Our Earth

Not only are our cities and almost every product we use derived from the ground, so is almost all our energy. Yet minerals and petroleum products are only the start. Every culture has wondered about the origin and nature of the earth and geology offers a rich and cautionary explanation.

Rocks are complicated collections of mineral particles. Four silicate mineral groups make up 90% of the crustal rocks - mafic minerals, quartzes, feldspars and micas. Rocks come in three basic varieties - igneous, sedimentary and metamorphic. These are the ingredients of the rock cycle.

The forces of sun, wind and water have changed the face of earth just as much as tectonics. Weathering and erosion are driven by gravity, flattening the landscape. They create soil. Deposition starts the process of forming sedimentary rock.