cenozoic mammals and the modern world. cenozoic 65-0 myr
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Cenozoic
Mammals and the Modern World
Era Age (Myrs) Epoch
0.01Holocene
1.8Pleistocene
5.3Pliocene
23.8Miocene
33.6Oligocene
54.8Eocene
65Paleocene
144
206
248
290
323
354
417
443
490
543
2500
3800
Precambrian
Phanerozoic
Eon
Proterozoic
Archean
Hadean
Period
Quaternary
Tertiary
Neogene
Paleocene
Mississippian
Cenozoic
Mesozoic
Paleozoic
Cretaceous
Jurassic
Age of the Earth 4600 Myrs (4.6 Byrs)Source: Geological Society of America (1999)
Geologic Time Scale
Devonian
Silurian
Ordivician
Cambrian
Triassic
Permian
Pennsylvanian
Cenozoic
65-0 Myr
Highlights of the Cenozoic:Geology
1. Continents move into their current configurations. (Western NA remains active.)
2. Tethys Sea closes with the Alpine/Himalayan Orogeny.
3. Minor sea level fluctuations4. Temperature peaks in the Eocene
and drops through the Pliocene/Pleistocene Ice Age.
Highlights of the Cenozoic:
Life1. Mammals and angiosperms
(including grasses) diversify and dominate.
2. Mammals return to the sea.3. Two minor mass extinctions -
Eocene and Pleistocene/Holocene.4. Humans appear in the Pliocene
and by the late Holocene become a “geologic force”.
Cenozoic Geology
Late Cretaceous
Early Eocene
Late Eocene
Early Miocene
Late Miocene
Separation of
Antarctica&
Climate
Alpine/Himalayan Orogeny & the Closing
of the Tethys Sea
The Rise and Fallof the Western US
Subduction to San Andreas
Laramide Orogeny to Basin and Range
Subduction of the
Farallon Plate:
Origin of the San Andreas
Fault and the Gulf of California
Subduction of a
Spreading Ridge
The Laramide Orogeny(Rocky Mountains)
The Basin and Range
The Basin and Range
Curiosities: The Grand Canyon
<5 Myr Old!
Curiosities: Yellowstone
Curiosities: The Olympics
Curiosities:
Chesapeake Bay
Late Eocene
Curiosities: Central America
Central American Land Bridge
Climate - Hot
to Cold
Sea Level
Fluctuations
Transgression Regression
The Pliocene/Pleistocene
Ice Age
The Final
Ice Age
What Causes Ice Ages?
1. Position of the Continents• Changes to Ocean Currents• Closer o Poles
2. Orogenies / Uplift of Land Surface• Changes in air circulation• Increased erosion
3. Changes in Greenhouse Gases
Glacial Cycles within an Ice Age
What Cause
s Cycles?
Some Effects of the Ice
Changing Ecosystems