|Geologic age||Lower to Middle Devonian|
|Comments||part of Onondaga Limestone and Ulster Group 100-500 ft. (30-150 m) Second part of description from USGS Lexicon website (ref. NY046) and reference NY017: Middle Devonian Onondaga of NY represents broad, carbonate platform facies deposited during early to middle Eifelian time. Carbonates are characterized by calcarenitic to cherty to argillaceous limestones and minor shales deposited in a shallow epicontinental sea. The Selinsgrove Limestone Member of the Needmore Formation of central PA is the direct equivalent of the Onondaga Limestone in NY. The Onondaga is generally subdivided into four members across NY: Edgecliff, Nedrow, Moorehouse, and Seneca. These four members are directly equivalent to those of the Buttermilk Falls Limestone of eastern PA. The Clarence Member has been recognized only in western NY and is here designated a local informal facies of the Edgecliff. The informal Jamesville Quarry facies of the Edgecliff is also named in this report for the chert-poor, crinoidal pack- and grainstone that occurs at the Edgecliff type locality. Several marker beds within the Nedrow Member are recognized and the upper boundary with the Moorehouse Member is redefined. The Moorehouse contains several fossil horizons and the Seneca contains several bentonite beds, including the Tioga B or Onondaga Indian Nation Bentonite, which defines its base. The Lower-Middle Devonian (Emsian-Eifelian) boundary, long placed at the base of the Onondaga in NY, could lie as high as the base of the Nedrow Member according to Kirchgasser and Oliver (1993), as there are no age diagnostic fossils in the Edgecliff (Brett and Ver Straeten, 1994). Named the Onondaga limestone in PA, NY, western MD, VA, and WV for Onondaga Co., PA. Also called gray crinoidal limestone. Consists of gray or grayish-blue compact crystalline limestone. Overlies the Oriskany sandstone and underlies the Seneca limestone. Named the Schoharie grit for Schoharie, Schoharie Co., eastern NY. Consists of calcareous fine-grained sandstone that is readily recognized by peculiar mineral characters and fossils. Overlies the CAUDA-GALLI grit (Esopus grit) and underlies the Onondaga limestone. Carlisle Center formation is buff to brown, sandy shale with top 6 in. being a greenish, glauconitic, sandy shale. Base of unit marked by local glauconite bed. Thickness is 5 to 45 ft. Overlies Esopus formation; underlies Springfield Center Member (new) of Onondaga formation. Age is Early or Middle Devonian. Named the Esopus shales for Esopus, Ulster Co., eastern NY. Unit also occurs in northern NJ and northeastern PA. Term Esopus shales replaces CAUDA-GALLI grit. Consists mainly of fine-grained, dark gray arenaceous rock with well developed slaty cleavage. West of Schoharie, unit is moderately hard, dark gray or buff to light olive sandy shale. Unit thickness to east and south; thickness in Albany Co. is 110 feet and in Ulster Co., 200 to 300 feet. The Esopus is of Early Devonian age.|
|Primary rock type||shale|
|Secondary rock type||limestone|
|Other rock types||siltstone|
Sedimentary > Clastic > Mudstone > Shale
Sedimentary > Carbonate > Limestone
Sedimentary > Clastic > Siltstone
NYS Museum, NYS Geological Survey, NYS Museum Technology Center, 1999, 1:250,000 Bedrock geology of NYS, data is distributed in ARC/INFOr EXPORT format (with ".e00" extension) in 5 seperate files based on printed map sheets, http://www.nysm.nysed.gov/gis.html.
D. W. Fisher; Y. W. Isachsen, L. V. Rickard, 1970, Geologic Map of New York State, consisting of 5 sheets: Niagara, Finger Lakes, Hudson-Mohawk, Adirondack, and Lower Hudson, New York State Museum and Science Service, Map and Chart Series No. 15, scale 1:250000.
|Counties||Albany - Columbia - Greene - Herkimer - Oneida - Orange - Otsego - Schoharie - Sullivan - Ulster|