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 of the Winds (New York) Cave of the Winds (New York) The Cave of the Winds was a natural cave behind Bridal Veil Falls at the Niagara Falls. The cave was some high, wide and in depth. It was discovered in 1834, and originally dubbed Aeolus' Cave, after the Greek god of winds. Guided tours began officially in 1841, through Goat Island and descending down a staircase closer to the falls, into the cave. A rock fall closed the tour in 1920. It officially reopened in 1924, bringing visitors to the front of the Bridal Veil instead of behind it, on a series of decks