Igneous rock the partial melting of rocks within the mantle and crust. Extrusive igneous rocks cool and solidify quicker than intrusive igneous rocks. They are formed by the cooling of molten magma on the earth's surface. The magma, which is brought to the surface through fissures or volcanic eruptions, solidifies at a faster rate. Hence such rocks are smooth, crystalline and fine-grained. Basalt is a common extrusive igneous rock and forms lava flows, lava sheets and lava plateaus. Some kinds of basalt solidify to form long polygonal columns. The Giant's Causeway in Antrim, Northern Ireland is an example. The molten rock, with
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