Final answer:
Sediment characteristics such as well-sorted, poorly sorted, rounded, and well-rounded can indicate the distance sediments have traveled from their source. Well-sorted sediments are typically far from their origin, while poorly sorted sediments are closer. Rounded grains suggest long-distance transport, with well-rounded ones having traveled far and angular grains indicating proximity to the source.
Step-by-step explanation:
The characteristics of sediment, such as grain size, sorting, and roundness, can reveal much about the sediment's history, including its transport and deposition. Well-sorted sediments have grains that are roughly the same size, typically indicating the sediment has been transported a far distance from its source. Poorly sorted sediments display a mix of grain sizes and are often found nearer to their origin. As for roundness, sediments that are well-rounded, with smoothed edges, have also often traveled a long distance, being worn down through the journey. In contrast, angular grains with sharp edges have not been transported far.
Grain size analyses help geologists to understand the transport and depositional history of sediments. Traditional methods involved sieving sediment and measuring the weight of different size fractions, while more modern techniques use computerized particle sizers for accuracy.