High Point Member

(Drake, 1991) - Medium-dark-gray, thin-bedded shale, siltstone and fine-grained sandstone, containing turbidite sequences Tbcde to Tcde of Bouma (1962). Interbedded with less abundant, light-yellowish-gray-weathering, medium-gray to medium-dark-gray, medium-grained, medium- to thick-bedded and massive, quartz- and calcareous-cemented quartz sandstone containing rip-ups of medium- to dark-gray shale and siltstone that commonly consist of Bouma (1962) turbidite sequences Tab to Ta. Restricted to northeast section of Martinsburg outcrop belt. Thermally metamorphosed near intrusive bodies. Grades along strike to the southwest into Ramseyburg Member by decrease in average grain size, absence of shale rip-ups, and lack of siliceous cement. Lower contact gradational and placed at base of lowermost thick-bedded graywacke or amalgamated graywacke containing shale rip-ups. Unit assigned to Orthograptus ruedemanni zone to Climacograptus spiniferus zone of Riva (1969, 1974) using graptolites collected by Parris and Cruikshank (1992). Thickness ranges from 0 to 1,370 m (0-4,500 ft).
State New Jersey
Name High Point Member
Geologic age Upper Ordovician
Lithologic constituents
Sedimentary > Clastic > Sandstone (Bed)fine-grained sandstone, containing turbidite sequences Tbcde to Tcde of Bouma (1962).
Sedimentary > Clastic > Mudstone > Shale (Bed)containing turbidite sequences Tbcde to Tcde of Bouma (1962)
Sedimentary > Clastic > Siltstone (Bed)containing turbidite sequences Tbcde to Tcde of Bouma (1962).
Comments Martinsburg Formation

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.


Bouma, A.H., 1962, Sedimentology of some flysch deposits; a graphic approach to facies interpretation: New York, Elsevier Publishing Co., 168 p.

Riva, John, 1969, Middle and Upper Ordovician graptolite faunas of St. Lawrence lowlands of Quebec and Anticosti Island, in Kay, Marshall, ed., North Atlantic; geology and continental drift: American Association of Petroleum Geologists Memoir 12, p. 513-556

Riva, John, 1974, A revision of some Ordovician graptolites of eastern North America: Paleontology, v.17, pt. 1, p.1-40.

Parris, D.C., and Cruikshank, K.M., 1992, Graptolite biostratigraphy of the Ordovician Martinsburg Formation in New Jersey and contiguous areas: New Jersey Geological Survey, Geological Survey Report 28, 18 p.

Drake, A.A., Jr., 1991, The High Point Member (Upper Ordovician) of the Martinsburg Formation in northern New Jersey and southeastern New York, in Drake, A.A.,Jr., ed., Contributions to New Jersey geology: U.S. Geological Survey Bulletin 1952, p. B1-B9.


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Counties Sussex