Plate Tectonics

What evidence did Wegener use to estimate the time of Pangea's break up?

• magnetic isochrons

• coal deposits

• ocean floor topography

• fossil data

What is the name of Alfred Wegener's hypothesis about moving landmasses?

• continental movement

• plate tectonics

• continental drift

• seafloor spreading

What was the one reason that Wegener's hypothesis of continental drift was rejected?

• He could not explain what was moving the continents

• He could not support the idea that climates of certain landmasses had been different

• He could not support that the continents were once adjacent

• He could not explain where the continents had moved

What type of information was NOT collected by Wegener to support his continental drift hypothesis?

• fossils

• seafloor magnetic data

• rocks

• glacial deposits

Why did Wegener think that the Antarctic continent had been closer to the equator in the geological past?

• Deep sea trenches were found near the equator

• Natural gas deposits in North America suggested it was closer ot the equator at one time

• Coal beds were found to exist near the equator

• Rivers run towards the equator proving Wegener's belief that the continents were once close to the equator

Harry Hess' theory of _____ explained how ocean crust is generated and destoryed

• continental drift

• continental movement

• seafloor spreading

• plate tectonics

_____ is a device that can detect changes in the strenght of the magnetic fields

• GPS

• Sonar

• Magnetometer

• satellite

Places where two tectonic plates are moving away from each other are called

• convergent boundries

• divergent boundries

• earthquake boundries

• transform boundries

What is the process called when one plate is forced beneath another at a convergent plate boundry?

• transformation

• subduction

• convergence

• subtraction

When a divergent plate boundry forms on continents, a _____ forms

• crater

• volcano

• mid-continent ridge

• rift valley