GMS 14-1 - Geological Survey

DEPARTMENT OF ENVIRONMENTAL PROTECTION
WATER RESOURCES MANAGEMENT
NEW JERSEY GEOLOGICAL AND WATER SURVEY
Prepared in cooperation with the
U.S. GEOLOGICAL SURVEY
NATIONAL GEOLOGIC MAPPING PROGRAM
INTRODUCTION
AR
IT
AN
N
W
TO
TS
)
IT
(P
50'
31
13
Qal
Qst
18
TRpg
22
Jd
74o45'
40o30'
47'30"
(FLEMINGTON)
TRp
21
TRp
29
TRp
14
Qe
Qps
17
15
Qst
TRpg
15
25
29
16
16
15
Cu
7
8
17
TRpg
TRpg
15
20
TRp
TRp
22
TRpg
TRp
16
UD
17
11
15
18
Qst
29
U D
15
14
15
13
Qst
Qal
20
16
21 19
19
16
Qst
Qcs
17
TRp
Qst
27
15
Qal
14
26
Qst
TRp
Qst
TRp
Qst
18
38
TRp
A
Qal
Jd
19
Qcal
12
19
6
9
11
18
18
12 12
5
r
be
E
em
rE
M
em
be
33
12
16
32
13
Qst
11
Qal
Qst
20
Qcs
15 21
24 13 18
15
Qal
Qcal
Qal
Jd
TRpg
18
13
Qcal
Qcal
Qcal
30
13
23
11
12
7
Qcal
17
20
16
17 18
14
TRp
24
16
11
TRpg
14
Qalb
24
21
15
13
Qcal
20
rQ
em
18
M
st
on
la
et
22
a
sh
24
16
sie
TRp
17
(STOCKTON)
17
Qalb
Qcd
Qcal
16
13
16
26
16
TRp
20
Qcal
23
Qaf
Qcd
Qcal
34
14
23
27
Qcs
21
16
23
20
20
25
16
23
21
23
26
16
18
24
TRp
22
TRph
Qcal
24
TRlh
Jd
TRpg
23
Qalb
18
20
17
16 2214
22
Qcs
19
Qcd
23
TRp
21
23
Qcd
Qcal
18
15
22
20
19
26
Qcd
17
Qcal
TRp
23
Qcd
M
Qalb
23
Qcd
Qcal
TRph
Qcal
30
TRph
Qalb
22
Qcd
TRlh
Qalb
21
S
O
U
R
L
A
N
O
U
N
T
A
Qcal
IN
25'
D
Qal
TRlh
14
Qalb
Qcal
Jd
TRph
19
Qalb
Qcd
14
Qal
23
10
11
Qcd
Qcs
23
9
Qalb
18
27
12
21
35
TRlh
5
18
Qcs
Qcs
Qcs
TRl
Qcs
18
14
Qcd
21
TRph
Jd
18
20
19
12
8
10
Qcs
TRl
19
TRpg
16
TRp
11
Qal
17
Qcs
25
Downhole Optical Televiewer interpretation. Shows marker beds identified in borehole projected to land surface using
bed orientation identified in well. In igneous rocks, shows orientation of flow structures. Red dot shows well location.
Data from Herman and Curran (2010a, 2010b).
Strike ridge - ridge or scarp parallel to strike of bedrock. Mapped from stereo airphotos.
Strath - Erosional terrace cut into bedrock by fluvial action.
REFERENCES CITED AND USED IN CONSTRUCTION OF MAP
17
19
32
TRp
31
28
38 30
23
38
TRph
18
Qaf
24
Jd
Qcs
Qcs
TRpg
21
Qst
40o22'30"
74o52'30"
Qcs
Qcal
Qcal
(PENNINGTON)
TRph
Qcd
A’
TRph
Jd
40o22'30"
74o45
47'30"
Qcd
GE
TER
WA
1000
TH
EW
1000
2000
1
SUR
VE
NOR
JERSEY
N E T IC
TRUE NORTH
Y
N
LOCATION IN
NEW JERSEY
0
3000
4000
0
.5
Qps
1 MILE
&
o
121/2
APPROXIMATE MEAN
DECLINATION, 1981
0
2
5000
6000
Research supported by the U.S. Geological Survey, National Cooperative
Geologic Mapping Program, under USGS award number 00HQAG-0110.
The views and conclusions contained in this document are those of the authors
and should not be interpreted as necessarily representing the official
policies, either expressed or implied, of the U.S. Government.
7000 FEET
1 KILOMETER
Shale, sandstone, and mudstone colluvium—Silt, sandy silt, clayey silt, reddish-brown to yellowish-brown, with
some to many subangular flagstones, chips, and pebbles of red and gray shale, mudstone, and minor sandstone.
Poorly sorted, nonstratified to weakly stratified. Flagstones and chips have strong slope-parallel alignment of a-b
planes. As much as 30 feet thick. Forms footslope aprons along base of hillslopes. Chiefly of late Wisconsinan age.
Diabase colluvium—Clayey silt to clayey sandy silt, yellowish-brown to reddish-yellow, with some to many
subrounded boulders and cobbles of diabase. Poorly sorted, nonstratified to weakly stratified. As much as 15 feet thick
(estimated). Forms footslope aprons along base of hillslopes. Includes some areas of boulder lag formed by footslope
groundwater seepage, with little or no accumulation of colluvium. Chiefly of late Wisconsinan age.
)
SCALE 1:24 000
1
Eolian deposits—Silt and very fine-to-fine sand, reddish yellow. Well-sorted, nonstratified. As much as 5 feet thick.
These are windblown deposits blown from stream terraces in the Raritan River valley.
N
GICAL
O
ET
LO
C
Bedrock geology mapped by G.C. Herman in 1992-2013
D.H. Monteverde in 2001-2013
Surficial geology mapped by S.D. Stanford in 1990
Digital cartography by D.H. Monteverde
Reviewed by MaryAnn Malinconico
Base map from U.S. Geological Survey, 1954
North American datum 1927
Revision based on photographs taken in 1970
O
IN
R
(P
LE
50'
Jd TRp
Stream-terrace deposits—Silt, fine sand, and pebble-to-cobble gravel, moderately sorted, weakly stratified. Deposits
in the Neshanic River basin are chiefly reddish-yellow to reddish-brown silt with minor fine sand and trace of red and
gray shale, mudstone, and sandstone pebble gravel, and are generally less than 10 feet thick. They form terraces 5 to
10 feet above the modern floodplain. Deposits in the Beden Brook basin near Hopewell are dominantly flagstone
gravel and minor reddish-brown silt and fine sand. They are as much as 15 feet thick and form terraces 5 to 10 feet
above the modern floodplain. They are likely of both late Wisconsinan and postglacial age.
23
Qcd
23
TRl
8
Qe
18
TRs
18
TRp
Alluvial fan deposits—Flagstone gravel as in unit Qal and minor reddish-brown silt and fine sand. Moderately sorted
and stratified. As much as 15 feet thick. Form fans at mouths of steep tributary streams.
32
21
23
TRph
18
Qaf
Qst
33
Qcs
29
MAG
Anders, M.H., and Schlische, R.W., 1994, Overlapping faults, intrabasin highs, and the growth of normal faults: Journal of
Geology, v.102, p.165-180.
Darton, N. H., 1896, The relations of the Traps of the Newark System in the New Jersey Region, U.S. Geological Survey
Bulletin No. 67., 97 p., 1 plate, 1:538360 scale.
De Boer, J.Z., and Clifford, A.E., 1988, Mesozoic tectogenesis: development and deformation of 'Newark' rift zones in the
Appalachians (with special emphasis on the Hartford basin, Connecticut): in, Manspeizer, W., ed., Triassic-Jurassic
rifting, continental breakup and the origin of the Atlantic Ocean and passive margins, part A., Elsevier Science
Publishers, B.V., New York, p. 275-306.
Faust, G.T., 1978, Joint systems in the Watchung Basalt flows, New Jersey: US Geological Survey Professional Paper
864B, 46 pages.
Herman, G.C., 2005, Joints and veins in the Newark basin, New Jersey, in regional tectonic perspective: in, Gates, A.E.,
editor, Newark Basin – View from the 21st Century: 22nd Annual Meeting of the Geological Association of New
Jersey, College of New Jersey, Ewing, New Jersey, p. 75-116.
Herman, G.C., 2009, Steeply-dipping extension fractures in the Newark basin, New Jersey, Journal of Structural Geology,
v. 31, p. 996-1011.
Herman, G.C., 2010, Hydrogeology and borehole geophysics of fractured-bedrock aquifers, Newark basin, New Jersey,
in, Herman, G.C., and Serfes, M.E., eds., Contributions to the geology and hydrogeology of the Newark basin,
New Jersey Geological Survey Bulletin 77, p. F1-F45.
Herman G.C., and Curran, J.F., 2010a, Summary of borehole geophysical studies in the Newark Basin, New Jersey:
Diabase and Brunswick Basalt in the Watching Zone: in, Herman, G.C., and Serfes, M.E., eds., Contributions to
the geology and hydrogeology of the Newark basin, New Jersey Geological Survey Bulletin 77, Appendix 1,
p.1A1-1F4.
Herman G.C., and Curran, J.F., 2010b, Summary of borehole geophysical studies in the Newark Basin, New Jersey:
Brunswick mudstone, siltstone and shale; middle red, middle gray, lower red and lower gray zones: in, Herman,
G.C., and Serfes, M.E., eds., Contributions to the geology and hydrogeology of the Newark basin, New Jersey
Geological Survey Bulletin 77, Appendix 3, p.3A1-3Q3.
Herman, G.C., Dooley, J. H., and Monteverde, D. H., 2013, Structure of the CAMP bodies and positive Bouger gravity
anomalies of the New York Recess, in Benimoff, A. I., ed., Igneous processes during the assembly and breakup of
Pangaea: Northern New Jersey and New York City: Proceedings of the 30th Annual Meeting of the Geological
Association of New Jersey, College of Staten Island, N.Y., p. 103-142.
Houghton, H.F., ca. 1985, unpublished data on file in the office of the New Jersey Geological Survey, Trenton, New
Jersey.
Houghton, H.F., Herman, G.C., and Volkert, R.A., 1992, Igneous rocks of the Flemington fault zone, central Newark
basin, New Jersey: Geochemistry, structure, and stratigraphy: in, Puffer J.H., and Ragland, P.C., eds., Eastern
North American Mesozoic Magmatism: Geological Society of America Special Paper 268, p. 219-232.
Hozik, M. J., and Columbo, R., 1984, Paleomagnetism in the central Newark basin, in, Puffer, J. H., ed., Igneous rocks of
the Newark basin: Petrology, mineralogy, ore deposits, and guide to field trip: Geological Association of New
Jersey 1st Annual Field Conference, p. 137-163.
Husch, J., 1988, Significance of major- and trace-element variation trends in Mesozoic diabase, west-central New Jersey
and eastern Pennsylvania: in, Froelich, A. and Robinson, G., eds., Geology of the Early Mesozoic Basins of
Eastern North America, United States Geological Survey Bulletin, no. 1776, p. 141-150.
Husch, J. M., Bambrick,T. C., Eliason, W. M., Roth, E. A., Schwimmer, R. A., Sturgis, D. S., and Trione, C. W., 1988, A
review of the petrology and geochemistry of Mesozoic diabase from the central Newark basin: new petrogenetic
insights, in, Husch, J. M., and Hozik, M. J., eds., Geology of the Central Newark Basin: Field Guide and
Proceedings of the Fifth Annual Meeting of the Geological Association of New Jersey, Lawrenceville, NJ, p.
149-194.
Kummel, H.B., ca. 1900, unpublished data on file in the office of the New Jersey Geological Survey, Trenton, New Jersey.
Lucas, M., Hull, J., and Manspeizer, W., 1988, A Foreland-type fold and related structures in the Newark Rift Basin: in,
Manspeizer, W., ed., Triassic-Jurassic rifting, continental breakup and the origin of the Atlantic Ocean and passive
margins, part A., Elsevier Science Publishers, B.V., New York, p. 307-332.
Malinconico, M.L., 2010, Synrift to early postrift basin-scale ground water history of the Newark basin based on surface
and borehole vitrinite reflectance data: in, Herman, G.C., and Serfes, M.E., eds., Contributions to the geology and
hydrogeology of the Newark basin, New Jersey Geological Survey Bulletin 77, p. C1-C38.
Marzoli, A., Renne, P.R., Piccirillo, E.M., Ernesto, M., Bellieni, G., and De Min, A., 1999, Extensive 200-million-year-old
continental flood basalts of the Central Atlantic Magmatic Province, Science, v. 284, p. 616-618.
McLaughlin, D. B., 1945, Type sections of the Stockton and Lockatong Formations: Proceedings of the Pennsylvania
Academy of Science, v. 20, p. 89-98.
McLaughlin, D. B., 1946, The Triassic rocks of the Hunterdon Plateau, New Jersey: Proceedings of the Pennsylvania
Academy of Science, v. 19, p. 102-103.
McLaughlin, D. B., 1959, Mesozoic rocks: in, Willard, B., et al., Geology and mineral resources of Bucks County,
Pennsylvania, Pennsylvania Geological Survey, Bulletin C-9, p. 55-114.
Olsen, P.E., 1980a, The latest Triassic and Early Jurassic formations of the Newark basin (eastern North America,
Newark Supergroup): Stratigraphy, structure, and correlation: New Jersey Academy of Science, Bulletin, v. 25, p.
25-51.
Olsen, P.E., 1980b, Fossil great lakes of the Newark Supergroup in New Jersey: in, Manspeizer, Warren, ed., Field
studies of New Jersey geology and guide to field trips: 52nd annual meeting of the New York State Geological
Association, p. 352-398.
Olsen, P.E., 1997, Stratigraphic record of the early Mesozoic breakup of Pangea in the Laurasia-Gondwana rift system,
Annual Reviews of Earth and Planetary Science, v. 25, p. 337-401.
Olsen, P.E., and Kent, D.V., 1996, Milankovitch climate forcing in the tropics of Pangaea during the Late Triassic:
Palaeogeography, Palaeoclimatology, Palaeoecology, v. 122, p. 1-26.
Olsen, P.E., Kent, D.V., Cornet, Bruce, Witte, W.K., and Schlische, R.W., 1996, High-resolution stratigraphy of the
Newark rift basin (early Mesozoic, eastern North America): Geological Society of America, Bulletin, v. 108, p.
40-77.
Olsen, P.E., Kent, D.V., Whiteside, J., 2011, Implications of the Newark Supergroup-based astrochronology and
geomagnetic polarity time scale (Newark-APTS) for the tempo and mode of the early diversification of the
Dinosauria: Earth and Environmental Science Transactions of the Royal Society of Edinburgh, v. 101, p. 201-229.
Olsen, P.E., Schlische, R.W., and Gore, P.J., 1989, Tectonic, depositional, and paleoecological history of Early Mesozoic
rift basins in eastern North America: Field trip guidebook T351, American Geophysical Union, 174 pages.
Parker, R.A., and Houghton, H.F., 1990, Bedrock geologic map of the Rocky Hill quadrangle, New Jersey: U.S.
Geological Survey, Open-File Map 90-218, scale 1:24,000.
Sanders, J.E., 1962, Strike-slip displacement on faults in Triassic rocks in New Jersey, Science, v. 136 (3510), p. 40-42.
Schlische, R.W., 1992, Structural and stratigraphic development of the Newark extensional basin, eastern North America:
Evidence for the growth of the basin and its bounding structures: Geological Society of America, Bulletin, v. 104,
p.1246-1263.
Schlische, R.W., 1993, Anatomy and evolution of the Triassic-Jurassic continental rift system, eastern North America:
Tectonics, v.12, p. 1026-1042.
Schlische, R.W., 1995, Geometry and origin of fault-related folds in extensional settings: American Association of
Petroleum Geologists, Bulletin, v. 79, p. 1661-1678.
Schlische, R.W., 2003, Progress in understanding the structural geology, basin evolution, and tectonic history of the
Eastern North American Rift System: in, LeTourneau, P.M., and Olsen, P.E., eds., The great rift valleys of Pangea
in Eastern North America, v. 1, Columbia University Press, New York, p. 21-64.
Simonson, B. M., Smoot, J. S., and Hughes, J. L., 2010, Authigenic minerals in macropores and veins in Late Triassic
mudstones of the Newark basin; implications for fluid migration through the mudstone, in, Herman, G.C., and
Serfes, M.E., eds., Contributions to the geology and hydrogeology of the Newark basin: N.J. Geological Survey
Bulletin 77, Chapter B, p. B-1 – B26.
Smoot, J., 2010, Triassic depositional facies in the Newark basin, in, Herman, G.C., and Serfes, M.E., eds., Contributions
to the geology and hydrogeology of the Newark basin, New Jersey Geological Survey Bulletin 77, p. A1-A100.
Van Houten, F.B., 1969, Late Triassic Newark Group, north central New Jersey and adjacent Pennsylvania and New
York: in, Subitzky, S., ed., Geology of selected area in New Jersey and eastern Pennsylvania and guidebook of
excursions; Rutgers University Press, New Brunswick, New Jersey, p. 314-347.
Withjack, M.O., Olsen, P.E., and Schlische, R.W., 1995, Tectonic evolution of the Fundy basin, Canada: Evidence of
extension and shortening during passive-margin development, Tectonics, v. 14, p. 390-405.
Withjack, M.O., Schlische, R.W., Malinconico, M.L., and Olsen, P.E., 2012, Rift-basin development—lessons from the
Triassic-Jurassic Newark basin of eastern North America, in, Mohriak, W.U., Danforth, A., Post, P.J., Brown, D.E.,
Tari, G.C., Nemcock, M., and Sinha, S.T., eds., Conjugate Divergent Margins, Geological Society (London) Special
Publication 369, p. 301-321.
TRpg
21
TRp
17
36
30
24
21
13
Qal
F
ell
ew
p
Ho
13
12
23
lt
au
Qst
17
10
13
)
Abandoned copper mine, location of photographs shown in figure 3
Alluvium and boulder lag—Silt, sand, minor clay and organic matter, dark brown, brown, yellowish-brown,
reddish-yellow, moderately sorted, weakly stratified, overlying and alternating with surface concentrations (lags) of
rounded to subrounded diabase (and, in places, hornfels) boulders and cobbles. As much as 10 feet thick (estimated).
Formed by washing of weathered diabase and hornfels by surface water and groundwater seepage.
Colluvium and alluvium, undivided—Interbedded alluvium as in unit Qal and colluvium as in unit Qcs in narrow
headwater valleys. As much as 10 feet thick (estimated).
16
12
BE
RT
VI
L
Cu
Alluvium—Silt, pebble-to-cobble gravel, minor fine sand and clay. Moderately to well-sorted and stratified. Contains
minor amounts of organic matter. Color of fine sediment is reddish-brown to brown, locally yellowish-brown. Gravel is
dominantly flagstones and chips of red and gray shale and mudstone with minor pebbles and cobbles of basalt,
diabase, sandstone, and hornfels. Silt, fine sand, and clay occur as overbank deposits on floodplains along
low-gradient stream reaches. Overbank silts are sparse or absent along steeper stream reaches. Gravel is deposited
in stream channels and is the dominant floodplain material along steeper stream reaches. Flagstone gravel typically
shows strong imbrication. As much as 10 feet thick.
Qcal
37
TRl
21
48
Qcal
TRs
11
18
23
Qalb
17
16
24
Qal
18
20
Qcs
AM
Abandoned rock quarry
28
Qal
Qalb
18
22
TRl
19
30
TRph
(L
Other features
DESCRIPTION OF MAP UNITS
18 13
17
Qcd
27
Strike and dip of flow foliation in igneous rocks
TRs
Qalb
13
18
Strike and dip of inclined beds
9
19
TRl
8
TRph
11
At the quadrangle’s northwest corner the Neshanic copper mine lies adjacent to the Copper Hill dike. Recent excavation
at this site for a single-family housing tract exposed numerous shafts and drifts as well as the bedrock, hornfels and dike
relationships. Results describe the steeply to moderately dipping Copper Hill dike cut by shear planes displaying
normal-oblique slip with common right-lateral shear indicators. Locally a small intrusive tongue developed as a sill and
associated hornfels zone that was intersected by the mine workings (fig.3).
Qcal
9
Qalb
Qcs
TRl
Qcd
Jd
Qcd
Planar features
The Lambertville sill is the major igneous body on the Hopewell quadrangle. It lies along the western quadrangle
boundary and continues eastward across a narrow saddle structure near Rocktown where it thickens and underlies
Sourland Mountain. This intrusive sheet is part of the larger Palisades-Rocky Hill-Lambertville mega sheet (Van Houten,
1969). Husch and others (1988) interpreted these intrusions as a large, continuous, northwest dipping, nonconformable
sheet that intrudes upsection through the Stockton, Lockatong and into the Passaic with the more primitive,
orthopyroxene-rich bodies in older sedimentary units in contrast to the more highly fractionated and contaminated
granophyre varieties higher into the Passaic Formation. These sheets were subsequently segmented by normal faults.
Recent work by Herman and others (2013) suggest that multiple feeders tapped the same parent magma source for the
Palisades-Rocky Hill-Lambertville mega sheet intrusive complex and the magma migrated from west to east. The
Lambertville sill displays indicators of this west to east flow emplacement. Evidence suggests that the
Lambertville-Sourland intrusive complex may have stepped stratigraphically upward off the flanks of a structural dome
centered near Buckingham, Pennsylvania about 8 miles to the southwest.
Jd
Qcd
TRlh
22
20
23 21
Syncline - showing trace of axial surface, direction and dip of limbs, and direction of plunge.
26
Qcs
24
25
26
25'
13
TRlh
23
17
Anticline - showing trace of axial surface, direction and dip of limbs, and direction of plunge.
Extension fractures are ubiquitous in the basin. Most extension fractures encountered in the subsurface are veins that
exhibit secondary minerals (Herman, 2005, 2009, 2010; Simonson and others, 2010), that are mostly removed near land
surface from interaction with weakly-acidic groundwater. Extension fracture orientations were analyzed using circular
histograms within each geologic unit (figure 2). The analysis displays a temporal, systematic counterclockwise rotation of
the finite-stretching direction from the older to younger units; the Stockton Formation strikes about N35oE maximum, in
the Lockatong Formation about N25oE, and in the Passaic Formation about N5oE. This rotation occurred during the Late
Triassic and agrees with the results of Herman (2005, 2009).
Qalb
17
24
Folds
Qcd
21
Jd
Motion is unknown
Sedimentary beds and the igneous intrusives mostly dip gently northwest at angles ranging from about 10o – 30o. The
Hopewell Fault, one of the major intrabasinal faults, cuts the southeastern corner of the quadrangle along a N50oE strike.
The fault dips at about 45o southeast and separates the Passaic Formation in the hanging wall from the Stockton
Formation in the footwall. It displays normal-oblique slip elsewhere in the area (Sanders, 1962; Herman and others,
2013). Several small-scale transverse folds are mapped along the fault trace near Hopewell Borough. Minor differences
in sediment thickness across transverse fold hinges elsewhere in the basin indicate concurrent deposition and faulting
(Schlische 1995, 2003; Olsen and others, 1996). Recently palinspastic reconstruction of structural models of the basin
support the notion that most of the folding and intrabasinal faulting was post-depositional (Withjack and others, 2012).
TRpg
24
22
Arrows show relative motion
STRUCTURE
TRlh
17
Faults - U, upthrown side; D, downthrown side. Ball and post indicates direction of dip.
Dashed where approximately located; queried where uncertain; dotted where concealed.
The Lambertville sill is about 1000-ft. thick where it intrudes the uppermost section of the Lockatong Formation. The sill is
enveloped by hornfels with thicker hornfels occurring atop the sheet and thinner ones along the sheet base and flanking
dikes. The hornfels extent was mapped mostly using loose exposures of weathered material (float) due to its limited
exposure. The nonconformity location is based on the first occurrence of hornfels float located downslope from the ridge
crests. Several small sills and a long, thin, continuous (Copper Hill) dike cuts the Passaic Formation immediately north of
the Rocktown saddle structure. This dike cuts obliquely across the Passaic Formation and terminates northward near an
Orange Mountain Basalt outcrop just north of the quadrangle boundary in Flemington (Darton, 1896; Herman, 2005).
16
18
21
21
23
Jd
TRp
27
13
17
TRp
25
Qaf
18
Qcal
21
18
16
19
TRp
15
r
Mb
Pe
18
TRlh
19
Jd
rka
22
21
19
10
TRpg
M
?
Late Triassic diabase sills and dikes intrude the Lockatong and Passaic Formations in the Hopewell quadrangle. These
intrusive bodies are part of a regional dolerite sheet and dike complex that share parent magma with the Orange
Mountain Basalt, the oldest of the three basalt sequences in the basin (Hozik and Colombo, 1984; Husch, 1988). Basin
sedimentation continued into the Early Jurassic (194+5 Ma; Malinconico, 2010) after igneous activity.
Qalb
11
18
TRpg
Ne
Qcs
Li
vi
ng
M
c
ni
23
Qal
M
br
M
br
21
13
TRpg
14
12
21
be
br
rs
Qcal
18
13
TRp
TRp
16 23
Qcal
(ROCKY HILL)
20
D
Bedrock units range in age from the Late Triassic to Early Jurassic (Olsen, 1980a) and consist of a thick sequence of
alluvial and lacustrine sedimentary rocks deposited in the Newark basin that were locally intruded by earliest Jurassic
igneous rocks. Sedimentary rocks cover most of the mapped area. The basal Stockton Formation is dominantly an
alluvial sequence of red, light brown, gray, and buff sandstone, arkosic sandstone, and conglomerate. Sandstone,
siltstone and mudstone are more common in the upper half of the Stockton (McLaughlin, 1945, 1959). The overlying
Lockatong and Passaic Formations are dominantly red, gray, and black shale, siltstone, and argillite that were deposited
cyclically in lacustrine environments. Olsen and Kent (1996) and Olsen and others (1996) show that the lacustrine cycles
reflect climatic variations influenced by celestial mechanics (Milankovitch orbital cyclicity). The basic (Van Houten) cycle
correlates with the ~20,000-yr precession cycle and consists of about 20 feet of lacustrine sediment deposited in a
shallow-deep-shallow lacustrine environment. Other climatic cycles are correlated with ~100 ky, 404 ky and 1.75 my time
periods. The 404 ky cycles are thought to correlate with Triassic formations in the basin (Olsen and others, 1996, 2011).
22
13
21
17
16
TRph
13
18
Bedrock Contact - Dashed where approximately located; queried where uncertain; dotted where concealed.
24
9
13
32
27'30"
Qcal
TRp
24
17
JTRp
Qcal
Qcal
15
Qcal
Qcal
Qcal
14
TRpg
16
TRpg
25
25
22
16
TRp
TRp
18
Qcal
TRp
TRp
18
15
18
Qcal
21
27'30"
Qcs
21
AA
M
TRp
24
TRpg
19
14
Qcal
r
Qst
?
U
Quaternary surficial deposits in the Hopewell quadrangle include fluvial, colluvial, and windblown sediment. The oldest
surficial material (unit Qps) is weathered gravel on a bedrock bench about 50 feet above the Raritan and Neshanic
Rivers in the northeast corner of the map area. This gravel may be of Pliocene or early Pleistocene age, because its
topographic position and degree of weathering are similar to gravels of this age in the Delaware Valley west of the
quadrangle and in the Millstone valley to the east of the quadrangle. After deposition of this gravel, the Raritan and its
tributaries deepened their valleys into bedrock by 50 to 100 feet, in the early and middle Pleistocene (2.5 Ma to 125 ka).
During the late Wisconsinan glaciation, which reached its maximum extent about 25 ka, ice advanced to a maximum
position about 30 miles north of Hopewell. During this and earlier cold periods, tundra climate and permafrost formed in
the region south of the ice sheet. Erosion on hill slopes increased, and the eroded material was laid down on foot slopes
and valley bottoms. In the Hopewell quadrangle, sediment aggraded in tributary valleys (units Qst, Qaf), colluvium
collected on foot slopes (units Qcs, Qcd), and silt and fine sand were blown off of terraces in the Raritan Valley (unit Qe).
By about 10 ka, permafrost had melted and forests grew, stabilizing hill slopes. Streams incised into terraces to form the
present-day floodplains. Channel and overbank deposits have aggraded on these floodplains within the past 10 ka (unit
Qal). In headwater areas during this and earlier temperate periods, colluvium and weathered rock material have been
incised, washed, and winnowed by runoff and groundwater seepage (units Qcal, Qalb).
15
25
be
18
21 15
Qcal
em
26
16
Qcal
17 18
TRp
18 18
Qst
20
17
12
18 13
34
Surficial Contact - contacts of units Qal and Qst are well-defined by landforms and are drawn from
1:12,000 stereo airphotos. Contacts of other units are drawn at slope inflections and are
feather-edged or gradational.
STRATIGRAPHY
24
Qst
Qst
TRpg
12
18
TRp
16
Qst
M
TRp
18
13
Qcs
20
TRp
TRpg
11
Qcal
15
20
20
BB
12
Qal
13
11
Qst
21
TRpg
8
17
TRp
TRp
6
18
Qst
12
EXPLANATION OF MAP SYMBOLS
Withjack and others (2012) proposed that most of the tilting of basin strata, intrabasinal faulting and transverse folding of
strata in hanging-wall fault blocks near the traces of large faults occurred during late deformational phases after
cessation of basin sedimentation. Post-rift contraction and localized basin inversion has been recognized in other
Mesozoic rift basins (de Boer and Clifford, 1988; Withjack and others, 1995). Recently, Herman and others (2013)
mapped a structural dome in the basin near Buckingham, Pennsylvania having substantial positive structural relief. The
dome is considered to stem from dolerite magma emplacement into the basin as part of the Central Atlantic Magmatic
Province (Marzoli and others, 1999). Sourland Mountain and the associated Copper Hill dike (Herman, 2010) are part of
this intrusive complex.
Qcs
8
Pre-Mesozoic undifferentiated—only depicted in cross section
PMu
TRpg
18
Qst
35
Qcal
TRp
Stockton Formation (Upper Triassic)—Unit is interbedded sequence of gray, grayish-brown, or slightly reddish-brown,
medium- to fine-grained, thin- to thick-bedded, poorly sorted, to clast imbricated conglomerate, planar to trough
cross-bedded, and ripple cross laminated arkosic sandstone, and reddish-brown clayey fine-grained, sandstone, siltstone
and mudstone. Coarser units commonly occur as lenses and are locally graded. Finer units are bioturbated and fining
upwards sequences. Conglomerate and sandstone units are deeply weathered and more common in the lower half;
siltstone and mudstone are generally less weathered and more common in upper half. Lower contact is an erosional
unconformity. Thickness is approximately 4,500 feet.
TRs
The Newark basin is a continental rift basin formed during the breakup of the supercontinent Pangaea (Olsen, 1997). The
basin is filled with Late Triassic to Early Jurassic sedimentary and igneous rocks (Olsen and others, 1996, 2011;
Malinconico, 2010) that have been tilted, faulted, and locally folded (Schlische, 1992, 1993). Most tectonic deformation of
the basin fill is probably Late Triassic to Middle Jurassic age (Lucas and Manspeizer, 1988; de Boer and Clifford, 1988;
Withjack and others, 2012). Southeast-dipping normal faults along the basin's northwestern margin primarily influenced
basin morphology, sediment deposition patterns (Smoot, 2010), and the orientation of some secondary bedrock
structures (Herman, 2009). Later stages of intrabasinal normal and transcurrent faulting segmented the basin into three
major fault blocks, with the Hopewell quadrangle located within the central block bounded by the Flemington fault system
(Houghton and others, 1992) to the north and the Hopewell fault to the south.
17
11
TRpg
TRlh
GEOLOGIC SETTING
19
Qcal
14
TRp
9
Qcs
Qcs
TRpg
TRp
Lockatong Formation (Upper Triassic)—Cyclically deposited sequences of mainly gray to greenish-gray, and, in upper
part of unit, locally reddish-brown siltstone to silty argillite and dark-gray to black shale and mudstone. Siltstone is
medium- to fine-grained, thin-bedded, planar to cross-bedded with mud cracks, ripple cross-laminations and locally
abundant pyrite. Shale and mudstone are very thin-bedded to thin laminated, platy, locally containing desiccation
features. Thermally altered to dark gray to black hornfels (TRlh) where intruded by diabase. Lower contact gradational into
Stockton Formation and placed at base of lowest continuous black siltstone bed (Olsen, 1980a). Maximum thickness of
unit regionally is about 2,200 feet (Parker and Houghton, 1990).
TRl
The Hopewell 7.5-minute topographic quadrangle lies within the Newark basin in the Piedmont Physiographic Province,
in Hunterdon, Mercer and Somerset Counties, west-central New Jersey. The quadrangle lies south of the Wisconsinan
terminal moraine where the variable distribution of stratified Late Triassic sedimentary strata and Early Jurassic diabase
results in alternating ridges and stream valleys of low relief. Diabase underlies Sourland Mountain and other small
igneous bodies that form prominent ridges mostly striking northeast with elevations reaching above 400 ft. Sourland
Mountain separates the area into the main Raritan watershed to the northwest and the Stony Brook-Millstone, and Beden
Brook subbasins of the Raritan watershed to its southeast. The Neshanic River is the largest watercourse in the north
and flows eastward to the Raritan River in Somerset County. Stony Brook, the main watercourse south of Sourland
Mountain, flows southeastward. Small brooks and creeks dominantly flow approximately parallel to bedrock strike with
short courses that cut perpendicularly to strike following cross strike joints. The topography is more varied in the
southeast where elevations range from about 100 to 400 feet. Sedimentary rocks commonly form lower elevations
ranging between 80 and 350 feet. Abundant rock ledges crop out along stream banks and in stream beds where most
outcrops are found. Historically an agricultural area, the Hopewell region has become increasingly suburban since the
mid-20th century.
(R
)
74o52'30"
40o30'
GEOLOGIC MAP OF THE HOPEWELL QUADRANGLE,
HUNTERDON, MERCER, AND SOMERSET COUNTIES, NEW JERSEY
GEOLOGIC MAP SERIES GMS 14-1
Jd
Geologic Map of the Hopewell Quadrangle,
1835
Pre-Illinoian fluvial deposit—Silt and clayey silt, reddish-yellow to light reddish-brown, with some pebble and fine
cobbles. Poorly sorted, nonstratified. As much as 6 feet thick. Gravel includes subrounded white and gray quartz,
quartzite, and chert, gray and red conglomerate, reddish-purple mudstone, and brown and gray sandstone and gneiss.
The sandstone and gneiss pebbles are partially to fully decomposed. Occurs as an erosional remnant of a terrace
deposit on a rock bench 40 to 50 feet above the modern floodplain of the Raritan River. Of pre-Illinoian age, possibly
Pliocene or early Pleistocene.
Diabase (Lower Jurassic)—Fine-grained to aphanitic dikes (?) and sills and medium-grained, discordant, sheet-like
intrusion of dark-gray to dark greenish-gray, sub-ophitic diabase; massive-textured, hard, and sparsely fractured.
Composed dominantly of plagioclase, clinopyroxene, and opaque minerals. Contacts are typically fine-grained, display
chilled, sharp margins adjacent to enclosing sedimentary rock. Sills exists on Sourland Mountain and on Mount Rose,
south of Hopewell Borough, a continuation of the Rocky Hill Diabase. These sheets may be the southern extension of
the Palisades sill. The thickness of the Rocky Hill diabase in the quadrangle, known mainly from drill-hole data, is
approximately 1,325 feet.
0
1
1
0
3000
1
3
2
3000
9000
0
1
4
21000
15000
3
2
30000 FEET
27000
6
5
4
6 MILES
5
8 KILOMETERS
7
Figure 1. LIDAR (Light Detection And Ranging) map of the Hopewell quadrangle showing the correlation of igneous units and strike of
ridge lines (green) with topography.
N
30
20
N
N
10
10
10
20
30
30
20
20
30
10
5
5
Total data points = 10
Sector angle = 10°
Maximum = 33.3%
Total data points = 340
Sector angle = 10°
Maximum = 34.7% (
15
10
10
15
Total data points = 10
Sector angle = 10°
Maximum = 18%
Strike and dip azimuth (blue) of all bedding
Strike of joints in Stockton Fm
Dip azimuth of joints in Stockton Fm
N
N
N
9
12
12
9
9
15
Total data points = 28
Sector angle = 10°
Maximum = 14.3%
12
12
5
15
10
9
Total data points = 90
Sector angle = 10°
Maximum = 16.7%
10
5
Total data points = 90
Sector angle = 10°
Maximum = 13%
Stike of joints in diabase
Strike of joints in Lockatong Arg
Dip azimuth of joints in Lockatong Arg
N
N
N
5
10
5
10
15
12
9
6
10
5
6
9
12
15
Total data points = 518
Sector angle = 10°
Maximum = 16.6%
Total data points = 28
Sector angle = 10°
Maximum = 13%
Dip azimuth of joints in diabase
10
5
Total data points = 518
Sector angle = 10°
Maximum = 13%
Strike of joints in Passaic Fm
Dip azimuth of joints in Passaic Fm
Figure 2. Rose diagrams of structural data.
3B
R
Tph
3C
Jd
Hunterdon, Mercer, and Somerset Counties, New Jersey
TRp
by
TRpg
Donald H. Monteverde, Gregory C. Herman and Scott D. Stanford
TRph
2014
Passaic Formation (Upper Triassic)—Interbedded sequence of reddish-brown to maroon and purple, fine-grained
sandstone, siltstone, shaly siltstone, silty mudstone and mudstone, separated by interbedded olive-gray, dark-gray, or
black siltstone, silty mudstone, shale and lesser silty argillite. Reddish-brown siltstone is medium- to fine-grained, thinto medium-bedded, planar to cross-bedded, micaceous, locally containing mud cracks, ripple cross-lamination, root
casts and load casts. Shaly siltstone, silty mudstone, and mudstone form rhythmically fining upward sequences up to
15 feet thick. They are fine-grained, very-thin- to thin-bedded, planar to ripple cross-laminated, fissile, locally
bioturbated, and locally contain evaporate minerals. Gray bed sequences (TRpg) are medium- to fine-grained, thin- to
medium-bedded, planar to cross-bedded siltstone and silty mudstone. Gray to black mudstone, shale and argillite are
laminated to thin-bedded, and commonly grade upwards into desiccated purple to reddish-brown siltstone to
mudstone. Thickness of gray bed sequences ranges from less than 1 foot to several feet thick. Where possible,
individual members of Olsen and others (1996) have been identified. Thick thermally metamorphosed sections (TRph)
exist on both flanks of Sourland Mountain. Unit is approximately 11,000 feet thick in the map area.
R
Tph
Jd
CORRELATION OF MAP UNITS
location of
photo 3B
Surficial Units
Qal
Qalb
ift
dr
Holocene
Qcal
Qaf
Qst
Jd
Qcs
Qcd
late Pleistocene
Qe
R
Tph
lars
Met
ton
ngs
Livi
-1000
Jd
TRp
ie
kas
Per
Hopewell Fault
Sourland Mountain
1000
Sea Level
ic
han
-1000
TRl
Nes
Jd
TRs
Jd
-2000
-2000
TRph
TRp
TRlh
TRl
-3000
TRs
Surficial units not shown on section
R
Tph
Tpg
R
R
Tp
3A
R
Tlh
Triassic
TR l
-4000
Figure 3. Photographic montage of the Neshanic Copper Mine looking north along the western contact of the western dike. (A) dike dips gently west and pinches out at a
slight angle into west-dipping red mudstone. (B) Copper carbonate ore resides in hornfels beneath the sheet and (C) along shear zones. Historical documents describe
early mine activity that predates the American Revolutionary War.
Unconformity
PMu
PMu
-4000
shaft
Intrusive contact
R
Ts
TRp
TRp
-3000
TRph
TRp
TRlh
Jd
Jd
Jurassic
TRp
TRlh
EE
TRp
Mercer County
N.J. Route 31
Sea Level
early PleistocenePliocene?
Bedrock Units
NEWARK BASIN
A’
Elevation in feet
Elevation in feet
1000
Qps
ift
A
middle Pleistocene
dr
Hunterdon County
R
Tph
erosion
Pre-Mesozoic