Pockmarks in Pliocene-Quaternary continental slope deposits offshore Angola show features related to: (1)
fluid leakage craters that formed repeatedly, (2) authigenic methane-derived carbonates that indicate the
(former) presence of hydrocarbons and (3) erosional--depositional structures that are clearly related to
current activity. Depending on topography, the pockmarks show differing development: ''Advancing
Pockmarks" preferentially developed on regional slopes or inclined topography (> 2.5°-3°). They arranged
in a chain-like pattern and mimic the outline of buried turbidite channels below. These pockmarks and their
infill migrated downslope in response to shifting vents. "Nested Pockmarks" occur in gently sloping areas ( <
2°). Their isolated conical infill records slope-parallel migration within a specific depth range pointing to the
influence of contour currents. Both pockmark types are long-lived and they record preferential fluid
migration along specific pathways, which developed at the downcurrent sidewalls of pockmarks due to flow
separation initiating "cavity flow" within the pockmarks. The durable specific migration paths include
pockmark sidewalls, vertically stacked erosional-interface of sediment waves, or entire pockmark bodies.
The vertical extent of both pockmark types from End Miocene to the present-day seafloor documents
various intensities of episodic fluid bursts followed by periods of quiescence and fill.