GLG 114 Module 3A Quiz

What statement most accurately describes the theory of seafloor spreading?

Oceanic crust continuously forms at mid-oceanic ridges, moves away from these ridges by seafloor spreading, and is consumed at subduction zones.

_______ was a short lived hypothesis stating that the magnetic north pole moved around rather than the continental plates moving?

Polar wandering

During the 19th century, Geologist thought the Earth was cooling, and shrinking, so mountains formed through a process called _____.

contractionism

What are the three major types of plate boundaries?

convergent, divergent, and transform

Mantle plumes and hot spots help geologists ____.

determine both direction and rate of plate movement

If the continents were once joined together, rocks and mountain ranges on the margins of each should have ____.

formed under the same conditions and in the same sequence

The distribution of a number of terrestrial ________ flora and fauna is cited as critical evidence that the continents have moved through time.

fossils

Wegner relied heavily on matching _____ patterns as well as ______ events that he argued could only occur if all the continents were connected ?

geologic, glacial

Geologists know that oceanic ridges are geologically very active because they ____.

have many small earthquakes and are the site of recent volcanic eruptions

What is the driving mechanism for plate tectonics?

heat deep within Earth

At transform plate boundaries, ____.

lithosphere is neither created or destroyed

Geologists have a very good record of the breakup of Pangaea because of ____.

magnetic anomalies preserved in oceanic crust

Wegner began looking for evidence of a super continent after reading a paper about _______?

matching terrestrial Permian fossils in South America, India, Africa, Antarctica, and Australia

Magnetic reversals ____.

occur when magnetic north and magnetic south poles switch positions

Interest in continental drift waned until studies of Earth's magnetic field and oceanographic research showed that ____.

present-day ocean basins are not as old as continents but instead, are geologically young features that resulted from the breakup of Pangaea

When minerals in a magma cool and solidifies the magnetic field of the Earth is set in the minerals, which is known as ______.

remnant magnetism

Divergent plate boundaries most commonly occur along ____.

the crests of oceanic ridges

The seafloor spreading hypothesis indicates what as the primary cause of continental movement?

the formation and destruction of ocean basins

Glacially deposited strata were important in the development of continental drift theory because ____.

the glacial deposits indicated that all of the southern continents must have been closer to the South Pole and contiguous

The study of paleomagnetism is possible because ____.

the magnetic minerals in a cooling lava point toward the north magnetic pole

Geologists know that oceanic plates are subducting beneath continental plates at convergent margins because ____.

there are shallow earthquakes near the ocean trench and deeper ones progressively further inland

Shield areas of continents are found in modern ____.

Wrong Answer: divergent plate boundaries

What have differing paleomagnetic records for each continent shown?

Wrong answer: both the poles and the continents have moved over time

Wegener's critics pointed out to him that the configuration of coastlines results from erosional and depositional processes and therefore is continuously being modified. What idea were they arguing against?

Wrong answer: land bridges continually appearing and disappearing