The Louisiana slope is an excellent area to study the relationship of sedimentation halokinesis, and related structures. The stratigraphic and structural geometries of Tertiary deepwater strata and allochthonous salt are well imaged on high quality seismic data. Multiple episodes of faulting, folding, erosion, sediment bypass, ponding, and concentration due to salt movements are observed in the numerous intraslope minibasins in Green Canyon, Ewing Bank, and Mississippi Canyon. Accurate timing and section balancing have been made with a subregional interpretation of up to 32 Tertiary horizons based on an integrated sequence stratigraphic study. A series of subregional sequence isochrons and facies maps were made to reconstruct the paleo positions of salt, depositional fairways, and depocenters through time.
Salt on the slope deformed in stages in response to changes in sedimentation. The generalized stages are: differential loading by turbidites during lowstands; salt deflation/inflation and initiation of growth faulting; diapirism; formation of a dynamic salt bulge and growth fault, formation of salt tongues, and downslope glacier-like spreading; finally, salt source depletion, weld formation, and cessation of growth faulting. This process occurred in the Miocene, Pliocene, and Pleistocene.
An apparent lag of about 1.5 million years between sedimentation and subsequent halokinesis was observed in the vicinity of a massive slump in Mississippi Canyon.
Most salt thrusting on the slope is within the shallow sediments; however, a few cases of deep (below 5000’) active thrusting were observed. Young faults (some offset the sea floor) are linked to shallow as well as deeply buried (in excess of 10,000’) salt, indicating that salt is mobile under a variety of conditions.