Philip Fralick, geology professor at Lakehead University in Thunder Bay, Ont., is part of an international team studying a rare Ontario rock formation to determine the origin of oxygen in the ...

Tower Rock, a limestone formation in the middle of the Mississippi River, is newly accessible by foot. The destination is now popular with tourists, the Missouri Department of Conservation said. The ...

Bare limestone rises from the shore, like the battlements of a citadel. Gulls wheel about the Black Head lighthouse, clinging to a lonely cape.

Located in the Pembrokeshire Coast National Park, the carboniferous limestone rock formation is about 80 feet (24 meters) high and 66 feet (20 meters) in length. It gets its name from the green ...

Tower Rock, a 400-million-year-old limestone formation usually surrounded by the waters of the Mississippi River, is now becoming a popular visitor destination, thanks to the river's historic low ...