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Earth History
GEOL 2110
The Cenozoic Era
The Modern World Emerges
Tectonics
Major Concepts
• The volcanic null that corresponded with the Laramide
Orogeny starting in the late Cretaceous ended in the late
Eocene epoch (~40Ma) with the resumption of arc
magmatism along the western margin of NA
• Starting in the Miocene (~20Ma), the collision of the East
Pacific Rise created a transform boundary between the
Pacific and NA plates; this brought on the Basin and
Range-style extension tectonics, the uplift of the
Colorado Plateau, the creation of the Rio Grande Rift, and
shift in the motion of the Pacific plate
• The collision of India and various microcontinents spalled
from Gondwana’s break-up closed the Tethy’s Sea and
created the Alpine-Himalayan orogenic belt
Summary of the Cenozoic
PEOMPP
Early Cenozoic (66-40 Ma)
Paleocene - Mid-Eocene
Laramide
Orogeny
Block uplift
of the
Precambrian
basement
Laramide Orogeny
Magmatic Null Zone – Shallow Slab Subduction
Sedimentation in Laramide
Intermontane Basins
BH
WR
PR
GR
U
Coal Seams in the Powder River Basin, WY
Lacustrine Shales Marls Bryce Canyon NP, UT
Lacustrine Shales of the Green River Basin, UT
Middle Cenozoic (40-20 Ma)
Late Eocene – Oligocene – Mid-Miocene
Resumption
of continental
volcanic arc
magmatism as
subduction of
the Farallon
Plate steepens
Tectonics during the
Oligocene (~30 Ma)
Middle Cenozoic (40-20 Ma)
San Juan Volcanic Field
La Garita Caldera (28Ma)
San Luis Tuff, Wheeler Geologic Monument
Middle Cenozoic (40-20 Ma)
Burial and Exhumation of the Laramide Mountains
66Ma
35 Ma
Laramide Mtns Re-Buried
57 Ma
Laramide Mtns Buried
50 Ma
15 Ma
Laramide Mtns Re-Exhumed
Post- Laramide Orogeny
Laramide Orogeny
Laramide Mtns Exhumed
Laramide Sediments and Volcanic Ash
Spreads across the Great Plains
Eocene –
Oligocene fluvial
sediments of the
White River
Group,
Badlands, SD
Late Cenozoic (20-0 Ma)
Mid-Miocene – Pliocene –Pleistocene - Holocene
Mid-Miocene (~15 Ma)
Pliocene (~5 Ma)
Collision of East Pacific Rise with NA plate creates the San Andreas
Transform Fault System, Basin and Range Province, Colorado Plateau
and Rio Grand Rift
Basin and Range Province
Extensional Thinning of the Crust
Sevier Deformation
Listric Normal Faults
Basin and Range Province
Extensional Thinning of the Crust
Basin and Range Province
Extensional Thinning of the Crust
Extension due to
mantle upwelling in
area of Slab Gap
Basin and Range Province
Extensional Thinning of the Crust
As the SA transform boundary grows, Basin and Range Extension
migrates to the North. Establishment of rift zone in the Gulf of
California kills extension in the southern Basin and Range.
The Slicing and Dicing of California
Narrow fault –bound basins
rapidly fill with great thickness of
sediment that are simultaneously
deformed (e.g., Ventura Basin)
Pliocene (~5 Ma)
Uplift of the Colorado Plateau
Rejuvenation of Mature Rivers
Mantle
Upwelling?
Pliocene (~5 Ma)
Columbia River Basalts, Snake River
Basalts, and the Yellowstone Hotspot
Edge of
Craton
Yellowstone
Newberry
Mantle Plume-Generated Volcanism
Columbia River Basalts
Yellowstone Hydrothermal Field
Newberry Rhyolite
Present-Day Tectonic Picture
Pacific Plate Tectonics
Passive Margins East and South
Erosion of North America – River and Deltaic Deposits
Triassic-sourced Halite Deposits
Pangea Break-up – Shallow Marine Deposits
Passive Margins East and South
Rejuvenation of the Appalachians
The
Closing of
the Tethys
Sea
25 Ma
The Closing of
the Tethys Sea
5-6 Ma
Mediteranean Dries
Up -Evaporites
4 Ma
Straits of Gibraltar
open up
Tectonics of East Asia
Next Lecture
The Cenozoic
The Modern World Emerges
Climate and Life
Quiz on Chapter 15