ABSTRACT

Foreland basin style deposition began in Western Canada during Oxfordian time with the appearance of sediments derived from the west in southwestern Alberta (Passage Beds). By Kimmeridgian time, a major landmass was well established in the west, shedding coarse clastics east-ward into a narrow, rapidly subsiding trough (Kootenay/Minnes/Nikanassin). A major relative sea level fall near the end of Valanginian time precipitated basin-wide erosion, which lasted until Barremian time (pre-Cretaceous unconformity). Fluvial sedimentation resumed during the Barremian (Cadomin/Gething/Ellerslie/Dina) with rivers flowing northwestward (basin axial) to a boreal sea in the Northwest Territories. By the end of Aptian time, the Boreal Sea had advanced southeastward across much of Alberta and Saskatchewan, first as brackish embayments (Calcareous/Ostracode/Cummings) then as a marine seaway (Glauconitic/Bluesky/Wabiskaw/Lloydminster). In early Albian time, the boreal coastline retreated northward due to a strong sediment influx from the Cordillera (Upper Mannville/Spirit River). In middle Albian time a major relative sea level fall exposed much of the basin (post-Cadotte unconformity). From late Albian to early Campanian time, a major sea level rise created dominantly marine conditions across the basin (Colorado Group). This was interrupted several times by short periods of lowered relative sea level and coarse clastic input (Viking, Dunvegan, Cardium, Chinook). During Campanian time, a strong sediment pulse from the Cordillera began pushing coastlines eastward and southeastward (Belly River) so that by Maastrichtian time, the entire basin was subaerial (Edmonton). Compressional tectonics ended during the Paleocene (Paskapoo) with major uplift and erosion.

End_of_Record - Last_Page 181-------