|Titre||Detrital zircons as provenance indicators in the Lower Cretaceous sedimentary rocks of the Scotian Basin, eastern Canada: a SEM-CL study of textures|
|Auteur||Triantafyllidis, S; Pe-Piper, G; Yang, X; Hillier, C|
|Source||Commission géologique du Canada, Dossier public 5746, 2008, 89 pages, https://doi.org/10.4095/226104 (Accès ouvert)|
|Éditeur||Ressources naturelles Canada|
|Media||numérique; en ligne|
|Province||Région extracotière de l'est|
|Lat/Long OENS||-61.0000 -57.0000 46.0000 43.0000|
|Sujets||Crétacé inférieur; grès; lithofaciès; analyses stratigraphiques; corrélations stratigraphiques; modèles stratigraphiques; diagenèse; analyses par microscope électronique; milieu sédimentaire; origine;
analyses au microscope électronique à balayage; microscopie électronique à balayage; zircon; Puit Alma K-85 ; Puit Glenelg A-49 ; Puit Thebaud C-74 ; Puit Venture 1 ; Puit Venture 2 ; Formation de Missisauga ; Formation de Logan Canyon ; Formation de
Mic Mac ; 3; géologie marine; stratigraphie; sédimentologie; Crétacé; Jurassique|
|Illustrations||location maps; images; pie charts; tables|
|Programme||Sécurité de l'approvisionnement énergétique du
|Diffusé||2008 12 04|
|Résumé||(disponible en anglais seulement)|
In this project, detrital zircons from the Lower Cretaceous sandstones form the Scotian basin were studied. The backscattered electron and cathodoluminescent
characteristics of detrital zircons were used as provenance indicators to help provide evidence for or against the paleogeographic models proposed by Pe-Piper and MacKay (2006 and Pe-Piper et al. (2007). A second objective was to complete a regional
study of zircons from the on-land Chaswood Formation (Noftall, 2007). The zircon grains came from sandstone samples collected from conventional cores from the wells Alma K-85, Thebaud C-74, Glenelg N-49, Venture 1 and 4, Peskowesk A-99 and Dauntless
D-35, and heavy mineral separates of cutting samples from the Fox I-22 and Crow F-52 wells. A sample from the upper part of the Chaswood Formation from Diogenes Brook, western Cape Breton Island, was also studied to complete a regional study of the
on-land Chaswood Formation.
The zircons were classified in three distinct groups: igneous first cycle, metamorphic first cycle, and polycyclic zircons. The igneous first cycle grains were further subdivided into six different subgroups based on a
series of criteria.
The Alma K-85, Thebaud C-74, Glenelg N-49 and Venture 1 and 4 wells cover geographically the central part of the basin. The western (Alma K-85 and Glenelg N-49) wells, and the eastern (Venture 1 and 4) wells have different
zircon assemblages and were therefore supplied by two different sediment types, resulting in the differences in the zircon populations observed. The Lower Missisauga zircon population of the Thebaud C-74 well is dominated by polycyclic zircons and
this is a unique feature for the central part of the Scotian Basin.
Zircons from Peskowesk A-99 show minor stratigraphic differences, but have persistent differences from the same stratigraphic level in the central part of the basin, indicating
variability in sediment sources. Fresh igneous zircons dominate in the Missisauga Formation of the Dauntless D-35 well, and the participation of polycyclic and metamorphic zircons is small. The differences between the Upper Missisauga Formation in
Dauntless D-35 and Peskowesk A-99 are sufficiently large to suggest a different sediment source.
For Diogenes Brook, fresh igneous zircons dominate in the upper part of the Chawood Formation and the participation of polycyclic zircons is small.
This is consistent with other Chaswood Formation localities, arguing for progressive unroofing of crystalline basement.
Such a study is particularly useful for assessing the role of polycyclic sediment supply and a useful precursor to more
expensive single grain zircon dating.