Continental Drift Evidence Fossils Matching Mountain Ranges Glacier

Continental Drift

Evidence: Fossils

Matching Mountain Ranges

Glacier Evidence

A new hope: Sea-Floor Spreading MID-ATLANTIC RIDGE 50, 000 km. Long mountain range on the ocean floor

Sea-Floor Spreading is a Divergent Plate Boundary Creates New Crust

OCEAN CRUST - CONTINENTAL CRUST SUBDUCTION – TRENCH FORMS

Oceanic-Continental Convergent Boundary - SUBDUCTION DENSER OCEANIC CRUST GOES DOWN INTO MANTLE

Oceanic-Continental Convergent Boundary - SUBDUCTION DENSER OCEANIC CRUST GOES DOWN INTO MANTLE

OCEAN CRUST –OCEAN CRUST CONVERGENCE - SUBDUCTION

Continental Crust – Continental Crust Convergent Boundary NO SUBDUCTION - COLLISION ZONE

Collision of India and Asia

TRANSFORM PLATE BOUNDARIES Transform Fault Boundaries u At a transform fault boundary, plates grind past each other without creating or destroying the lithosphere. u SHALLOW EARTHQUAKES Transform faults • Most join two segments of a mid-ocean ridge. • At the time of formation, they roughly parallel the direction of plate movement.

Boundaries: Transform

SAN ANDREAS TRANSFORM FAULT

SUMMARY 3 PLATE BOUNDARIES q DIVERGING q CONVERGING (SUBDUCTION ZONE) Oceanic Crust – Continental Crust Oceanic Crust - Oceanic Crust q CONVERGING (COLLISION ZONE) Continental Crust – Continental Crust q TRANSFORM

Convection Currents in the mantle drag and pull the lithospheric plates above them

More Evidence for Plate Tectonics Hot Spots • A hot spot is a concentration of heat in the mantle capable of producing magma, which rises to Earth’s surface; The Pacific plate moves over a hot spot, producing the Hawaiian Islands. • Hot spot evidence supports that the plates move over the Earth’s surface.

Hot Spot