Turbidite facies and their inferred processes have been dealt with in many papers among which those by Mutti and Ricci Lucchi (1972, 1975), Walker and Mutti (1973), Walker (1978), Mutti (1979, 1992), Nardin et al. (1979), Lowe (1982), and Pickering et al. (1986, 1989) are the most widely accepted in subsequent literature.

These facies schemes differ from each other in many ways. Some schemes emphasize the objective recognition of facies characteristics, others emphasize the genetic relationships between facies and processes, while others have the tendency to combine descriptive and genetic approaches. The reader is referred to Mutti (1992) for a more extensive discussion.

The genetic approach is process-oriented, implying a continuum of genetically related processes and facies the last expression of which is the deposit of depletive and waning low-density turbidity currents. Following Kuenen’s broad definition of turbidites (see above), the approach also implies that the continuum does not only define those beds which can be interpreted as the deposit of a turbulent turbidity current, but also those beds or portions of beds which can be interpreted as the deposit of other kinds of processes which — regardless of their inferred characteristics — are high-density currents most commonly moving under more dilute and fully turbulent flows.

In these notes we will follow the process-oriented “facies tract“ concept as discussed by Mutti (1992), that is the downcurrent association of different but genetically related types of facies which are time-equivalent and, within each system considered, record the downstream evolution of sediment gravity flows. An ideal