EVERYDAY SCIENCE

Detailed explanation-1: -Extrusive, or volcanic, igneous rock is produced when magma exits and cools above (or very near) the Earth’s surface. These are the rocks that form at erupting volcanoes and oozing fissures.

Detailed explanation-2: -Igneous rock forms when magma cools and hardens. This can happen either above or below the Earth’s surface, creating two different kinds of igneous rocks-Intrusive and Extrusive.

Detailed explanation-3: -Igneous rocks form when magma (molten rock) cools and crystallizes, either at volcanoes on the surface of the Earth or while the melted rock is still inside the crust.

Detailed explanation-4: -Lava cools to form volcanic rock as well as volcanic glass. Magma can also extrude into Earth’s atmosphere as part of a violent volcanic explosion. This magma solidifies in the air to form volcanic rock called tephra. In the atmosphere, tephra is more often called volcanic ash.

Detailed explanation-5: -Intrusive Igneous Rocks Deep in the crust, magma cools slowly. Slow cooling gives crystals a chance to grow. Intrusive igneous rocks have relatively large crystals that are easy to see. Intrusive igneous rocks are also called plutonic.