|Titre||Lithofacies and diagenesis of selected conventional core from Jurassic and Early Cretaceous terrigenous clastic rocks, Scotian Basin|
|Auteur||Gould, K M; Karim, A; Piper, D J W; Pe-Piper, G|
|Source||Commission géologique du Canada, Dossier public 6945, 2011, 272 pages, https://doi.org/10.4095/289629 (Accès ouvert)|
|Éditeur||Ressources naturelles Canada|
|Media||en ligne; numérique|
|Province||Région extracotière de l'est|
|Lat/Long OENS||-64.0000 -53.0000 46.0000 43.0000|
|Sujets||lithofaciès; pétrographie; grès; mudstones; turbidites; lithologie; faciès; faciès sédimentaires; pétrologie du sediment; diagenèse; milieu sédimentaire; Formation de Logan Canyon ; Formation de Mohican ;
Puit Mic Mac J-77 ; Puit Mic Mac H-86 ; Puit Wyandot E-53 ; Puit Sable Island C-67 ; Puit South Desbarres O-76 ; Puit Wenonah J-75 ; Puit Mohican I-100 ; géologie marine; sédimentologie; Mésozoïque; Crétacé; Jurassique|
|Illustrations||location maps; tables; stratigraphic columns; photographs|
|Programme||Géoscience en mer, Analyse de bassin et ressources géoscientifiques|
|Diffusé||2011 12 20|
|Résumé||(disponible en anglais seulement)|
This Open File presents lithologic and petrographic detail from conventional cores from wells located across the Scotian Basin; specifically, from the Abenaki
subbasin: the Mic Mac D-89, Mic Mac J-77, Mic Mac H-86, North Banquereau I-13, and Wyandot E-53 wells; from the Sable subbasin: the Marmora P-35, Onondaga O-95, Sable Island C-67, South Desbarres O-76 and Wenonah J-75 wells; and from the edge of the
Shelburne subbasin: the Mohican I-100 well. Core samples from the Mic Mac D-89, Wyandot E-53 and Mohican I-100 wells are from the Middle Jurassic Mohican Formation; the remaining wells sampled either the extreme top of the Late Jurassic Mic Mac
Formation or the Early Cretaceous Missisauga and Logan Canyon formations For all cores, except those in the Mohican Formation, detailed core logs are presented that use a lithofacies scheme previously applied to many other wells in the Scotian Basin.
Diagenetic minerals have been studied in petrographic thin section, with selected minerals also studied by electron microprobe. Porosity and permeability data from core plug analysis have been compiled.
Middle Jurassic Mohican Formation
terrigenous sediment facies differ from those of the Early Cretaceous, reflecting the more arid climate conditions at that time. Other than the presence of early diagenetic anhydrite in the Mohican I-100 well, diagenetic minerals in sandstones are
similar to those found in Early Cretaceous sandstones.
A brief analysis of the differences in reservoir quality between the Sable and Abenaki subbasins shows that the Abenaki subbasin has proportionally better reservoir quality in the Cree Member,
but proportionally poorer quality in the Middle Member of the Missisauga Formation and in the uppermost Jurassic Mic Mac Formation, compared to the Sable subbasin. In both subbasins, excellent reservoir quality is associated with chlorite rims on
framework grains. Loss of reservoir quality is commonly related to carbonate cements, which are sparse to absent in the Cree Member and the Upper Member of the Missisauga Formation in the Abenaki subbasin. Lithofacies in the two subbasins are in part
controlled by rates of subsidence and sediment supply, which were both greater in the Sable subbasin. River-mouth sandstones, which form the best quality reservoirs, are thicker in the Sable subbasin, where greater subsidence created greater
accommodation. Widespread tidal-flat facies in the Abenaki subbasin host poorer quality reservoir sandstones.