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
Fingal Head, New South Wales a rocky uninhabited island first charted by James Cook in 1770. The stretch of water to the island is called the "Giants Causeway", named after the famous Giants Causeway between Northern Ireland and Western Scotland. Cook Island was made a marine reserve in 1998 and as such fishing is prohibited in the waters nearby. There has been controversy over the naming of Fingal Head by James Cook in May 1770 for many years. Strong evidence suggests that Fingal Head was, in fact, the point James Cook named Point Danger. In 1823, John Oxley took shelter from Southerly winds, while sailing