Plate Boundaries and California Chapter 5

The Big Idea California is located on a plate boundary, where major geologic events occur. Lesson 1: Interactions at Plate Boundaries There are three main types of plate boundaries, where stresses cause rocks to deform. Lesson 2: California Geology Many of California’s landforms were produced by plate tectonic activity, which continues today.

Lesson 1: Interactions at Plate Boundaries There are three main types of plate boundaries where stresses cause rocks to deform. What you’ll learn: Describe types of stress that deform rock. Relate geologic features of Earth’s surface to types of plate boundaries. So What?! Understanding geologic events that occur at plate boundaries can save lives and prevent damage to property.

Review Vocabulary Lithospheric Plate: Large, brittle pieces of Earth’s outer shell composed of crust and uppermost mantle.

New Vocabulary Long, narrow valley formed as the hanging wall of a divergent boundary slips down. rift valley Fracture in which rocks on one side of the fracture move relative to rocks on the other side. fault Divergent P.B. Boundary formed where plates move apart Transform P.B. Boundary formed when two plates move sideways past each other.

New Vocabulary fracture Break or crack in rock continental rifting Process that pulls apart a continent. Convergent P.B. Boundary formed when two plates move toward each other.

Academic Vocabulary Sloping, slanting, or leaning relative to the horizontal or vertical inclined The Leaning Tower of Pisa inclines about 3.99 degrees. In other words, the top of the tower is displaced horizontally 12 ft 10 in from where it would be if the structure were perfectly vertical.

Rocks are pushed together; makes rock layer thick. Drifting Continents Types of Rock Stress Tension Compression Shear Rocks are pulled apart; causes stretching and thinning of the lithosphere. Rocks are pushed in opposite directions; neither thickens nor thins lithosphere Rocks are pushed together; makes rock layer thick.

3 Main types of Faults Normal Fault Reverse Fault Strike-Slip Fault Click on the types of faults for a link to http://science.howstuffworks.com/nature/natural-disasters/earthquake3.htm. It includes animations of the three different types of faults from “How Stuff Works.”

Rephrase the main ideas of this section in your own words. Summarize It Rephrase the main ideas of this section in your own words.

Types of Plate Boundaries Sequence the events that occur during continental rifting. A continent splits apart at a divergent plate boundary. Tension stress causes rocks to break and form normal faults. The hanging wall slips down and forms a rift valley.

Types of Plate Boundaries Distinguish 3 types of convergent plate boundaries. Describe what happens at each type of boundary. Ocean-to-Ocean Ocean-to-Continent Continent-to-Continent Colder, denser slab is forced down, forming a trench; water is released and melts rocks, forming magma. Denser ocean plate always sinks below continental plate; melting forms a string of volcanoes along edge of continent. Compression forces force crust to rise, forming tall mountains.

Types of Plate Boundaries Complete this paragraph about transform plate boundaries. At transform plate boundaries, plates ______________________________. In the ocean, these boundaries connect ________________________. On the continents, _________________ can occur along these boundaries. Move sideways past each other pieces of mid-ocean ridges large earthquakes

Summarize three (3) main ideas of the above sections. Summarize It! Summarize three (3) main ideas of the above sections.

Lesson 2: Plate Boundaries and California Many of California’s landforms were produced by plate tectonic activity, which continues today. What you’ll learn: Describe California’s current plate tectonic setting and how plate movements have produced landforms. Predict future changes in California’s tectonic setting and topography. So What?! Interactions between the North American Plate and the Pacific Plate produce California’s mountains and basins and cause earthquakes and volcanoes.

Review Vocabulary uplift Any process that moves Earth’s surface to a higher elevation. uplift

New Vocabulary San Andreas Fault The S.A.F. is a transform boundary (and a strike-slip fault) between the N.A. Plate and the Pacific Plate. It extends all the way from Cape Mendocino in the north to the Salton Sea in the south.

* The San Andreas Fault is a boundary between two adjacent plates. Academic Vocabulary adjacent Next to or very near * The San Andreas Fault is a boundary between two adjacent plates.

Plate Tectonics in California Distinguish two plate boundaries found in California. 1. The San Andreas Fault System, a continental transform boundary cutting across the state. 2. A convergent plate boundary offshore in the northern part of the state. Click on the smaller picture for a link to a website showing a video of the seafloor spreading.

Plate Tectonics in California Identify three features of California geology caused by plate tectonics. 1. earthquakes 2. volcanoes 3. mountains

Plate Tectonics in California Create a diagram showing the San Andreas Fault.

Summarize the main ideas of the above section of the lesson. Summarize It! Summarize the main ideas of the above section of the lesson.

Plate Tectonics in California Analyze the role of a convergent plate boundary in shaping CA geology. The Gorda and Juan de Fuca plates are forced beneath the coast. Melting above the subduction zone produces the volcanic mountains in the Cascade Range.

California’s Mountains Organize information about the formation of mountains in California. Subduction A. B. II. Rifting Granite rocks formed under volcanic mountains when plates converged. An ancient oceanic plate subducted, forming rocks in several mountain ranges. Tension stresses cause continental rifting. Panamint Range rises as the crust stretches.

Future Plate Movements Summarize two changes that might occur in the future as a result of plate tectonics. The Pacific Plate will keep moving northwest, bringing Los Angeles and San Francisco closer. Death Valley and the Gulf of California are dropping and opening up as a result of tension stress.

Rephrase the main ideas of the lesson in your own words. Summarize It! Rephrase the main ideas of the lesson in your own words.