Geology of Ireland longest known free-hanging stalactites. 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
Cave-in-Rock State Park Cave-in-Rock State Park Cave-In-Rock State Park is an Illinois state park, on 240 acres, in the town of Cave-in-Rock, Hardin County, Illinois in the United States. The state park contains the historic Cave-In-Rock, a landmark of the Ohio River. It is maintained by the Illinois Department of Natural Resources (IDNR). Cave-in-Rock's primary feature is a striking -wide riverside cave formed by wind and water erosion and cataclysmic effects of the 1811–12 New Madrid earthquakes at Cave-in-Rock State Park , just upriver from the village. The Cave-in-Rock was worn into the limestone bluffs of the Ohio River by floods, especially during