Vocab
Multiple Choice
Short Answer
Plate boundaries
100
Evidence of life millions of years ago
Fossils
100
Which of the following provides evidence that the continents on tectonic plates have moved away from each other in the past?
A. The composition and thickness of rock layers varies at different depths.
B. The frequency of volcanic activity is higher at edges of tectonic plates.
C. Ocean currents can be disrupted near boundaries between tectonic plates.
D. Fossils of the same plants and animals are found on widely separated continents.
D. Fossils of the same plants and animals are found on widely separated continents.
100
Why do scientists believe that some tectonic plates are moving away from each other?
Evidence suggests that at one point in time they were connected.
They have since separated, so they must be moving away from each other.
Evidence of movement (ie: earthquakes)
Evidence at mid ocean ridges forming patterns on either side
- Same species of fossils found on different continents
100
What do convergent plates (continental -><- continental) form?
Mountains
200
The theory that continents were once connected but have moved apart
Continental Drift
200
Before there was evidence from rocks and fossils, many scientists theorized that the continents were once joined together. Using only maps, these scientists observed that...
A. the shapes of the continents allowed them to fit together.
B. weathering and erosion have reshaped the surface of the Earth.
C. the oceans have become smaller throughout Earth’s history.
D. the continents were all bordered by mountain ranges.
A. the shapes of the continents allowed them to fit together.
200
How are fossils used by scientists to show that the theory of Continental Drift is correct?
They show us how the continents were connected together, by demonstrating how fossils on one continent were present on other continents at the same time, even though the animals could not have crossed an ocean if there was one in the way. This means that they must have been able to walk from one continent to another because the continents all made one giant landmass.
200
What happens at convergent plates? (continental -><- oceanic)
Subduction
300
The process in which a denser plate is pushed beneath a less dense plate
Subduction
300
The distribution of fossils is used as evidence for plate tectonics. The distribution of four different fossil organisms over three different continents is shown in the diagram/model.
The distribution of which organisms can be used as evidence that Africa was once connected to South America?
A. Lystrosaurus, Mesosaurus, and Glossopteris
B. Cynognathus, Glossopteris, and Lystrosaurus
C. Glossopteris, Cynognathus, and Mesosaurus
D. Cynognathus, Mesosaurus, and Lystrosaurus
C. Glossopteris, Cynognathus, and Mesosaurus
300
How can the ocean floor be created and/or destroyed?
New crust is created due to seafloor spreading. When the plates spread, magma is forced through the cracks and then cools, forming new land.
At subduction zones where plates meet, some crust can be forced underneath other crust, causing the destruction of ocean floor.
300
Why does subduction occur when a continental plate pushes against an oceanic plate?
The more dense oceanic plate is pushed underneath the less dense continental plate
400
A boundary formed when two plates move away from each other
Divergent boundary
400
New seafloor material is formed at places in Earth’s crust where...
A. rock is broken into pieces as tectonic plates push against one another.
B. one tectonic plate slides beneath another and is forced downward.
C. lava flow from volcanic eruptions builds up over many thousands of years.
D. magma rises into the spaces where tectonic plates pull away from one another.
D. magma rises into the spaces where tectonic plates pull away from one another.
400
The seafloor is pushed down by subduction, melted into magma, and recycled back into the mantle
400
What happens at divergent plate boundaries in the ocean?
Mid ocean ridges form, magma rises from the mantle, moves along the ocean floor, solidifies, and creates patterns on either side
500
An underwater mountain system formed by plate tectonics
Mid-ocean ridge
500
Part of the recycling of seafloor material includes its destruction. This happens...
A. through weathering and erosion of exposed rock layers.
B. as a result of violent and frequent volcanic activity.
C. at trenches where rock material is subducted.
D. when elements in rock are rearranged chemically.
C. at trenches where rock material is subducted.
500
Changes in magnetic polarity causes the rock to be pulled towards different directions at different points in earths history
500
What is is it called when two plates slide past each other? (Like the sandpaper part of the lab)
Transform plate boundary