SEG Iberia - Society of Economic Geologists

SEG
Student Chapter
The University of British Columbia
Iberia
International Field Trip Report, 2015
Table of Contents
Foreword...............................................................................................................................3
Sponsors................................................................................................................................4
Participants...........................................................................................................................5
Itinerary.................................................................................................................................6
May 3rd – Madrid................................................................................................................8
May 4th –Iberian Geology at the Complutense University of Madrid.........................9
May 5th – Las Médulas Historic Roman Mines..............................................................10
May 6th – Lagares Au Project, Portugal...........................................................................11
May 7th – Los Santos W Mine...........................................................................................12
May 8th – Panasqueira W Mine........................................................................................13
May 9th – Visit to Lisbon, Portugal..................................................................................14
May 10th – Rio Tinto Museum and Historic Mines......................................................14
May 11th – Aguablanca Ni-Cu-PGE Mine.....................................................................15
May 12th – Las Cruces Mine............................................................................................16
May 13th – Almadén Hg District.....................................................................................17
May 14th – Visit to La Alhambra, Granada, Spain........................................................18
May 15th – Rodalquilar Epithermal Historic Mines....................................................19
Acknowledgements...........................................................................................................21
Forward
The University of British Columbia’s Society of Economic Geologists Student Chapter (UBC-SEG)
aims to provide its members a greater knowledge and interest in the field of economic geology. Our group
seeks to bridge the gap between academia and industry by enhancing our members’ understanding on
how the geologic science is applied to mineral exploration and mining. We organize courses, lectures
and presentations, and field trips to bring the knowledge and expertise of the industry to the students.
Likewise, we place great value in establishing a strong connection between our student members and the
professional geoscientists in industry, academia, and the government.
The UBC-SEG Student Chapter’s Annual International field trip has enjoyed fourteen years of success in giving students and industry participants the opportunity to experience world-class mineral deposits and geology abroad. The trip also allows for enthusiastic students to gain leadership experience
through organizing the logistics of the trip, and a chance for students and industry to interact with one
another.
The 2015 “Iberian Adventure” to Spain and Portugal was attended and led by eleven UBC-SEG students and eight members from the industry. The theme of the Spain and Portugal trip focused on the
Iberian Peninsula’s rich mining history, combining the historic, millennia–aged mining antiquity with that
of the modern day mines in this jurisdiction. Prior to visiting any mines, professors from the Complutense
University of Madrid gave an overview presentation on the regional geology and metallogeny of the Iberian Peninsula. Some of the highlights of the trip included the ancient Roman placer gold workings of Las
Médulas, the giant tungsten mines of Panasqueira and Los Santos, and several world-class Cu-Pb-Zn VMS
deposits of the Iberian Pyrite belt. Spain and Portugal’s rich cultural history was marveled as well with a
trip to the historic cities of Salamanca, Seville, and Granada, and a tour through the 11th century Moorish
Palace of Alhambra.
The trip’s focus on several mines in the Iberian Pyrite Belt was also a great opportunity for students
to make comparisons with the local field trip to the Myra Falls VMS mine in British Columbia held earlier
this year. Students were able to compare and contrast the geology and styles of mineralization for two
VMS systems around the world. Finally, the professional networking between students, industry participants, and the local geologists met during our trip was made easier and more approachable, as many student and industry participants to the trip are fluent Spanish speakers.
The following report was written by student participants of the trip. Final compilation and editing
was completed by Kaleb Boucher and Raja Yarra.
Sponsors
The UBC SEG Student Chapter would like to express our sincerest appreciation for the generous support
and financial contributions we received from our industry sponsors.
Society of Economic Geologists
Hecla Mining Ltd.
Anglo American Exploration Canada Ltd.
Balmoral Resources Ltd.
E.B. Holding
SRK Consulting Canada Inc.
Equity Exploration Consultants Limited
Silver Standard Resources Inc.
B.J. Price Consulting
Miro Mytny Consulting
Juan C. Marquardt Consulting
Paul Wojdak Consulting
Linda Dandy
Uwe Schmidt
Participants
Name
Kaleb Boucher
Paula Brunetti
Anna Grau
Guillaume Lesage
Nader Mostaghimi
Matt Bodnar
Matt Manor
Agustin Guitart
Martin Marquardt
Raja Yarra
Rachel Kim
Ed Balon
Uwe Schmidt
Dave Nickerson
Myro Mytny
Paul Wodjak
Linda Dandy
Juan Carlos Marquardt
Henry Awmack
Organization
MSc Student - UBC
MSc Student - UBC
MSc Student - UBC
MSc Student - UBC
MSc Student - UBC
MSc Student - UBC
MSc Student - UBC
MSc Student - UBC
MSc Student - UBC
MSc Student - UBC
MSc Student - UBC
Industry Professional
Industry Professional
Industry Professional
Industry Professional
Industry Professional
Industry Professional
Industry Professional
Industry Professional
Itinerary
Day Date
0
5/3/2015
1
5/4/2015
2
5/5/2015
Activity
Madrid - R & R
Madrid
(Lecture Iberian
Geology
Las Médulas
3
5/6/2015
Lagares
4
5/7/2015
Los Santos
5
5/8/2015
6
7
5/9/2015
5/10/2015
8
5/11/2015
9
5/12/2015
10
5/13/2015
11
5/14/2015
12
5/15/2015
13
5/16/2015
Day Description (Overnight Location)
Hotel Check-in in Madrid, rest, and introduction dinner to the trip.
In this day we will visit the Universidad Complutense de Madrid to
have a brief introduction to the Ibearian Geology and Metallogenesis. After lunch we will be driving (4 h) to Villafranca del Bierzo.
Drive from Villefranca to Las Médulas Site. The Site itself can have
guided tours (payment required) or self-guided along hike. Drive to
Porto to overnight.
Drive from Porto to Lagares site. Tour 9-12:30, then go to lunch on
site. Drive to Salamanca (~4 hrs).
Drive from Salamanca to Los Santos Mine (1 hr). Tour 10-13:30, then
go to lunch in a town. Drive to Foundao, Portugal (~3 hrs).
Panasqueira
Departure from Fundao at 7 AM. Mine tour starts at 8 AM (underground or open pit). Lunch will be provided in local restaurant in
town. At 15:30 departure to Lisbon (3.5 h drive)
Lisbon
Sleep in or wake up early. Tour Lisbon. Depart at 1500 for Beja.
RioTinto
Drive from Beja to Rio Tinto District (3 hrs). Museum Tour 10:3013:30. Rio Tinto Mine Tour. 14:30-18:00. Drive to Aracena (~1 hr).
Aguablanca
Depart Aracena at 8 am, arrive at Aguablanca mine between 9-9:30
am. General presentation and field tour, ending with core visit
around 1:30 pm. Bag lunches or stop in a town on the drive back to
Aracena. Tour Aracena and surroundings in the evening.
Las Cruces
We will be departing from Aracena at 8:00 am and will be driving
directly to Las Cruces Mine, the approximate travel time should be
1hr 30 min to 2hrs. Leave Las Cruces for Seville.
Almaden
We will drive from Sevilla to Almaden (3 h) and meet Prof. José
Esbri (Universidad de Castilla-La Mancha) to have a presentation,
visit to open pit mine (El Entredicho), and the parque minero. From
Almaden we will drive to Cordoba (1.5 h).
Granada
Drive from Cordoba to Granada (2.5 hours). Visit of La Alhambra
at 2 pm for those interested. Possibility to go hiking in the Sierra
Nevada National Park.
Rodalquilar
We will leave Granada at 8 am and drive to Rodalquilar (1.5-2
hours). We plan to visit a few localities within the Rodalquilar mining district. We will then drive back to the town of Rodalquilar from
the mining district to visit the geo-mining museum "La Casa de Los
Volcanes". We will spend the night in Nijas (45 min from Rodalquilar).
Drive to Madrid Drive back to Madrid, to depart the next day back to Vancouver.
UBC SEG Student Chapter 2015 Iberian Adventure Itinerary Map with stars indicating mines/projects visited and numbers referring to Day Number in table above.
Day Zero (May 3rd)
Madrid
Following the long journey from Vancouver to Madrid, the trip participants got a chance to rest and
enjoy an afternoon in the capital of Spain before the trip began. Many trip-goers took advantage of the incredible food scene in Madrid, tasting an amazing array of tapas. Some other sights to see included El Retiro
Park, Plaza Mayor, and the Puerta de Alcala. Finally, the group had their first dinner together that evening,
which included Spanish dishes and tapas, and local wines.
Stopover in New York before flying to Madrid
Day One (May 4th)
Madrid
On our first official day of the trip, we visited the Universidad Complutense de Madrid (Complutense
University of Madrid) for an introduction to the regional geology and metallogeny of Iberia. We had two
presentations given to us: “Geology of the Iberian Peninsula” from Dra. Agustín Piéren and “Iberian Metallogenic Provinces” from Dr. Lorena Ortega. We also met Dr. Roberto Oyarsun and Dra. Maria Luisa Canales.
The talks focused on the deposits that we would visit throughout the trip.
Following the presentations, we
drove for about 4 hours to the town of
VillaFranca del Bierzo to spend the night
and have our first group dinner in a local
restaurant. This small and touristic town
has a rich heritage, particularly for the
pilgrimage trail, Camino de Santiago, and
was an excellent stop to rest on our journey.
Left: Geological presentation on the Iberian
tectonics. Bottom: A group picture of trip
participants before starting our adventure.
Day Two (May 5th)
Las Médulas- Historic Roman Au Mines
The group spent the third day of the trip in northwestern Spain to visit the UNESCO heritage site of
Las Médulas. Easily recognized by spires of red sediments among the rolling hills, the marrows (from which
Las Médulas gets its name) is all that is left of the mountain that was exploited for gold. Mining activity is
responsible for this dramatic landscape, where the Romans extracted alluvial gold hosted in the Miocene
and Quaternary sedimentary deposits of the region. The Romans employed the use of aqueducts and paid
labour from local villages to excavate 300,000,000 m3 of material. The group spent the day exploring this
historic site via self-guided hiking tours on a network of trails. Notable stops along the hike included the top
ridge of Las Médulas, large, water-carved caverns, and the interactive signs explaining the Romans’ mining
process. Afterwards, the group departed for the city of Porto for the evening.
Top: A panoramic view of Las Medulas historic mining
district. Right: a closer look at the Las Medulas Conglemerate which was mined by the Romans on a large scale to
extract alluvial gold.
Day Three (May 6th)
Lagares- Au Project
Medgold Resources Ltd. operates their Lagares Au project in
the northern Iberian massif, 22 km east of Porto, northern Portugal.
In the morning of May 6th, 2015, our group was very fortunate to
be introduced to Medgold’s facilities by exploration manager Jim
Royall and included the core shed, drill pads, historical Roman open
pits and trenches, and modern day adits. He first outlined the QA/QC
methods they use to successfully operate and provide results for this
intrusion-hosted Au prospect, which was noted as being above and
beyond the norm for most motdern exploration companies (yet extremely necessary process!). Boxes of drill core from three representative holes provided the context needed to understand the style of
mineralization of the area, and why past exploration programs have
failed. Medgold faces quite a challenge by having to compile historic
data and determine its quality. Fifteen minutes away, the drill rigs sat
upon a beautifully forested plot on rolling hills amongst fields that
produce world-renowned wine and port. Jim led the group through
the site to observe previous work completed by others prior to Medgold’s acquisition in
2014. This included Henry Awmack, Juan Carlos Marquardt and
Raja Yarra observe the core from the Lagares
two large open pits project
excavated by the Romans as early as the 1st Century A.D. Medgold is constantly
aware of environmental impact by being located in the middle
of a developed region. Of particular concern are the protected native cork oak trees. Medgold’s activities thus far include
channel sampling and a series of diamond drill holes. Most of
these locations were available for us to observe including one
operating drill rig. We ended the day with a typical, lengthy
Portuguese lunch, with plenty of wine of course! Thanks to
everyone at Medgold Resources for a wonderful tour.
Top: Jim showing trip participants historic Roman
open pit mining areas at the Lagares project.
Right: The group looking at an interesting outcrop
at the Lagares
project. World
class Portuguese
vineyards can be
seen in the background.
Day Four (May 7th)
Los Santos -W Mine
On May 7th we visited the Los Santos Mine, owned and operated by Almonty Industries Inc (TSX:All).
The Los Santos mine is a skarn-hosted scheelite (tungsten) deposit located in Los Santos-Fuenterroble mining district, 40 km south of the beautiful city of Salamanca in the Central Iberian Zone. This district contains
numerous low-tonnage tungsten skarn and vein deposits.
The visit included a presentation of the historical overview of the mine, geology and deposit mineralization.
This was followed by a tour to a view point of the open pit, the milling and lab facilities, and finally the coreshack to see beautiful scheelite samples. The visit was organized and supervised by chief mine geologist,
Alicia Bermejo.
Los Santos Open Pit Mine.
The Los Santos deposit is an excellent
example of tungsten-bearing skarn related to
a granite intrusion. The host rocks are carbonate-rich sedimentary units that are completely
or partially replacement by calc-silicate or siliceous minerals (eg. cordierite, garnet, vesuvianite, fluorite, pyroxene, apatite). The skarn
alteration shows a complex geometry related to the main faults, granitic intrusions and
stratabound traps. Syn- to post-mineralization
granitic intrusions are common and have regularly shaped contacts marked by a cm-thick
zone of fine-grained quartz, feldspar, and biotite. Mineralization at the deposit consist mainly of fine grained scheelite (CaWO4) associated
with massive pyroxene skarn, and locally, wollastonite, disseminated pyrite, pyrrhotite and
A handsample containing Scheelite fluoresces under ultraviolet light (The
chalcopyrite. The deposit lies in the NW margin Scale unfortunately did not glow in the dark, hand sample is approxiof a plutonic complex unit that is believed to mately 30 cm in width)
be genetically related to the mineralization.
Day Five (May 8th)
Panasqueira- W Mine
From the city of Fundao we drove to the Panasqueira tungsten mine early on the morning of the 8th.
Our visit started with a brief introduction to the company that runs the mine, Sojitz Beralt Tin and Wolframite, (Portugal) S.A., the geology of the deposit, and the mining methods utilized by the company. The visit
was led by the Geology Department Manager, Romeu Vieira.
Because of limited time and space for the
mine tour, the group was divided in two separate tour: one group visited the underground
mine while the second toured the metallurgic process at the plant. Some of the participants of the underground tour were even
lucky enough to grab some stunning hand
samples to take home! After a lunch of bread,
tomatoes, and serrano ham and cured meats
in town, the group visited the museum on
the mine site, full of beautiful and rare mineral specimens from the mine site. In fact,
Panasqueira is world renown for it’s pristine
and gorgeous minerals, particularly quartz.
The tour was concluded with a trip to the core
shack to observe some of the distinguishing
ore textures and mineralization. The day ended with a drive to Lisbon.
Top: Quartz vein with lenses of wolframite (dark mineral). Bottom: Department manager Romeu answers
questions about core and geology in the Panasqueira
core shack.
Day Six (May 9th)
Lisbon, Portugal- Rest Day
After days of travel, tours and geology, May 9th was planned as a day of leisure and cultural exploration within the historic city of Lisbon, Portugal.
Attendees were encouraged to enjoy a relaxing morning then make their way to the Museu Geológico. This historical museum has origins back over 150 years being the center of Portugese geoscience and
today hosts the federal geoscience and resource ministry
known as (National Laboratory of Energy and Geology)
(LNEG). A small group a dedicated individuals made the
2km journey from the hotel to find more than expected.
Room after room, case after case, display after display of
priceless fossils, Roman artifacts and mineral specimens
(many from localities visited on the trip) were enjoyed.
Perhaps a favorite of the group was a Roman aged bronze
tablet with hand chiseled scripture describing mining
methodology to be followed by laborers.
The remainder of the day was spent by most touring around the city. Nearby landmarks included the Arco
Triunfal da Rua Augusta and the Praca do Comercio. It was
a Saturday afternoon with plenty of activities including a
festival of indigenous Iberian cultures featuring a loud and
colourful parade. With curiosities quenched and the late
afternoon upon us, the convoy departed Lisbon via the impressive Vasco da Gama Bridge. The 2 hour journey to Beja
in the southern region of Portugal gave time for some to
take in the scenery of cork tree forests and others to catch
up on some much needed shut eye.
Day Seven (May 10th)
Rio Tinto Museum and Historic Mine
On May 10th we visited the Rio Tinto museum and main open pit historic mines. The Rio Tinto district
is located 40 km northwest of the beautiful city of Sevilla, Huelva. This district is one of the most important
and charismatic mining districts of the Iberian Pyrite Belt, which include historical underground mines and
inactive open pits. The area has been worked for over 3000 years successively, by Phoenicians, Romans and
more recently, British and Spanish companies. It contains enormous quantities of altered rock and metal
concentration, whereby the region gets its name from the particular red colors of the landscape and river.
Despite the inactivity, the EMED Tartessus Company and owner of the Rio Tinto Mine is planning to restart
the operation within the main open pit.
In the morning, we visited the Rio Tinto
Museum, Pena de Hierro mine and the headwaters of the Rio Tinto River, followed by a
traditional Spanish meal. Our guide for the
morning was led by Marco who was friendly
and knowledgeable and from the local area.
He explained and showed an overview of
mining archeological works from ancient cultures, the stages and growth of the mine opTrip participants observe the massive sulphide lenses below the gossan
alteration.
erated by British in the last centuries, and historical and social issues such the displacement of the town. He also showed some spectacular mineralogical
and biological species present only in the Rio Tinto region.
In the afternoon we visited the main open pit of Rio
Tinto and the remarkable view point of the abandoned Atalaya open pit. The visit was supervised by chief geologist
Angelo Farci. In the open pit we were shown the ore mineralization and alteration. Massive sulphide, mainly pyrite and
chalcopyrite, occurs in stockworks, breccias, and irregular
and stratabound lenses between felsic and mafic volcanic
rocks interbedded with shales. The upper parts of the deposits are characterized by a gossan formed by the supergene alteration and oxidation of massive sulphides that
is developed at up to 70 m depth. Following the tour, we
made our way to the town of Aracena to spend the night.
Top: Headwaters of the Rio Tinto
River
Left: Linda Dandy and Raja Yarra
lookout at the Rio Tinto open
pit.
Day Eight (May 11th)
Aguablanca- Ni-Cu-PGE Mine
Just over the halfway mark on the trip, May 11th began with a 45-minute drive from Aracena to El
Real de la Jara, southern Spain. Only 100 km north of Seville, the Aguablanca nickel deposit is situated in the
Ossa-Morena Zone of the Iberian massif. There, Lundin Mining operates the Aguablanca Ni-Cu-(PGE) mine,
southern Europe’s only producing nickel mine. This unique experience prefaced primarily by the deposit
type, a convergent margin-related magmatic Ni-Cu-PGE sulphide, was added upon by our guide and chief
geologist César Martinez, who has been working on this deposit since early exploration began in the early
1990s. César first introduced the group to the mine operations currently underway then gave general knowledge about magmatic Ni-Cu-PGE deposits while specifically outlining observations at Aguablanca. After donning our PPE and shuffling cars we were led out on site for a tour.
Agustin Guitart and other trip participants overlook the Aguablanca openpit.
The mine was in the process of converting from
open pit to underground operations so the closest we
were allowed to the pit was a viewpoint along the western wall. Here, we had discussions about the structures
thought to have facilitated the transport of Ni-sulphide
laden magma into the crust, and how they envisioned
the deposit forming during the Carboniferous. César
then led us to the stock pile where we were allowed
take samples and discuss the primary and secondary
mineralogy defining the Aguablanca stock and related
Ni-Cu-PGE sulphide mineralization. We marveled over
the coarse-grained dodecahedral pyrite formed from
hydrothermal fluids along the margins of the intrusion.
Our last stop was Lundin Mining’s core shed in El Real
de la Jara where geological contacts and mineralogy Above: Core from Aguablanca, Pyrite with pentlandite
and pyrrhotite rims.
were clearly visible. Despite being a busy day for the
mine staff, our group was shown incredible hospitality
during our visit. We appreciate their help in organizing
a great day in southern Spain!
Day Nine(May 12th)
Las Cruces
After a 8am departure from Aracena the group traveled to the Las Cruces mine owned by First Quantum Minerals Ltd. The Las Cruces deposit is a VMS deposit within the world class Iberian Pyrite belt extending from Portugal to Spain. Complex faulting, weathering and geochemical processes the geologists at Las
Cruces have outlined several different orebodies varying in continuity and grade.
A detailed presentation by their geologists outlined three distinct ore facies consisting of: a primary
body which is further split into a massive sulfide zone, semi-massive sulfide zone and stockwork zone; a
secondary enrichment facies and finally a gossan facies. The primary massive sulfide body extends over
1km striking E-W dipping at 35o to the north, and remains open along dip. The secondary enrichment zone
is non-tabular and non-uniform overlaying the massive sulfide zone and formed beneath the gossan zone.
Secondary Cu-rich mineralization characterizes this zone and consists of an average 50m – thick lens. Secondary enrichment can also be observed surrounding the primary body up to 12m thick and is associated
with deeper subhorizontal fault zone. Mineral assemblage of both lenses are principally Cu-Rich. The Gossan
mineraliztaion is located between the upper sedimentary cover sequence (Tertiary Marl) and the secondary
enrichment zone. The gossan ranges in thickness between 0-20m witch thicker portions in the central and
western parts of the deposit. The zone is characterized by siderite, calcite, Fe-sulfides and Galena and relict
goethite and hematite.
The CLC processing plant at Las Cruces uses advanced leaching and electrowinning technology to
produce copper cathode. The CLC plant uses a process known as “Clean Technology” thanks to which the
copper produced is ready for sale as “Grade A” copper directly from the plant. The extraction process is
cleaner than conventional pyrometallurigcal processing. The plant is designed to produce approcimately
72,000 tonnes of copper cathode per year which is shipped as final product.
Following an in depth presentation on the geology and mining method of Las Cruces, the group was
able to see a planned explosion, intended to expand the open pit. Following the ‘explosive tour’, the group
headed to the city of Seville.
Left: Las Cruces Open pit, the
dust cloud to the left shows the
location of the explosion.
Day 10 (May 13th)
Almaden- Hg District
From Seville, we drove three hours to the historic mercury mines of Almadén, where we met Eva
María García Noguera. We started the visit at the museum in the Mining Interpretation Centre and continued
through the historic mine workings of the San Aquilino and San Teodoro shafts.
The tour inside the mine began by going down into the San Teodoro shaft until reaching the 1st floor, 50 metres down, in a miner’s cage. The walking tour traverses through the actual historic mine shaft, operated in
the 16th and 17th centuries. To bring us up back to the surface, we even got to ride in an old (though recently
rebuilt to run on electricity) mine cart, which was enjoyed by students and industry folk alike!
Following the underground mine we visited the Mercury Museum, with exhibitions of the local geology and
palaeontology, interactive physics and chemical experiments with mercury. The museum also gave a history
of this metal’s metallurgy and transportation to America.
Our visit continued to the School of Engineering at the Universidad Castilla-León in
the city of Almadén. We visited the ruins of
the old jail in the town, were the prisoners
were forced to work in the harsh conditions
of the mine. After the visit we headed to the
beautiful city of Cordoba, were we rested,
and prepared for a drive to the next day off in
Granada.
Top: Cinnabar ore from the Almaden Hg district. Right: a pool of mercury showcased at
the Almaden museum.
Day 11 (May 14th)
Alhambra, Granada- Drive and Rest
There was no mine visit on May 14th, though instead, the group had the opportunity to visit the
mosque in Cordoba in the early morning. We then left Cordoba and drove to Granada, where we all gathered
again at the La Alhambra for the start of the visit at 2 pm, where the trip participants spent all afternoon
visiting the ancient Moorish palace.
La Alhambra, the complete form of which was Calat Alhamra, is a palace and fortress complex located in Granada, Andalusia, Spain. It was originally constructed as a small fortress in 889 and then largely
ignored until its ruins were renovated and rebuilt in the mid-11th century by the Moorish emir Mohammed
ben Al-Ahmar of the Emirate of Granada, who built its current palace and walls. It was converted into a royal
palace in 1333 by Yusuf I, Sultan of Granada.
Alhambra’s Islamic palaces, as we know them today, were built for the last Muslim emirs in Spain
and the court of the Nasrid dynasty. After the conquest of Granada by the Reyes Católicos (“Catholic Monarchs”) in 1492, some portions were used by Christian rulers. The Palace of Charles V, built by Charles V, Holy
Roman Emperor in 1527, was inserted in the Alhambra within the Nasrid fortifications. After being allowed
to fall into disrepair for centuries, the buildings being occupied by squatters, Alhambra was rediscovered in
the 19th century by European scholars and travelers, with restorations commencing. It is now one of Spain’s
major tourist attractions, exhibiting the country’s most significant and well-known Islamic architecture, together with 16th-century and later Christian building and garden interventions. Alhambra is a UNESCO World
Heritage Site and the inspiration for many songs and stories.
Trip participants enjoyed the intricate, complex and beautiful architecture
and gardens of the Alhambra palace and grounds on their half day off in
Granada.
Day 12 (May 15th)
Rodalquilar Mine District
On this day the group met inside “La Casa
de los Volcanes”, a museum of the Rodalquilar
mine district in the small town of Rodalquilar.
The hosts for the day outlined the plans and introduced the history of the area and mining, and
formation of the high- sulfidation (Au-(Cu-Te-Sn)),
and low-sulfidation (Pb-Zn-(Cu-Ag-Au) epithermal
deposits. The Rodalquilar caldera was formed at
11 Ma along with the deposition of the Cinto ignimbrite, and the emplacement of annular felsic
Map of the town of Rodalquilar. Red dot in the inset box shows the
domes. Shortly after, the Las Lazaras ignimbrites location of Rodalquilar.
were emplaced and the smaller Lomilla caldera
was formed from collapse, eventually nesting inside the Rodalquilar caldera. This was followed by doming
of the south-central part of the Rodalquilar caldera and opening of large faults and fractures, developing a
hydrothermal system and the epithermal deposit. The self-guided tour made three stops in the Rodalquilar
mine area:
Stop 1. The first stop was located at the lookout on the unpaved road (ALP-824 road) that ascends into the mine, where we observed secondary alunite alteration. The highest grade of mineralization is commonly associated with vuggy quartz veins that enclose high-grade hydrothermal breccias. The rock is advanced argillically altered and can contain rare chalcedonic quartz
enclosed in a matrix of white chalcedony. Grades of 0.1 g/t are rarely exceeded, and only within the top 100 m within veins. Primary mineralization is observed in 1-5 mm rims of black chalcedony around lithic fragments that contain fine-grained calverite, native Te, and minor pyrite.
However, these minerals are generally oxidized and replaced by native Au, tellurite, goethite,
rodalquilarite, etc.
Left: Open pit 2, looking towards the northern Lomilla Caldera. Open pit 2 of the Transaction Mine is the largest of all the open pits
at the mine. Approximately 200 m from the top to the bottom of the pit. Right: Matt Bodnar taking a closer look at the Maria Josefa
vein at the top of Cerro de la Cruz, looking north, and down-strike of the vein.
Day 12 (May 15th)
Rodalquilar Mine District (Cont’d)
Stop 2. The second stop was made at the end of the road about 2 km west of the town of Hortichuelas. After leaving our vehicles and walking a few minutes along the old road, we reached
the north wall of the Lomilla caldera and Intracaldera Cinto ash-flow tuff and collapse breccias.
Over 200 m of intracaldera facies Cinto ash-flow tuff and collapse breccia are exposed inside the
caldera wall.
Stop 3. The third stop intended to locate mineralized structures located peripherally to the core
of advanced argillic alteration at the Maria Josefa mine, located on the western side of Cerro de
la Cruz near the western margin of the Lomilla caldera. We drove on the unpaved road from Los
Albaricoques to Cortijo del Fraile and stopped near the entrance of the gallery located at the
base of Cerro de la Cruz. We then hiked about 200 m up the path towards some ruins on Cerro
de la Cruz. The Maria Josefa mine (low sulfidation) is actually located on the other side of the hill.
The veins at Maria Josefa contain some of the typical characteristics of Au mineralization in the
Rodalquilar deposits. Maria Josefa mine was one of the first Au mines in the Rodalquilar district
in 1864, after mining in the district switched from Zn, Cu and Pb.
The evening was spent in the small town of Nijas, to the north of Rodalquilar where the group enjoyed a fantastic meal at El Plavazo. The group left early the following day to make the long journey back to
Madrid, and eventually the long flight back to Vancouver.
Acknowledgements
We would like to thank all of the Society of Economic Geologists and again to our industry sponsors
who made this trip possible. We would also like to give a special thanks to Dr. Josep Maria Mata Perelló and
Dr. Pura Alfonso from the Politechnical University of Catalonia (UPC) for their help in acquiring contacts and
entrance to several of the mine visits; Dr. Jim Mortensen from UBC for his geologic knowledge of the area
and presenting an overview of the region for the students at UBC; Dr. Fernando Tornos from the from the
Centro de Astrobiología, CSIC-INTA, Madrid, for his help in finding contacts and advice on trip logistics; Dra.
Agustín Piéren, Dr. Lorena Ortega, Dr. Roberto Oyarsun, and Dr. Maria Luisa Canales from the Complutense
University of Madrid for giving all members an excellent overview of the metallogeny of Iberia; Jim Royall
and the Medgold geologists for their tour of the Laragres project; Alicia Bermejo and the staff from Almonty Industry for our visit to Los Santos; Romeau Vieira and the geologists at Sojitz Beralt Tin and Wolfram,
(Portugal) S.A. for their gracious hospitality at Panasqueira; Angelo Farci and the Rio Tinto geologists for
their amazing tour of the historic pits of Rio Tinto; César Martinez and Lundin Mining staff for the tour of
the Aguablanca; First Quantum Minerals Ltd. for their tour of Las Cruces; Eva María García Noguera for her
insightful visit to Almadén; and finally all of the hotel staff who were kind to us and patient with hosting the
19 members of the trip. It’s because of the support and expertise from the above mentioned people that
made this trip an incredible learning and adventurous experience for industry members and students alike.
It was truly an amazing “Iberian adventure”, and it was a pleasure to travel with my fellow students and the
industry members. Thanks for making such a great trip!
From: Kaleb Boucher