Continental Scale Landscape Analysis:
Landforms occur in patterns across the surface of the globe, and these landform complexes often define geographic or landscape regions. One way of looking at landforms is through elevation changes. A contour map is a useful two-dimensional representation of the surface and the most common way we have of symbolizing the relief of the surface. However, a type of map called a “shaded relief” map provides a more intuitive grasp of elevation.
Another way to understand landform regions or landscapes is to use a map that displays information about the geology. In the study of landforms, an understanding to the subsurface geology is critical. Understanding a geologic map requires a rough understanding of geologic time. A geologic map has the following properties:
- It recognizes similarities and differences among materials that make up the Earth’s crust and classifies them by type of rock or surficial deposit;
- It places Earth materials into a specific environment or origin- for example, a volcano, river deposit, windblown dune, limestone reef, alteration at depth by heat or pressure;
- It identifies rock formations of distinctive materials and ages that are the three-dimensional building blocks of the Earth’s crust; it further shows the relative position of one formation to another at the Earth’s surface;
- It arranges rock formations of different ages into a time sequence from which the geologic history of the planet can be deciphered.
For this lab we will address the following questions: Can we use a map of elevation (and rock age) to identify large-scale patterns in the landscape? What are the physiographic characteristics of North America?