Depositional processes and facies of Trail Fan sandflat: Death Valley, California

Conference · Wed Jan 01 00:00:00 EST 1992 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5932221

Malicse, A E; Mazzullo, J M; Eide, M G ^[1]

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1. Texas A and M Univ., College Station, TX (United States)

A study was conducted of the alluvial fan to playa transition along Trail fan in Death Valley, California with the primary objectives of documenting sedimentary facies and textural features of so-called arid region sandflat. The study involved description of sedimentary structures along trenches and meter-deep cores, description of surficial bedforms, and collection of samples for lithological analyses. Surficial features of Trail Fan sandflat gradually change downdip as a function of texture, ground water depth, and runoff. They include: (1) tongues of mudflows; (2) shallow braided channels that taper out into mudflat or coalesced into single channels; (3) puffy grounds; and (4) flat-smooth surface of the mudflat. The sediment's texture shows a fining downdip trend except when the surface are draped by mudflows. Four facies are distinguished downdip from the alluvial fan to playa mudflat. Facies 1 consists of massive, light gray, matrix to grain supported gravel, and is interpreted as debris flow or streamflow deposit. Facies 2 consists of thin-bedded (0.6--0.06 m), tan, massive, gravelly mud and is interpreted as mudflow deposit. Facies 2 consists of repeated sequences of thick-bedded (0.15 to 0.3 m), massive to planar stratified, graveliferous sand with mud drape and is interpreted as poorly sorted sheetflood or streamflow deposit. Facies 4 consist of light gray, planar laminated, coarsening upward mud to muddy sand, and is interpreted as mudflat facies. This study shows that arid region sandflat facies is a mosaic of mudflow, debris flow, sheetflood and streamflow deposits and is more complex than previous sandflat models described.

• OSTI ID: 5932221
• Report Number(s): CONF-921058-; CODEN: GAAPBC
• Journal Information: Geological Society of America, Abstracts with Programs; (United States), Vol. 24:7; Conference: 1992 annual meeting of the Geological Society of America (GSA), Cincinnati, OH (United States), 26-29 Oct 1992; ISSN 0016-7592
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
ALLUVIAL DEPOSITS
DEPOSITION
STRATIGRAPHY
CALIFORNIA
GEOLOGIC HISTORY
GEOLOGIC MODELS
GEOLOGIC STRUCTURES
GROUND WATER
LITHOLOGY
TEXTURE
THICKNESS
VALLEYS
DEVELOPED COUNTRIES
DIMENSIONS
GEOLOGIC DEPOSITS
GEOLOGY
HYDROGEN COMPOUNDS
NORTH AMERICA
OXYGEN COMPOUNDS
PETROLOGY
USA
WATER
580000* - Geosciences