Earth science questions?

Turbidite is correct. The sediments which deposit at the outfall of a river into the ocean will range from clay to gravel, forming a delta or estuary. In situations where the river has a large sediment outflow it will form a prograding delta - a m of sediment which constantly moves outward, and usually also sinks under the weight of the sediment. Where the sediment outflow is small, an estuary results, which is usually sand-dominated in the channel, and with muddy margins (usually with mangroves and mud flats).