Sequence stratigraphy of the Jurassic-Cretaceous Morrison and Cedar Mountain Formations, NE Utah--NW Colorado

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

OSTI ID:5436541

Currie, B S ^[1]

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1. Univ. of Rochester, NY (United States). Dept. of Geological Sciences

The Jurassic-Cretaceous Morrison and Cedar Mountain of NE Utah and NW Colorado record nonmarine deposition during early development of the Cordilleran foreland basin. Contained within these formations are three distinct depositional sequences that represent changes in sedimentary architecture due to fluctuations in development of basin accommodation. The first of these sequences comprises the Oxfordian transition from marine to nonmarine sedimentation. Morrison Formation marginal marine and nonmarine facies prograded across shallow marine facies of the Stump Formation (Redwater Member), during a period of increased accommodation. The base of the second depositional sequences within the Morrison Formation was produced by a decrease in regional accommodation. The Cretaceous Cedar Mountain Formation unconformably overlies the Morrison Formation and its base marks the lower boundary of the third depositional sequence. The unconformity surface represents a decrease in regional accommodation and is marked by fluvial incision and evidence of subaerial exposure and intense weathering of the upper Brushy Basin Member. Increased basin accommodation during the early Cretaceous (Aptian-Albian ) resulted in valley fill deposition of the braided fluvial Buckhorn Conglomerate Member of the Cedar Mountain Formation. This conglomerate is overlain by Cedar Mountain anastomosing fluvial and lacustrine facies which were deposited during continued accommodation development. The Sequence is capped unconformity by the Albian-Cenomanian Dakota Formation.

• OSTI ID: 5436541
• 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
COLORADO
COMPARATIVE EVALUATIONS
CONGLOMERATES
CRETACEOUS PERIOD
DEPOSITION
DEVELOPED COUNTRIES
EVALUATION
GEOLOGIC AGES
GEOLOGIC FORMATIONS
GEOLOGY
JURASSIC PERIOD
MESOZOIC ERA
NORTH AMERICA
PETROLOGY
ROCKS
SEDIMENTARY ROCKS
SHALES
STRATIGRAPHY
USA
UTAH