Channel-fills in the McMurray Formation: their recognition, delineation, and impact at the Syncrude Mine

CIM Bulletin, Vol. 82, No. 928, 1989

R.G. Cuddy and W.K. Muwais, Syncrude Canada Ltd.

The Lower Cretaceous McMurray Formation contains the bitumen reserves of the Syncrude Mine in northeastern Alberta. This formation comprises sediments deposited sequentially in fluvial, estuarine and marine depositional environments. The Syncrude Base Mine area consists mostly of estuarine sediments, as much of the original marine sediments have been eroded away. These estuarine deposits consist of channel-fill sediments and interchannel tidal flat sediments with the channel-fills comprising most of the orebody. Channel-fills contain, among other lithologies, interbedded sand, silt and clay rich layers that often occur as sequences of inclined beds with dips up to 25 degrees or more. A detailed knowledge of the distribution of these inclined beds, their lithological characteristics and their continuity is very important in assessing the risk of mine highwall instability. Techniques used to identify and characterize adverse structures are reviewed.

Keywords: Athabasca oil sands, Geology, Oil sands, Mine Operations, Sedimentology, Structural analyses, Channel-fills