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TitreForaminiferal evidence of the Early Albian Moosebar/Clearwater Seaway in Mannville Group strata, Fort à la Corne kimberlite field, east-central Saskatchewan
AuteurMcNeil, D H; Zonneveld, J -P
SourceSummary of investigations 2004, volume 1, Saskatchewan Geological Survey; Saskatchewan Industry and Resources Miscellaneous Report 2004-4.1, 2004, 9 pages (Accès ouvert)
LiensOnline - En ligne
Séries alt.Commission géologique du Canada, Contributions aux publications extérieures 2003327
Documentfichier d'ordinateur
MediaCD-ROM; numérique
Formatspdf (Adobe Acrobat Reader)
Lat/Long OENS-105.5000 -105.0000 53.2500 53.0000
Sujetsmicrofossiles; fossiles; Albien; paléoenvironnement; kimberlites; sédiments marins; organismes marins; zones fossilifères; mégaspores; dépôts estuairiens; Crétacé
Illustrationslocation maps; cross-sections, stratigraphic; photomicrographs; photographs
Résumé(disponible en anglais seulement)
ABSTRACT Microfossil analysis of nine samples from the 106 m thick Cantuar Formation in the Star 96-03 borehole, Fort à la Corne kimberlite field, east-central Saskatchewan, has resulted in the recognition of three distinct microfossil assemblages (A to C). Assemblage A, in the lower part of the Cantuar, consists of thecamoebians occurring below and above coaly strata and is characteristic of fresh- to brackish-water environments. Assemblage B, in the lower part of the middle Cantuar, comprises foraminifera of the latest Early Albian Verneuilinoides cummingensis Subzone, as well as pyritized diatoms, rare radiolarians, fish fragments, and transported megaspores, and is characteristic of marginal-marine environments. Assemblage C, in the upper part of the Cantuar, consists of megaspores (aquatic ferns and club moss from flood-plain lakes and swamps) that are either in situ or transported by aqueous means into estuarine and tidal-flat environments. The marginal-marine microfossil assemblage (B) is a significant record of the Early Albian Moosebar/Clearwater Seaway in east-central Saskatchewan and indicates close proximity to the southeastern limit of this boreal seaway.
The occurrence of the V. cummingensis Subzone (assemblage B) establishes a maximum age for kimberlite activity at the Star 96-03 site. The oldest kimberlite in the borehole is a 3 m thick, primary, pyroclastic, airfall deposit occurring at mid-Cantuar level, approximately 17 m above the microfossil zone.