Igneous Rocks
5 questions tagged Igneous Rocks — spanning every one of the seven Ws.
Why does granite form deep underground?
Granite forms deep underground because magma cools slowly inside the crust, giving crystals time to grow. Slow cooling produces the coarse-grained texture typical of granite.
What is a batholith?
A batholith is a huge mass of intrusive igneous rock that crystallized deep underground. It is usually larger than 100 square kilometers at the surface exposure.
What is a dike in geology?
A geological dike is a sheet of igneous rock that cuts across older rocks after magma fills a crack and cools.
What is a sill in geology?
A sill is a sheet of igneous rock that intrudes between older rock layers and cools parallel to them.
Whose classification of igneous rocks introduced the idea of fractional crystallization?
Norman L. Bowen is credited with that idea through his work on the Bowen reaction series. He showed how minerals crystallize from cooling magma in a predictable order.