Unique geologic structure
left by previous strip mining
showing tight folding. Note
the group of students at right
center on top of the anticline.

Older (Pre-Surface Mining Act)
anthracite coal mining along the
exposed limb of a syncline

Folded beds exposed in highwall in limestone quarry near Nazareth, Northampton County

Folds produce complex geology exposed in limestone quarry highwall near Nazareth, Northampton County.

Recumbent folds and overturned strata exposed in a limestone/dolomite quarry in Whitehall, Lehigh County.

Recumbent folds and overturned strata exposed in a limestone/dolomite quarry in Whitehall, Lehigh County.

Sinkhole formation in Berks County quarry; likely formed as a result of a clay seam shrinking due to the drought and then being flushed by heavy rains.