Umbrella structure and channel-wall stoping in the Cambrian St. Roch Formation, Quebec Appalachians: significance for particle support mechanisms and turbulence development in hyper-concentrated sediment gravity flows

Hesse, Reinhard; Fong, Christopher C. K.

doi:10.1007/s00531-013-0968-3

Cited by 2 publications

(1 citation statement)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The original interpretation of the depositional environment of the Kamouraska quartz arenites as shallow marine (beach and near-shore sands) and the associated conglomerates as alluvial fan deposits (Hubert 1973) has been revised by subsequent studies to take into account the deep-water continental-margin environment of the southern margin of Laurentia (St. Julien and Hubert 1975;Vallières 1984;Lebel and Hubert 1995;Van Staal 2005). Malhame and Hesse (2011) and Hesse and Fong (2014) made a point for identifying continental slope deposits within this deep-water passive margin. In this tectonic setting, a thick quartz arenite unit appears as a distinct petrologic anomaly that represents one extreme in the tectonic sandstone provenance scheme of Dickinson and Suczek (1979).…”

Section: Introductionmentioning

confidence: 99%

Quartz arenites of the Cambro–Ordovician Kamouraska Formation, Quebec Appalachians, Canada: II. Eolian sands in deep-sea sedimentary gravity-flow deposits

Malhame

Hesse

2015

Can. J. Earth Sci.

Self Cite

View full text Add to dashboard Cite

The Kamouraska Formation is a quartz-arenitic unit of latest Cambrian -earliest Ordovician age in the Quebec Appalachians that was deposited by hyperconcentrated to concentrated density flows in a meandering submarine canyon on the continental slope bordering the Iapetus Ocean, as outlined in a companion paper. Detailed petrographic study of the quartz arenites of the Kamouraska Formation combined with scanning electron microscopy of grain surface textures suggests that the quartz sands are of eolian origin having been derived from an inland desert or, less likely, a barrier beach dune system. Transport of the mature quartz-arenitic sand onto the shelf and deposition into the deep sea was not accompanied by substantial mixing with material from other sources thus preserving the inherited eolian characteristics. A modern analogue for the eolian interpretation of the deep-sea quartz-arenite beds is as follows: thick, Late Pleistocene eolian sand beds on a modern abyssal plain in the East Atlantic referred to as eolian-sand turbidites that were deposited in the deep sea during glacial sea level lowstands when eolian sand transport to canyon heads was enabled by an exposed and shortened shelf. Similarly, an established sea level lowstand at the Cambro-Ordovician boundary would have facilitated the introduction of eolian sand of the Kamouraska Foundation into canyon heads on the upper slope from where turbidity currents and related density flows were triggered. Correlation of the Kamouraska Formation with the quartz arenites of the Cairnside Formation of Quebec (Keeseville Formation in northern New York State, Nepean Formation in southern Ontario) links the deep-sea deposits with remnants of an inland dune system. Résumé : La Formation de Kamouraska est constituée d'une unité d'arénite quartzique (Cambrien supérieur -Ordovicien inférieur) dans les Appalaches du Québec; elle a été déposée par des courants de densité hyperconcentrés à concentrés dans un canyon sous-marin à méandres sur la pente continentale à la bordure de l'Océan Iapetus, tel que souligné dans un article complémentaire. Une étude pétrographique détaillée des arénites quartziques de la Formation de Kamouraska jumelée à une microscopie électronique à balayage des textures de surface des grains suggèrent que les sables quartzeux sont d'origine éolienne et qu'ils proviennent d'un désert d'arrière-pays ou, ce qui est moins probable, d'un système de dunes de cordon littoral. Le transport du sable arénite-quartz mature sur la plateforme continentale et sa déposition en mer profonde n'ont pas été accompagnés d'un malaxage important avec du matériel d'autres sources, préservant ainsi les caractéristiques éoliennes héri-tées. Un analogue moderne pour l'interprétation éolienne des lits d'arénite quartzique de mer profonde est le suivant : d'épais lits de sables éoliens (Pléistocène tardif) sur une plaine abyssale moderne dans l'Atlantique Est, connus en tant que turbidites de sables éoliens, qui ont été déposés en mer profonde durant les périodes de bas niveau de...

show abstract

Section: Introductionmentioning

confidence: 99%