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
Geological history of the Chiricahua Mountains hundreds of thousands of years of weathering and erosion. The hoodoos originated from a thick deposit of tuff laid down by the Turkey Creek Caldera. As the tuff cooled, it contracted and formed joints. Differential chemical and physical weathering concentrated along these joints, initiating the formation of thousands of rock columns. Balanced rocks that perch, sometimes precariously, on top of many of the hoodoos are a distinctive feature of the monument. Geological history of the Chiricahua Mountains The Geologic history of the Chiricahua Mountains concerns the Chiricahua Mountains, an inactive volcanic range located in Coronado National Forest of southeastern Arizona,