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Cenozoic -The development of the Earth as we know it today. At only 66 million years long, the Cenozoic is only 1.4% of all geologic time. Age of Ocean Basins Is Well Constrained. The Circum-Pacific Orogenic Belt. Geological Provinces of the U.S. The North American Cordillera.
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Cenozoic -The development of the Earth as we know it today • At only 66 million years long, • the Cenozoic is only 1.4% of all geologic time
The North American Cordillera • The North American Cordillera is one large segment of the circum-Pacific orogenic belt extending from Alaska to central Mexico • In the United States it widens to 1200 km, stretching east-west from the eastern flank of the Rocky Mountains to the Pacific Ocean
Cordilleran Mobile Belt Antler Orogeny in Devonian
Change from Subduction • As the North American Plate overrode the Pacific–Farallon Ridge, its margin became transform faults • the San Andreas • and the Queen Charlotte • alternating with subduction zones
Plate Interactions Continue http://earth.geol.ksu.edu/sgao/research/data/seiswus/example1.gif
The Laramide Orogeny • Most active in Late Cretaceous to Eocene • Formation of the Rockies
Cascade Range • Some of the highest mountains in the Cordillera are the Cascades • California, Oregon, Washington, British Columbia • Thousands of volcanic vents are present • dozen large volcanoes • Lassen Peak in California • world's largest lava dome • Related to subduction of the Juan de Fuca plate http://www.cr.nps.gov/history/online_books/resedu/resedu2a.htm
Colorado Plateau • Mesozoic sedimentary rocks in the Valley of the Gods, Utah • Paleozoic rocks exposed in the Grand Canyon, Arizona
The Continental Interior • A vast area called the Interior Lowlands • the Great Plains • and the Central Lowlands
The Southern and Eastern Continental Margins • The Atlantic Coastal Plain and the Gulf Coastal Plain form a continuous belt from the Northeastern United States to Texas
Coastal Plain Similarities • Both areas have horizontal or gently seaward-dipping strata deposited mostly on land or in shallow water them • Seaward of the coastal plains lie the continental shelf, slope and rise, which are areas of notable Mesozoic and Cenozoic deposition http://www.missgeo.com/directors%20-%20mail.htm
Gulf-Coastal-Plain Deposition • Depositional provinces and surface geology • Cenozoic Deposition on the Gulf Coastal Plain Cross section showing seaward thickening O strata
Global climate of the Cenozoic was controlled by plate motions, and associated changes in ocean circulation, and by glaciation in Antarcitca
The Ice Volume Record for the Cenozoic • Isotope record records ocean temperature and ice volume • Eustatic record derived from seismic stratigraphic studies • When did glaciation begin?
Pleistocene Fluctuations You Are Here! Northern Hemisphere Glaciation Cyclicity
Closing of the Isthmus of Panama • Shut off E/W global ocean flow American plates collided ~ 3.5 Ma
This may have resulted in glaciation in the northern hemisphere Caribbean warms Gulf Stream moves warm water north Increases ocean evaporation and precipitation on land