Final answer:
Sediment sorting refers to the range of grain sizes in a deposit and indicates transport distance, with well-sorted sediment usually traveling a greater distance than poorly sorted sediment. Sediment roundness also plays a role, with well-rounded grains suggesting longer transport.
Step-by-step explanation:
Sediment sorting refers to the distribution of grain sizes within a sedimentary deposit. When sediment is well-sorted, it generally contains grains that are about the same size, a characteristic that suggests the sediment has been transported over a long distance from its source. Poorly sorted sediment, on the other hand, contains a mix of grain sizes and usually indicates a short distance of transport from the source. The roundness of sediment, often described as sphericity, also provides insights into transport history.
Sorting can occur through various natural processes, including water and wind transport. Sediment deposited by fast-moving water, such as rivers, can display a range of grain sizes and indicate variable energy environments. Conversely, sediments deposited by wind, like those found in deserts, are often well-sorted with uniform grain sizes.
In geological terms, sorting is important for interpreting sedimentary environments and the history of the sediments. For instance, graded bedding, a structure found in sedimentary rocks, shows a progression in grain size from coarse at the bottom to fine at the top of a bed.