Learning: Topic 14: Convergent Boundaries: Origin of Mountains

Which term refers specifically to geologic mountain building?

• Orthorhombic

• Ontogeny

• Origami

• Orogeny

Orogeny

Which one of the following is an example of an isostatic movement?

• Numerous aftershocks associated with deep-focus earthquakes

• Stream downcutting following a drop in sea level

• Arching of strata at the center of a dome

• Uplift of areas recently covered by thick continental ice sheets

Uplift of areas recently covered by thick continental ice sheets

What North American mountains are a geologically old mountain range that was folded and deformed during the Paleozoic?

• The Appalachians in the eastern United States

• The Rockies in the western United States

• The Cascades in the northwestern United States

• The Alps in Europe

The Appalachians in the eastern United States

Of the following, which have a crust about twice as thick as normal?

• The Basin and Range Province in Arizona and Nevada

• The Coast Ranges and the Sierra Nevada in California

• The Himalayan Range and the Tibetan Plateau in northern India and southwestern China

• The Blue Ridge Mountains in the southeastern United States

The Himalayan Range and the Tibetan Plateau in northern India and southwestern China

Which of the following best characterize the tectonic development of fault-block mountains?

• Reverse faults; crustal shortening and plastic flowage of the lower crust

• Reverse faults; crustal stretching and brittle failure of the lower crust

• Normal faults; crustal shortening and plastic flowage of the upper crust

• Normal faults; crustal stretching and brittle failure of the upper crust

Normal faults; crustal stretching and brittle failure of the upper crust

Which of the following statements best describes topographically high-standing mountainous areas?

• They are generally underlain by greater-than-average thicknesses of lower-density crustal rocks.

• They experience rapid erosion that thins the crust and causes the area to subside.

• They subside rapidly to compensate for erosion.

• They have thicker, higher-density mantle rocks beneath them at shallow depths.

They are generally underlain by greater-than-average thicknesses of lower-density crustal rocks.

What happens to create an accretionary wedge?

• The edge of the overriding plate faces a subduction zone.

• The base of a passive continental margin meets the seafloor.

• Oceanic plate volcanoes are fed by long-lived hot spots in the mantle.

• An oceanic plate moves along a transform fault.

The edge of the overriding plate faces a subduction zone.

What term describes the zone where two continents collide, often preserving slivers of oceanic lithosphere between the colliding plates?

• Terrane

• Ophiolite

• Passive margin

• Suture

Suture

What types of materials are characteristic of volcanism along a continental arc?

• Rhyolitic pyroclastic materials and lavas

• All of the listed options

• Andesitic lavas and pyroclastic materials

• Basaltic lava flows

Andesitic lavas and pyroclastic materials

What concept shows that rocks of the crust and upper mantle are floating in gravitational balance?

• Isotropy

• Ecstasy

• Isometrics

• Isostasy

Isostasy

Which of the following is not a feature found in subduction zones?

• Suture zones

• Deep-ocean trenches

• Forearc basins

• Volcanic arcs

Suture zones

What is the name of a thick accumulation of sediments and small, tectonic blocks formed of material scraped off a descending lithospheric plate?

• Subterranean-accumulation complex

• Mass-movement complex

• Continental shelf terrain complex

• Accretionary-wedge complex

Accretionary-wedge complex

Which of the following forces create backarc regions?

• Compression

• Extension

• Shearing

• Uplift

Extension

What type of basin is characterized by thick sequences of relatively undeformed sedimentary rocks?

• Transform fault

• Evaporite

• Backarc

• Forearc

Forearc