Annotated record of the detailed examination of Mn deposits from DSDP Leg 79 (Holes 544A and 546)

Seaward of the Mazagan Escarpment and slope is a band about 50 km wide where structures interpreted as diapirs stand like columns within a pile of sediments about 5 km thick . Dredges and cores from Vema cruise 30-13 and Valdivia cruise West Africa 1979 on the slopes of the most landward of these structural highs, just 10 km from the foot of the escarpment recovered fragments of sheared granite. It was hypothesized that, if this structure were a salt diapir, it might have carried upward very old sediments, dating to the earliest stages of Atlantic evolution, in the Early Jurassic or late Triassic. DSDP Leg 79, sites 544 through 547 were closely located on the structure area.