Silicified Sandstone

Last Updated: April 4, 2023

Silicified sandstone, Talbort County, Maryland.

Type Silicified

Collection Location:
Native Americans utilized Miocene Silicified Fossiliferous Sandstone which occurs within Zone 2 of the Calvert Formation. Inundated outcrops are located at the mouth of the Choptank River. The dark gray sample variety came from the Choptank River, Maryland, and the light variety came from Wye River, Maryland.

When freshly flaked the silicified sandstone has a distinctive gray/blue translucent appearance. Along with fine quartz sand grains, micro-fossils and small particles of lignite occur within the matrix of the material. Dolomite, calcium carbonate, and silica seem to be the primary bonding agents which have cemented the sand grains. The silicified sandstone occurs in three forms within Zone 2: 1) internal molds of mollusks, 2) micro-fossiliferous sheets or plates, and 3) irregular clumps with dense shell lag.

Eastern Shore of Maryland.

Cultural Implications
Because the material weathers heavily, the preservation of artifacts in the archaeological record is dependent on soil chemistry, wave action, individual artifact size and mass, and age of the artifact. The earliest diagnostic artifact recognized from the material is an Early Archaic Kirk Stemmed point. As a result of preservation, earlier artifact, if made, will not be recognized, thus biasing the archaeological record. During or slightly before the Early Woodland Period the material ceases to appear in the archaeological record, probably due to the fact of sea level rise that inundated the quarry locations within Zone 2 of the Calvert Formation.


Prepared By Egloff 2008