Exam 2: Plate Tectonics: A Unifying Theory

Why are hot spots considered useful for determining the absolute motions of plates?

Briefly explain the mechanism of convective heat transfer.

Why are convergent plate boundaries strongly associated with geological disasters?

What happens at oceanic-continental convergent plate boundary?

Hot spots are locations on Earth where new divergent plate boundaries are beginning to form.

Why was the Glossopteris flora on Gondwana continents considered evidence for continental drift?

New evidence from seafloor exploration and paleomagnetism provide such overwhelming evidence for tectonic plate movement that plate tectonic theory is accepted without a driving mechanism.

What happens when two continents converge?

The currently accepted hypothesis for the driving mechanism of plate tectonics is based on

What evidence was there that the northern continents were once joined and located along the equator?

Who proposed the hypothesis of sea-floor spreading?

Magnetic minerals in similar age rocks from Europe and North America point to different magnetic pole locations indicating that the pole is variable and migrates over time.

Give an example of a long, narrow sea which has formed over a divergent boundary, as a result of continental rifting.

Briefly explain the "ridge-push-slab-pull"mechanism which has been proposed to drive plate motions.

What presently accepted piece of evidence for continental drift/plate tectonics was first observed at least as early as 1620?

An acceptable hypothesis concerning the driving mechanism of plate tectonics must explain

Beside his hypothesis of continental drift, Frank Taylor (1910) correctly proposed that

In the thermal convection model, each plate corresponds to a single convection cell.

According to the supercontinent cycle hypothesis, approximately how long is the cycle during which supercontinents form, break up, and reform?

The maximum age for oceanic crust is___________ million years.