What are the principal sedimentary rocks? What is the genesis (origin) of each sedimentary rock type?

The sedimentary rocks are those that are formed due to the compaction and lithification of sediments. Some of the examples are shale, mudstone, sandstone and limestone.

This sedimentary rocks are divided into 2 principle types. They are as follows-

(1) Clastic sedimentary rocks - This type of rocks are formed when the rock particles are weathered physically from the terrestrial rocks (source area) and are transported from one place to another by means of wind, water and ice. These rocks are named depending on the size of the sediment particles. Conglomerates and sandstone are examples of clastic sedimentary rocks.

(2) Chemical (Carbonate) sedimentary rocks - This type of sedimentary rocks are formed due to the precipitation of certain minerals from water. Due to this precipitation, the water releases the dissolved minerals. Some of them are also comprised of carbonate minerals that precipitates when reacts with water. In addition to that, some fragments of marine fossils are also found to be accumulated in this type of rocks. For example, rock salt, halite, dolomite, chert and limestone.