• At only 66 million years long, – the

Cenozoic is only 1.4% of all geologic time

Cenozoic -The development of the Earth as we know it today

Age of Ocean Basins Is Well Constrained

The Circum-Pacific Orogenic Belt

Geological Provinces of the U.S

• 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

The North American Cordillera

Cordilleran Mobile Belt

Antler Orogeny in Devonian

• 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

Change from Subduction

Plate Interactions Continue

http://earth.geol.ksu.edu/sgao/research/data/

seiswus/example1.gif

• Most active in Late Cretaceous to Eocene

• Formation of the Rockies

The Laramide Orogeny

• 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

Cascade Range

http://www.cr.nps.gov/history/online_books/resedu/resedu2a.htm

Colorado Plateau

– Paleozoic rocks exposed in the Grand Canyon, Arizona

Colorado Plateau

– Mesozoic sedimentary rocks in the Valley of the Gods, Utah

• A vast area called the Interior Lowlands

– the Great Plains

– and the Central Lowlands

The Continental Interior

• The Atlantic Coastal Plain and the Gulf Coastal Plain form a continuous belt from the Northeastern United States to Texas

The Southern and Eastern Continental Margins

• 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

Coastal Plain Similarities

http://www.missgeo.com/directors%20-%20mail.htm

• Cenozoic Deposition on the Gulf Coastal Plain

Gulf-Coastal-Plain Deposition

– Depositional provinces and surface geology

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?

Northern Hemisphere Glaciation Cyclicity

You Are Here!

Pleistocene Fluctuations

• Shut off E/W global ocean flow

American plates collided ~ 3.5 Ma

Closing of the Isthmus of Panama

Caribbean warms

Gulf Stream moves warm water north

Increases ocean evaporation and precipitation on land

This may have resulted in glaciation in the northern hemisphere

The Last Glacial Maximum