Chapter 5 Review

Vocabulary  All of the Earth’s landmasses were once joined in the supercontinent __________.  Pangaea

Vocabulary  At the mid-ocean ridge, ______ occurs because of the welling up of molten material from the mantle.  Sea-floor spreading

Vocabulary  A plate boundary where two plates come together is called a _________.  Convergent boundary

Vocabulary  The process of one plate moving under another is ______.  Subduction

Vocabulary  The theory of _______ states that the lithosphere of the Earth is divided into moving pieces.  Plate tectonics

Vocabulary  Any plate boundary where the plates move away from each other is called a _________.  Divergent boundary

Vocabulary  When a plate is subducted, a deep ocean valley, or ________, is formed.  Trench

Vocabulary  A plate boundary where two plates slide past each other is a _________.  Transform boundary

What’s the Difference?  Convergent Boundary vs. Divergent Boundary  Convergent- when two plates come together. Divergent- when two plates move away from each other.

What’s the Difference?  Lithosphere vs. Tectonic Plate  A tectonic plate is one of the pieces that make up the lithosphere.

What’s the Difference?  Subduction zone vs. Trench  Subduction zone- the place where one plate is pushed down under another. Trench- and ocean valley that forms in a subduction zone.

Check Your Knowledge  How did scientists prove that sea-floor spreading occurs?  Scientists found a patter of parallel magnetic stripes in the sea floor and found that the age of the crust increases the farther away you get from the ridge.

Check Your Knowledge  List the three ways in which plates can interact with one another.  Plates can converge, diverge, or slide past one another.

Check Your Knowledge  How do the marks left by ancient glaciers provide evidence for continental drift?  Glaciers always flow toward oceans, so the marks left in rocks by a glacier should point toward an ocean. Some glacial marks do not point toward present-day oceans, indicating that the landmasses were not always oriented as they are today.

Check Your Knowledge  Explain the two models proposed for how convection moves plates.  One model says that the plates are simply floating on convection cells. The other model says that the plates are actually part of the convection cells.

Check Your Knowledge  What landforms can result when two plates meet at a convergent boundary?  Trenches, volcanoes, and mountain ranges.

Check Your Knowledge  What is the theory of continental drift?  The theory of continental drift states that the Earth’s landmasses were once connected, have moved apart, and are still moving.

Check Your Knowledge  How does the age of rocks found at the bottom of the ocean compare to the age of rocks found on the continents?  Ocean rocks are younger than rocks from continents.

Check Your Knowledge  List the three kinds of convergent boundaries.  Oceanic-oceanic, oceanic- continental, and continental- continental.

Check Your Knowledge  What two continents were formed when Pangaea broke apart? During which era of geologic time did this occur?  Laurasia and Gondwanaland. Mesozoic Era.

True or False?  The present-day continents of Africa, South America, Australia, India, and Antarctica were once joined as the continent Laurasia.  False; Gondwanaland

True or False?  The mid-ocean ridges are all subduction boundaries.  False; divergent

True of False?  Tectonic plates “float” on the lithosphere.  False; asthenosphere

True or False?  The density of oceanic crust if greater than the density of continental crust.  True

Check Your Understanding  Where is new crust created?  Along a divergent boundary.

Check Your Understanding  How do continental plates differ from oceanic plates?  Continental plates include both continental and oceanic crust.

Check Your Understanding  What happens to the rock material of a subducting plate?  The rock material melts and is absorbed into the mantle.

Check Your Understanding  Where do we typically find ocean trenches?  Associated with subduction zones.

Check Your Understanding  What kind of fault line is the San Andres Fault?  A transform boundary

Check Your Understanding  What is another name for the Earth’s internal heat?  Geothermal energy.

Check Your Understanding  What kind of boundary were the Himalayan Mountains formed at?  A convergent boundary.