 |
Journal articles
Subsidence dynamics of the Montney Formation (Early Triassic, Western Canada Sedimentary Basin): insights for its geodynamic setting and wider implications
Abstract : This study presents the first published subsidence analysis during the deposition of the Montney Formation. It was deposited during the Early Triassic (ca. 252.2–245 Ma) in the Western Canadian Sedimentary Basin (WCSB) located along the western margin of the North American craton. Subsidence analyses of six representative wells and two outcrop sections along a proximal to distal transect are presented using a backstripping method integrating recent high-resolution stratigraphic correlations for the Montney Formation. The entire Paleozoic to Cenozoic sedimentary column of the WCSB was backstripped to put the deposition of the Montney Formation into a broader context and provide results regarding the type of subsidence and geodynamic setting for the Montney Formation.
The spatial and temporal evolution of the subsidence during the deposition of the Montney Formation indicates that the most likely basin setting is a foreland. The tectonic subsidence during the Triassic is herein interpreted as a combination of the topographic loading of the orogenic wedge (flexure) and the sublithospheric “loading” caused by slab load-driven subsidence (dynamic subsidence). This suggests that the retro-foreland basin setting was associated with an eastward dipping subduction during the deposition of the Montney Fm.
Three foreland stages are thus recorded in the whole WCSB, with evidence for: 1) a Late Permian (fore-arc) pro-foreland setting; then 2) a Triassic collisional retro-foreland basin prior to the well-known; 3) Jurassic-Cenozoic collisional retro-foreland.
Keywords :
geosynclines
geodynamics
foreland basins
lithosphere
Lower Triassic
high-resolution methods
Alberta
backstripping
basins
British Columbia
Canada
Canadian Cordillera
clastic rocks
correlation
deformation
deposition
flexure
fold and thrust belts
Mesozoic
miogeosynclines
Montney Formation
North America
North American Cordillera
North American Craton
oceanic lithosphere
Omineca Belt
outcrops
Pacific Plate
plate collision
plate tectonics
sandstone
sediment supply
sedimentary rocks
shale
siltstone
slabs
Slide Mountain Terrane
subduction
subsidence
tectonic wedges
terranes
thickness
Triassic
Western Canada
Western Canada Sedimentary Basin
Yukon-Tanana Terrane
Cited literature [77 references]
https://hal-ifp.archives-ouvertes.fr/hal-02196726
Contributor : Nadine Couëdel Connect in order to contact the contributor
Submitted on : Monday, July 29, 2019 - 1:01:25 PM
Last modification on : Monday, July 29, 2019 - 2:24:57 PM
Contributor : Nadine Couëdel Connect in order to contact the contributor
Submitted on : Monday, July 29, 2019 - 1:01:25 PM
Last modification on : Monday, July 29, 2019 - 2:24:57 PM
File
Post Print 2018 Rohais.pdf
Files produced by the author(s)