Sedimentary Features Produced by Efflorescent Salt Crusts, Saline Valley and Death Valley, California
Published:January 01, 1994
Joseph P. Smoot, Barbara Castens-Seidell, 1994. "Sedimentary Features Produced by Efflorescent Salt Crusts, Saline Valley and Death Valley, California", Sedimentology and Geochemistry of Modern and Ancient Saline Lakes Models, Robin W. Renaut, William M. Last
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Efflorescent salt crusts composed primarily of halite dominate the saline mudflats of Saline Valley and Death Valley, California. These crusts form by the complete evaporation of saline groundwater at the sediment-air interface. Efflorescent crusts also form where halite dust is introduced by wind, then dissolved by rain and reprecipitated as the rainwater is evaporated. Wind-blown silt and clay adhere to thin hydroscopic water films coating crystals in the efflorescent crusts, and coarser sediment is trapped in surface depressions. The sediment is left as a lag deposit when the halite dissolves at the base of the crust in the undersaturated waters below the surface. Efflorescent crust deposits slowly aggrade producing irregular sand and silt lenses in poorly sorted porous mud. The sand and silt lenses have distinctive cuspate contacts, ragged edges, and irregular layering and grain-size distributions. Efflorescent crusts growing on sandy sediment distort the upper surface into polygonal bowl shapes, or deform ripples into hump-shaped lenses. Deposition during flooding over an efflorescent crust commonly produces local areas of solution collapse, which are filled with the sediment as it accumulates. The latter resemble load casts but do not have associated flame structures. Efflorescent crust fabrics similar to those in Saline Valley and Death Valley are documented in the lacustrine Blomidon Formation (Fundy basin, Nova Scotia, Canada) and Bigoudine Formation (Argana basin, Morocco). Efflorescent crusts composed of less soluble minerals, such as gypsum or borates, may leave humpy layers of broken crystals and plates. Powdery efflorescence of minerals, such as thenardite or thermonatrite, generally only disturbs the internal layering of sandy deposits. Puffy ground in dry mudflats, formed by powdery efflorescence growth in mudcracks, produces a distinctive granular fabric.
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Sedimentology and Geochemistry of Modern and Ancient Saline Lakes Models
Sedimentology and Geochemistry of Modern and Ancient Saline Lakes - This volume of papers grew out of a four-day symposium entitled ?Sedimentary and Paleolimnological Records of Saline Lakes? held at Saskatoon, Canada in August, 1991. The aim of this Special Publication is to bring together selected papers from this conference that deal specifically with the sedimentological, inorganic geochemical, and hydrological aspects of salt lakes and their stratigraphic records. This volume is divided into four sections. The first section contains papers that deal with modern saline lakes. The second section contains papers dealing with sedimentation and diagenesis of late Quaternary salt lakes. The third and fourth sections contain papers devoted to ancient (pre-Quaternary) Lacustrine sequences.