One of the types of rocks that can be found on the Earth are sedimentary rocks. There are two other kinds which are igneous and metamorphic rock. Sedimentary rocks cover about 75 to 85 % of the land on Earth. When pieces of rock or parts of once- living organisms or minerals from precipitation deposit and solidify on Earth’s surface they for sedimentary rocks. (Murck, et al., 2008) In addition, the way the plate tectonics move, can significantly affect sedimentation and the formation of sedimentary rocks.
There are three main types of sedimentary rocks which are classified by the source of the sediments. They are clastic, biogenic, and chemical sedimentary rocks. Each category of sedimentary rock has distinct characteristics and depositional environments. Once the sediments are deposited a process called “lithification” or rock forming begins. For the newly deposited, loose sediment to be lithified and be turned into rock, the individual particles must be bound together in a cohesive unit. Once there is a layer of sediment buried either by accumulation of more sediment or by the tectonic processes it is under high pressure, which leads to compaction. Compaction is usually the first step in the lithification process. There are several ways that this can happen. The other two ways that this can happen is through cementation or recrystallization. Cementation is the process in which substances dissolve in pore water precipitates out and forms a matrix in which grains of sediment are joined together. Recrystallization is the process where the formation of new crystalline mineral grains from old ones. (Murck, et al., 2008)
Types of Sedimentary Rocks
When clastic sediment is lithifies it will produce a rock that’s properties will reflect the type of sediment that it originated from. There are four basic classes of clastic sediment which is conglomerate, sandstone, siltstone and mudstone or otherwise known as shale. Conglomerate is a clastic sedimentary...
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