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.
It is the lowest unit of the Glenarm Group (or Supergroup).Setters Formation, National Geologic Map Database, Geolex — Unit Summary. Accessed 12 May 2025. The overlying formations of the group are the Cockeysville Marble and the Wissahickon Formation.
Outcrops Some outcrops listed by the USGS 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
References