Geology of Ireland Geology of Ireland The geology of Ireland consists of the study of the rock formations in Ireland. The island contains rocks from every age from Proterozoic to Holocene and a large variety of different rock types is represented. The basalt columns of the Giant's Causeway together with geologically significant sections of the adjacent coast have been declared a World Heritage Site. The geological detail follows the major events in Ireland's past based on the geological timescale. The oldest known Irish rock is about 1.7 billion years old and is found on Inishtrahull Island off the north coast of Ulster. Outcrops
Big Bone Cave Big Bone Cave (Big) Bone Cave is a cave located in Van Buren County, Tennessee, in the community of Bone Cave that is named after it. It is notable both for its history and current recreational use. It is listed on the National Register of Historic Places and a designated National Natural Landmark. It is a State Natural Area managed by Rock Island State Park. It is named for the discovery of the bones of a giant ground sloth in 1811. The cave was operated as a saltpeter mine, notably during the War of 1812 and the American Civil War.