Northern Mackenzie Corridor project

Example 4 – Regional carbonate platform development above basement basins and arches.

During the Paleozoic Era, the current study area straddled the boundary between the Selwyn Basin to the southwest and the carbonate platform that developed to the southeast, northeast, and north. Porous platform margin facies were deposited at the boundary between basinal and platformal strata. These rocks are analogous to the reservoir rocks of the Beaver River, Kotaneelee, Pointed Mountain, and Liard gas fields in the southern N.W.T. and Yukon. The boundary zone migrated over time, in response to changes in sea level, sediment influx, and tectonic adjustments.

The Selwyn Basin developed over the Proterozoic Mackenzie Rift Basin, and its margins are defined by reactivation along many pre-existing Proterozoic rift faults. The figure shows major rift faults identified using the potential field data, superimposed on Paleozoic structural and stratigraphic features. From this figure it is evident that Paleozoic arches such as the Ogilvie, Redstone, and Bulmer Lake Arches developed on the platformal side of major rift fault zones. Likewise, the Paleozoic Selwyn Basin and ‘satellite’ basins such as the Root Basin and Misty Creek Embayment developed on the basinal or hanging-wall side of the fault zones. The fault zone(s) is now identified as a major exploration fairway, since not only is it the location of platform margin facies (dependant on temporal variations in sea level), but is also the focus of hydrothermal fluids escaping from the Proterozoic strata in the basin, and the potential focus of Laramide inversion producing a structural closure.

As well as confirming the position and extents of known Paleozoic features this study predicts the existence of an additional major arch termed the “Arctic Red River Arch”, after the river that follows its location.