Silurian pinnacle reefs of the Canadian Arctic

Journal Article · Thu Apr 01 04:00:00 EST 1993 · Palaios; (United States)

DOI:https://doi.org/10.2307/3515170· OSTI ID:6377086

De Freitas, T A; Dixon, O A ^[1]; Mayr, U ^[2]

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1. Univ. of Ottawa, Ontario (Canada)
2. Institute of Sedimentary and Petroleum Geology, Alberta (Canada)

Pinnacle reefs are commonly an attractive target for oil exploration because they are usually porous carbonate bodies entombed in impervious, deep-water shales that provide both the source and the seal for hydrocarbons. Silurian pinnacle reefs, the first described in the Canadian Arctic Archipelago, are exposed on Ellesmere and Devon Islands. Two main reef trends occur, one of early middle Llandovery to middle Ludlow age and a second of middle Ludlow to Late Silurian or Early Devonian age. Reefs of both phases contain lime mudstone cores: some are stromatactoid-rich and others consist predominantly of microbialite-rich lime mudstone or microbial boundstone. Facies sequences of both reef phases show evidence of upward-shallowing overall, but, in the older reefs, isochronous capping facies are dominated either by coral-mirian or by stromatoporoid boundstone and floatstone. This difference perhaps reflects variation in wave stress and apparent ability of a few corals,thickly encrusted by or associated with microbial boundstone and skeletal algae, to withstand greater wave energy than a stromatoporoid-coral-rich reef community. These reefs constitute one of the bright prospects of hydrocarbon exploration in rocks of the Franklinian succession. 43 refs., 9 figs.

• OSTI ID: 6377086
• Journal Information: Palaios; (United States), Journal Name: Palaios; (United States) Vol. 8:2; ISSN PALAEM; ISSN 0883-1351
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
ARCTIC REGIONS
CANADA
CRYOSPHERE
DEVELOPED COUNTRIES
EXPLORATION
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
GEOLOGY
ISLANDS
MINERAL RESOURCES
NORTH AMERICA
ORIGIN
PALEOZOIC ERA
PETROLEUM DEPOSITS
PETROLEUM GEOLOGY
POLAR REGIONS
REEFS
RESOURCE POTENTIAL
RESOURCES
SILURIAN PERIOD
STRATIGRAPHY