Paleogeography and Geologic History
The chart below shows all colors and symbols used on the tectonic maps.
Chart showing all colors and symbols used on tectonic maps
The two map below compare Jurassic and Present terrane distribution
Map showing present distribution of terranes
Map showing general Jurassic distribution of terranes (modified from Saleeby and Busby-Spera, 1992)
The following paleogeographic and tectonic maps and accompaning text summarize our understanding of the Mesozoic geologic history of Western North America.
Early Jurassic (180Ma)
Middle Jurassic (160Ma)
Late Jurassic (145Ma)
Early Cretaceous (125Ma)
Late Early Cretaceous (105Ma)
Late Cretaceous (85Ma)
Tertiary - Cretaceous (65Ma)