Hyperspectral imaging as an aid for facies analysis in massive-appearing sediments: a case study from the middle McMurray Formation

Abstract The paleoenvironments represented by the middle McMurray Formation have been actively debated within the last few decades. Highly detailed core studies have investigated the ichnology of the middle McMurray to gain insight on the paleodepositional conditions of these sediments. However, oil saturation makes diagnostic sedimentary and biogenic features difficult to see in core surfaces. Following on earlier published research, shortwave infrared (SWIR) hyperspectral imagery is collected, analyzed and compared to a previously studied McMurray Formation core. The method is tested on one well to be applied to the future studies. SWIR imagery significantly enhances the visibility of physical and biological sedimentary structures, especially within coarse-grained, bitumen-saturated intervals. The new observations provide support for interpretations derived from the direct study of the core and, in some cases, provide new observations that refine the core interpretation. Specifically, based on additional trace-fossil observations, lithosome L1 (high- and low-angle cross-stratified sandstone) is interpreted to represent bioturbation consistent with the middle estuary rather than the inner estuary. Deposition of lithosomes L2a (sandstone-dominated IHS) and L2b (equally interbedded sandstone and mudstone IHS) likely occurred in the middle estuary instead of inner to middle estuary. Interpretation of depositional locale is not changed for L2c, whereas L2d (mudstone-dominated burrowed IHS) is now interpreted to be deposited in the middle estuary instead of the previously suggested inner-middle estuary.