1.5 Tectonic Plate Interactions

At the San Andreas fault,

• two oceanic plates are moving apart

• two oceanic plates are colliding

• two plates are sliding horizontally past each other

• one plate is subducting beneath another plate

Pangaea became the continents we see today because of plate motion

• along divergent boundaries only

• along convergent boundaries only

• along both divergent and convergent boundaries

• none of these

What is a byproduct of subduction?

• the creation of mid-ocean ridges

• the creation of fault-block mountains

• the recycling of oceanic crust

• the melting of continental crust

Deep seas trenches are associated with which of the following?

• transform boundaries

• fault-block mountains

• subduction zones

• rift valleys

A geologist is studying an ancient syncline in the Appalachian Mountains. How did this feature form?

• extension during convergence

• extension during divergence

• compression during convergence

• compession during divergence

Each type of plate boundary is associated with a different primary force. Which of the following pairings of plate boundary and force is correct?

• convergent boundary: shear force; divergent boundary: faulting force

• convergent boundary: faulting force divergent boundary: shear force

• convergent boundary: compressional force divergent boundary: extensional force

• convergent boundary: compressional force divergent boundary: shear force

A geologist is studying the Franciscan assemblage in Northern California, a melange of sediments that originally formed in the ocean. How might this unit most likely have formed?

• the breaking of rock into rising blocks as plates move apart at a fault

• the grinding of tectonic plates sliding past each other at a fault

• the accretion of rock on crust during a mountain-building event

• the cooling of lava as it flows through a spreading center

A hypothetical supercontinent moves over the North Pole. How do geologists think this event could affect the planet?

• plunge the planet into an extreme greenhouse climate

• plunge the planet into an extreme icehouse climate

• cause the planet's climate to cycle between icehouse and greenhouse conditions every fe thousand years

• likely have no significant effect on the planet's climate

A geologist is comparing volcanism at two different locations. Location A is a volcanic arc system. Location B is a spreading center. Which conclusion is the geologist most justified in making?

• The volcanism is more explosive at location A than location B

• The volcanism is more explosive at location B than location A

• The volcanoes are active at location A and dormant at location B

• The volcanos are active at location B and dormant at location A

The Himalayan Mountains are being formed by ___________.

• two tectonic plates moving apart

• two tectonic plates are colliding

• two tectonic plates are sliding horizontally past each other

• a continental plate is subducting beneath an oceanic plate