1.200 million years ago, tectonic forces began moving the North American Plate westwards, it eventually collided with the Pacific Plate, and the force of the collision, called the Columbia Orogeny, moved east over North America, cracking enormous masses of rock and forcing the sedimentary layers up and over the adjacent land. This process created the main ranges of the western and central Rocky Mountains. A second collision, known as the Laramide Orogeny that ended about 35 to 55 million years ago, created the foothills and the front ranges of the Rocky Mountains. This was also a time of volcanic activity in the Rocky Mountains, but eventually the volcanic activity ceased and the magma cooled, leaving craterlike formations called calderas. In the millennia that followed, water flow carried sediment from high in the mountains into the valleys and plains below, creating v-shaped valleys like Hell’s canyon at 7800 feet, which was shaped by the Snake River. Many of the features of the mountainous west were created
As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.
Temple University Fox School of Business ‘17, Course Hero Intern
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University of Pennsylvania ‘17, Course Hero Intern
The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.