Sediment transport trends in Bahía Concepción, Baja California Sur, Mexico, based on textural parameters and heavy mineral concentrations

摘要

The dispersion pattern of the modern sediments of Bahía Concepción, Baja California Sur, Mexico was obtained based on the spatial trends of their textural properties and heavy mineral content. The McLaren and Bowles and LeRoux models were applied to a sediment texture data set. The McLaren and Bowles method was the most appropriate for the present study due to the elongated nature of the bay and sampling design, but it was complemented by the LeRoux model, providing in some cases a lateral transport component. Seven heavy minerals were identified and their sources were located with the aid of Principal Component Analysis. Two main sources were evident based on the spatial textural trends; one located between Playa Santispac and Punta Santa Bárbara, and the other adjacent to the Cadejé Basin. A bi-directional transport pattern was found at the mouth of the bay with sediment being exported near the margins and imported through the deeper central portion. Transport along the western margin was mostly towards the head of the bay, and towards the north along the eastern margin. In both cases the transport trends indicate a component of transport toward the deeper parts of the bay. A good agreement was found among the three methods in identifying the clastic-sediment sources and their main transport directions.