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
Gellért Hill Cave the chapel reopened on 27 August 1989 with the destruction of the thick concrete wall that had sealed the cave. By 1992, the Chapel had been restored and the Pauline Order had returned to the cave. Today, the monks continue to perform religious functions within, though the cave is also a common tourist attraction. The church is complemented by a mysterious monastery carved into the rock and decorated with striking neo-gothic turrets. The walls of the cave are formed of all-natural living rock. The church features many rooms, worthy of attention is the one in which all the ornaments have