glg101
Sedimentary Rocks
Mgt 350 When we think if sediment most people think of the soft silky sand that is found on the bottoms of rivers and along the shorelines at some beaches. We need to look at what makes up the sediment before we can look at the types of rocks is produces. Sediment is a mixture of loose materials such as clay, sand, grave, and other rocks. The erosion of sediment is deposited and buried and forms new rock; this is called Lithification. mgt 350 The lithification of rocks are layers that are bound together by dirt or more rocks; after being under immense pressure of through the movement of tectonic plates new rock is formed. The pressure that the rock sediment undergoes is called compaction. Compaction works like a trash compactor in your home; it squeezes everything together very tightly getting all of the trash into a small space. This is essentially what happens mgt 350 class with the rocks as well. Lithification can occur through cementation. Cementation is when substances such as ground water evaporates and all moister comes out of the rocks. The result is that grains of sand get in between the rocks and the along with the pressure cement together. Another form of lithification is recrystallization. When less stable minerals break apart and recrystallize, or come together, they form a strong bond; this is seen in corral beds quite often with the breakdown of aragonite and the recrystallaztion and it becomes calcite. glg101 Now that we know how rocks sediments are formed we can look into the three different types of sedimentary rocks; they are clastic, chemical, and biogenic. Let’s take a look at the clastic rocks first. Clastic sediment if forms by the fragments of rock and mineral debris; this is caused by erosion and weathering. glg 101 glg 101 class glg101 |