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Warm UP. 12 / 03/ 12 Give the three sources of evidence to support the theory of Continental Drift. Tectonic Plates have boundaries. 3 Types of Boundaries Divergent boundaries Convergent boundaries Transform boundaries. DIVERGENT BOUNDARIES. Occurs where plates move apart
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Warm UP 12 / 03/ 12 Give the three sources of evidence to support the theory of Continental Drift
Tectonic Plates have boundaries 3 Types of Boundaries • Divergent boundaries • Convergent boundaries • Transform boundaries
DIVERGENT BOUNDARIES • Occurs where plates move apart • Most of these boundaries are found in the oceans
CONVERGENT BOUNDARIES • Occurs where plates push together • Can be Oceanic to Oceanic, Oceanic to Continental, and Continental to Continental
CONTINENTAL – CONTENENTAL COLLISION • Occurs where two plates carrying continental crust push together. • Both crusts are the same density. • This collision forms Mountain Ranges
Oceanic-Oceanic Subduction • Subduction – when one plate sinks under the other • This occurs where one plate with oceanic crust sinks, under another plate with oceanic crust • Forms deep ocean trenches and island arcs
Oceanic – Continental Subduction • Occurs when ocean crust sinks under continental crust • Forms deep-ocean trenches and coastal mountains
TRANSFORM BOUNDARIES • Occurs where plates scrape past each other • Occurs mostly on the sea floors near mid-ocean ridges • Example of one on land is the San Andreas Fault in California