South Mountain, Adams County, Pennsylvania, United States, North America
Accession Date:
29 Dec 2016
Collection Date:
Not given
Notes:
L-1563 (South Mountain Metarhyolite): Provenience includes prehistoric quarry. Collection from archaeological context. Known collection procedure. Collection includes raw material, outer surface, archaeological specimens, and naturally-weathered specimens.
L-1563 (South Mountain Metarhyolite)
South Mountain Metarhyolite is also known as Catoctin, Caledonia, Caledonia Rhyolite, Gettysburg Rhyolite, South Mountain, or South Mountain Rhyolite. It is a blue, blue banded, or red/lavender metarhyolite. It can be mottled with black bands, streaks, or patches 1-4 cm wide. There is insignificant color change when heat-treated. When weathered some types develop a patina, others do not. It has multicolored phenocrysts of quartz and feldspar. It has a coarse to fine grained texture. Deposits include outcrops of bedrock, boulder fields often associated with outcrops or without them, streambed cobbles, and terrace deposits.
Location remarks: Blue Ridge province of Maryland and Pennsylvania; Ten locations of South Mountain Metarhyolite are listed on page 7 by Stewart (1984); Cashtown Gap, Franklin Township, Adams County, PA.
Archaeology remarks: South Mountain Rhyolite was used during the Early Archaic through the late Woodland times.