Previous investigations of the East Breaks slide interpreted this site as having been formed by a single mass-wasting event at the terminus of a late Wisconsinan shelf-edge delta. According to these interpretations, after initiation, this slide/slump propagated downslope and divided into two major lobes as it encountered a bathymetric high formed by a salt diapir. This study used a large, new data base of high-frequency 3.5-kHz acoustic reflection profiles and piston cores that shows that the two lobes were genetically separate. Their formation involved the two major types of downslope sediment transport mechanisms that dominate continental slopes: gravity-driven slide/slump/debris...