Setters Formation

The Setters Formation is a geological formation that is located in Maryland, Pennsylvania, and Delaware in the United States. The formation is metamorphic and consists of a complex suite of schist, gneiss, and quartzite.^[1]

Setters Formation
Stratigraphic range: late Precambrian
Outcrop of Setters Formation along Marriottsville Road, Baltimore County
Type	metamorphic
Unit of	Glenarm Group
Underlies	Cockeysville Marble
Overlies	Baltimore Gneiss
Lithology
Primary	Mica-schist
Other	Muscovite-gneiss and quartzite
Location
Region	Piedmont of eastern North America
Country	United States
Extent	Maryland, Pennsylvania, Delaware

It is the lowest unit of the Glenarm Group (or Supergroup).^[2] The overlying formations of the group are the Cockeysville Marble and the Wissahickon Formation.

Outcrops

Some outcrops listed by the USGS^[2] are:

• Setters Ridge, which forms north front of Chattolanee anticline, Baltimore County, Maryland.
• Quarries in Avondale, Pennsylvania.
• Eastburn's quarry, New Castle County, Delaware.

Gallery

• 
  Setters Formation showing schist with tourmaline or hornblende crystals on the foliation plane