Exam 5: Plate Tectonics: A Scientific Revolution Unfolds

The temperature below which magnetic material can retain a permanent magnetization is called the ________.

The ________ is an example of a modern convergent boundary where two continents meet.

Examine the image. It shows ________, a freshwater reptile whose fossils Alfred Wegener cited as evidence of continental drift.

The plate tectonics model has been verified by multiple lines of evidence.

Rock in the asthenosphere is mostly molten.

What evidence did Alfred Wegener use to support his hypothesis of continental drift? What additional evidence was added later (post-World War II)that suggested seafloor spreading? How do these two ideas unite to form the theory of plate tectonics?

The oldest rocks on the seafloor are much younger than the oldest rocks on the continents.

The rate of seafloor spreading is, on the average, about two or three meters per year.

You are dropped off by helicopter at a site on the land. You are told that it is a plate boundary. Almost immediately, you feel an earthquake. You look around and note the absence of volcanoes, but you notice an offset stream channel, and find a vertical fault with two kinds of rock on either side of it. What sort of plate boundary are you most likely on?

Imagine that you were given a ship equipped with a device that could measure how deep the water is. You are asked to use this ship to find a subduction zone. What would you look for as you sailed around the world's oceans?

A transform plate boundary is characterized by ________.

A global positioning system (GPS)locator at site A reveals that it is moving at 2.1 centimeters per year to the east. A second GPS locator is tracking site B, which is moving at 2.0 centimeters per year to the west. What sort of plate boundary is this?

________ was a supercontinent that existed in the late Paleozoic era of geologic time.

In convection, warm material rises because it is more dense.

Continental rifts are associated with ________ plate boundaries.

Which of these two sets of apparent polar wander paths shows the "fixed continent" model and which shows the "plate tectonics" model? Explain.

In general, rocks of the continental crust are less dense than rocks of the oceanic crust.

The ________ is weaker and less rigid than the overlying lithosphere.

Linear, magnetic patterns associated with mid-ocean ridges are configured as ________.

Examine this map of the Lutgens Archipelago, a chain of hotspot-related islands atop the Tarbuck Plate in the Tasa Sea. Use the information given to determine the (a)direction and (b)rate of movement of the Tarbuck Plate.