The elongate geometry of the abyssal plain with its single dominant source of sediments produced laterally continuous deposits from both large and small flows. These covered the entire 356 km length of the plain. Grain-size analysis of the four thickest turbidites (H₂, H₃, H₈, and H₉) demonstrates only slight downcurrent fining and vertical grading, expressed best in the ratio of coarse silt to fine silt plus clay. A small amount of sand is carried the length of the plain. The thicker units all show the same pattern of thickness, with a maximum in the middle of the plain around a topographic constriction and bend. This is most plausibly explained as due to reduction in flow speed of an initially supercritical flow causing enhanced deposition Some of the beds appear to have a double coarse layer in the base, which may indicate partial reflection of flows from the side of the basin. It is suggested by application of equations for flow behavior that both thick ( 3 m) and thin ( 0.3 m) beds are due to supercritical flows a few tens of meters high. However, the thick beds resulted from high-concentration flows (C_v 4% by volume) whereas thinner beds require low concentration (C_v < 1%) to run out over the full length of the basin.

The stratigraphy is tied into the dated oceanic pelagic record by analysis of foraminifera in the pelagic layers above the turbidites and through recognition of two Heinrich layers (H-1 and H-2, ages 14.3 and 21 ka). The resulting age framework shows higher turbidite frequency in the glacial (2.7/kyr) than interglacial (Holocene) (1.0/kyr). This also gives higher mass flux during the glacial. Emplacement of turbidites cannot be clearly related to sea-level changes but may well be due to seismic activity. However, one of the largest earthquakes in human experience (Lisbon in 1755) triggered only a thin turbidite, invalidating the term "seismite" for thick turbidites.