Assignment: Sedimentary Rocks
* Where do sedimentary rocks originate?
Sedimentary rocks are the most common rock on earth. Sedimentary rocks form at, or very near, the Earth's surface where rocks particles transported by wind, water and ice are deposited on dry land, on the beds of rivers and lakes and in marine environments: beaches, deltas and the sea (Sedimentary Rocks, 2001). The earth surface is constantly moving, materials are continually being deposited through various parts of the earth until the materials and minerals are bonded together through cementation. Cementation is created by the materials settling and eroding on the earth’s surface. Sedimentary rocks also originate from sediments that are formed inside the earth’s basin; includes chemical, biochemical, and organic sedimentary rocks. Sedimentary rocks cover most of the earth’s surface. However, the layer of sedimentary rock is thin, ranging from 25 to 62 miles deep compared to the igneous rocks that are a very thin layer.
* How are they formed?
The formation of sedimentary rock takes a considerably amount of time, it is slow but persistent and as long as the earth continues to rotate the formation of sedimentary rock will continue to form. The earth’s surface is exposed to the natural elements that occur daily such as rain, ice, wind, and the sun. Rocks and the partials that are carried around the earth’s surface expand in some heating conditions and contract when cooled. During the heating and cooling process partials break off the surface to settle in an ideal area. Once the particle has settled in a perfect resting position the wind blows against the rocks of mountains and the earth’s surface erodes them, dust particle by dust particle. Dust particles are very small and that is why it takes a long time for the sedimentary rocks to form. The debris starts accumulating in convenient places and their pile up builds pressure on the lowest layer. This pressure compresses and brings...
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