GEOLOGICAL DEVELOPMENT OF NORTH AMERICA

In the 1980’s I was teaching a course titled “Geological Development of North America” at George Mason University in Fairfax, Virginia, using the text by Philip King on “The Evolution of North America” (1977). I taught about regional geology, the geologic time scale and the geologic development of North America.

In class, I reviewed in greater detail the geologic and geomorphologic development of each physiographic region of North America. The students extracted data from state geologic maps to construct cross-sections spanning two or more states. In the cross-sections students had to include the thickness of the crust, the structural geology, sedimentary and stratigraphic information, and historical information. I asked the students to use their state geologic map to study the area and be able to describe the geological development of the area. It was a challenging project. Plotting the surface data on a cross-section is a simple transfer of data, but interpreting the subsurface geometry is very difficult, requiring a synthesis of data and processes.

The exercise demonstrated that the students were able to take the principles of geologic history and structural and surface development to create final cross-sections that reflected a relatively accurate interpretation of their states. While this assignment was done years ago, the exercise would still be relevant today.