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Plate tectonics

1) The Mid Atlantic Ridge is found :
a) near the middle of a continental plate.
b) where two tectonic plates collide
c) along divergent plate boundaries
d) at a subduction zone
e) associated with a hot spot.

2) The magnetic stripes from seafloor data recorded off the coast of Vancouver and Washington State:

a) were created by magnetite in lava flows.
b) are caused by radioactive decay
c) are indicators of past earthquake sites.
d) are indicators of future earthquake sites
e) always run perpendicular to the equator

3) What is always characteristic of a tectonic plate?
a) made of basalt
b) comprised of crust and mantle material
c) occurs at angles nearby parallel to longitude.
d) has a thickness of at least 35km
c) all of the above

4) Which of the following statements describes features on the Earth?
a) there has always been at least one polar ice cap
b) there have always been tropical rain forests
c) the Atlantic Ocean was formed billions of years ago
d) All the Earth's features are constantly changing
c) the solid surface of the Earth is one feature that never changes

5) Glacial periods are not caused by
a) changes in the tilt of the Earth's axis.
b) changes in the shape of the Earth's orbit
c) decreased precipitation and decreased solar energy absorption
d) location of land masses or mountain chains.
e) all of the above can cause glacial expansion

Solution Preview

1) The Mid Atlantic Ridge is found along divergent plate boundaries. The Mid Atlantic ridge is where new ocean crust is being formed. The crust is forced up through the ocean floor then is pushed to either side to make room for more crust. This slow process has the effect of moving the continents across the earth at about the same rate as your fingernails grow.

2) At mid-oceanic ridges, the new oceanic crust spreads outward symmetrically. It has been found that this crust displays bands that run parallel to the ridge, based on the age of the new crust. ...

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