Evolution of a synextensional Miocene basin

Conference · Thu Apr 01 04:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5022165

Miller, J M.G. ^[1]; John, B E ^[2]

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1. Vanderbilt Univ., Nashville, TN (United States). Dept. of Geology
2. Univ. of Wyoming, Laramie, WY (United States). Dept. of Geology

Sedimentologic and structural data reveal the synextensional basin history of a 15 km[sup 2] area in the N. Mohave Mts. Conglomerate and sandstone, [approximately] 600 m thick with interbedded megabreccia, tuff and basalt, unconformably overlie the Peach Springs Tuff (18.5 Ma). The Peach Springs Tuff (Tps) was tilted gently S or SW (< [approximately]17[degree]) and folded on a small scale about axes now trending NNW-SSE before deposition of the overlying sediments. The sedimentary section buttresses against the tilted Tps, which is absent locally in the east. A pronounced facies change occurs from coarse, crudely bedded conglomerate in the west to well-bedded sandstones farther east. Megabreccia bodies, ill-defined in shape, appear to be interbedded with the conglomerate. A sheet-like megabreccia, [approximately]10 m thick, is conformable in the section and can be traced over 2 km laterally. Asymmetry of minor folds below it indicates movement towards the SW off a paleo-dip slope. Facies changes and preliminary paleocurrent measurements indicate transport toward the E away from a paleo-fault scarp. Facies suggest alluvial fan and lacustrine deposition in a small half-graben basin bounded by a fault scarp < 2 km to the west.

• OSTI ID: 5022165
• Report Number(s): CONF-9305259--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 25:5
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ALLUVIAL DEPOSITS
ARIZONA
BASALT
CENOZOIC ERA
CONGLOMERATES
DEVELOPED COUNTRIES
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
GEOLOGY
IGNEOUS ROCKS
MIOCENE EPOCH
NORTH AMERICA
ORIGIN
ROCKS
SANDSTONES
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
STRATIGRAPHY
TERTIARY PERIOD
TUFF
USA
VOLCANIC ROCKS