West Falls Group

West Falls Formation
West Falls Formation
Stratigraphic range: Frasnian
	Fractured concretions in Rhinestreet Shale Member of West Falls Formation
Type	Geologic Group
Sub-units	Angola Shale (NY); Nunda Sandstone (NY,PA); West Hill Formation (NY); Gardeau Formation (NY,PA); Grimes Siltstone (NY); Rhinestreet Formation (NY,PA); Walton Formation (NY); Moreland Shale (NY); Millport Shale (NY); Beers Hill Formation (NY); Slide Mountain Formation (NY); Honesdale Formation (NY);
Underlies	Java Formation
Overlies	Sonyea Group
Lithology
Primary	Shale
Other	Black shale
Location
Region	Appalachian Basin
Country	United States
Extent	Kentucky, New York, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia
Type section
Named for	West Falls, New York

The West Falls Group is a geologic group in the Appalachian Basin. It dates back to the Devonian period. Also stratigraphically equivalent to the Portage Group.