Question

How would a geologist identify where an igneous rock was formed? A. If it has coarse grains, then it cooled slowly on the surface of the earth. If it has fine grains, then it cooled rapidly beneath the earth's surface. B. If it has coarse grains, then it cooled rapidly on the surface of the earth. If it has fine grains, then it cooled slowly beneath the earth's surface. C. If it has coarse grains, then it cooled rapidly beneath the surface of the earth. If it has fine grains, then it cooled slowly on the earth's surface. D. If it has coarse grains, then it cooled slowly beneath the surface of the earth. If it has fine grains, then it cooled rapidly on the earth's surface.

Answer 1

D. If it has coarse grains, then it cooled slowly beneath the surface of the Earth. If it has fine grains, then it cooled rapidly on the Earth's surface.

Step-by-step explanation:

The easiest way for a geologist to identify where the igneous rocks have formed is to look at their grains. There's two types of igneous rocks, intrusive and extrusive. The intrusive igneous rocks have formed from the magma that has cooled off slowly deeper into the crust, thus their crystals had more time to grown, and they have coarse grains. The extrusive igneous rocks have formed from the lava that has cooled off quickly on the surface, thus their crystals had very little time to grow, so they have fine grains.