Multiphysics: Fluid Mixing and Brine Pool Formation for Economic Geology Applications

C. Schardt[1]
[1]University of Minnesota-Duluth, Duluth, MN, USA
Published in 2014

Significant submarine mineral deposits form when hot, metal-laden, saline fluids emerge onto the seafloor and mix with ambient seawater. Resulting density changes of fluid mixtures can trigger fluid buoyancy reversals, brine pool formation, and metal accumulation (Figure 1). While some of these processes are known from experiments, the inception, development, and physical-chemical processes operating within brine pools are poorly understood. These processes are crucial for our understanding of submarine fluid dynamics, mineral deposit formation, and exploration. Recent modeling results (Schardt, 2014) yield realistic submarine fluid discharge properties of such hydrothermal systems such as temperature, discharge velocity, and salinity. COMSOL Multiohysics® software will be used to integrate these results as well as field observations and theoretical studies of submarine fluid discharge to investigate the free mixing of ingression hot, saline hydrothermal fluids with cold seawater in a submarine depression. The development of resulting fluid temperatures, salinity/density changes, and buoyancy reversal will be studied and the conditions for brine pool formation investigated under realistic conditions (concurrent changes in temperature, salinity/density, fluid convection patterns). Results will be compared with field data from an active brine pool (Atlantis II Deep) to gain insight into the processes controlling internal processes and trace the mineralization history of brine pools.