-137 concentrations in the
sedimented soils were decreased by nearly 20% during the
monitoring period.
10,000
Radioactivecaesium
concentration/kBqkg-1
Reductive decomposition of phase D
by formation of Fe-bearing
aluminous bridgmanite
Cs-134
Cs-137
1,000
100
10
Figure 1: The concentration of radioactive cesium in
sedimented soils in the soil-saving dam.
1. Watanebe, T., et al., 2016, Japan Geoscience Union
Meeting 2016.
Re-Os isotope and highly siderophile
element constraints on the origin of
ancient depleted domains in the
modern convecting mantle
AKIRA ISHIKAWA 1, 2*, RYOKO SENDA2, KEN-ICHIRO
TANI3, KATSUHIKO SUZUKI2 AND TERUAKI ISHII4
Discovery of several new seafloor
hydrothermal deposits by the
regional survey, such as Gondou Site,
in central part of the Okinawa
Trough, Japan
NOBUAKI ISHIKAWA1, HARUHISA MOROZUMI2 AND
SATOSHI SHIOKAWA3
1
The University of Tokyo, Tokyo 153-8902, Japan
(*correspondence : [email protected])
2
Japan Agency for Marine-Earth Science and Technology,
Yokosuka 237-0061
3
National Museum of Nature and Science, Tsukuba 305-0005
4
Fukada Geological Institute, Tokyo 113-0021
Recent accumulation of Os isotope data obtained either
from abyssal peridotites or from ocean island peridotite
xenoliths has clearly demonstrated that the modern convecting
mantle is substantially heterogeneous. Unlike other radiogenic
isotope systematics in oceanic basalts, largely controlled by
incorporation of recycled crustal materials, the observed range
of Os isotope compositions in oceanic peridotites likely reflect
varying degrees of ancient melt extraction from peridotitic
mantle. However, the nature and timing of this melt extraction
still remain elusive.
We examined the 187Os/188Os ratios and highly siderophile
element (HSE: Os, Ir, Ru, Pt, Pd, Re) concentrations in
peridotite-serpentinite recovered from the Pacific area (Hess
Deep in the East Pacific Rise, Taitao ophiolite in Chile, IzuOgasawara and Tonga forearc, peridotite xenoliths from
Hawaii and Malaita) because the number of data available is
yet scarce when compared with data from other oceans
(Atlantic, Arctic and Indian Ocean). Our primary purpose is to
test whether mantle regions underlying four major oceans are
distinct in terms of Os isotope variations, reflecting the pattern
of mantle convection or mixing efficiency. The results
demonstrate that samples from each area display very similar
Os-isotope variations with a pronounced peak in 187Os/188Os
=0.125-0.128. The relatively larger datasets obtained from
Hess Deep, Taitao, Hawaii and Malaita clearly exhibit the
presence of secondary peak in 187Os/188Os =0.114-0.120 (Redepletion ages 1-2 Ga). These characteristics are almost
identical to the global population mainly comprised of data
from other oceans. The most unradiogenic 187Os/188Os samples
in the global population tend to be restricted in harzburgites
(Al2O3 <2 wt%) with low-Pd/Ir ratios (<1.0), suggesting that a
common melt extraction process created highly depleted
residues in Proterozoic. These residual harzburigtes were
transported into deep mantle, and are now homogeneously
distributed over large scales as ancient depleted domains in the
modern convecting mantle.
1
Japan Oil, Gas and Metals National Corporation
([email protected])
2
([email protected])
3
([email protected])
JOGMEC conducted the regional survey by use of the
research vessel Hakurei and chartered vessels from fiscal year
2014. It takes a marine investigation approach to select
promising areas regarding seafloor mineral resources for seas
around Japan. Firstly, Multibeam Echo Sounder (MBES) on
vessel can conduct a bathymetric mapping to reveal
topographical details (such as caldera, seamount, ridge, etc.).
Then, Autonomous Underwater Vehicle (AUV) can acquire
higher resolution bathymetry than vessel by onboard the echo
sounder closer to seafloor. As the result of the regional survey
in back arc basins behind the Ryukyu trench-arc, the central
part of Okinawa Trough during recent 3-years period,
JOGMEC confirmed new 4 sites (Noho, Gondou, Dana, Higa)
of seafloor hydrothermal deposits by the Remotely Operated
Vehicle (ROV). In either sites, a lot of active hydrothermal
chimneys and more widely distributed inactive mounds
consists of various sulphide minerals. Especially in Gondou
site, the mineralogical composition of sulfide ores is
dominated by chalcopyrite, sphalerite, wurtzite, pyrite,
marcasite and galena with minor tetrahedrite. Chalcopyrite is
the most abundant copper mineral at Gondou site (1-40 modal
%). Chalcopyrite occurs as subhedral to anhedral grains
interstitial to sphalerite, and sometime forms intergrowth with
it. Six samples taken by manipulator arm of ROV from
mounds and chimneys averaged 13.0 % copper, 12.3 % zinc,
5.2 % lead, 1.7 grams/tonne gold and 326 grams/tonne silver.
And otherwise, as for Noho site, pyrite/marcasite and
sphelerite were abundant. In addition, as for Dana site, pyrite,
sphalerite and chalcopyrite were abundant. On the other hand,
as for Higa site, low porosity and large grains of sulfide ores is
dominated by sphalerite and galena. Currently, the drill core
samples at Hakurei site in the Izena cauldron, pyrite/marcasite
and sphalerite were abundant and found to be porous. 392 drill
core bulk samples from ores averaged 0.51 % copper, 9.69 %
zinc, 3.49 % lead, 3.2 grams/tonne gold and 250 grams/tonne
silver. As above, the transition of mineral assemblage in each
site might be caused by various geological process with
magma reacting to various strata of the stratigraphy. These
discoveries has enhanced the possibility to secure further
mineral resources for seas around Japan. The data in this
presentation have been collected as a part of sponsored
projects by Agency for Natural Resources and Energy,
Ministry of Economy, Trade and Industry (METI), Japan.
Molecular dynamics simulations to
reveal physico-chemical properties of
water confined between quartz
surfaces
Boron and lithium isotope constraints
on fluid-rock interactions in the
shallow megathrust at the Japan
Trench
SATORU ISHIKAWA1*, HIROSHI SAKUMA2,
NORIYOSHI TSUCHIYA1
TSUYOSHI ISHIKAWA1, JUN MATSUOKA2, KAZUYA
NAGAISHI2, JUN KAMEDA3 AND JAMES SAMPLE4
1
Graduate School of Enviromental Studies, Tohoku
University, Sendai 980-8579, Japan (*correspondence:
[email protected])
2
National Institute for Materials Science, Tsukuba 305-0044,
Japan
1
Interfacial water, of which physicochemical properties were
different from bulk water, was recognized in the vicinity of
solid surface. The physical properties of interfacial water show
unique characteristics, for example the self-diffusion
coefficient, thermal expansion coefficient and freezing point.
The property of interfacial water is essential for understanding
geophysical and geochemical phenomena. In this study, we
performed the molecular dynamics (MD) simulations to
understand the structure and dynamics of water confined
between quartz surfaces at 298-573 K, 10 MPa.
We tested some systems of water confined between quartz
surfaces characterized by the termination of silanol (Si-OH)
group. At low temperature, the density profiles showed several
layered structures near the surface, and the self-diffusion
coefficient was reduced in 1.0 nm distance from the surface.
At high temperatures, the layered structures were disappeared
and the self-diffusion coefficient was reduced in 1.5 nm.
The activation energies of the diffusion process in confined
geometries were calculated based on the Arrhenius theory, and
these values were close to that of bulk water. This implied that
the diffusion mechanism in confined geometries is similar that
in bulk and the activation energy may be interpreted by the
dissociation energy of hydrogen bond.
IODP Expedition 343 (JFAST) drilled through the plate
boundary near the Japan Trench to investigate the cause of
very large fault slip during the 2011 Tohoku-Oki earthquake.
Here, we report B and Li isotope systematics of interstitial
fluids and rocks from JFAST, and evaluate fluid-related
processes that occurred in the shallow megathrust fault zone at
the Japan Trench.
Depth profiles of B content and δ11B value for the
interstitial fluids show a clear minimum and a maximum,
respectively, around the plate-boundary fault, with the vicinity
of the fault being characterized by lower B content and higher
δ11B value compared with seawater. The Li contents and δ7Li
values of the JFAST fluids are thoroughly higher and lower
than seawater, respectively, without no significant minimum
nor maximum around the fault. The B and Li contents and
δ11B values of the plate-boundary fault rocks are
indistinguishable from those of equivalent source smectiterich sediments.
In the systems composed of seawater-like fluid and
sediment, both B concentrations and δ11B values in the fluid
and solid phases are temperature-sensitive, and higher
temperatures result in higher B and lower δ11B in the fluid
phase and lower B and lower δ11B in the solid phase. Actually,
interstitial fluids and rocks from ODP site 808 (Nankai
Trough) showed such characteristics at the depths with
temperatures higher than 50 oC for fluids and higher than 100
o
C for rocks (You et al., Geoogy, 1995). The B and δ11B
characteristics observed for the JFAST fluids and rocks thus
indicate that fluids and rocks within and around the plateboundary fault analyzed here have no clear record of fluidrock interactions at high temperatures. The lack of hightemperature signals around the fault is also consistent with the
Li and δ7Li data for the JFAST fluids and rocks. These
observations provide constraints on the nature of fluid-rock
interactions in the shallow megathrust fault zone during the
Tohoku-Oki earthquake.
Kochi Instute for Core Sample Research, JAMSTEC, Japan (
[email protected])
2
Marine Works Japan Ltd., Japan
3
Hokkaido Univ., Japan
4
Northern Arizona Univ., USA
Investigation of unique oxidizing
capacity of the Antarctic atmosphere
based on O-MIF signatures in
atmospheric sulfate and nitrate
Paleoenvironmental
reconstructions for the Bonaparte
Gulf, Australia using 14C age
differences between molluscs and
organic matter
S. ISHINO1*, S. HATTORI1, J. SAVARINO2,3, B.
JOURDAIN2,3, S. PREUNKERT2,3, M. LEGRAND2,3, AND N.
YOSHIDA1,4
TAKESHIGE ISHIWA1*, YUSUKE YOKOYAMA2,
YOSUKE MIYAIRI3, MINORU IKEHARA4, STEPHEN
OBROCHTA5, TAKENORI SASAKI6, AKIHISA KITAMURA 7
1
Tokyo Institute of Technology, Yokohama 226-8502, Japan
2
Univ. Grenoble-Alpes, LGGE, F-38000, Grenoble, France
3
LGGE/CNRS, F-38000, Grenoble, France
4
Earth-Life Science Institute, Tokyo, Japan
O-MIF signatures (Δ17O) in sulfate and nitrate in the
Antarctic ice cores are used as proxy for the reconstruction of
oxidizing capacity in the past Earth’s atmosphere because they
reflect the relative importance of O3 (Δ17O = 25-35‰) and
other oxidants (e.g. OH radical; Δ17O = 0‰) during their
formation [1]. While it is necessary to understand the
oxidizing capacity of the present Antarctic atmosphere for the
interpretation of the proxy, it still remains to be constrained
because of the complicated chemistry induced by high NOX
emissions from snowpack [2]. For this issue, we investigated
the seasonal variations of Δ17O values of both sulfate and
nitrate in the aerosols collected at Dumont d’Urville, coastal
Antarctica, throughout the year 2011.
The Δ17O values of sulfate and nitrate showed the clear
seasonal variations with summer minima and winter maxima.
These trends are resulted from the seasonal changes in the O3 /
OH ratios decreased in summer by ozone destruction and OH
production via UV irradiance. Indeed, both Δ17O values of
sulfate and nitrate were correlated with ozone mixing ratios.
Despite the almost same ranges of ozone mixing ratios for
spring and autumn, the sensitivity of Δ17O values of sulfate to
ozone mixing ratios in spring was lower than that in autumn.
In contrast, this phenomenon was not observed for nitrate. The
relatively low Δ17O values of sulfate in spring may be due to
the lower O3 / OH ratios caused by the NOX emission from
snowpack triggered by the UV irradiance, which enhances OH
production exceeding O3 production [3]. It is not easy to
identify the precise processes, but this study shows first
observational evidence of the contribution of snow-sourced
NOX emission on sulfate production through the changes in
the oxidizing capacity.
[1] Alexander and Mickley (2015) Curr. Pollution Rep. 1, 57–
69. [2] Chen et al. (2001) Geophys. Res. Lett. 28, 19, 36333636. [3] Zatko et al. (2015) Atmos. Chem. Phys. Discuss 15,
18963–19015.
1
Department of Earth and Planetary Science, the University of
Tokyo (*correspondance: [email protected])
2
Atmosphere and Ocean Research Institute, the University of
Tokyo ([email protected])
3
Atmosphere and Ocean Research Institute, the University of
Tokyo ([email protected])
4
Center for Advanced Marine Core Research, Kochi
University ([email protected])
5
Faculty of International Resource Sciences, Akita University
([email protected])
6
The University Museum, the University of Tokyo
([email protected])
7
Faculty of Science, Shizuoka University
([email protected])
Radiocarbon dating is an essential dating methods for late
Quaternary samples. Further, ages of different material
preserved in a same horizon of geological strata could provide
paleoenvironmental information. We define the age
differences between molluscs and organic matter as “14C age
offset”, which can be an indicator of relative terrigenous
carbon contributions to the sediments deposited at certain
period in the past. The Bonaparte Gulf, northwestern
Australia, has a broad continental shelf with the water depth
shallower than ~200 m. This region has a carbonate platform,
which had been exposed during sea level lowstand. Here we
present the paleoenviornmental reconstructions in the
Bonaparte Gulf, using 14C age offset combined with other
geochemical and geophysical proxies.
The variation of 14C age offset is correlated with TOC,
C/N ratios, and Ca/Ti. The increased terrigenous carbon
contributions make an oragnic matter age older and change 14C
age offset larger. These variations suggest that the
paleoenvionrmental change as the exposure of carbonate
platforms occurred at ca. 26 ka. We concluded that the
application of 14C age differences between molluscs and
organic matter ages is useful in the reconstruction of
paleoenvironmental change in this region.
Geochemical & geochronological
constraints on the subduction
initiation of the Izu-Bonin arc
Hydrochemical Characterization and
Groundwater Evaluation of the Area
West El-Minia District, Egypt
O. ISHIZUKA12*, K. TANI3, Y. HARIGANE1, Y. OHARA4,
R.N. TAYLOR5,Y. KUSANO1, R. HICKEY-VARGAS6, G. M.
YOGODZINSKI7, M. SUDO8, A. MCCARTHY9, I.P.
SAVOV10, R.J. ARCULUS11, K. BOGUS12
ESAM ISMAIL1, RAFAT ZAKI1, ALI KAMEL1
1
Geological Survey of Japan/AIST, *correspondense:[email protected]
2
JAMSTEC, Japan
3
National Museum of Nature and Science, Japan
4
Hydrographic and Oceanographic Department of Japan
5
University of Southampton
6
Florida International University
7
University of South Carolina
8
Universitaet Potsdam
9
University of Laussane
10
University of Leeds
11
Australia National University
12
Texas A&M University
Recent geological surveys including IODP expeditions in
the Philippine Sea are providing new geochronological and
geochemical constraints to tectonic reconstruction of the
Philippine Sea Plate for the period immediately before and
after the subduction initiation (SI) to form Izu-Bonin-Mariana
(IBM) arc. 1) OIB-like magmatism in the Philippine Sea
forms time-progressive volcanic chain mirrored either side of
the West Philippine Basin (WPB) backarc spreading center
[1]. This implies that the Mesozoic arc terrane of Daito Ridge
Group were split by regional upwelling centered on the impact
of the mantle plume at close timing to SI of the IBM arc. 2)
New geochronological and magnetic anomaly data seem to
indicate that ocean basins occupying southern part of the
Philippine Sea, i.e., WPB and Palau Basin, formed
contemporaneously. This means that these basins formed after
SI of the IBM arc. 3) IODP Exp.351 recovered basaltic
basement of Amami Sankaku Basin, i.e., pre-IBM arc oceanic
crust [2]. This basement is strongly depleted in highly
immobile elements and has strong similarity to forearc basalt
(FAB) at SI, but distinct from many Philippine Sea basin
basalts. Biostratigraphy of sediment above basement
determined that the basement is contemporaneous, or slightly
older than FAB, and Ar/Ar dating of basement basalt is under
way. We will discuss possible tectonic reconstructions for the
period of SI.
REFERENCES:[1] Ishizuka, Taylor, Ohara & Yuasa
(2013), Geology 41, 1011-1014. [2]Arculus, Ishizuka, Bogus
et al. (2015), Nature Geoscience 8, 728-733.
1 Geology Department, Faculty of Science, Minia
University, Egypt
The present study assesses groundwater resources of the
densely populated area of Egypt by integrating conventional
hydrochemistry and statistical analysis. Since the quantity and
quality of water available for irrigation in Egypt is variable
from place to place. Groundwater is exploited from
Pleistocene aquifer which represents the main aquifer in the
study area and it is composed of sands and gravels of different
sizes, with some clay intercalations. Chemical characterization
and quality of groundwater in west El-Minia district mainly
depends on the complete chemical analysis of collecting 88
samples covered all the study area. The groundwater samples
were categorized as Ca(HCO3)2 water type, and the
hydrochemical classification shows that, most of the studied
water samples are meteoric origin. The quality assessment was
made by estimating pH, electrical conductivity, total dissolved
solids, and hardness, besides major cations (Ca2+, Mg2+, Na+,
and K+) and anions (HCO3-, Cl-, and SO42-). As well as,
irrigation quality parameters were calculated, i.e., sodium
absorption ratio, Na %, residual sodium carbonate,
concentration of boron, total hardness, and permeability index.
The results indicate that most of the collected water samples
are suitable for drinking and irrigation purposes.
Use of 1012 and 1013 ohm resistor
amplifiers for uranium isotopic
measurements by TIMS and MCICPMS
Stability of Fe,Al-bearing
bridgmanite in the lower mantle and
synthesis of pure iron bridgmanite
L.ISMAILOVA1,2, E.BYKOVA1,M.BYKOV1,
V.CERANTOLA1,C.MCCAMMON1,T.BOFFA
BALLARAN1,A.BOBROV3,N.DUBROVINSKAIA2,L.DUBRO
VINSKY
1
1
Bayerisches Geoinstitut, University of Bayreuth, D-95440
Bayreuth, Germany
2
Laboratory of Crystallography, University of Bayreuth, D95440 Bayreuth, Germany
3
Department of Petrology, Geological Faculty, Moscow State
University, 119234 Moscow, Russia
The physical and chemical properties of the Earth’s mantle
as well as its dynamics and evolution depend heavily on the
phase composition of the region. The lower mantle consits
predominatly
of
bridgmanite
(perovskite-structured
(Mg,Fe)(Si,Al)O3), thus experimental studies of geophysical
and geochemical properties are essential for undertsanding the
structure and evolution of the Earth’s interior.
Based on experiments in laser-heated diamond anvil cells
we demonstrate that Fe,Al-bearing bridgmanite (magnesium
silicate perovskite) is stable to pressures over 120 GPa and
temperatures above 3000 K. Ferric iron stabilizes Fe-rich
bridgmanite such that we were able to synthesize pure iron
silicate perovskite at pressures between ~45 GPa and 110 GPa
with the composition (Fe2+0.64(2)Fe3+0.24(2))Si1.00(3)O3.
Fitting the data on pure iron bridgmanite to a 3rd order
equation of state gives the zero-pressure bulk modulus
K0,300=190(4) GPa and unit-cell volume V0=178.98(6) Å3. Such
value of the bulk modulus is exceptionally low and haven’t
been observed for any silicate perovskites.
The crystal chemistry of ferric iron-bearing Febridgmanite is also remarkable. First, all iron is located in the
A-site (bicapped prism) and within the accuracy of
determination of the occupancies of structural positions (better
than 5%) there is no iron in the octahedra (B-site). Second, it
contains a significant amount of vacancies (about 12%) at the
A-site. All these data show the significance of Fe3+-bearing
perovskite and suggest that lower mantle can contain
previously unknown phases.
These results have important implications for the global
Earth dynamics and interpretation of enigmatic seismic
features beyond ~2000 kilometers depth. The elastic
properties of iron bridgmanite different to any known silicate
perovskites, which has direct implications for the
interpretation of seismic tomography data.
ISNARD H. 1*, AUBERT M. 1, NONELL A.1, CHARTIER F.2
1
Commissariat à l'Energie Atomique, DEN/DPC/SEARS/LANIE,
91191 Gif-sur-Yvette Cedex, France, [email protected]
2
Commissariat à l'Energie Atomique, DEN/DPC, 91191 Gif-surYvette Cedex, France
The determination of uranium isotope ratios is major in
different fields such as geochronology, nuclear safeguards and
forensics, environmental monitoring or health monitoring.
Mass spectrometric techniques such as thermal ionization
mass spectrometry (TIMS) or multiple collector inductively
coupled plasma mass spectrometry (MC-ICPMS) are the
techniques of choice for precise and accurate measurements of
uranium isotope ratios. Due to the large range of uranium
isotope ratio that can be encountered, particularly in the
nuclear domain, different types of detection systems (Faraday
cup, Daly detector, Secondary Electron multiplier..) are
typically used for measurements of both major and minor
isotopes. An advanced development is the fabrication of 1012
and more recently 1013 ohm resistors mounted in the feedback
loop of Faraday cup amplifiers in order to improve the signal
to Johnson noise ratio at low ion beam intensities.
In this work we present the results obtained with the use of
Faraday cup connected to amplifiers equipped with 1012 and
1013 ohm resistors in static multicollection mode for the
determination of minor isotope ratios of uranium (234U/238U
and 236U/238U). Measurements are performed by TIMS and
MC-ICPMS (Triton Plus and Neptune Plus, Thermo Fisher)
on five IRMM standards (IRMM-183, 184, 185, 186, 187)
with 234U/238U and 236U/238U ratios ranging from 4x10-4 to
1x10-7. We have compared the repeatability of isotope ratio
measurements for different ion beam intensities measured with
Faraday cups connected to 1012, 1013 ohm resistors and with a
Secondary Electron Multiplier. Different strategies for
baseline, hydride and peak-tailing corrections have been
investigated. Expanded uncertainty obtained on isotope ratio
measurements was calculated in accordance with the ISO
GUM and for each method the dominant uncertainty
components were identified. This study demonstrate the
potential of Faraday cups using new current amplifiers for
precise and accurate analysis of uranium isotope ratio in
nuclear or geological samples.
Greater South China: detrital zircon
chronology of Paleozoic sandstones in
Japan and Primorye, Russia
Distribution of total dissolved
chromium in Pacific and Indian
oceans
YUKIO ISOZAKI1*, HIROKI NAKAHATA1, SHUHEI
SAKATA1, YURI ZAKHAROV2, TAKAFUMI HIRATA3
KENJI ISSHIKI1*
1
Department of Earth Science and Astronomy, the University
of Tokyo, Japan/[email protected]
2
Russian Academy of Science, Vladivostok,
Fig. Vertical Profile
of total dissolved Cr.
Russia/[email protected]
(A) Pacific3 Department
Ocean, (B) Indian
Ocean.
of Earth
and Planetary Science, Kyoto
University/[email protected]
The origin of proto-Japan was clarified by the latest study
on detrital zircon chronology of Middle–Upper Paleozoic
sandstones of continental shelf in SW Japan by LA-ICPMS.
Additional study on coeval sadnstones from the Sergeevka
belt around the Khanka block in Primorye, Far East Russia,
indicate the similar origin; i.e. the South China block. These
sandstones share similar age spectra of detrital zircons, with
dominant Phanerozoic grains and the significant cluster of
Neoproterozoic ones. The latter were likely derived from the
South China block but nowhere else among possible older
continental blocks in East Asia. During the Paleozoic, the
conterminous South China on the mainland, the East China
Sea, SW-NE Japan, and a part of Primorye belongd to a large
continnental entity named “Gretaer South China (GSC)”
(Isozaki, 2014), which was twice larger than the present South
China block. GSC was born when the supercontinent Rodinia
broke up around 700 Ma, and existed until the mid-Triassic
collision with North China block; i.e. the amalgamation into
Asia. GSC is exotic to Central Asian Orogenic Belt, and all
Paleozoic subduction-related orogenic elements in Japan and
surroundings were formed along the Pacific margin of GSC.
1
Community Center for Advancement of Education and
Research, University of Kochi, Eikokuji-cho, Kochi 7808515, Japan (*correspondence: [email protected])
Sampling and determination method
Seawater samples in Pacific Ocean have been taken in the
cruise of KH-05-2 and those in Indian Ocean in the cruise of
KH-09-5(ER). All samples have been taken from a CTD-CMS
clean sampler through fiber filters and stored in LDPE bottles
after acidification at pH 2. Total dissolved Cr (both Cr(III) and
Cr(VI)) was preconcentrated as 8-quinolinol complex by solid
phase extraction after the reduction of Cr(VI) to Cr(III), and
then determined by GFAAS[1].
Results and discussion
Figure indicates the vertical distribution of total dissolved
Cr at the stations along latitude 160 W in Pacific Ocean, and
that at the stations in Indian Ocean. The profile at almost all
stations indicates weak nutrient-type. There is no remarkable
difference between vertical profile patterns. The average
concentration in Pacific Ocean (7 nmol/L) is higher than that
in Indian Ocean (4 nmol/L).
The relationship between the vertical cross section of the
concentration of total dissolved Cr and other seawater
parameters will be presented and discussed in the Session.
Total Cr/ (nmol/L)
Total Cr/ (nmol/L)
0
0
5
10
15
0
5
10
15
1000
[1] Isozaki et al. (2014), GFF 136, 116-119.
Depth / m
2000
3000
4000
5000
6000
[1] K. Isshiki, Y. Sohrin, H. Karatani & E. Nakayama (1989)
Anal. Chim. Acta, 224, 55-64.
Numerical analysis of nitrogen
deposition from atmosphere on East
Asian oceans
Isolation and purification of
individual amino acids by HPLC for
precise small-scale radiocarbon
dating of archaeological bones.
SYUICHI ITAHASHI1*, HIROSHI HAYAMI1, ITSUSHI UNO2,
MITSUO, UEMATSU3
Environmental Science Research Laboratory, Central
Research Institute of Electric Power Industry (CRIEPI),
Chiba 270-1194, Japan (*correspondence:
[email protected])
2
Research Institute of Applied Mechanics (RIAM), Kyushu
University, Fukuoka 816-8580, Japan
3
Atmosphere and Ocean Research Institute (AORI), The
University of Tokyo, Chiba 277-8564, Japan
Y. ITAHASHI1*, Y. TAKANO2, Y. CHIKARAISHI2,
N. O. OGAWA2, N. OHKOUCHI2, M. YAMANE23,
Y. YOKOYAMA23, T. NAGATA3, M. YONEDA1
1
Introduction
Rapid economic development in East Asia has been
accompanied by increases in NOx emissions from
anthropogenic sources; it is expected that the atmospheric
input of nitrogen compounds into oceans will have a
considerable effect. In this study, the atmospheric input of
anthropogenic total reactive oxygenated nitrogen (NOy) to
ocean regions in East Asia during 2002–2004 was revisited
with an updated regional chemical transport model and the
latest emissions inventory [1]. The updated model treats both
fine- and coarse-mode nitrate (NO3-). Coarse-mode NO3- is
produced by the reaction of nitric acid (HNO3) and sea salt.
Discussion on Results
The modeling system reproduced the atmospheric
concentration and wet deposition amount of NO3- compared
with observations. The fraction of coarse-mode NO3-, defined
as the ratio of coarse-mode NO3- to the sum of fine- and
coarse-mode NO3-, was also well captured. NOy deposition
amounts over marginal seas and open oceans were 733 and
730 Gg-N/yr, which repectively increased by 1.6- and 2.2-fold
including coarse-mode NO3-. Anthropogenic NOx emissions
from China were 5377 Gg-N/yr, and 3060 Gg-N/yr was
exported from China; therefore, the total deposition amount
over ocean regions in East Asia (1463 Gg-N/yr) was
corresponded to the almost half (48%) of the export amounts.
Coarse-mode NO3- originated with the reaction of mineral
dust were not exactly treated in the current modeling system.
Based on the observed results during the dust and non-dust
year, 27% increase of NOy deposition over marginal seas
were estimated. This results also supported the significant
impact of NOy deposition over East Asian oceans as
atmospheric input.
[1] Itahashi et al. (2016) submitted to Geophys. Res. Lett.
1
The University Museum, Univ. of Tokyo, Tokyo 113-0033,
JAPAN (*correspondence: [email protected])
2
JAMSTEC, Kanagawa 237-0061, JAPAN
3
Atmosphere and Ocean Research Institute, Univ. of Tokyo,
chiba 277-8564, JAPAN
To obtain accurate radiocarbon dates, individual amino
acids, specifically for hydroxyproline (Hyp), isolated from
protein with high performance liquid chromatography (HPLC)
have been recently anticipated to be a compound group suited
for radiocarbon dating [1]. We have optimized a method of
isolation of individual amino acids using reversed-phase
HPLC and further purification step prior to the compoundspecific radiocarbon measurement.
The average recoveries of the authentic standard amino
acids were better than 70% and the 14C difference was
approximately 14‰ through the entire purification processes.
We have also applied the method to some archaeological
human and animal bone collagen samples with known ages. In
the result, the 14C age differences between bulk collagen and
Hyp were small and constant. With a purification step after the
HPLC separation, this method enable isolation of individual
amino acids with a small effect for radiocarbon age.
Figure 1: The verification of consistency for pMC of samples
between with and without LC treatment.
[1] McCullagh et al. (2010) Radiocarbon 52, 620–634.
Mercury stable isotope in skipjack
tuna (Katsuwonus pelami), a tracer of
methyl mercury spatial distribution
in Ocean?
TAKAAKI ITAI1,2, DAVID POINT2, JEROEN E. SONKE2,
ANNE LORRAIN3,4, JEAN MARIE MUNARON3, PATRICK
HOUSSARD3,4, TOSHIKI KAMEI1, AND SHINSUKE TANABE1
11
Center for Marine Environmental Studies (CMES), Ehime
University, Bukyo-cho 2-5, Matsuyama, Ehime 790-8577,
2
Geosciences Environnement Toulouse, Université de
Toulouse 3, CNRS-IRD-UPS, Toulouse, France
3
Laboratoire des Sciences de l'Environnement Marin LEMARIRD, Pouzane, France
4
Centre IRD Nouméa, Nouméa, Nouvelle-Calédonie
Mercury (Hg) level in tuna is a valuable bioindicator of
marine methylmercury (MeHg) since >90% of total Hg (THg)
is in the form of MeHg. Application of Hg stable isotope to
tuna highlight the potential of this tool as a unique
geochemical tracer of MeHg. However, interpretation of stable
isotope data in highly migratory species is still a matter of
debate. In this study, we measured Hg stable isotope ratio
along with carbon (C) stable isotope ratio in muscle tissue of
skipjack tuna collected from North Western Pacific. Typical
north-south seasonal migration of this species enable us to
compare the latitudinal gradiant of δ13C in particulate organic
carbon (POC). It helps to discuss metabolic turnover issue.
The δ13C showed increasing trend from north to south which is
consistent with the global latitudinal gradient of POC.
According to the recent experimental studies using bluefin
tuna, turnover rates of C and MeHg are similar and these take
around one year. Their turnover rate of skipjack tuna might be
shorter considering its life span, but is likely in the order of
several months. Nevertheless, δ13C seem to reflect, at least
partly, recent isotope signal before catching. Based on this
assumption, we interpreted the geographical variation of Hg
stable isotope along with the biogeochemical dataset of ocean.
The δ202Hg and Δ199Hg showed significant geographical
variation among the three different ocean currents, i.e., (i)
Oyashio (North Pacific Subpolar Gyre), (ii) Kuroshio (North
Pacific Gyre), (iii) Equatorial Counter Current (ECC).
Variation of Δ199Hg most likely reflects depth of migration.
Shallower migration in Oyashio than warmwater currents is
consistent with general ecological understanding of this
species. Lower THg level in ECC than Kuroshio is consistent
with reported MeHg distribution in ocean. Overall, we
conclude that Hg stable isotope in skipjack tuna is a good
tracer for spatial distribution of MeHg in Ocean.
Accurate LA-ICP-MS determination
of HREE abundances in monazite
KEITA ITANO1*, TSUYOSHI IIZUKA1, KOJI ICHIMURA1,
MIHOKO HOSHINO2
1
Department of Earth and Planetary Science, The University
of Tokyo, Tokyo 113-0033, Japan (*correspondence:
[email protected])
2
National Institute of Advanced Industral Science and
Technology (AIST), Tsukuba, 305-8567, Japan
Monazite is an useful geochrnonometer and its
geochemical composition, especially rare earth element
(REE), can provide clues to its genesis. The LA-ICP-MS
technique has been widely used for REE analysis. However,
determination of heavy-REE (HREE) abundances in monazite
using LA-ICP-MS can be challenging, because of the
interferences of light-REE (LREE) oxides on HREEs. The
interferences are problematic especially for monazites in
which HREEs are highly depleted. Accurate determination of
HREE abundances in such monazites requires the correction
for the oxide interferences. For solution ICP-MS analysis, the
correction has been made by assuming a linear relation
between Log (MO+/M+) and M–O bond energy [1]. It has been
shown, however, that the assumption is invalid for LA-ICPMS analysis [2].
In this study, we have investigated oxide production rates
of REE, U and Th during LA-ICP-MS analysis using natural
and synthetic REE phosphates as well as NIST SRM 610.
Analyses were carried out at gas flow rates from 0.75 to 1.0 L
min-1. We found that ThO+/Th+ and UO+/U+ are identical
between natural monazite and NIST SRM 610, indicating that
the matrix effect is insignificant for the oxide production rates.
We identified two distinct behaviors of oxide formation
among the analyzed elements: MO+/M+ of Y, La, Ce, Pr, Nd,
Gd, Tb, Th and U are sensitive to the changes in gas flow
rates, whereas those of Sm, Eu, Dy, Ho, Er, Tm, Yb and Lu
are relatively small and almost constant among variable gas
flow rates. The distinct behaviors are attributed to the relative
significance of oxide dissociation and ionization: the former
group elements have M–O bond energies higher than M–O
ionization energies. We conclude that the most accurate
correction for the REE oxide interferences can be made by the
directly measuring MO+/M+ of REEs using synthetic REE
phosphates. We apllied this correction method to natural
monazites and demonstrated its versatility.
[1] Aries et al. (2000) Geostandard Newslett. 24. 19-31.
[2] Kent & Ungerer (2005) J. Anal. Atom. Spectrom. 20. 12561262.
Fe and Pb isotopic signatures of the
processing of REE-bearing heavy
minerals in a contaminated stream
near Ipoh city, Malaysia
1*
1
2
3
A. ITO , T. OTAKE , K. SHIN , K. S. ARIFFIN , F. Y.
YEOH3, AND T. SATO1
1
Division of Sustainable Resource Engineering, Graduate
School of Engineering, Hokkaido University, Sapporo,
Japan
*(correspondence : [email protected])
2
Center for Research Promotion, Research Institute for
Humanity and Nature, Kyoto, Japan
3
School of Materials and Mineral Resources Engineering,
Universiti Sains Malaysia, Penang, Malaysia
The processing of igneous-type rare earth element
(REE) deposits may generate radioactive wastes as well as
acid drainage due to their high content of radioactive elements
(e.g. Th, U) and the use of acids to decompose REE minerals.
To establish appropriate indicators and assess the
environmental impacts of REE extraction, we have
investigated geochemical and isotopic signatures of
contamination from heavy mineral processing in Kinta River
and two of its tributaries near Ipoh city, Malaysia as a case
study. Our preliminary investigation showed that water from a
tributary near an ilmenite processing plant was
anthropogenically influenced, as indicated by low pH and high
Fe and Cl concentrations, while water qualities of others were
mainly controlled by the underlying lithology.
The REE patterns and Pb isotope ratios of the water
and sediment samples from the tributary resemble those of
leaked water from the tailings pond of the ilmenite processing
plant. These data suggest that contamination of REEs, U, and
Th in the tributary is due to heavy mineral processing.
Therefore, they may be used as indicators of environmental
impacts. In this tributary, the Fe isotope ratios decrease
downstream with decreasing Fe concentrations, which may be
due to isotope fractionation during oxidative precipitation of
Fe-hydroxides. However, the fraction of remaining Fe in the
downstream seems to be overestimated due to the effect of
colloidal Fe. The concentrations of REEs, U and Th decrease
downstream
with
different
removal
efficiencies
(Th>U>REEs). The results of geochemical modeling suggest
that Th may be removed by precipitation with increasing pH
while U may be taken up and transported by Fe-hydroxides
precipitated from the stream water. Therefore, Fe isotope
signatures and geochemical modeling may be useful to
understand chemical processes occurring in a contaminated
river.
Global modeling study of dust source
and Fe input to the Southern Ocean
AKINORI ITO1* AND JASPER F. KOK2
1
Yokohama Institute for Earth Sciences, JAMSTEC,
Yokohama, Kanagawa, 236-0001, Japan
2
Department of Atmospheric and Oceanic Sciences,
University of California, Los Angeles, CA 90095, USA
Atmospheric deposition of dust source materials is a
significant source of exogenous iron (Fe) in marine
ecosystems. Especially, the Southern Ocean is the most
biogeochemically important ocean because of its large spatial
extent and its considerable influence on the global carbon
cycle. The major sources of atmospheric Fe to the Southern
Ocean include South America (Patagonia), Australia, and
southern Africa. However, there is large uncertainty in our
estimate of the dust emissions in the Southern Hemisphere.
Recently, the dust sources in these regions have received
considerable attention, both for their potential impacts on
climate and ecosystems and for their susceptibility to climate
and land-use changes.
Here, we use an atmospheric chemistry transport model to
investigate the supply of soluble Fe from dust source regions
to the oceans in the Southern Hemisphere [1]. We do so using
a physically-based dust emission parameterization to better
capture emissions from dry soils in non-vegetated areas, and
validated the simulated aerosol optical depth (AOD) using
ground-based sun photometer (AERONET) measurements
near dust source regions [2, 3]. Our improved model results
suggest that dust emissions from open shrublands in arid and
semi-arid regions can be a key contributor to Southern
Hemispheric dust, and thus to bioavailable Fe deposition to
the Southern Ocean. These results highlight the necessity of
improving the process-based quantitative understanding of the
dust source fluxes in sparsely vegetated areas with changing
climate and land-use practice.
[1] Ito, A., and Z. Shi (2016) Atmos. Chem. Phys., 16, 85–99,
doi:10.5194/acp-16-85-2016. [2] Kok, J. F., et al. (2014)
Atmos. Chem. Phys., 14, 13023–13041, doi:10.5194/acp-1413023-2014. [3] Kok, J. F., et al. (2014) Atmos. Chem. Phys.,
14, 13043–13061, doi:10.5194/acp-14-13043-2014.
History of the Kikai Caldera that
devastated the prehistoric Jomon
culture in southern Japan as revealed
by zircon U-Pb dating
HISATOSHI ITO1 AND SHIMPEI UESAWA2
1
Central Research Institute of Electric Power Industry, Chiba
270-1194, Japan ([email protected])
2
Central Research Institute of Electric Power Industry, Chiba
270-1194, Japan
The largely submerged Kikai Caldera, situated ~50 km off
the Kyushu Island, is well-known as the caldera that
devastated the prehistoric Jomon culture in southern Kyushu
when it erupted huge tephras (K-Ah) at ~7,300 years ago (7.3
ka). Understanding the eruptive history of the Kikai Caldera is
critically important because it may affect long time safety of
radioactive waste depository and so on. At least two calderaforming eruptions before K-Ah were assumed so far: the K-Tz
and Ksd. The eruption age of the K-Tz is well constrained at
~95 ka while that of the Ksd is poorly constrained at 0.58 ±
0.16 Ma (2 σ) by the glass fission-track (FT) method [1].
Here, we dated K-Tz and Ksd by the zircon U-Pb method
using LA-ICP-MS for samples collected at Yakushima Island,
~25 km south of the Kikai Caldera. We also dated the Anbo
tephra which was originally dated at 0.78 ± 0.18 Ma (2 σ) by
the glass FT method. As a result, both Ksd and Ando were
dated as 0.63 ± 0.04 Ma (95% conf.; n=19, MSWD=3.0) and
0.73 ± 0.04 Ma (95% conf.; n=40, MSWD=1.6), respectively,
which are much tightly constrained ages than those by the
glass FT method. Some zircons from the K-Tz showed similar
ages of both Ksd and Anbo, therefore it was assumed that the
Anbo tephra was also originated from the Kikai Caldera. If
this is the case, the initial caldera-forming eruption occurred at
~0.73 Ma followed by ~0.63 Ma, ~0.1 Ma and the latest ~0.01
Ma (or 7.3 ka). If this periodicity persists, the volcanic activity
at the Kikai caldera may be subdued for another 0.5 million
years.
[1] Moriwaki et al. (2008) Quaternary International 178, 128–
137.
Formation processes and human
impact for sediments in Majuro Atoll
L. ITO1*, T. YAMAGUCHI2, T. OMORI3, M.
YONEDA3, S. MUTO1, R. TADA1 AND Y.
TAKAHASHI1
1
Department of Earth and Planetary Science, The University
of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
2
Faculty of Letters, Keio University
3
The University Museum, The University of Tokyo
In Majuro Atoll, Marshall Islands, people have lived for
more than 2000 years, even though atolls are vulnerable to
natural disasters and climate change. The sediments are
originally composed of coral gravel and foraminifera.
However, they are easily affected by human activities such as
cultivation of crops. We focus on the changes of physicochemical conditions of sediments that could be affected by
human activities to evaluate anthropogenic impacts depending
on the depth of the sediments in Majuro Atoll.
X-ray fluorescence (XRF) and Inductively-coupled plasma
mass spectrometry (ICP-MS) analyses were used to measure
concentration of major and trace elements, respectively. X-ray
absorption fine structure (XAFS) analysis was conducted to
examine their detailed chemical form. Accelerator Mass
Spectrometry (AMS) was applied for 14C dating using
foraminifera.
The concentrations of toxic elements such as Zn, Cu, and
Pb increased sharply in upper layer, which were correlated
with that of total organic carbon (TOC) in Laura and Calalen
islands, whereas Mg increased as the increase of the depth.
Speciation of the elements suggested that the former elements
are of anthropogenic origin, whereas the latter is by the release
of Mg from magnesian calcite due to the acidification of the
surface sediment.
Development of a noble pretreatment
system for the determination on the
triple oxygen isotopes of dissolved
oxygen
M. ITO1, H. SAKUMA1, D. D. KOMATSU2, F.
NAKAGAWA1, U. TSUNOGAI1, T. ISHIMURA3
M. ITO1*, Y. KEBUKAWA2, A. IJIRI1 AND H. NARAOKA3
2
1
Graduate School of Environmental Studies, Nagoya
University (*correspondence: [email protected])
2
School of Marine Science and Technology, Tokai University
3
National Institute of Technology, Ibaraki College
17
Coordinated NanoSIMS and iMScope
analyses for extraterrestrial organics
in Murchison matrix.
17
The triple oxygen isotopic compositions (∆ O = ln(δ O +
1) – 0.518ln(δ17O + 1)) of photosynthetic O2 are about +150 to
250 per meg higher than those of atmospheric O2. While both
δ17O and δ18O of O2 fractionate during respiration along with
“the mass-dependent relation”, ∆17O value is stable during
respiration. As a result, measurements on the ∆17O values for
dissolved O2 in hydrospheric samples enabled us to estimate
the mixing ratios between photosynthetic O2 and atmospheric
O2 in each dissolved O2 and thus to estimate either gross
primary production rate or air-water gas exchange coefficient
in each hydrosphereric system.
In most of the previous studies, however, ∆17O values of
dissolved O2 had been measured together with Ar during mass
spectrometric analyses, because of the similarities between O2
and Ar in the physical characteristics such as boiling points,
which made them difficult to separate each other
cryogenically. Therefore, additional corrections must be
needed subsequent to the mass spectrometric analyses on O2
isotopes for the samples having O2/Ar ratios deviated from the
atmospheric O2/Ar ratios, leading poor accuracy on the ∆17O
measurements.
In order to determine accurate ∆17O values for dissolved
O2 in various types of water samples including those having
different O2/Ar ratios from the atmosphere, we constructed a
fully automated pretreatment system. In this system, dissolved
gases including O2 and Ar are extracted from water samples
effectively. Then, extracted O2 is separated from the other
gases including Ar using GC column, and then obtained pure
O2 is concentrated in a cryogenic trap held at 10K. In this
study, we would like to present the ∆17O values of dissolved
O2 measured using the system for the samples showing
substantially lower O2/Ar ratios than that of atmosphere, such
as those taken in the water column of Lake Biwa where
hypoxia had been developed in summer hypolimnion in recent
years.
Kochi Institute for Core Sample Research, JAMSTEC.
2
Faculty of Engineering, Yokohana National University
3
Department of Earth and Planetary Sciences, Kyushu
University
Carbonaceous chondrites contain a variety of
extraterrestrial organic molecules (e.g., Sephton and Botta,
2005). Chemical, structural and stable isotopic characteristics
in those organics suggest that several environments (the
interstellar space, the solar nebula and the meteorite parent
body) may have contributed to the formation of organics
(Sephton, 2002). Therefore, it is important to know spatial
distributions of these orgcanics in the host mineral matrix, and
relationship to the isotopic compositions of H, C and N.
Simon and coworkers reported the coordinated chemical
and isotopic in-situ measurements in a carobonaceous
chondrite (Simon et al., 2014). They developed the JSC
µ-L2MS instruments to obtain chemical map of organics
whthin the sample. Using the capability, they succesfully
acquire chmical image (m/z ~ 15 to 250) in the CM2 Bells
chondrite together with C and N isotope maps obtained by
NanoSIMS in the same region.
In this study, we plan to perform the coordinated
NanoSIMS (isotopes) and iMScope (chemistry) study for
Murchison CM chondrite to acquire spatial distributions of H,
C and N isotopes and chemistry in spatially distributed
organics in the chondrite. We carried out chemical imaging in
the Murchison matrix using the Shimadzu iMScope imaging
mass microsope that allows us to identify and visualize the
spatial distribution of organic molecules. We obtained
organics chemistry maps (#a: 380 x 320 and #b: 800 x 800
µm2) with a spatial resolution of ~5 µm and m/z = 50 to 800.
Chemical map shows that organics were widely spreaded
within the Murchison matrix. Several hots spots, ranging from
50 µm to 200 µm and with m/z ~ 93 and 149, were found in
the matrix #b . We analyzed selected mass peaks using a
Kendrick Mass Defect method (e.g., Schmitt-Kopplin et al.,
2010) to arrange the diverse compositions with common
repeat units, e.g., CH2 and COO, and determined possible
structures of organics from selected mass peaks. We will
performe a NanoSIMS imaging to acquire H, C and N isotopic
compositions in selected hot spots, and then will show a
relationship between isotopes and chemical formula
(structure) in the conference.
Perylene in Lake Biwa, Japan
NOBUYASU ITOH
1
Origin of extremely deuterium-rich
isotopic compositions of phosphates
from LL4-6 ordinary chondrites
1
National Metrology Institute of Japan (NMIJ), National
Institute of Advanced Industrial Science and Technology
(AIST)
Perylene, which is a polycyclic aromatic hydrocarbons
(PAHs) that consists of five benzene-rings, has been widely
found throughout the world, but it has different vertical
distributions compared to other PAHs. Since the discovery of
perylene in aquatic sediments, many researchers have reported
the abundance of perylene in both marine and lacustrine
sediments and have discussed its source, route to sediments,
reactions, etc. Lake Biwa is the largest lake in Japan and its
sediment commonly contain very high amounts of perylene
(μg g−1-level). Thus, Lake Biwa must be a suitable site for
elucidation of perylene origin and transforming process as
well as its possibility for an indicator of environmental
change.
In the dated-sediment core collected from near the river’s
mouth in Lake Biwa, concentration of perylene increased with
increase of terrestrial materials and a transformation of
perylene from its precursor compounds is ongoing within the
deeper layers of sediments. Moreover, no remarkable
concentration of perylene has been observed in the sinking
particles collected from water at 5 m above the lake bottom.
These results suggest that sedimentary perylene originates
from outside the lake and that a transformation of perylene
from its precursor compounds occurs mainly after deposition
in Lake Biwa. The stable carbon isotope compositions (δ13C
values) of perylene in Lake sediment (–27.8‰ ± 0.3‰) was
clearly more negative than those of Japanese aquatic plants
(C3, –16.5‰ to –14.6‰), it can be considered that the
perylene originated from the land, principally from
gymnosperms. Furthermore, it was clarified that
transformation of perylene from 4,9-dihydroxyperylene-3,10quinone (DHPQ), which originates from Cenococcum
geophilum, a type of rhizobia, in a catchment area at Lake
Biwa. Because a remarkable amount of DHPQ also exists in
the humic acids of soils and because the inputs of compounds
to the lake depend strongly on the rivers, precursor of perylene
in the Lake Biwa sediment must originate from the land.
Considering the fact that perylene showed the temporal
increase corresponding to layer of the flood in the dated-core
(Isewan Typhoon in AD 1959), perylene should be a useful
indicator of flood in sediment cores.
S. ITOH1, Y. HIGASHI1, M. HASHIGUCHI2,3, I.
SAKAGUCHI3, K. YANAI4, S. S. RUSSELL5, J. P.
GREENWOOD6, T. HIRATA1 AND H. YURIMOTO4
1
Kyoto University, Kyoto, JAPAN.
([email protected])
2
JAXA, Kanagwa, JAPAN.
3
NIMS, Tsukuba, JAPAN.
4
Hokkaido University, Sapporo, JAPAN.
5
NHM, London, UK.
6
Weslayen University, CT, USA.
The origin of water in the Earth and asteroids in the
Earth’s orbit have been recently discussed with chondrites,
comets, Kuiper-belt objects and interstellar organic matter
(e.g., [1–3]). One of significant possible precursor of H20 ice
in Earth’s orbit have been predicted as the delivery from
cometary ice and from outside the orbit of Jupiter with the
hydrogen isotopic compositions of apatites, fluid inclusions
and phyllosilicates in ordinary chondrites (OCs) [1,3-5].
In this study, we applied in-situ measurement technique
[2] of water content and hydrogen isotopic compositions of
phosphate minerals from LL4-6 OCs by 1270 SIMS [6]. All
D/H ratios in the phosphate minerals are D-rich (δD ~ +2000
to +25000). In contrast, water contents of these phosphate
shows the range of 10-100ppm and that of LL6 is the highest
water content and D-rich isotopic compositions (δD ~ +10000
to +25000). This signature suggests that the Rayleigh
fractionation in H2O during thermal metamorphism in the
parent body is not much significant of D-enrichment in
phosphates because apatite in LL6 shows the maximum H2O
even in highest temperature metamorphism but the origin of
D-rich hydrogen isotopic compositions of LL6 phosphates is
resulting from diffusion among phosphates and D-rich water
or interstellar organic matter during thermal metamorphism. In
this talk, the diffusion sources of H2O or H2 to the apatite
during thermal metamorphism are discussed with Hdiffusivity in apatite [7-8] and the possibilities for the origin of
D-rich signature are discussed with fractionated residual water
or cometary ice.
[1] Yurimoto et al. (2014) Geochem. J. 48, 549-560. [2]
Greenwood et al. (2011) Nature Geosci., 4, 79-82. [3] Robert,
(2011) Science, 293, 1056–1058. [4] Deloule and Robert
(1995) GCA, 59, 4695-4706. [5] Robert (2003) Space science
reviews, 106, 87-101. [6] Itoh et al. (2015) Goldschmidt 2015
abstract: 5138. [7] Itoh et al. (2015) Goldschmidt 2015
abstract: 5138. [8] Higashi et al. (2016) Goldscmidt2016.
Fungal-prokaryotic consortia in
oceanic igneous crust
IVARSSON, M.1, BENGTSON, S.1
1
Swedish Museum of Natural History, Department of
Palaeobiology, Box 50007, Stockholm, Sweden. Email:
[email protected]
Vertical profile of dissolved 137Cs
concentrations of soil water in
Fukushima after Fukushima Dai-ichi
Nuclear Power Plant accident
S. IWAGAMI1*, M. HADA2, I. PUN2, H. KATO1, A.
KAWAMORI1, M. TSUJIMURA2, Y. ONDA1
1
The oceanic crust makes up the largest potential habitat
for microbial life on Earth, yet next to nothing is known about
the abundance, diversity and ecology of its biosphere. Because
of issues involved in sampling live specimens, paleontological
material has been proven central in the exploration of the
subseafloor biosphere. Studies of two drill cores from Nintoku
and Koko Seamounts, respectively, belonging to the Emperor
Seamounts in the Pacific Ocean have revealed fungalprokaryotic consortia in subseafloor basalts to a depth of ~300
mbsf. At Koko Seamount fungal colonization was initiated by
a biofilm lining the interior of vesicle basalt from which
hyphae protruded and formed complex mycelia-like networks.
Between the hyphae minute cells were suspended in a
cobweb-like fashion; interpreted as prokaryotes involved in
iron oxidation. Microstromatolitic Frutexites representing
remains of iron oxidizing bacterial communities also used the
fungal mycelia as basis for their growth. At Nintoku Seamount
microstromatolitic bacteria predated fungal colonization,
which was initiated by the formation of a biofilm from which
hyphae and yeast-like growth structures protruded. Both
studies show that the microbial colonization of subseafloor
basalts is an early event that predates substantial rock
alteration and coeval with the precipitation of secondary
minerals like carbonates and zeolites. A symbiotic relationship
with chemoautotrophs may be a prerequisite for the eukaryotic
colonization of crustal rocks and enables fungi to expand their
ecological niches. In fact, fungi appear to play an important
ecological role in subseafloor crust being involved in mineral
weathering and precipitation, mobilization of elements and
engaging in symbiotic relationships; a geobiological agent not
yet accounted for in the oceanic igneous crust.
Center for Research in Isotopes and Environmental
Dynamics, University of Tsukuba, 305-8577, Japan
([email protected])
2
Department of Sustainable Environmental Studies, Graduate
School of Life and Environmental Sciences, University of
Tsukuba, Tsukuba, 305-8572, Japan
Soil water samples were sampled and dissolved 137Cs
concentrations were measured at four sites with different land
use (meadow land, pasture land, and young/mature cedar
forest) in Yamakiya District, located ~35 km northwest of
Fukushima Dai-ichi Nuclear Power Plant (FDNPP) from July
2011 to October 2012. Meadow land and pasture land are not
covered by any kind of trees and therefore there might no
input of 137Cs by throughfall. At young/mature cedar forest,
137
Cs input by throughfall was expected. Rainfall at meadow
land, pasture land and throughfall at young/mature coniferous
forest were also sampled and dissolved 137Cs concentrations
were measured. Soil water samples were collected by suction
lysimeters in three different depths at each site (depth of 0.1,
0.3 and 0.5 m at meadow land and young/mature cedar forest;
depth of 0.1, 0.2 and 0.3 m at pasture land). The dissolved
137
Cs concentration was analyzed by Germanium Gamma ray
detector.
dissolved 137Cs concentrations of soil water showed high
value of 0.011-2.5 Bq/L around July to August 2011, whereas
dissolved 137Cs concentrations of throughfall were 47-450
Bq/L during that period. The declining trend of dissolved 137Cs
concentrations of soil water seems to be similar with that of
stream water. Where the dissolved 137Cs concentrations of
stream water declined in a two-component exponential model
[1]. The k1 factor of declining trend of dissolved 137Cs
concentrations of soil water showed good correlation with
Radiocesium interception potential (RIP) factor reported in the
same site [2].
[1] Iwagami et al. (2015) Journal of Environmental
Radioactivity. (in press). [2] Takahashi et al. (2015) Journal of
Environmental Radioactivity. 139, 351-361.
Role of water in subduction zone
dynamics
Subduction factory and its impact on
global mantle heterogeneity
H. IWAMORI1,2, S. HORIUCHI1, A. NAKAO2,
T. NAKAKUKI3
H. IWAMORI1,2, A. IKEMOTO3, H. NAKAMURA1,2, M.
YOSHIDA4, R. YANAGI2
1
1
2
2
Dept. Solid Earth Geochemistry, JAMSTEC, Japan
Dept. Earth Planet. Sci., TITECH, Japan
3
Dept. Earth Planet. Sys. Sci., Hiroshima Univ., Japan
Within the solid Earth system, water plays crucial roles in
both physical and chemical aspects, e.g., reducing rock
strength and density, decreasing melting temperature, and
redistributing elements and isotopes effectively during waterrock interactions. Although each effect has been vigorously
studied, less attention has been paid to their interplay. As an
example in subduction zone, dehydration of a subducting slab
hydrates the overlying mantle wedge, reducing the viscosity.
Then, the flow-thermal field is modified to accommodate the
extent and the locus of dehydration and melting, which in turn
affects again the viscosity and thermal-flow field, forming a
non-linear feedback system [1]. We investigate such systems
by numerical simulation of two-phase mantle convection
models, involving water transport, hydrous phase relation,
fluid generation and migration, and fluid-rock reactions. The
water transport and the mantle convective flow are interactive
through rheology, density and phase relation for hydrateddehydrated rocks.
Based on the numerical models, we demonstrate how the
influences of water on phase relation, rheology, density, and
flow-thermal structure appear as observable variables and
phenomena, such as the location of arc volcanic zone, the
subduction velocity and angle of plate, slab morphology,
stress field, trench migration and back-arc spreading. One of
the key parameters is effective viscosity of hydrous minerals,
which is not tightly constrained at present: e.g., development
of serpentinite just above the subducting slab critically
controls the mechanical coupling between the slab and the
mantle, leading to various flow-thermal structures depending
on the viscosity. It has been also found that rheological
weakening of the continental lithosphere by fluid upwelling as
well as effective density reduction of the hydrated slab have
significant impacts on the back-arc basin formation, trench
mobility and convergence rate, and determine the subsequent
evolution of slab morphology over the global scale [2]. The
observed variations in subduction mode, at least partly, could
be attributed to different degrees of water effects (e.g., water
content of slab) on subduction dynamics.
[1] Horiuchi & Iwamori (2016) JGR in revision. [2] Nakao,
Iwamori, Nakakuki (2016) JpGU abstract.
Dept. Solid Earth Geochemistry, JAMSTEC, Japan
Dept. Earth Planet. Sci., TITECH, Japan
3
Shinsei Bank, Limited, Japan
4
Dept. Deep Earth Struct. and Dyn. Res., JAMSTEC, Japan
“Subduction factory” produces arc magmas as a main
output, which has been extensively studied to probe the subarc structure and processes. Another equally important product
is the residual material that subducts deeper into the mantle;
e.g., dehydrated or melted slab and mantle materials.
Importance of such processed materials has been repeatedly
argued for geochemical heterogeneity and global material
cycling in the mantle [e.g., 1-3]. In spite of its importance,
compared to the arc magmas, the residual materials have been
less constrained partly due to its inaccessibility. Of several
approaches for quantitatively identifying such processes and
materials, based on the fluid dynamical model for trace
element transport in subduction zones [4], as well as 3-D
mantle convection model that incorporates water transport
[5,6], we discuss what comes out and what goes down to the
deep mantle, and how the subducted materials may contribute
to global geochemical structures, including east-west mantle
geochemical hemispheres [7].
Within the subduction factory, melting and melt extraction
create compositionally zoned mantle, which is dragged down
by corner flow to encounter the fluid from the slab [4]. It has
been found that this combined process creates highly
complicated 2-D distribution of elements, as well as large
variability in parent/daughter ratio of radionuclides, which are
comparable to the global variability. Outside the subduction
factory, the heterogeneous materials are transported and
redistributed by both solid convective flow and percolating
fluid that is released upon dehydration of hydrous minerals
(including nominally anhydrous minerals) at various depths
over the whole mantle, resulting in effective delivery of water
(and associated elements) to a broad but a certain region of the
mantle.
[1] Chauvel et al. (1995) Chem. Geol. 126, 65-75. [2] Kellogg
et al. (2007) EPSL 262, 328-342. [3] Iwamori and Albarède
(2008) G-cubed 9:4 [4] Ikemoto & Iwamori (2014) Earth,
Planets & Space 66:26. [5] Yoshida (2013) GRL 40, 681–686.
[6] Yanagi et al. (2016) JpGU abstract. [7] Iwamori &
Nakamura (2012) Geochem. J. 46, e39-e46; (2015) Gondwana
Res. 27, 1131–1152.
Numerical simulation of sedimentbound 137Cs deposition on a
floodplain of the Abukuma River
The characterization of ice nucleating
particles by combined AFM, RMS,
and SEM-EDX
T. IWASAKI1*, Y. SHIMIZU2, Y. ONDA3
A. IWATA1* AND A. MATSUKI2
1
University of Illinois at Urbana-Champaign, Department of
Civil and Environmental Engineering,Urbana, IL, 61801
Correspondence: [email protected]"
2
Faculty of Engineering, Hokkaido University, Sapporo,
0608628, Japan, [email protected]
3
Center for Research in Isotopes and Environmental
Dynamics, University of Tsukuba, Tsukuba, Japan, 3058572, [email protected]
The radionuclides released by the Fukushima Dai-ichi
Nuclear Power Plant accident in 2011 have been transported
and redistributed in the natural environment by several
physical factors (e.g., wind, surface water flow, and sediment
transport). A better understanding of the fate of such
radionuclides is key to assessing their future impact on the
environment. This study presents numerical simulations of
sediment-bound radiocesium (137Cs) transport and deposition
in the Abukuma River, Japan. We numerically simulated the
transport, deposition, and re-entrainment of 137Cs contaminants
associated with suspended sediment transport. The model was
validated by field measurements of radiocesium deposition on
a floodplain of the Abukuma River. The numerical model
reasonably reproduced the observed depositional pattern of
137
Cs on the floodplain (Fig. 1). The results show that
repetition of several flood events is an important factor in
controlling radiocesium deposition on the floodplain. A
moderate flood event could cause either deposition or reentrainment of radiocesium, whereas, a large flood event may
re-entrain the previously deposited radiocesium, and deposit
newly transported radiocesium on the floodplain.
1
Graduate school of Natural Science and Technology,
Kanazawa University, Kanazawa 920-1192, Japan
(*[email protected])
2
Institute of Nature and Environment, Kanazawa University,
Kanazawa, Japan
The aerosol – cloud interactions, remain as one of the most
uncertain aspects in our understanding of the climate system
[1]. It is in large part due to the lack of understanding in the
characteristics (chemical composition, mixing state, and
morphology) of ice nucleating aerosol particles in the actual
atmosphere. In the present work, we investigated the
characteristics of the atmospheric aerosols that form ice
crystals through heterogeneous nucleation.
Aerosol particles sampled on Si wafer by impaction were
exposed to supersaturated air. Following droplet activation by
condensation, particles were cooled down to -30℃ under
optical microscope (Fig.1). The ice nucleating particles were
analyzed individually by Atomic Force Microscopy (AFM),
Raman Microspectrometry (RMS), and Scanning Electron
Microscopy (SEM) coupled with Energy Dispersive X-ray
spectroscopy (EDX). One can obtain the detailed 3D
morphology of individual particles by AFM. RMS provides a
nondestructive means to identify chemical compounds present
within individual particles and ascertain how they are
distributed relative to one another under atmospheric pressure.
More examples of individual particles analyzed by the current
method will be presented at the poster presentation.
Figure 1: Single droplet freezing method
Figure 1. Depositional pattern of 137Cs on a floodplain of the
Abukuma River: a)observation and b)simulation.
Figure 2: The mesurement results of the atmospheric aerosol
by AFM, RMS, and SEM
[1] Flato et al. (2013) Cambridge University Press, 741–866
Chemical and isotopic study of the
impact on groundwater environment
by an large underground facility
IWATSUKI, T. 1, KATO, T. 1, NAKATA, K. 2, HASEGAWA, T. 2
1
Japan Atomic Energy Agency, 1-64, Yamanouchi, Akeyocho, Mizunami-shi, Gifu, 509-6132, Japan
2
Central Research Institute of Electric Power Industry, 1646
Abiko, Abiko-shi, Chiba-ken 270-1194, JAPAN.
This study aims to evaluate a geochemical method to
estimate groundwater environment in and around a large
underground facility. Water chemistry, isotopes (δD, δ18O, 3H,
δ13C, 14C) and chlorofluorocarbons (CFCs) in groundwater
down to a depth of 500 m were monitored in the Mizunami
Underground Research Laboratory (MIU), Japan. In the MIU
site, sedimentary rock formations with the thickness of about
170 m unconformably overlie basement granite. The granite is
divided into a weathered zone at uppermost part, an upper
highly fractured domain (UHFD) and a lower sparsely
fractured domain (LSFD). Baseline of groundwater chemistry
prior to the facility construction was characterized; Na-CaSO4-HCO3 type in shallow sedimentary rocks and Na-Ca-Cl
type of water which salinity increases with depth in granite.
The groundwater level was lowered by long-term drainage
of groundwater from the galleries. The monitoring of water
chemistry for more than 10 years shows the increase of SO4
and HCO3 concentrations in UHFD at depths between 200 400 m. The shallow groundwater probably inflows into deeper
depths with time. 3H and CFCs as an index of surface water
were detected in several monitoring points at these depths.
Based on those concentration the mixing proportion of
shallow groundwater was estimated up to about 50 %. On the
other hand groundwater in LSFD at the depth of 500 m does
not show increase of SO4 and HCO3 concentrations nor
include 3H, suggesting relatively isolated condition from the
hydraulic disturbance by the facility construction. 14C
concentration in dissolved inorganic carbon was measured to
understand residence time of the isolated groundwater. Then
addition of 14C-free carbon from carbonate minerals to
groundwater was corrected by geochemical model using δ13C
value. Corrected 14C value ranges from 5 to 11 pMC and it
corresponds to the residence time of 18 - 25 ka.
The impact on the groundwater environment caused by a
large underground facility was considerably different
depending upon hydrogeological structure. The concomitant
use of 3H, δ13C, 14C and CFCs is an effective method to
identify the hydrochemical condition in the disturbed domain
and undisturbed domain around the underground facility.

Detrital zircons record rigid continents after 2.5 Ga Quantifying gas

Transcription

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