Turbidity currents can be initiated by earth quakes, rivers in flood, and sediment failure in rapidly deposited delta fronts.  The initial sediments in the current will reflect the source.

Major features

• Sandstones and shales are monotonously interbedded.
• Beds tend to have sharp, flat bases, with no indication of erosion of sea floor.
• The sharp bases of beds have abundant markings (tool marks carved by rigid objects).
• Within sandstone beds, the grain size commonly decreases upward (graded bedding; see Bouma sequence).

• Classical Turbidites: characterized by monotonous interbeds of sandstone and shale, with no evidence of topography on the seafloor. All sandstones cab be described using the Bouma sequence. In this sequence, deposits fine upward.
• Massive Sandstones: Much more evidence of erosion of substrate; beds are commonly associated with channels many meters deep. The deposits of successive flows also join together (amalgamation) to make comosite beds (the monotonous aspect of sandstone-shale interbedding is lost). Most common sedimentary structure of this type is dish and pillar structure which indicate abundant fluid escape during deposition (see images from sedimenphica reference).
• Pebbly sandstone: beds tend to be well graded with internal stratification fairly abundant and consists of coarse, crude horizontal stratification and commonly channeled and laterally discontinuous.

• Conglomerates: Imbrication features which typified by clasts whose long axes lie parallel to flow and dip upstream. This signifies that clasts have not rolled on the bed.

• Pebbly mudstone, debris flows, slumps and slides: Consist of pebbles and distorted clasts of sandstone and mudstone, dispersed in a silty mudstone matrix.

Reference
Galloway, W. E., Hobday, D. K., Terrigenous Clastic Depositional Systems. Springer-Verlag, 1983
Walker, R. G., James, N. P., Facies Models. Geological Association of Canada, 1992