|Geologic age||Late Devonian|
Sedimentary > Clastic > Mudstone > Shale > Black-shale (Bed)
|Comments||First published use in Atoka quad, Johnston and Atoka Cos, OK, South Oklahoma folded belt and Ouachita tectonic belt provinces. Intent to name not stated; probably named for town of Woodford, Carter Co, OK. No type locality designated. Exposed in northwestern part of Atoka quad. Forms low ridges and hills, Composed of thin strata of dark chert, cherty shale, and black, fissile, bituminous shale aggregating 500-700 ft in thickness. Is variable as to thickness and position of beds. Locally, chert makes up large part of the formation; elsewhere it is largely siliceous black shale. Concretions of flint found near base. Some cherty beds approach siliceous limestone. (Taff, 1902).|
Heran, W.D., Green, G. and Stoeser, D.B., 2003, A Digital Geologic Map Database of Oklahoma: USGS Open File Report 03-247, scale 1:250,000.
Hart, D.L., 1974, Reconnaissance of the water resources of the Ardmore and Sherman quadrangles, southern Oklahoma: Oklahoma Geological Survey, Hydrologic Atlas 3, scale 1:250,000, 4 sheets. (Geology on sheet 1 compiled by D.L. Hart, and R.O. Fay, in 1970.)
Cederstrand, J.R., 1996a, Digital geologic map of Ardmore-Sherman quadrangles, south-central Oklahoma: U.S. Geological Survey Open-File Report 96-370, (3 diskettes), URL address is: http://ok.water.usgs.gov/gis/geology
|Counties||Atoka - Bryan - Carter - Coal - Garvin - Grady - Johnston - Love - McClain - Marshall - Murray - Pontotoc - Stephens|