Three-dimensional reconstruction of an evolving fluvial system: Chinle Formation, northeastern Arizona

Conference · Wed Mar 01 04:00:00 EST 1989 · AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States)

OSTI ID:6120480

Deacon, M W; Middleton, L T

Exceptional three-dimensional (3-D) exposures of the Triassic Chinle Formation in northeastern Arizona allow detailed architectural analyses of a complex fluvial system. Lateral profiling, element analysis , and hierarchy of bounding surfaces demonstrate deposition in both low- and high-sinuosity channel systems. Two conglomerate bodies, the Shinarump and the Sonsela, were deposited in low-sinuosity, valley-confined systems as indicated by internal sequences of sedimentary structures and geometry of the macroforms. Stacked channel sequences consist of in-channel sandy bed forms separated from large, in-channel, downstream-accreting sandy macroforms (up to 5 m thick by 50 m long) bounded by fourth-order surfaces. Within localized channels, conglomerate bar complexes (up to 10 m thick by 150 m long) record downstream and oblique accreting macroforms bound both laterally and vertically by in-channel elements. Architectural features in the Chinle reflect intrabasinal as well as extrabasinal controls on sedimentation. Major changes in stream sinuosity are largely controlled by gradient changes associated with increased subsidence rates with time.

• Research Organization: Northern Arizona Univ., Flagstaff (USA)
• OSTI ID: 6120480
• Report Number(s): CONF-890404-
• Conference Information: Journal Name: AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States) Journal Volume: 73:3
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
ALLUVIAL DEPOSITS
ARIZONA
CONGLOMERATES
DEPOSITION
FEDERAL REGION IX
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
MESOZOIC ERA
NORTH AMERICA
ROCKS
SEDIMENTARY ROCKS
TRIASSIC PERIOD
USA