By the end of this chapter you should be able to:
- Diagram a cross section of the Earth's interior and describe each layer.
- Diagram the rock cycle
- Define what a mineral is and describe the major mineral families that make up most rocks.
- Describe the origin and characteristics of sedimentary, metamorphic, and igneous rocks.
- Create a diagram of intrusive igneous rock bodies.
- Compare and contrast the orders of relief.
Physical geographers recognize that to uncover the spatial relationships of earth surface phenomena they must have a good understanding of what the Earth is composed of and how it affects landscape development. Here we will review the fundamental building blocks of Earth, how they change through time, and what effects they have on Earth surface processes and form.
- 14.3: Orders of Relief
- The topography of the Earth is a product of endogenic and exogenic processes. Relief is simply the difference in elevation between two points. When the surface is relatively flat we say it has low relief. Conversely, mountainous regions have high relief. The relief features of the earth are be divided into three orders based on what created them and their size.
- 14.4: Minerals
- A mineral is a naturally occurring inorganic substance with a unique crystal structure. The physical and chemical composition of a mineral is consistent between samples. There are nearly 3000 minerals, only 20 are common, and 10 make up 90% of the minerals of the crust.
- 14.5: Rocks
- Rocks are assemblages of minerals. Unlike minerals, the composition of a particular rock type varies from sample to sample depending on the proportions of minerals contained within. A physical geographer needs a fundamental understanding of the properties and characteristic of rocks to understand the geographical variation of Earth surface features.
Thumbnail: Columnar Basalt Flows. Titon Valley, Yakima County, Washington (Courtesy USGS)