Summit Climb #3 - Theory of Plate Tectonics

In the early 1900s, a hypothesis was introduced that proposed a single large landmass broke into smaller landmasses and formed the continents, which drifted to their present locations. What is the name of this hypothesis?

• Continental Drift
• Continental Shift
• Plate Movement
• Plate Tectonics

Look at the figure below. A world map showing all the continents are together. Which explanation best summarizes the hypothesis shown in the figure?

• The present continents will gradually move to form a single landmass called Pangaea.
• The continents were once a large landmass named Pangaea, which broke apart and gradually drifted to the present-day locations of the continents
• The continents were once a large landmass, but the north and south magnetic poles pulled the continents apart toward the poles.
• The continents were once a large landmass, but the ocean levels rose, and these oceans separate today's continents.

Which location on the continent of Africa would have once corresponded to Location R on South America before the landmass Pangaea broke apart?

• Location 1
• Location 2
• Location 3
• Location 4

Mesosaurus is a reptile that has been extinct for nearly 300 million years. Fossil remains of this animal have been found in both South America and Africa. Which statement explains the location of these fossils on opposite sides of the Atlantic Ocean?

• South America and Africa were once connected.
• Mesosaurus crossed land bridges with early humans.
• Adaptations resulted in identical species in different ecosystems.
• The reptile changed into a marine organism and swam the Atlantic Ocean.

Select all of the following pieces of evidence for continental drift. (Select Four)

• Mapmakers noticed that continents had coastlines that seemed to match up. (Shapes of Continents Clues)
• Fossils of the same plant and animal species are found on continents that are separated by vast oceans. (Fossil Clues)
• Matching rock layers of the same age on different continents. (Rock Clues)
• Glacial grooves observed in areas with warmer climates like Africa. (Climate Clues)
• Mapping the locations of volcanoes. (Volcano Clues)

Why didn't the scientific community accept Alfred Wegener's idea about continental drift?

• He had too much evidence.
• He could not explain how the continents moved apart.
• The Theory Plate Tectonics had already been widely accepted.
• Alfred Wegener was not viewed as a real scientist.

There are long mountain belts that divide the sea floor and generate new sea floor as magma rises and erupts onto Earth’s surface. What are these mountain belts known as?

• magnetic poles
• mid-ocean ridges
• ocean trenches
• subduction zones

In 1968, the Deep Sea Drilling Project began extracting sediment cores from the ocean floor. Analysis of these cores has since shown that the ocean basins are very young compared to the accepted age of the Earth. No rocks older than 180 million years have been found. The cores further indicate that ocean sediments are absent at the mid-ocean ridge and get thicker moving away from the ridge. This evidence helped to confirm what aspect of the plate tectonic theory?

• sea-floor spreading
• paleomagnetic reversals
• existence of land bridges
• location of the lithosphere

Select the two processes that occur at mid-ocean ridges.

• Material rises from the mantle to the crust.
• Sediments from the crust sink into the mantle.
• Crustal rock subducts into the mantle and melts.
• Thermal energy rises from the mantle to the crust.
• Tsunami waves transfer from the crust to the mante.

Imagine you collected the data below to study the age and location of rocks on the sea floor. Based on the chart above, if a rock is located about 50 km from the mid-ocean ridge, how old is it likely to be?

• 500,000 years old
• 1,000,000 years old
• 2,000,000 years old
• 4,450,000 years old