GENERAL GEOLOGY

Detailed explanation-1: -Some of the magma may feed volcanoes on the Earth’s surface, but most remains trapped below, where it cools very slowly over many thousands or millions of years until it solidifies.

Detailed explanation-2: -Intrusive igneous rocks form inside (below the surface) of the Earth. The cooling rate of intrusive rocks tends to be very slow because they are insulated by surrounding rocks. This slow rate of cooling leads to larger crystal grains because the crystals have time to grow.

Detailed explanation-3: -Intrusive igneous rocks cool from magma slowly in the crust. They have large crystals. Extrusive igneous rocks cool from lava rapidly at the surface.

Detailed explanation-4: -Intrusive igneous rocks cool from magma slowly because they are buried beneath the surface, so they have large crystals. Extrusive igneous rocks cool from lava rapidly because they form at the surface, so they have small crystals. Texture reflects how an igneous rock formed.

Detailed explanation-5: -Intrusive igneous rocks form when the magma comes from deep underground and is forced into the upper layers of the Earth’s crust, where it cools slowly. Extrusive igneous rocks form when the magma erupts from a volcano and cools quickly on the ground.