Sediments are transported downhill by either water or air until they meet a depression in the surface of the Earth.
Most sediments are eventually deposited in large depressions which we call sedimentary basins. As more sediment is deposited within a sedimentary basin, subsidence occurs (brought about by the weight of the sediments) and the basin becomes deeper, thus allowing even more sediment to be deposited. Sedimentary basins can form in a number of different environments, both on land (e.g. lakes) or sea (e.g. ocean basins).
How sediments are transported
Sediments can be transported in three different ways:
- Suspension load is when sediments are carried in suspension (usually fine-grained sediments that can be carried along easily by the flow)
- Bed load is when the forward force of the moving current acts more directly on the larger particles at the bottom as it pushes, rolls, and slides them along
- Saltation is more complex and usually affects sand-sized particles. Here, the particles are sucked up by eddies into the flow, travel with the flow for a while, and then fall back to the bottom
Ondine Evans , Web Researcher/Editor