The Onondaga Indian Nation Bentonite, introduced by Conkin and Conkin (1979) in a field trip guide for the Ninth International Congress of Carboniferous Stratigraphy and Geology, is here formally presented in accordance with the North American Stratigraphic Code. The bentonite occurs in the uppermost part of the Moorehouse Member of the Onondaga Limestone, 1.9 to 2.15 ft below its contact with the Seneca Member. It is represented in the Marblehead Member of the Columbus Limestone, in Franklin Co., OH. Unit is described as an unctuous, variegated, clay approximately 0.75 ft thick at its type locality. Locally it may be a bleached biotite tuff. At other localities in OH, IN, KY, and Ontario, CAN, it is an extremely thin magenta pyroclastic deposit. It lies an average of 25 ft below the Tioga Bentonite throughout NY, from Erie to Otsego Cos. It has until recently been misidentified as the Tioga by several authors. The First and Second Cheektowaga Bentonites (new name) also occur in the Moorehouse Member of the Onondaga Limestone, several feet below the Onondaga Indian Nation Bentonite. Age is Early Devonian (Onesquethawan).

Source: GNU records (USGS DDS-6; Reston GNULEX).

Onondaga Indian Nation Bentonite (also known as Tioga B) is here placed at the base of the Seneca Member of the Onondaga Formation in central NY. Overlies the Moorehouse Member. Bed is 15 to 20 cm thick. Age is Middle Devonian (Eifelian).

Source: GNU records (USGS DDS-6; Reston GNULEX).