|Name||Trenton Group and Black River Group, undivided|
Sedimentary > Carbonate > LimestoneTrenton Group: dark, crystalline, nodular, and argillaceous limestones. Black River Group: predominantly gray aphanitic limestones, with many bioclastic streaks; siliceous in the lower part.
Sedimentary > Clastic > Mudstone > Claystone > BentoniteTrenton Group: with some metabentonite streaks
|Comments||Printed map has no indiviual description for this unit and no name, but has individual symbol and color. Only uses brackets to combine Ot and Obr. Otbr is used in digital map, so combined Ot and Obr together and called this the "Trenton Group and Black River Group, undivided". Combined thickness: Northeastern 470-1010 ft, Western 890 ft, Southeastern 665 ft.|
Cardwell, D.H., Erwin, R.B., and Woodward, H.P., 1968 (slightly revised 1986), Geologic Map of West Virginia: West Virginia Geological and Economic Survey, Map 1, East Sheet, scale 1:250,000.
|Counties||Berkeley - Jefferson - Mercer - Monroe|