Giant's Causeway cases the horizontal fracture has resulted in a bottom face that is convex while the upper face of the lower segment is concave, producing what are called "ball and socket" joints. The size of the columns is primarily determined by the speed at which lava from a volcanic eruption cools. The extensive fracture network produced the distinctive columns seen today. The basalts were originally part of a great volcanic plateau called the Thulean Plateau which formed during the Paleocene. According to legend, the columns are the remains of a causeway built by a giant. The story goes that the Irish
Cave S Cave S Cave S is a limestone cave in the British Overseas Territory of Gibraltar. It is located on the eastern side of the Rock of Gibraltar, near Holy Boy's Cave. Human remains were found in the cave in 1910 that did not appear to be of a modern man. Captain Sewell discovered what is now known as Cave S or Sewell's Cave. Sewell also gave his name to Sewell's Fig Tree Caves which are now known as Goat's Hair Twin Caves. Sir Charles Warren carried out a survey of Gibraltar in 1864 which recorded the cave as being above