3Anticipatory setRecall the types of movements that occur along each of the three major types of tectonic plate boundaries (chapter 4).
4standardsS 6.1.f – Students know how to explain major features of California geology in terms of plate tectonics
5The big ideaHow does plate tectonics help to explain features of California’s geology?
6Key termsBasin – a broad, bowl-shaped valley formed where the crust is bent downwardCentral Valley – the large basin in California between the Coast Ranges and the Sierra Nevada
7Read “California Geology” on page 235 of your textbook
8Plate tectonics and california The movement of the Pacific and North American plates produce California’s major geological features:FaultsVolcanoesMountain rangesBasins
9faults Faults are often found along or near the boundaries of plates The Pacific and North American plates slide past each other along the San Andreas fault
10volcanoesIn the Pacific Ocean the Juan de Fuca plate is being subducted beneath the North American plateMount Shasta and Lassen Peak in northern California are volcanoes that resulted from this process
11Mountain rangesPlate motion provides the force that pushed up California’s mountainsThe Sierra Nevada began to form several million years ago as plate movements pushed up a batholithPlate motions folded the crust to push up the northern Coast RangesThe Transverse Ranges formed as plate motions rotated a block of crust and squeezed it upward
12basinsPlate movements sometimes cause the crust to warp, or bend, downwardThe result is a basinMillions of years ago, some of California’s basins slowly sank below sea levelLater, plate motions pushed the crust above sea level again
13Check for understanding What four features of California geology does plate tectonics explain? How does the San Andreas fault help to explain why there are so many other faults in California?
14Check for understanding What four features of California geology does plate tectonics explain? The four features of California geology explain by plate tectonics are faults, volcanoes, mountain ranges, and basins. How does the San Andreas fault help to explain why there are so many other faults in California? The San Andreas fault explains the other faults in California because movement along the main fault causes rocks to be pulled and pushed by enormous forces, which cause them to break.
15Guided practiceLos Angeles lies on the Pacific plate. San Jose lies on the North American plate. How will the distance between the two cities change over millions of years?
16Guided practiceLos Angeles lies on the Pacific plate. San Jose lies on the North American plate. How will the distance between the two cities change over millions of years? Over millions of years the distance between Los Angeles and San Jose will increase as the Pacific plate moves northwest relative to the North American plate.