scientific discipline that is concerned with the physical and chemical properties of sedimentary rocks and the processes involved in their formation, including the transportation, deposition, and lithification (transformation to rock) of sediments. The objective of much sedimentological research is the interpretation of ancient environmental conditions in sediment source areas and depositional sites. Sedimentologists study the constituents, textures, structures, and fossil content of the deposits laid down in different geographic environments. By these means they can differentiate between continental, littoral, and marine deposits of the geologic record.