Plate Tec Evidence

Evidence for Plate Evidence for Plate TectonicsTectonics

The Old Stuff andThe Old Stuff and

The New StuffThe New Stuff

Wegener’s EvidenceWegener’s Evidence

The Old StuffThe Old Stuff

Puzzle Fit ContinentsPuzzle Fit Continents

Mesosaurus FossilsMesosaurus Fossils

Mountain Range EvidenceMountain Range Evidence

Problem with Wegener’s StuffProblem with Wegener’s Stuff

New Evidence for New Evidence for Plate TectonicsPlate Tectonics

The New StuffThe New Stuff

Earthquake DataEarthquake Data

Hot SpotsHot Spots

Ocean DrillingOcean Drilling

Location Age of Rocks

Ridge Crests Youngest

Continental Margins 180 mya

Continental Crust 4.0 bya

Mantle ConvectionMantle ConvectionConvergent Divergent

Downward

Upward Arm

Slab Pull

Ridge Push

Seafloor SpreadingSeafloor Spreading

The seafloor contracts and sinks.

Crust spreads along an ocean ridge and magma fills the gap that is created.

Hot magma, which is less dense than the surrounding material, is forced toward the crust.

New seafloor moves away from the ridge, cools and becomes more dense than the material beneath it.

New seafloor forms as the magma hardens.

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Do you believe in Plate Do you believe in Plate Tectonics?Tectonics?