A fault is a fracture in the Earth's crust along which the rocks on either side have undergone significant relative displacement. Large-scale fracture structures are also commonly referred to as fractures or fault zones.
The ozone hole refers to a phenomenon in which halogenated hydrocarbons and other anthropogenic pollutants enter the stratosphere, where—through photochemical reactions and catalytic decomposition—ozone is massively depleted, causing total ozone column values to fall significantly below normal levels.
Sedimentary rocks make up about 75% of all rocks exposed on the Earth’s surface. They also are the result of change, but they form at or near the Earth’s surface, which makes them very different than metamorphic rocks.
Metamorphic rocks are the masters of change! Because of intense heat and pressure deep within the earth, these rocks have undergone a total transformation from their original form.
Joints are simply cracks in rocks, a type of fracture structure where rock splits without obvious shifting of rock masses on either side of the crack.
Granite is a common and widespread igneous rock on Earth. It forms when magma originating deep in the crust or upper mantle intrudes into the middle-upper crust and cools slowly and crystallizes. It is therefore also called intrusive rock. Its formation depth is usually 5–30 km below the Earth’s surface, so it is also classified as a plutonic rock.
