Tectonic History of Western North America and Southern California - B2

High quality: http://www.youtube.com/watch?v=VM_IyR5QX9o&fmt=18

An Animated Tectonic History of Western North America and Southern California.
Tanya Atwater, Dept. Geological Sciences, University of California, Santa Barbara, CA

Summary list of QuickTime animations:

A.Pacific-North America Plate Tectonic History (map views)
1. Pacific Hemisphere, 80 Ma to Present
2. N.E. Pacific and W. North America, 38 Ma to Present
3. California, 20 Ma to Present
4. Southern California, 20 Ma to Present
5. Southern California Paleomagnetic Vectors
6. Southern California, Origin and Dispersal of the Poway Conglomerate

B.Geologic History of the Transverse Ranges, Southern California
1. Mesozoic Subduction
2. Miocene: Rifting and rotation, volcanism and deposition in marine basins
3. Plio-Pleistocene: Oblique Shortening against the "Big Bend"
4. Santa Barbara Channel Oil

B.2. Miocene: Rifting and rotation, volcanism, crustal upwelling and deposition in marine basins
When the Pacific Plate began scraping against North America, the Transverse Ranges block broke off and twirled around.
The stretching thinned the crust, drawing lavas and lower crustal rocks up to fill the gap. The Santa Monica mountains and parts of the offshore Channel Islands are made of the lavas from these volcanoes. Conejo Mountain, near Oxnard is the throat of an old volcano.
The stretching broke the continental shelf into many marine basins, very rich living places for marine life. These basins formed excellent habitats for microscopic floating plants called diatoms,.and the diatoms were food for swarms of tiny shrimp, and these, in turn, were scooped up by whales.
The pastey looking rocks that form many of our sea cliffs started out as a pile of microscopic skeletons from these diatoms. The organic parts of the diatoms slowly decayed to form natural gas, oil and tar. Fossil whale bones form the stones on some of our beaches.

Category:

Science & Technology

Tags:

• Tanya Atwater
• geology
• plate
• tectonics
• paleomagnetism
• baja
• california
• santa barbara
• pacific
• north
• northern
• america
• Farallon plate
• pacific plate
• north american plate
• triple junction
• Juan de Fuca plate