Physical Features of the Grand Canyon

Physical features of the Grand Canyon

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The Grand Canyon is located in the state of Arizona. It was carved up by the copper colored Colorado River creating a colorful rock layer. The canyon is steep-sided with a composition of rocks that tell a story of its formation over millions of years. Its stretches about 1 mile in depth and is 2,400 feet deep below the Yavapai Point on the South Rim. Towards the North Rim, it extends 7800 feet deep widening to about 277 miles along its path. The Grand Canyon tells a significant percentage of the earth's history. Proof of this is the metamorphic rocks, schists, present within the canyon aging at about 1.75 billion years old (Darling, 2015). Formation of the metamorphics rocks took place under high pressures and temperatures altered the original rocks of the area. The Colorado River and its influence on the formation of the Grand Canyon have been a constant subject of debate. Scientists agree the Colorado River had a main role in forming the canyon by being the primary agent of erosion thereby creating it (Simoni, 2014).

Sediments of silt and sand carried by the river increased the ability of the Colorado River to cut through the rock layers. This scraped through the scour and rock surface both at the bottom and at the edge of the river. A large amount of sediment carried by the river was in a vast amount giving the murky reddish brown color to the water (Simoni, 2014). Deepening of the grand canyon took place over millions of years since the river remained undammed retaining its ability to erode the canyon. The erosive force was weakened when the Canyon Dam was constructed in 1963.An interesting geographical subject of the Grand Canyon is its deep sense of geology. As a physical characteristic of the Grand Canyon, its geology gives a story of its ancient history. This is currently a subject of deliberation among scientists who argue about the age of the canyon ranging from millions to billions of years old (Crow, 2015).

The difference of opinion on this subject is promoted by sections of the canyon having young geologic deposits (Crow, 2015). This is present in caves or debris flow deposits continuing each year. Its landscape, in particular, is geologically young being formed in the last six million years. The geological time perspective of the canyon is drawn from the rock walls creating a vast and detailed fossil record of the area. This explains its unique and great significance as a historic site consisting of a great variety of rocks. The depth of perception of the walls is further enhanced by the clarity of the rocks exposing its beautiful geological composition (Darling, 2015).  

As a river valley, the Grand Canyon is the most majestic canyon of the Colorado Plateau. Formation of the canyon begins at the bottom with exposure of rocks at this level known as Vishnu Basement Rocks (Bowman, 2006). This is a composition igneous and metamorphic rocks. Several layers of sedimentary rocks exist above the Vishnu Basement Rocks and are referred to as the Grand Canyon Supergroup. The dominant rocks in this layer are shale and limestone with traces of igneous rocks. This group was formed between 740 million and 1.25 billion years ago. An interesting subject is the absence of rocks formed in the next 250 million years not existing (Abbott, 2016).