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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 65 (1981)

Issue: 5. (May)

First Page: 934

Last Page: 934

Title: Facies Anatomy of Modern Continental Sabkha, Bristol Dry Lake, California: ABSTRACT

Author(s): C. Robertson Handford

Article Type: Meeting abstract


Bristol Dry Lake is a 155-sq km fluvial-lacustrine dominated, continental sabkha, or playa, in the Mojave Desert of southeastern California, and is filled with at least 300 m of interbedded terrigenous clastics, gypsum, anhydrite, and halite. The evaporite facies roughly form a bull's-eye pattern with abundnat gypsum and anhydrite surrounding a basin center accumulation of halite. Transects through Bristol Dry Lake, from the alluvial fan and sand flat to the center of the playa, reveal (1) crudely bedded, coarse-grained clastics prograding over and interfingering with either (2) wadi (alluvial/eolian) sand and silt, or (3) mud-flat facies of nodular to enterolithic gypsum or anhydrite and blades of gypsum in red-brown silt and clay, followed by (4) saline mud-flat facies f red-brown silt and clay crowded with giant (15 cm diameter), displacive, hopper-shaped crystals of halite, and (5) salt-pan beds of chaotic mud-halite up to 4 m thick in the center of the playa.

Deposition of terrigenous clastics was by fluvial-sheetflood processes around the toes of alluvial fans, fluvial flow through very shallow rills and suspension settling in the mud-flat environments. Much of the sediment is reworked by eolian processes. Evaporites are precipitated at or just below the sabkha surface from discharging brines.

Lithofacies of this modern continental sabkha are nearly identical to those comprising the Middle-Upper Permian evaporites of the Texas and Oklahoma panhandles, and they are excellent process analogs for ancient facies analysis.

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