Sedimentary rock is classified into two main categories: clastic and chemical. Clastic or detrital sedimentary rocks are made from pieces of bedrock, sediment, derived primarily by mechanical weathering. Clastic rocks may also include chemically weathered sediment.
How Can Sedimentary Rocks Be Classified?
Sedimentary rocks are among the most diverse types of rocks found in the Earth’s crust. They form as a result of sedimentation and can range in composition from sandstone to shale to limestone. Sedimentary rocks are classified in several ways, including their composition, their structure, and the environment in which they were formed. Understanding how sedimentary rocks are classified can help geologists in identifying, dating, and interpreting the rocks in their area.
Sedimentary rocks are classified by their composition. This is done by examining the proportions of different minerals, such as quartz, feldspar, and clay, within the rock. By looking at the composition of the rock, geologists can identify the kind of sedimentary rock they are dealing with. For example, sandstone is composed of quartz and feldspar, while shale is composed of clay and small particles of quartz and feldspar.
Sedimentary rocks are also classified by their structure. This is done by looking at the size, shape, and sorting of the grains within the rock. For example, sandstone typically has larger grains that are well-sorted, while shale has smaller grains that are poorly sorted. Geologists can also look at the layering of