The balance between deposition and subsidence (tectonics) in a rift basin playa and its effect on the climatic record of an area: Evidence from Bristol Dry Lake, California
- CSIRO, Floreat Park (Australia)
Two continuous core intervals drilled in Bristol Dry Lake, a large (150 km{sup 2}) playa in the central Mojave Desert of California, penetrated over 500 m of sediment and did not reach basement. The repetitious nature of the alternating shallow brine pond halite and siliciclastic and the consistency of the carbonate isotopic data from the surface and core indicate a relatively stable brine composition for most of the history of Bristol Dry Lake. All sedimentary structures and primary halite fabrics in the core indicate shallow-water, brine-pond halite alternated with halite-saturated siliciclastic muds in the basin center. A delicate balance of subsidence and mechanical and chemical deposition of evaporite and siliciclastic minerals was necessary to maintain the largely ephemeral lake environment of deposition through over 550 m of basin fill. The alternating brine pond/saline lake setting in Bristol Dry Lake is not directly related to climatic influences, and the sediments do not record major climatic events demonstrated in other closed-basin lakes. The reason for this insensitivity to climatic events is explained by the interior location of the basin, the low relief of the mountains surrounding the catchment, the large surface area of the catchment, and the low average sedimentation rates. All of the above criteria are at least partially controlled by the tectonics of the area, which, in turn, affect the sedimentation rate and supply water to the basin. Therefore, it is important to consider the influence of the above factors in determining global versus local, or regional, climate curves for a particular basin.
- OSTI ID:
- 7259750
- Report Number(s):
- CONF-910403--
- Journal Information:
- AAPG Bulletin (American Association of Petroleum Geologists); (United States), Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Vol. 75:3; ISSN AABUD; ISSN 0149-1423
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
580000* -- Geosciences
ANHYDRITE
BRINES
CALIFORNIA
CHEMISTRY
DEPOSITION
DEVELOPED COUNTRIES
DRILL CORES
EVAPORITES
GEOCHEMISTRY
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOLOGY
HALIDE MINERALS
HALITE
ISOTOPE RATIO
LAKES
MINERALS
NORTH AMERICA
PALEOCLIMATOLOGY
PALEONTOLOGY
RIFT ZONES
ROCKS
SALT DEPOSITS
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
STRATIGRAPHY
SULFATE MINERALS
SURFACE WATERS
USA