1. The Cenozoic Era The Modern World Emerges Tectonics
Earth History GEOL 2110
The Cenozoic Era
The Modern World Emerges
Tectonics

2. 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

3. Summary of the Cenozoic
PEOMPP

4. Early Cenozoic (66-40 Ma) Paleocene - Mid-Eocene
Laramide Orogeny
Block uplift of the Precambrian basement

5. Laramide Orogeny Magmatic Null Zone – Shallow Slab Subduction

6. Sedimentation in Laramide Intermontane BasinsBH PR WR GR U
Coal Seams in the Powder River Basin, WY
Lacustrine Shales of the Green River Basin, UT
Lacustrine Shales Marls Bryce Canyon NP, UT

7. 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)

8. Middle Cenozoic (40-20 Ma) San Juan Volcanic Field
La Garita Caldera (28Ma)
San Luis Tuff, Wheeler Geologic Monument

9. Middle Cenozoic (40-20 Ma) Burial and Exhumation of the Laramide Mountains
Laramide Mtns Exhumed
66Ma
35 Ma
Laramide Mtns Re-Buried
Laramide Orogeny
Post- Laramide Orogeny
57 Ma
Laramide Mtns Buried
15 Ma
Laramide Mtns Re-Exhumed
50 Ma

10. Laramide Sediments and Volcanic Ash Spreads across the Great Plains
Eocene – Oligocene fluvial sediments of the White River Group,
Badlands, SD

11. 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

12. Basin and Range Province Extensional Thinning of the Crust
Sevier Deformation
Listric Normal Faults

13. Basin and Range Province Extensional Thinning of the Crust

14. Basin and Range Province Extensional Thinning of the Crust
Extension due to mantle upwelling in area of Slab Gap

15. 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.

16. 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)

17. Uplift of the Colorado Plateau Rejuvenation of Mature Rivers
Mantle
Upwelling?
Pliocene (~5 Ma)

18. Columbia River Basalts, Snake River Basalts, and the Yellowstone Hotspot
Edge of Craton
NA Drift
Yellowstone
Newberry

19. Mantle Plume-Generated Volcanism
Columbia River Basalts
Yellowstone Hydrothermal Field
Newberry Rhyolite

20. Present-Day Tectonic Picture

21. Pacific Plate Tectonics

22. Passive Margins East and South
Erosion of North America – River and Deltaic Deposits
Triassic-sourced Halite Deposits
Pangea Break-up – Shallow Marine Deposits

23. Passive Margins East and South
Rejuvenation of the Appalachians

24. The Closing of the Tethys Sea

25. 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

26. Tectonics of East Asia

27. Next Lecture The Cenozoic The Modern World Emerges Climate and Life Quiz on Chapter 15