Depositional and early diagenetic characteristics of modern saline pan deposits at the Bonneville Salt Flats, Utah, USA

Abstract

AbstractThe Bonneville Salt Flats form a saline pan in western Utah, USA. This modern saline pan has a unique history of land‐speed racing and potash mining. Multi‐decadal measurements record decreasing evaporite volume and extent, spurring multiple environmental studies. The goal of this work is to describe saline pan evaporite morphologies within the context of environmental measurements. Environmental data include field observations, groundwater and dust trap samples, precipitation, albedo, time‐lapse photography, groundwater level, and temperature measurements of air, groundwater and the shallow evaporite crust. Petrographic data include thick sections, evaporite slabs and sediments, and X‐ray computed tomography of evaporites. Diverse halite morphologies are formed at the surface, vadose and phreatic zones. The presence and preservation of these morphologies are influenced by spatially heterogenous natural and anthropogenic processes, including daily to seasonal changes in brine salinity, mineral saturation states, and water level within and across saline pan stages. In addition to hydrological balances delineated by the saline pan stages of flooding, evapoconcentration and desiccation, changes in vertical brine movement, temperature and surficial sedimentary structures influence evaporite morphologies. These results are transferable to the interpretation of altered evaporites and enhancing saline pan depositional models.