Transcript No Slide Title

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
• 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/re
search/data/seiswus/examp
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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_boo
ks/resedu/resedu2a.htm
Colorado Plateau
Colorado Plateau
– Paleozoic
rocks exposed
in the Grand
Canyon,
Arizona
– Mesozoic sedimentary rocks in
the Valley of the Gods, Utah
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
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Gulf-Coastal-Plain Deposition
• Cenozoic Deposition on the Gulf Coastal Plain
– 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?
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
The Last Glacial Maximum