Geology of the Grand Canyon area
The geology of the Grand Canyon area includes one of the most complete and studied sequences of rock on Earth. Uplift of the region started about 75 million years ago during the Laramide orogeny. Volcanic activity deposited lava over the area 1. 8 million to 500,000 years ago. There are at least 14 known unconformities in the geologic record found in the Grand canyon.
About Geology of the Grand Canyon area in brief
The geology of the Grand Canyon area includes one of the most complete and studied sequences of rock on Earth. Uplift of the region started about 75 million years ago during the Laramide orogeny. Volcanic activity deposited lava over the area 1. 8 million to 500,000 years ago. At least 13 lava dams blocked the Colorado River, forming lakes that were up to 2,000 feet deep. The end of the last ice age and subsequent human activity has greatly reduced the ability of the Colorado river to excavate the canyon. Earthquakes and mass wasting erosive events still affect the region. There are at least 14 known unconformities in the geologic record found in the Grand canyon. The Great Unconformity is one of best examples of an an unconformity, which is a type of rock that has been exposed above metamorphic units. In late Precambrian rocks, such as the Vishnu Basement Rocks, this type of bedded rock has been found in other parts of the world, including the Great Un Conformity in the Philippines and the Gascoyne Formation in Mexico. It is also seen in parts of Europe and South America, including in the Alps and the Pyrenees in France and the Andes in Spain and in the Adriatic Sea in Greece and Italy. It was formed 1. 75 billion to 1. 73 billion years ago and is the resistant rock now exposed at the bottom of the canyon in the Inner Gorge.
It consists of the metasedimentary Vishnu Schist and the metavolcanic Brahma and Rama Schists that were formed about 1. 7 billion years ago. The intrusion of the granite occurred in three phases: two during the initial Vishnu metamorphism period, and a third around 1. 4 billion Years ago. Part of this thickening created the 5-to-mile Mazatzal Mountains. Subsequent erosion lasting 300 million years stripped much of the mountains away. This reduced the exposed sediments and high ancestral mountains away to the very high mountains a few tens to hundreds of feet high. Other sediments may have added but, if they ever existed, they were completely removed by erosion. Such gaps in theGeologists by erosion have called these gaps by erosion “Unconformities by erosion” The Grand Canyon region is a major part of the U.S. National Park Service’s Grand Canyon National Park area. The park area is home to some of the best views in the world of the Canyon and the surrounding area. It also contains the largest concentration of desert scenery in the United States, including desert sand dunes and an extinct desert. The area is also home to the largest sand dune system in North America, which was once part of a vast desert. It has been called the “Grand Canyon of the West” and the “Canyon of the Southwest” by geologists.
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This page is based on the article Geology of the Grand Canyon area published in Wikipedia (as of Nov. 03, 2020) and was automatically summarized using artificial intelligence.
