USGS Home
Contact USGS
Search USGS

Mineral Resources > Online Spatial Data > Geology > by state > Pennsylvania Geology

Geologic units in Bradford county, Pennsylvania

Wiscoy Formation (Upper Devonian) at surface, covers < 0.1 % of this area

Wiscoy Formation - sandstone, shale; Hanover and Pipe Creek Shales.

Lithology: sandstone; black shale; shale

Huntley Mountain Formation (Mississippian and Devonian) at surface, covers 7 % of this area

Huntley Mountain Formation - Greenish-gray and light-olive-gray, flaggy, fine-grained sandstone, siltstone, and a few red shale interbeds; includes lower "Pocono" plus "Oswayo" of earlier workers. Forms transition between Catskill Formation and Burgoon Sandstone.

Lithology: sandstone; siltstone; shale

Upper Walton Formation (Upper Devonian) at surface, covers < 0.1 % of this area

Upper Walton Formation - shale, sandstone, conglomerate.

Lithology: shale; sandstone; conglomerate

Catskill Formation (Devonian) at surface, covers 30 % of this area

Catskill Formation - Grayish-red sandstone, siltstone, shale, and mudstone; locally conglomeratic; contains gray sandstone in upper part; lithologies arranged in fining-upward cycles; equivalent to the Hampshire Formation south of Pennsylvania.

Lithology: sandstone; siltstone; shale; mudstone; conglomerate

Gardeau Formation (Upper Devonian) at surface, covers < 0.1 % of this area

Gardeau Formation - shale, siltstone; Roricks Glen Shale.

Lithology: shale; siltstone

Lock Haven Formation (Devonian) at surface, covers 58 % of this area

Lock Haven Formation - Interbedded olive-gray mudstone, siltstone, sandstone, and thin conglomerate; marine fossils throughout; "Chemung" of earlier workers. Laterally equivalent to Scherr and Foreknobs Formations.

Lithology: mudstone; siltstone; sandstone; conglomerate

Nunda Formation, West Hill Formation (Upper Devonian) at surface, covers < 0.1 % of this area

Nunda Formation, West Hill Formation - Nunda: sandstone, shale; West Hill: shale, siltstone; Corning Shale.

Lithology: sandstone; shale; siltstone

Pottsville Formation (Pennsylvanian) at surface, covers 2 % of this area

Pottsville Formation - Predominantly gray sandstone and conglomerate; also contains thin beds of shale, claystone, limestone, and coal; includes Olean and Sharon conglomerates of northwestern Pennsylvania; thin marine limestones present in Beaver, Lawrence, and Mercer Counties; minable coals and commercially valuable high-alumina clays present locally.

Lithology: sandstone; conglomerate; shale; siltstone; claystone; limestone; coal

Burgoon Sandstone (Mississippian) at surface, covers 3 % of this area

Burgoon Sandstone - Buff, medium-grained, crossbedded sandstone; includes shale and coal; in places, contains conglomerate at base; contains plant fossils; equivalent to Pocono Formation of Ridge and Valley province.

Lithology: sandstone; conglomerate; shale; coal

Allegheny and Pottsville Formations, undivided (Pennsylvanian) at surface, covers 0.4 % of this area

Allegheny and Pottsville Formations, undivided - Sandstone, shale, and some coal; includes lower Pottsville conglomerate and overlying strata equivalent to Allegheny Formation in north-central outliers; formational boundary not determined due to lack of correlation with Brookville-Clarion coal.

Lithology: sandstone; shale; conglomerate; coal