Chapter 7, Problem 1RQ

To determine

The difference of the metamorphic rocks from that of the igneous rocks.

Answer to Problem 1RQ

The metamorphic rocks are formed due to extreme conditions of temperature and pressure, resulting in the transformation of the texture and mineralogy of the parent rock without undergoing any melting. The igneous rocks are not transformed from any source of the rocks and have no foliation, while metamorphic rocks possess the foliation due to the compression under stress.

Explanation of Solution

The igneous rocks are formed when the molten magma or lava consolidates completely. When rocks are exposed to the surface, they undergo the process of weathering, erosion, transportation, and deposition followed by compaction giving rise to sedimentary rocks. When any types of rocks get buried deep inside the earth, they are subjected to high pressure, temperature, and volatile conditions. This process changes the texture in rocks and yield of some new minerals which are formed under these conditions only. Thus, these formed rocks are known as metamorphic rocks.