Exam 12: Global Tectonics: Plates and Plumes

What evidence suggests to scientists that magma generation at convergent boundaries is different than magma generation at mid-ocean ridges?

Which of the following is an example of a slow moving plate?

All volcanic eruptions over the past 10,000 years occurred along or near plate boundaries.

90 million years ago India was

All of the following processes aid the lithosphere in becoming denser than the asthenosphere except

What does the Mantle-Plume hypothesis explain that plate tectonics cannot explain?

Why do plate traces appear to have a curved path when plotted on a map?

Judge the following sentence according to the criteria given below. Plate tectonic works because lithosphere is less dense than asthenosphere at divergent boundaries and more dense than asthenosphere at convergent boundaries.

Which of the following is least likely to be mapped with data about ancient igneous rocks?

Why does the heat flow dip east of the location where the Juan de Fuca Plate subducts beneath the North American Plate?

Which of the following is oldest?

All rift valleys extend sufficiently to form new continents and plate boundaries.

Judge the following sentence according to the criteria given below. Continental crust dominated by rocks older than 1 billion years but no ocean crust older than 180 million years exists because oceanic crust is created at mid-ocean ridges.

The seafloor spreading hypothesis predicts that the mid-ocean ridges should be locations of rising asthenosphere. This prediction is supported by seismic data that indicates

How do scientists measure the age of rocks at mid-ocean ridges?

What is the evidence that subduction occurs at convergent plate boundaries?

Figure 12.43 -According to Figure 12.43 when did the Caledonian Mountains form?

Why do hot spots form a trail of extinct volcanoes over time?

Figure 12.43 -According to Figure 12.43 when did the Rocky Mountains form?

What type of boundary is the San Andreas fault in California?