Deep-water carbonate slope failure events in a newly discovered Silurian basin, Blue Ridge province, southern Appalachians, Tennessee

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

OSTI ID:7158797

Unrug, R ^[1]

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1. Wright State Univ., Dayton, OH (United States)

Siliciclastic deep-water turbidites of the Walden Creek Group, Ocoee Supergroup, underlying the foothills of the Great Smoky Mountains, contain olistolith blocks and olistostromal debris-flow breccia beds. Paleozoic fossils discovered recently in the olistoliths indicate Silurian age of the carbonates. The Walden Creek Group is therefore Silurian or younger, not late Proterozoic in age, as believed previously. The carbonate olistoliths and breccias formed by collapse of post-Taconic Silurian carbonate-dominated basin present in the Blue Ridge province of the Southern Appalachians into the younger basin of the Walden Creek Group. Two modes of occurrence of the olistoliths are present: (1) discrete horizons in which olistoliths are sitting spaced ten to hundreds of meters apart underneath a widespread conglomerate bed and (2) accumulations of olistoliths in localized stacked horizons in the vertical sequence of the enclosing siliciclastic rocks. Both modes can be related to failure of active fault scarps. Rocks of the olistolith are lithologically varied and record an older event of slope failure within the Silurian carbonate-dominated basin. Three facies assemblages representing two sedimentary environments are present in the olistoliths. Facies assemblage A includes oolitic limestone, stromatolite, carbonate breccia encrusted by stromatolite, and massive sandy limestone. It represents a high-energy, shallow-water, carbonate platform environment. Facies assemblage B consists of bedded dark limestone, alternating with black shale, and represents sediments of the carbonate platform slope. Facies assemblage C includes carbonate breccias intercalated in the bedded limestones and shales and is interpreted as deposits of the lower slope formed by failure of the carbonate platform margin.

• OSTI ID: 7158797
• Report Number(s): CONF-910403-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 75:3; Conference: Annual meeting of the American Association of Petroleum Geologists (AAPG), Dallas, TX (United States), 7-10 Apr 1991; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
CARBONATE ROCKS
AGE ESTIMATION
SEDIMENTARY BASINS
STRATIGRAPHY
TENNESSEE
GEOLOGIC FAULTS
GEOLOGIC FORMATIONS
GEOLOGIC HISTORY
LITHOLOGY
SILURIAN PERIOD
DEVELOPED COUNTRIES
GEOLOGIC AGES
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOLOGY
NORTH AMERICA
PALEOZOIC ERA
ROCKS
SEDIMENTARY ROCKS
USA
580000* - Geosciences