Search results
Results From The WOW.Com Content Network
Pangaea or Pangea (/ p æ n ˈ dʒ iː ə / pan-JEE-ə) [1] was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. [2] It assembled from the earlier continental units of Gondwana , Euramerica and Siberia during the Carboniferous approximately 335 million years ago, and began to break apart about 200 million years ...
Flanking mountains are generally taller along the east side of the rift (although some of this relief may be Laramide in origin). [1] The thickness of the crust increases to the north beneath the rift, where it may be as much as 5 kilometres (3.1 mi) thicker than it is in the south. The crustal thickness underneath the rift is on average 30 ...
The Columbia Plateau is an important geologic and geographic region that lies across parts of the U.S. states of Washington, Oregon, and Idaho. [1] It is a wide flood basalt plateau between the Cascade Range and the Rocky Mountains , cut through by the Columbia River .
A flood basalt (or plateau basalt [1]) is the result of a giant volcanic eruption or series of eruptions that covers large stretches of land or the ocean floor with basalt lava. Many flood basalts have been attributed to the onset of a hotspot reaching the surface of the Earth via a mantle plume . [ 2 ]
Quizlet is a multi-national American company that provides tools for studying and learning. [1] Quizlet was founded in October 2005 by Andrew Sutherland, who at the time was a 15-year old student, [ 2 ] and released to the public in January 2007. [ 3 ]
Land added to Laurentia during the Grenville orogeny. The first mountain-building tectonic plate collision that initiated the construction of what are today the Appalachian Mountains occurred during the Mesoproterozoic era at least one billion years ago when the pre-North-American craton called Laurentia collided with other continental segments, notably Amazonia.
Mountain formation occurs due to a variety of geological processes associated with large-scale movements of the Earth's crust (tectonic plates). [1] Folding , faulting , volcanic activity , igneous intrusion and metamorphism can all be parts of the orogenic process of mountain building. [ 2 ]
The last glaciation did not cover this region (halting at the Des Moines terminal lobe mentioned above), so there is no glacial drift to form subsoils, giving the region the name of the Driftless area. As the topsoils are shallower and poorer than those to the west, dairy farming rather than cash crops is the principal agricultural activity.