Metamorphic rocks are igneous or sedimentary rocks that through the forces of tremendous heat and pressure present deep within the earth have morphed into a different class of rock. Metamorphic rocks are important to geologists because they provide clues on the physical and chemical conditions of the earth. These rocks can help determine when the next earthquake might occur or where the next volcanic eruption might happen.
When metamorphic rocks are exposed to high heat for long periods they break down. This breakdown can disrupt the rock cycle, which can have larger effects on the stability of the earth’s crust. By studying the changes and patterns in metamorphic rock, scientists can determine if the earth’s crust is decomposing, which is useful in predicting landslides and earthquakes.
Pressure and heat have the same overall effect on the metamorphic rock. When pressure is applied to the rock, it generates heat, and the pressure along with the added heat will cause the rock to decompose. Decomposition of the metamorphic rock based on pressure will also cause instability in the earth’s crust. Geologists studying the effects of pressure on the rocks can help determine which areas of land are safest and best suited for development and human habitation.
Metamorphic rocks have water trapped inside them. This water was present as the clay and sediment deposits were forming the rocks. When studying the composition of rock samples, geologists can determine what rock region has the highest water content and, therefore, where future wells and springs may be. Geologists can then apply pressure to the rocks in an aquifer to allow them to decompose and release the water they contain.
Metamorphic rock is the main type of rock that makes up the cone of a volcano. This type of rock is also what keeps the magma from Earth’s core from erupting. By studying metamorphic rocks, geologists can learn where and when the next volcanic eruption might occur. This is extremely important as historically, cities and even whole societies have been destroyed by a single volcanic eruption.