Shiloh Marl Member of the Kirkwood Formation

Clay, massive, dark-gray with abundant large mollusks. Unit subcrops near the Delaware River where the overlying Wildwood Member and Cohansey Formation have been stripped away. The Shiloh Marl Member averages about 30 m (98 ft) thick. Diatoms recovered from the Shiloh from the ACGS-4 corehole 5.3 km (3.2 mi) northwest of Mays Landing, Atlantic County, contain the diagnostic diatom Actinoptychus heliopelta (Andrews, 1987) indicating an early Miocene age. Strontium-isotope analysis of shells yielded an age of 20 Ma (Burdigalian) (Sugarman and others, 1993).
State New Jersey
Name Shiloh Marl Member of the Kirkwood Formation
Geologic age lower Miocene, lower Burdigalian
Lithologic constituents
Unconsolidated > Fine-detrital > ClayClay, massive, dark-gray with abundant large mollusks.
Comments part of the Kirkwood Formation (described seperately, but not mapped): Kirkwood Formation (middle and lower Miocene, Serravallian to Aquitanian) - Consists of the Wildwood Member and an informal lower member on the central sheet and the Belleplain Member, Wildwood Member, Shiloh Marl Member, and lower member on the southern sheet. The Belleplain Member is a new member named for beds occurring in a corehole drilled by the U.S. Geological Survey at Belleplain State Forest Headquarters, Cape May County. The Wildwood Member is a new member named for beds occurring in a drillhole at Wildwood Beach, Cape May County.

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.

Owens, James P., Sugarman, Peter J., Sohl, Norman F., Parker, Ronald A., Houghton, Hugh F., Volkert, Richard A., Drake, Avery A., Jr., and Orndorff, Randall C., 1998, Bedrock Geologic Map of Central and Southern New Jersey: U.S. Geological Survey Miscellaneous Investigations Series Map I-2540-B, 8 cross sections, 4 sheets, each size 58x41, scale 1:100,000.

Sugarman, P.J., Miller, K.G., Owens, J.P., and Feigenson, M.D., 1993, Strontium isotope and sequence stratigraphy of the Miocene Kirkwood Formation, southern New Jersey: Geological Society of America Bulletin, v. 105, no. 4, p. 423-436.

Andrews, G.W., 1987, Miocene marine diatoms from the Kirkwood Formation, Atlantic County, New Jersey: U.S. Geological Survey Bulletin 1769, 14 p.

NGMDB product
Counties Cumberland - Salem