Metamorphic rocks are unique for the fact that they are created when existing rocks are heated and pressurized within the surface of the Earth to create a new substance. These rocks always form from other types of rocks and include slate and marble as popular products that are used. Here are some interesting facts to help you get to know metamorphic rocks a little better.
1. Layer Upon Layer
Metamorphic rocks are often formed because the heat from the magma and pressure from the depths combine to peel off layers of existing rocks to create new layers of a new rock. This is even true when considering a thin metamorphic rock like slate. The layering gives the rock added strength, which gives us many different opportunities to use them, from roofing to kitchen counters.
2. Get Your Chalk On
Metamorphic rocks aren’t always just formed by one type of base rock. Marble, for example, is made from the combination of limestone and chalk. Even though marble is strong, what makes it a unique rock is that it can actually be dissolved because of its core components. All it takes is some acidic products, such as lemon juice.
3. A Fossil Fuel
One of the most useful metamorphic rocks that we have today is called anthracite. This rock is a form of coal that is different that other coal that is burned for power. Anthracite has a higher carbon count, but fewer impurities, so that its luster is greater. That shine makes it burn longer so more power can be created from it.
4. What Fossils?
We often look to the fossil record to determine the history of our planet. The fossil record can’t be 100% accurate, however, because rocks that contain them do not survive independently of the metamorphic process. Fossils are effectively erased as a new rock is formed, eliminating the historical information in the process.
5. Check Your Faults
Unique metamorphic rocks can be formed along planetary fault lines because of the tremendous pressures that exist there. Heat may or may not be involved with this process. The pressures are so strong, in fact, that even single mineral rocks can be metamorphic and changed into new substances over time.
Metamorphic rocks are unique, special, and useful. The Taj Mahal is even 100% constructed from this material and you use them every day. Remember that fact and you’ll get to know metamorphic rocks a little bit more.