Chapter 2
The oceanic crust is -------than the continental crust
sits lower in the mantle is more dense is thinner
What causes tectonics plates to move?
Convection in the Mantle
The Himilayan Mountains
Convergent Boundary
Why was Alfred Wegner's Theory of continental drift not accepted?
He could not explain what caused the continents to move.
Which of the following is NOT true about a hot spot?
Hot spots are primarily located near plate boundaries
Oceanic crust is formed at __________ boundaries and destroyed at ___________ boundaries.
divergent ; convergent
Approximately how fast do tectonic plates move?
1-15 cm/yr
The San Andreas Fault
Transform Boundary
Oceanic crust is primarily composed of __________ while continental crust is composed of ____________.
basalt ; granite
Magnetic minerals within rock which have an inclination of 90 degrees (are perpendicular to the surface) indicate that the rock formed ____________ .
At the magnetic pole
The Red Sea
Divergent Boundary
ectonic plates are part of the ____________ and float on the _____________ .
Lithosphere ; Asthenosphere
Paleomagnetic stripes on the ocean floor run parallel to _____________ .
Mid Ocean Ridges
Why isn't there much ocean crust older than 180 million years old?
Old ocean crust becomes cold and dense and eventually subducts back into the mantle
Which of the following did Alfred Wegner NOT use as evidence for his theory of continental drift?
Paleomagnetic stripes on the ocean floor
Divergent Boundary
Plates Spreading Apart
Converget Boundary
Plates moving together and colliding
Transform Boundary
Plates sliding next to each other side by side