Petrology of Tullock Member, Fort Union Formation, Wyoming and Montana: Evidence for early Paleocene uplift of Bighorn Mountains

Conference · Fri Sep 01 00:00:00 EDT 1989 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:5699563

Brown, J L; Hansley, P L ^[1]

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1. Geological Survey, Denver, CO (USA)

New petrologic data collected from sandstones in the Paleocene Tullock Member of the Fort Union Formation above the Cretaceous/Tertiary boundary in the Powder River basin (PRB) and from the lowermost Paleocene in the Bighorn basin, Wyoming and Montana, compel reevaluation of the timing of the bighorn uplift, formerly thought to be middle Paleocene. The Cretaceous/Tertiary boundary is identified by regionally valid palynological and trace element geochemical criteria. Basin-wide outcrop and subsurface studies of the Tullock Member indicate deposition on a low-gradient alluvial plain extending toward the retreating Cannonball sea. Eastward-flowing, low-sinuosity paleostreams containing small, sandy, stable channels characterized the fluvial systems.

• OSTI ID: 5699563
• Report Number(s): CONF-8910195-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (USA), Vol. 73:9; Conference: AAPG Rocky Mountain Section meeting, Albuquerque, NM (USA), 1-4 Oct 1989; ISSN 0149-1423
• Country of Publication: United States
• Language: English

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