The Waynesboro Formation is a limestone, dolomite, and sandstone

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

Virginia Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the Atlantic Coast and the Appalachian Mountains. The geography and climate of the Commonwealth ar ...

Maryland Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to ...

Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...

and

West Virginia West Virginia is a state in the Appalachian, Mid-Atlantic and Southeastern regions of the United States.The Census Bureau and the Association of American Geographers classify West Virginia as part of the Southern United States while the Bur ...

. In some areas it is composed of limestone and dolomite. The Waynsboro Formation is one of the formations that make up the

Shenandoah Valley The Shenandoah Valley () is a geographic valley and cultural region of western Virginia and the Eastern Panhandle of West Virginia. The valley is bounded to the east by the Blue Ridge Mountains, to the west by the eastern front of the Ridge- ...

. It dates back to the

Cambrian The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...

period and is not considered fossiliferous.

Description

The Waynesboro Formation is a predominantly limestone, dolomite, and sandstone formation that is found along the valley floor of the Shenandoah Valley. It can also contain sometimes large beds of siltstone and shale. The Waynesboro is often covered by gravel washes from surrounding mountains or by weathered debris from the formation itself, making finding outcrops for study difficult. The formation is thought to represent a shallow marine depositional environment. It was called the Watuga shale in parts of Virginia, but the name was abandoned in favor of the already established Waynesboro Formation. The Waynesboro Formation contains poorly preserved fossils of the brachiopod

Lingulella ''Lingulella'' is a genus of phosphatic-shelled brachiopod. It is known from the Middle Cambrian Burgess Shale (Canada) to the Upper Ordovician Bromide Formation (United States) in North America.Amsden, T.W. Catalogue of Fossils from the Middle a ...

and the trilobite Ptychoparia

Members

The Waynesboro Formation was recognized as having three members in Virginia, Maryland, and Pennsylvania. These members were later named the Red Run Member, the Cavetown Member, and the Chewsville Member. The Red Run Member is named after Red Run Creek near the Maryland-Pennsylvania state boundary, and forms the basal member of the formation. It consists of calcareous sandstone, sandy dolomite, and calcareous shale. Good exposures of the Cavetown Member are rare, but the member consists of limestone and dolomite with

bioturbation Bioturbation is defined as the reworking of soils and sediments by animals or plants. It includes burrowing, ingestion, and defecation of sediment grains. Bioturbating activities have a profound effect on the environment and are thought to be a pr ...

with some interbedded sandstone. The youngest member of the Waynesboro Formation is the Chewsville Member, which is named after Chewsville, Maryland. It is composed of interbedded siltstone, sandstone, and shale and is considered the most distinctive member of the formation.

References

Generalized Stratigraphic Chart for West Virginia
Cambrian West Virginia {{WestVirginia-geologic-formation-stub