seafloor age, Ma

Seafloor bathymetry

East Pacific Rise moving into North America

Terrane accretion

Suspect terranes along western North America

Interaction of East Pacific Rise and Western North America

• See Tanya Atwater’s plate reconstructions

• As before, you need Quicktime to run this file. You can also download the file; it’s big, over 15 mb

Western North American Transform system

This is a mercator projection with the pole of the projection = pole or relative motion between the Pacific and North American Plates

Black areas = magmatic extrusives; lines = faultsdouble lines = segment of oceanic spreading ridges

American Plate

Pacific Plate

Gulf of California

Rio Grande Rift

Basin and Range

Sierra Nevada batholith

Idaho batholithSnake River plain (Yellowstone hot spot track)

Remnant of Farallon Plate

Colorado

Plateau

San Andreas Fault

Cascadia vocanic arc

Shaded, 90m DEM

Transverse Ranges

Sierra Nevada

Great Valley

San Andreas Fault system

Basin and Range

Colorado Plateau

San Andreas transform system

San Andreas-Hayward- Caleveras system in region of San Francisco

San Andreas system in Southern California in the region of Los Angeles

Rotating blocks in Southern California

Rotating blocks in Southern California

Paleomagnetic declinations

Transverse Ranges formed by rotations

Oligocene

Miocene-Pliocene

Transverse Ranges formed by rotations

Present

transpression and transtension

crustal shortening: mountains

crustal thinning:

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zone