Beekmantown Group, Upper Part

(Clarke and Schuchert, 1899) - Locally preserved upper beds are light- to medium-gray- to yellowish-gray-weathering, medium-light- to medium-gray, aphanitic to medium-grained, thin- to thick-bedded, locally laminated, slightly fetid dolomite. Medium-dark to dark-gray, fine-grained, medium-bedded, sparsely fossiliferous limestone lenses occur locally. Lower beds are medium-dark- to dark-gray, medium- to coarse-grained, mottled surface weathering, medium- to thick-bedded, strongly fetid dolomite that contains pods and lenses of dark-gray to black chert. Cauliflower-textured black chert beds of variable thickness occur locally. Gradational lower contact is placed at top of laminated to thin-bedded dolomite of the lower part (Obl) of the Beekmantown Group. Contains conodonts high in the Rossodus manitouensis zone to low zone D of the North American midcontinent province as used by Sweet and Bergstrom (1986). Upper beds are included in Epler Formation; lower beds are included in Rickenbach Dolomite of Drake and Lyttle (1985) and Drake and others (1985); entire upper part (Obu) is Ontelaunee Formation of Markewicz and Dalton (1977). Thickness ranges from 0 to 244 m (0-800 ft).
State New Jersey
Name Beekmantown Group, Upper Part
Geologic age Lower Ordovician
Lithologic constituents
Major
Sedimentary > Carbonate > Dolostone (Bed)Locally preserved upper beds are light- to medium-gray- to yellowish-gray-weathering, medium-light- to medium-gray, aphanitic to medium-grained, thin- to thick-bedded, locally laminated, slightly fetid dolomite. Lower beds are medium-dark- to dark-gray, medium- to coarse-grained, mottled surface weathering, medium- to thick-bedded, strongly fetid dolomite.
Minor
Sedimentary > Carbonate > Limestone (Lens)Medium-dark to dark-gray, fine-grained, medium-bedded, sparsely fossiliferous limestone lenses occur locally.
Comments Kittatinny Supergroup (Lower Ordovician and Cambrian) (Drake and Lyttle, 1980)
References

Dalton, R.F., Herman, G.C., Monteverde, D.H., Pristas, R.S., Sugarman, P.J., and Volkert, R.A., 1999, New Jersey Department of Environmental Protection, Bedrock Geology and Topographic Base Maps of New Jersey: New Jersey Geological Survey CD Series CD 00-1; ARC/INFO (v. 7.1), scale 1:100,000.

Drake, Avery A. Jr.,Volkert, Richard, A., Monteverde, Donald H., Herman, Gregory C., Houghton,Hugh F., Parker, Ronald A., and Dalton, Richard F., 1996, Bedrock Geologic Map of Northern New Jersey: U.S. Geological Survey Miscellanenous Investigations Map I-2540-A, 4 cross sections, 2 sheets, size 56x40; 58x41, scale 1:100.000.

https://pubs.er.usgs.gov/publication/i2540A

Clarke, J.M., and Schuchert, Charles, 1899, The nomenclature of the New York series of geological formations: Science, new series, v. 10, p. 874-878.

Drake, A.A., Jr., and Lyttle, P.T., 1980, Alleghanian thrust faults in the Kittatinny Valley, 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: Newark, N.J., Rutgers University Press, p. 92-114.

Sweet, W.C., and Bergstrom, S.M., 1986, Conodonts and biostratigraphic correlation: Annual Review of Earth and Planetary Science, v. 14, p. 85-112.

Drake, A.A., Jr., and Lyttle, P.T., 1985, Geologic map of the Blairstown quadrangle, Warren County, New Jersey: U.S. Geological Survey Geologic Quadrangle Map GQ-1585, scale 1:24,000.

https://pubs.er.usgs.gov/publication/gq1585

Drake, A.A., Jr., Kastelic, R.L., Jr., and Lyttle, P.T., 1985, Geologic map of the eastern parts of the Belvidere and Portland Quadrangles, Warren County, New Jersey: U.S. Geological Survey Miscellaneous Investigations Series Map I-1530, scale 1:24,000.

https://pubs.er.usgs.gov/publication/i1530

Markewicz, F.J., and Dalton, Richard, 1977, Stratigraphy and applied geology of the lower Paleozoic carbonates in northwestern New Jersey, in Markewicz, F.J., Dalton, Richard, Spink, Walter, Metsger, Robert, and Lucey, Carol, Stratigraphy and applied geology of the lower Paleozoic carbonates in northwestern New Jersey, 42nd annual field conference of Pennsylvania Geologists, guidebook: Harrisburg, Pa., p. 1-37.

NGMDB product
Counties Hunterdon - Morris - Sussex - Warren