Department of Environmental Conservation

D E C banner

Wiscoy Creek

Wiscoy Creek contact between underlying South Wales Formation and overlying Mills-Mills

Wiscoy Creek
Located in Allegany County
Image courtesy of Gerald Smith

Type: Creekside

Features: Type localities for the Hume and Mills-Mills Formation.
Exposure top South Wales Formation - downstream; Black shale.

Feature Type: Type Section

Reference: NYS Geological Association Field Trip Guidebook, 71st Annual Meeting 1999;
Structure and Upper Devonian Stratigraphy in the Appalachian Plateau of Allegany County,
New York State, Including the Clarendon-Linden Fault System.
For online reference please visit -

Quadrangle: Portageville

Reason for Designation: The turbiditic sandstones of the Mills-Mills formation are representative of
similar Upper Devonian sandstones that form the Elk Group oil and gas reservoirs in NY, PA, and WV.
The black shale of the Hume Formation represent the last transgressive black shale in NYS.