GEOL 102 Historical Geology

Spring Semester 2011
The Cenozoic Era II: Neogene Geology

Paleogeography and Geology of the Neogene:
Continued Himalayan Orogeny (especially 20 Ma onward) lifts Himalayan Plateau:

Northward migration of Africa blocks off entrance to greatly reduced western Tethys (aka Mediterranean): Messinian salinity crisis:

Isthmus of Panama forms around 3 Ma: allows direct land-to-land connection between North and South America (see below), and blocks Atlantic-Pacific water interchange. Beginning of deep-sea Oceanic Conveyer Belt, isolating Arctic Ocean and beginning of northern polar ice.

In eastern North America, shallow water deposits including Chesapeake Group (Miocene). Erosion of Appalachian system causes pulses of isostatic uplift (at least three pulses), producing modern Appalachian Mountains out of fold-and-thrust belt.

Western North America has an extremely complex Neogene geological history:

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Last modified: 10 March 2011