Asymmetric anticline in Big Penn slate quarry. Slatedale, PA.
The slate is mined by cutting it with cables and carborundum (the curved lines). The slate is then polished on rotating tables, again using carborundum as the abrasive. The best pieces are used for pool tables, but most is now used for ornamental paving.
PhotoID321
Asymmetric anticline in Big Penn slate quarry. Slatedale, PA.
The slate is mined by cutting it with cables and carborundum (the curved lines). The slate is then polished on rotating tables, again using carborundum as the abrasive. The best pieces are used for pool tables, but most is now used for ornamental paving.
PhotoID321
Photograph: Jim Talbot