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Middle Mississippian Paleogeography of North America
Paleogeography and Geologic Evolution of North America
Images that track the ancient landscapes of North America
Introduction
The images presented here show the paleogeography of North America over the last 550 million years of geologic history. The 40 images shown here are selected from a suite of approximately 100 maps that are in time slices mostly 5-10 million years apart. By using such tightly spaced time slices, individual paleogeographic and tectonic elements can be followed and intuitively related from time slice to adjacent time slice. Because of space limitations only 40 of the 100 images are presented here but but most shifts of tectonic elements and depositional systems can still be followed. The maps were prepared with the core of North America (Laurentia) fixed. All other tectonic elements are shown moving against or splitting away from Laurentia, thus showing clearly accretionary and rifting events in North America's geologic history. The views were prepared by wrapping a rectangular outline map on a sphere and viewing the globe rotated to 35� N and 100� W. Various stratigraphic, tectonic, and sedimentologic data were added to the map. Topography was "cloned" from digital elevation maps of modern Earth from the USGS, NOAA, and other sources. Colors were adjusted to portray climate and vegetation for the given time and location. The geologic data were gathered from the references listed below.