Graywacke

Full definition of graywacke

Noun

1. Alternative form of greywacke
• 2007, December 12, Anthony Depalma, An Island in the Hudson, Plundered in Search of Indian Artifacts, Hundreds of projectile points and ceramic pieces from the island are stored in the State Museum in Albany, and archaeologists found human bones at a burial site from the early Woodland period at the back of the rock shelter, a 45-foot-long overhang of graywacke, a local sandstone.