Question

Explain how depositional environment is related to sedimentary rock type. Give specific examples using the sedimentary rocks

Answer 1

Sedimentary rocks can be classified into three major categories, these are:

• Clastic sedimentary rocks that are formed when the parent rocks are weathered, eroded and transported by the agents (like water, wind etc). This produces sediments or clasts which are then deposited and further loading produces compaction, cementation and lithification thus producing clastic sedimentary rocks. These rocks are associated with riven channel depositional environments and rocks are conglomerates, breccia, sandstone and shale.
• Chemical sedimentary rocks are formed when the mineral rock water evaporates and this precipitate the minerals which then forms the chemical rocks. The depositional environment associated with chemical rocks is deep and shallow marine and the rocks are gypsum, dolomite, chert, limestone etc.
• The last category is the organic sedimentary rock and it gets formed when the animals remains (hard parts like teeth, shells and bones) accumulate to form rock. These type of rocks are associated with lakes and deep marine environment and rocks of this category are coal, fossiliferous limestone etc.