Question

Which factors control the cooling time of magma within the crust?

Answer 1

Answer:

The depth of the intrusion,

the shape and size of a magma body

Explanation:

The depth of the intrusion, the shape and size of a magma body: the greater the surface area for a given volume of intrusion, the faster it cools, and the presence of circulating ground water: water passing through magma absorbs and carries away heat

Answer 2

Answer:

• Depth of the intrusion.

• The shape and size of the magma body

• Presence of groundwater

Explanation:

The depth of the intrusion, the shape and size of a magma body: the greater the surface area for a given volume of intrusion, the faster it cools, and the presence of circulating ground water: water passing through magma absorbs and carries away heat.

As the rate of cooling increases, crystal size decreases. This means that something which cools very quickly will have smaller crystal formations, and something which cools slowly will have larger crystal formations. This is easily seen in igneous rock, which may cool at variable rates.