Geology: Metamorphic Rocks

Geology: Metamorphic Rocks

Want to know how metamorphic rock is made? In this film geology expert, Matt Genge, will explain the basics of metamorphic rocks, and show you with beautiful pictures and diagrams how they're created.

Step 1: How is metamorphic rock made?

Metamorphic rock is made from igneous or sedimentary rock which has been changed by pressure or temperature.

Step 2: Rock metamorphosed by pressure

An example of this is slate, which is used on the roofs of many houses. This rock forms under high pressure, but relatively low temperature. The pressure from the layers of earth above it causes the minerals in the rock to rotate around, changing the structure of the rock.

Step 3: Rock metamorphosed by heat

An example of this is quartzite. It is formed from sandstone, which gets baked by the heat from nearby magmas. The heat causes the quartz crystals in the sandstone to get bigger, and grow into each other. This creates the hard, crystalline rock quartzite.