Question description
Introduction:
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?
Data and Methods:
You will need to:
- Download the maps
- Thelin and Pike Relief Map http://pubs.usgs.gov/imap/i2206/
- King and Beikman 1974 Geologic Map http://pubs.usgs.gov/imap/i2720/
- You can also play around with the dynamic digital version http://mrdata.usgs.gov/geology/kb.html
- Examine the maps in detail.
- Download and READ the materials that accompany the maps
- Thelin and Pike Relief Map http://pubs.usgs.gov/imap/i2206/i2206_pamphlet.pdf
- King and Beikman 1974 Relief Map http://pubs.usgs.gov/imap/i2720/i2720_pamphlet.pdf
- Finally (only after steps 1-3 are complete) Answer the questions. You will need to print an outline map to answer some of the questions. I have attached an outline map with this assignment. You may digitally edit the map instead of printing/scanning if you wish.