Structural Characteristics of Cohesive Gravity-Flow Deposits, And a Sedimentological Approach on Their Flow Mechanisms

Abundant mass-transport deposits characterize the seafloor of the northwestern continental slope and rise of Gulf of Mexico. Most of the deposits reveal a cohesive nature, consisting mainly of a silty-clay matrix with dominant to rare mud-clasts. Five types of cohesive gravity-flow deposits have been distinguished, based on their structural characteristics, nature of the mud matrix, and mud-clast percentage. Each type of the cohesive gravity-flow deposits implies different rheological behavior for the flows from which they originate, depending on their viscosity, mud-clast abundance, and external factors (e.g. hydroplaning), thus revealing that these deposits have resulted from a wide range of different types of flows.