Exam 6: The Active Earth: Plate Tectonics

A geologist who studies two continental plates which are pulling apart is examining what specific type of divergent plate   boundary?

The downslope sliding of the lithosphere away from a spreading center is called a ____.

Earth's outer core is _________________.

Explain why there are matching magnetic stripes on either side of a mid-oceanic ridge.

Continental crust does not normally sink into the mantle because continental crust is of lower density than mantle material as compared to oceanic crust that is high in iron and nickel.

Explain why the chemistry of oceanic plates cause them to sink beneath continent plates at subduction zones.

Explain why two converging continental plates produces the thickest crust on Earth.

The Mid-Oceanic Ridge is elevated above surrounding seafloor because it is made of hotter and less dense lithosphere than oceanic crust farther away from the divergent boundary.

According to the supercontinent model, ____.

Some scientists suggest that future plate motions will rearrange the current configuration of continents, and form the next supercontinent near the present-day ____.

In which part of the Earth's layers would a geologist expect to find predominantly peridotite which is a rock that is denser than the basalt and granite of the crust?

The _______________ includes Earth's crust and the uppermost strong and rigid part of the mantle.

The weight of an ice sheet can cause continental lithosphere to sink due to ____.

What is a possible explanation for why the chemical composition of basalts from mid-oceanic ridges is different than those that erupt at hot spots?

Alfred Wegener theorized that Earth's continents were once joined together and later split, and drifted apart because of which of the following pieces of evidence?

If you were a geologist studying the movement of tectonic plates, you expect a plate to typically move at rates of 1 to about 16 __________ per year.

Explain how a subduction zone is impacted by a mid-oceanic ridge (MOR).

Explain how pressure makes it difficult for a rock to melt.

In which part of the lithosphere would a geologist study convection which is the weak, plastic, and partly molten uppermost portion of the mantle?

If you were a geologist looking to identify the source of volcanic magma, you would search for evidence of a what? ______________