The stratigraphy and structure of the old, starved passive margin of the Mazagan Plateau and the adjacent Escarpment which extends from 1,000-3,000 m water depth was studied during the cofinanced French-German CYAMAZ deep diving campaign which obtained 130 in-situ samples, supplemented by direct sea floor observations during 18 dive traverses. The facies evolution of the Mazagan carbonate platform between kimmeridgian and Valanginian times was mainly influenced by blockfaulting and sea-level fluctuations. Regressive periods occurred during Kimmeridgia/Tithonian and Late Berriasian times, and are separated by a late Tithonian/early Berriasian transgression. The drowning of the main carbonate platform and the Early Cretaceous to Paleogene history of the hemipelagic to pelagic post-platform sediments was strongly influenced by vertical tectonics and sea level fluctuations. During Jurassic to mid-Cretaceous block-faulting events, migrating in a landward direction, the carbonate platform was structured into a succession of blocks, controlled by old Hercynian faults trending 160 degree or 20 degree (Atlantic direction) or 90-120 degree (Mediterranean direction).