Sediment transport patterns inferred from grain size trends and trace metal dispersion near the Santa Rosalía mining district, Gulf of California

Abstract The transport of continental materials of natural and/or anthropic origin as well as their dispersion and final deposition in marine environments can be inferred from the analysis of the textural tendencies of sediments. The exploitation of copper ore (since the 19th century) in the Santa Rosalia mining district has caused the accumulation of potentially toxic elements (PTEs) in sediments off the western coast of the Gulf of California; however, after several decades of mining, little is known about the mobilization and final destination of these PTEs. In the present work, the net sedimentary transport and dispersion of Cu and Zn is inferred in front of the mining district of Santa Rosalia at the western margin of the Gulf of California. Net sedimentary transport is dominantly towards the southeast, with a change towards the east of the port of Santa Rosalia. The spatial distribution of Cu and Zn showed the same pattern as the net sediment transport, which suggests that the dispersion of PTEs is controlled by the textural tendencies of the sediments and their transport, corroborated by hydrodynamic models of the marine currents at the western margin of the Gulf of California.