Subsurface mapping identified the Michoud fault, on the basis of well cutoffs and seismic surveys. Sedimentary growth implies that movement along the Michoud fault has been intermittent since Oligocene time (Bebout and Gutierrez, 1983). A cross section in McBride (1998) shows a high-angle normal fault that was correlated by Dokka (2006) with the Michoud fault. This fault merges with a low-angle detachment fault at –7 km deep that developed along the top of a slightly south-dipping zone of weak salt and shale. These structures are considered to be related to a regional south-vergent extensional-contractional complex described by Peel et al. (1995; Fig. 1). Movement of the complex and thus on the Michaud fault reflects gravitational instabilities and down-dip motion during times of high sedi