Conestoga Formation

The Conestoga Formation is a geologic formation in Pennsylvania.

Conestoga Formation
Stratigraphic range: Middle Cambrian to Early Ordovician
Thick-bedded crystalline limestone passing into finely laminated slaty limestone typical of the Conestoga, in quarry 1 mile northwest of Bellemont.
Type	sedimentary, metamorphic
Overlies	Vintage Dolomite
Lithology
Primary	limestone
Other	phyllite, conglomerate
Location
Region	Pennsylvania
Country	United States
Type section
Named by	Knopf and Jonas (1923)

Folded micaceous marble of Conestoga Formation, in a quarry a half-mile northwest of Quarryville

Basal Conestoga (slate and limestone conglomerate), unconformably overlying Vintage Dolomite, Bellemont Quarry

Description

Light-gray, thin-bedded, impure, contorted limestone having shale partings; conglomeratic at base; in Chester Valley, includes micaceous limestone in upper part, phyllite in middle, and alternating dolomite and limestone in lower part.^[1]

Type section

Named from outcrops along Conestoga River, Lancaster County, Pennsylvania.

References

1. Conestoga Formation, USGS Mineral Resources On-Line Spatial Data