Exam 13: Mountain Building and Continental Frameworks

Subduction ceases in a(n)________ type of convergent plate margin.

Under what terrane would you look to find the original rift zone tensional faults from the Proterozoic break up of Rodinia?

Mountains without active volcanic arcs are associated with a(n)________ margin.

Prolonged convergence across Aleutian-type margins can result in the ________.

Between the original Proterozoic rifting of Rodinia and the Late Paleozoic rifting of Pangaea, how much "real estate" was added to the North American continent?

Why would geologic mapping be particularly difficult in a region characterized by accreted terranes? Also, why would the recognition of such terranes in older, deeply eroded areas such as continental shields be important in understanding the geologic history of an area?

Any accreted crustal fragment that has a geologic history distinct from that of the adjoining fragments is termed a ________.

The earliest and most primitive crust to form was probably oceanic.

An ophiolite-complex terrane would contain abundant, rhyolitic, volcanic rocks, and sandstone.

What do the ophiolites signify that are found in the Himalayas or Alps?

Overthickened crust continues to slowly rise, even though its thickness is gradually being reduced by erosion.

The Himalayan Mountains and Tibetan Plateau are still rising today as Eurasia slides beneath the Indian subcontinent.

The Appalachians first started out as a rifted margin when Laurasia split apart in the Cambrian.

The Wilson Cycle was deduced from studies of old, complex mountain chains like the Appalachians.

Ophiolite accretion occurs most frequently by incomplete rifting on passive margins.

The elevation and uplift rate of mountain areas are determined isostatically by the densities and thicknesses of underlying rock layers all the way down to the mantle.

What kind of crust was the Avalon Terrane prior to its accretion to the Appalachians in the Acadian Orogeny in the Silurian and Devonian?

The term ________ refers specifically to the collection of all geologic processes and tectonic events that are responsible for building mountain belts.

As new layers of rocks are added to the crust, the elevation increases faster than the crustal thickness.

Well defined linear mountain ridges with southwesterly-dipping slopes, steep upturned bounding thrusts and intervening linear strike valleys are found in this part of the Rockies.