Publication Type:
Journal ArticleSource:
Precambrian ResearchPrecambrian Research, Elsevier, Amsterdam, International, Volume 278, p.179-206 (2016)ISBN:
0301-9268Keywords:
Australian Plate, basin analysis, basins, biogenic structures, Canada, carbonate rocks, clastic rocks, deep-water environment, depositional environment, diagenesis, Laurentia, lithofacies, lithostratigraphy, marine sedimentation, mesoproterozoic, paleoenvironment, plate tectonics, Precambrian, proterozoic, rifting, sedimentary basins, Sedimentary rocks, sedimentary structures, sedimentation, siliciclastics, stromatolites, turbidite, upper Precambrian, Wernecke Mountains, Western Canada, Yukon TerritoryAbstract:
The Mesoproterozoic Pinguicula Group (<1.38 Ga) is exposed in the Wernecke and Hart River inliers in northern Yukon, Canada. The Pinguicula Group records deposition of non-cyclic siliciclastic and carbonate strata on low-energy slopes affected by rare high-energy deposits in a tectonically active epicratonic setting. The succession is approximately 1.4 km thick at its measured type sections and comprises three newly formalised formations: the Mount Landreville, Pass Mountain, and Rubble Creek formations (formerly units A, B, and C, respectively). The Mount Landreville Formation is a predominantly siltstone succession with minor conglomerate and sandstone deposited below storm wave-base on a relatively gentle slope. The Pass Mountain Formation is a wispy- to planar-laminated carbonate succession deposited on a low-energy slope mostly below storm wave-base and is punctuated by rare high-energy gravity-flow deposits including debrites, grain-flows, turbidites, and micro-turbidites. The Rubble Creek Formation is dominated by repetitive centimetre- to decimetre-scale lime mudstone beds; it is distinguished from the Pass Mountain Formation by abundant zebra texture (an alternating dark grey and white banding caused by late diagenetic or hydrothermal fluid influx) and a lack of sediment gravity-flow deposits. The Pinguicula Group is the middle of five, unconformity-bounded, Proterozoic stratigraphic successions deposited on the northwestern margin of Laurentia (ancestral North America). The Pinguicula basin was epicratonic and deepened to the south (present coordinates). The basin formed during an amagmatic extensional event that contributed to the break-up of Columbia and the separation of Laurentia from Australia. Whereas most preserved Mesoproterozoic basins are dominated by shallow-water lithofacies deposited in rift and epicratonic settings, with few deep-water lithofacies preserved, the carbonate strata of the Pinguicula Group provide a rare insight into deeper-water carbonate environments. Abstract Copyright (2016) Elsevier, B.V.
Notes:
GeoRef, Copyright 2018, American Geological Institute.<br/>2016-058822<br/>Hart River Inlier<br/>Mount Landreville Formation<br/>northern Yukon Territory<br/>Pass Mountain Formation<br/>Pinguicula Basin<br/>Pinguicula Group<br/>Rubble Creek Formation
