Exam 2: The Way the Earth Works: Plate Tectonics

Why was the discovery of marine magnetic anomalies so important to the theory of seafloor spreading?

Transform boundaries occur most frequently along ________boundaries in order to break the ________ into segments so as to accommodate motion on a sphere.

The mid-ocean ridges are elevated above the surrounding seafloor because ________.

Under the theory of plate tectonics,the plates themselves are ________.

At transform plate boundaries,________.

Younger oceanic crust will have ________ ocean sediments,while older oceanic crust will have ________ oceanic sediments.

The image below shows a view of a typical segmented mid-ocean ridge.Which letter below marks the location of the active transform fault?

Plate tectonics theory is often referred to as the "unifying" theory in geology.Explain why plate tectonics is such an important theory to the study of Earth.

A geologist aboard a deep-sea research vessel has collected several drill cores of oceanic crust from the bottom of the ocean.The cores are collected in order from east to west along the bottom of the basin and are labeled A1,B1,C1,and D1,respectively.Core A1 has 2.88 meters (m)of clay and siliceous ooze covering 4.86 m of pillow basalt.Core B1 has 2.37 m of muddy,clayey ooze covering 3.57 m of basalt.Core C1 has 2.11 m of clay and siliceous ooze followed by 3.2 m of basalt.Core D1 has 1.87 m of siliceous ooze over 2.54 m of basalt.Which core is closest to the mid-ocean ridge?

The rate of seafloor spreading exactly matches the rate of ________.

Which of the following was NOT used as evidence for seafloor spreading?

The rate of motion of a lithospheric plate with respect to a stationary location inside Earth is termed ________ plate velocity,while the motion of a plate with respect to another is termed ________ plate velocity.

What would happen if the rate of seafloor spreading was faster than the rate of subduction?

The discovery of seafloor spreading finally provided a mechanism for ________.

Evidence that glaciers once covered an area might include ________.

According to the figure below,marine magnetic anomalies lay roughly ________ to mid-ocean ridges.

The distribution of ________ across the globe provides the primary indicator of boundaries between all tectonic plates.

Continental coastlines that occur within the interior of a tectonic plate are called ________ margins.

Limestone reefs and salt deposits are important rocks in the reconstruction of Earth's history because they ________.

The apparent tendency of the north (or south)magnetic pole to vary in position over time is termed ________.