Gravity-propelled currents that produce graded layers of sediment deposits are known as turbidity currents. Turbidity currents are dense, sediment-laden flows of water that can occur in rivers, oceans, and other bodies of water. They are typically formed when there is a sudden influx of sediment into a body of water, such as during a flood or a landslides.
As the sediment-laden water flows through the body of water, it becomes denser and heavier than the surrounding water, and it begins to sink. As it sinks, the sediment particles within the flow settle out, forming graded layers of sediment deposits. These sediment deposits can be composed of a variety of materials, including sand, silt, clay, and other particles.
Turbidity currents can have a significant impact on the geology of an area, as they can transport large amounts of sediment over long distances and deposit them in different locations. They are also important in the formation of many sedimentary rocks, including shale, sandstone, and conglomerate.