What was the Cordilleran orogeny? Briefly describe the four phases of the orogeny. What will be an ideal response?
The Cordilleran orogeny is the mountain-building activity that began during the Jurassic and continued
into the Cenozoic and is related to the westward movement of the North American plate as it overrode
the Pacific plate. During the Nevadan orogeny, the first phase, subduction of the Pacific plate beneath
North America generated large volumes of granitic magma at depths that were uplifted to become the
Sierra Nevada and other batholiths. During the second phase, the Sevier orogeny, older rocks were
thrust eastward on top of younger rocks in numerous overlapping, low-angle thrust faults producing
north-south-trending mountain ranges. The final pulse was the Laramide orogeny in which most of the
features of the present day Rocky Mountains began.
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Infant mortality rate refers to the number of children out of 1,000 that die
a. before birth b. in their first month c. in the first half-year of life d. by their first birthday e. by their fifth birthday
The official language of Iran is
A. Hebrew. B. Arabic. C. Berber. D. Farsi.
Tornado intensities are determined by the ____
a. Enhanced Fujita Scale b. Saffir-Simpson Scale c. Tornadic Scale d. Severe Weather Scale e. Coriolis Scale
The term of "Sedimentary Basins" refers to a depression, created as a consequence of subsidence that fills with sediment.
a. true b. false