- Relating geologic features in Tennessee to ancient tectonic events -
||Alfred Wegener proposed the theory of continental drift in his 1915
manuscript entitled "The Origin of Continents and Oceans." Although many
of his insights were correct, Wegener's theory fell short of explaining
how and why Earth's continents would "drift".
Today continental drift has been superceded by the much more scientifically fruitful theory of plate tectonics. However, one of the main precepts of continental drift -- the supercontinent Pangaea (Gr. "all lands") -- is still considered an important aspect of Earth history and a subject of continued scientific research.
During much of the Permian Period (290-248 million years ago [mya]) Pangaea included all of Earth's major land masses. The resulting world ocean is called Panthalassa, or "all seas." In a sense, the formation of Pangaea began with the breakup of the previous supercontinent -- Rodina -- in the Late Precambrian to Early Ordovician Period (~ 610-470 mya).
The assembly of Pangaea occurred over more than 400 million years (Ma). Assembly was accompanied by considerable upheaval of the Earth's crust along the eastern seaboard of the North American continent -- including earthquakes, volcanic eruptions, transgressions and regressons of the coastline, and multiple episodes of mountain building. Although sea level was periodically rising and falling, much of the time shallow, tropical seas covered what is now Tennessee, and it lay south of the equator.
These events left their mark on Tennessee's geology and a few of the resulting features are the focus of this virtual field trip. As with any field trip, this one consists of a series of field localities, or stops. At each stop, we'll illustrate one or more "mementos of Pangaea" as well as explaining how and why they developed.
Along the way, you'll learn a bit about a variety of geologic topics, including Tennessee's landscape and bedrock geology, the behavior of subduction zones, the nature of erosion, weathering, and soil formation, and the development of karst topography. Much of the focus will be on Middle Tennessee; however, a few other areas of the state will be discussed as well.
NOTE: GEOL-1031 students should visit the assigned question set either before or after visiting the field trip stops and answer the questions as discussed in your lab manual.
Now let's get a little background info
before we begin our virtual field trip:
||(click the arrow to proceed to the Introduction)|