DOI: 10.1016/j.epsl.2020.116492
论文题名: Shale and pyrite Re-Os ages from the Hornby Bay and Amundsen basins provide new chronological markers for Mesoproterozoic stratigraphic successions of northern Canada
作者: Rainbird R.H. ; Rooney A.D. ; Creaser R.A. ; Skulski T.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 548 语种: 英语
中文关键词: Dismal Lakes Group
; Mesoproterozoic
; Re-Os geochronology
; Shaler Supergroup
; stratigraphy
英文关键词: Barium alloys
; Binary alloys
; Geochronology
; Lakes
; Metals
; Osmium alloys
; Pyrites
; Rhenium alloys
; Sedimentation
; Stratigraphy
; Uranium alloys
; Weathering
; Baffin islands
; Calibration points
; Chemostratigraphic data
; Marine flooding
; Microfossils
; Northern Canada
; Source material
; Supercontinents
; Carbonaceous shale
; age determination
; calibration
; chemostratigraphy
; chronostratigraphy
; geochronology
; juvenile
; Laurentia
; paleoenvironment
; Proterozoic
; pyrite
; rhenium-osmium dating
; shale
; Amundsen Basin
; Arctic Ocean
; British Columbia
; Canada
; Gulf Islands
; Hornby Island
; Eukaryota
英文摘要: Here we present Re-Os geochronological data from two carbonaceous shale units from the Hornby Bay and Amundsen basins that provide important chronological markers for Mesoproterozoic stratigraphic successions within northern Canada. Shale from the basal Escape Rapids Formation yields a robust depositional age of 1067.3 ± 13.5 Ma for the lowermost Shaler Supergroup of Amundsen basin with a remarkably unradiogenic initial 187Os/188Os value (0.15), implying that it derived from weathering of juvenile source material, such as basalt. Sedimentological features, indicative of large basin conditions, suggest deposition within an extensive epeiric sea that was intermittently mixed with waters from an exterior ocean. This age, and the 720 Ma age of the uppermost Shaler Supergroup, constrain deposition of the ∼4 km-thick succession to a period of approximately 350 myr, recording sedimentation through a complete supercontinent cycle - amalgamation through to break-up of Rodinia. Further, it indicates that the Amundsen basin formed at the same time as the Borden, and Fury and Hecla basins on northern Baffin Island, and the Thule basin in northwestern Greenland, and that these basins were perhaps connected as part of a much larger basin situated in the interior of Rodinia. Diagenetic pyrite from sandstone dykelets in carbonaceous shales of the Fort Confidence Formation yielded a Re-Os model age of 1438 ± 8 Ma, providing a minimum age for deposition of the lower Dismal Lakes Group of the Hornby Bay basin. This age strengthens proposed regional correlation of the Hornby Bay basin with the large intracontinental Athabasca and Thelon basins, located on the Rae craton to the southeast, and is evidence for a Laurentia-wide marine flooding episode ca. 1500 Ma. Both new ages place important constraints on newly discovered eukaryotic microfossils from the Shaler Supergroup and Dismal Lakes Group and calibration points for critical chemostratigraphic data. © 2020 Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165224
Appears in Collections: 气候变化与战略
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作者单位: Geological Survey of Canada, Natural Resources Canada, Ottawa, ON K1A 0E8, Canada; Department of Earth and Planetary Sciences, Yale University, New Haven, CT 06511, United States; Dept. of Earth and Atmospheric Sciences, University of Alberta, 1-26 ESB, Edmonton, AB T6G 2E3, Canada
Recommended Citation:
Rainbird R.H.,Rooney A.D.,Creaser R.A.,et al. Shale and pyrite Re-Os ages from the Hornby Bay and Amundsen basins provide new chronological markers for Mesoproterozoic stratigraphic successions of northern Canada[J]. Earth and Planetary Science Letters,2020-01-01,548