Synextensional basin evolution, lower Miocene Clews Formation, central Mojave Desert, California

Conference · Fri Feb 01 04:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:5171388

Fillmore, R P; Walker, J D ^[1]

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1. Univ. of Kansas, Lawrence (United States)

The lower Miocene Clews Formation at Alvord Mountain, Mojave Desert, California, consists of up to 400 m of coarsening-upward continental deposits. During the initial stage of basin development, the depocenter was delineated by a lacustrine system that was bound to the west by alluvial fans and graded northward into a south-flowing fluvial braidplain. Lacustrine strata, composed of claystone, siltstone and carbonate, suggest an initially closed basin. Conglomerate and sandstone to the west represent small, sheetflood-dominated fans and contain igneous clasts and southeasterly paleoflow indicative of a proximal, relatively low relief source in the western Alvord Mountains. The second stage of deposition was dominated by coarse conglomerate and megabreccia with west-southwesterly paleotransport indicators and a distinctive metaigneous petrofacies that indicate a provenance in the Cronese Hills, 8 km to the east. These strata reflect rapid westward progradation of debris flow-dominated alluvial fans that advanced across the facia braidplain, eventually onlapping the smaller Alvord Mountain sourced fans across the basin. Influx of sediment from the paradise Range ceased. Based development resulted from regional northeast-southwest extensional deformation. The Alvord Mountain-Cronese Hills region was transported northeast as a single block on an east-dipping, low-angle normal fault associated with the Waterman Hills core complex 30 km to the west. Development of westward prograding fans is believed to record subsequence propagation of a northwest-trending, west-dipping normal fault associated with, but antithetic to the low-angle master fault.

• OSTI ID: 5171388
• Report Number(s): CONF-9103128--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Journal Volume: 75:2
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ALLUVIAL DEPOSITS
CALIFORNIA
CENOZOIC ERA
CONGLOMERATES
DEPOSITION
DEVELOPED COUNTRIES
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOLOGY
MIOCENE EPOCH
NORTH AMERICA
ROCKS
SANDSTONES
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
SEDIMENTATION
STRATIGRAPHY
TERTIARY PERIOD
USA