The characteristic properties of sedimentary rocks are generated by the depositional environment. Different geologists proposed different definitions of sedimentary environment, but they all have in common an emphasis on the physical, chemical, and biological conditions and processes of the environment. These processes operate at a rate and an intensity that generate characteristic properties, so that a distinctive deposit is produced.
This close genetic relationship between depositional processes and rock properties provides a potentially powerful tool for interpreting ancient depositional environments, which allows us to reconstruct the paleogeography of previous geologic periods as well as to evaluate the economic value of sedimentary rocks.
To reconstruct ancient depositional environment, we must study sediments and sedimentary processes in modern environments. Although it has limitations, this procedure of applying knowledge gained through study of modern depositional environments to interpretation of ancient sedimentary environments is the essence of environmental analysis. （字数 145）。
Proposed by: Charlson