Guliov and Broughton reported in 1971 that the distribution of the economic lignite reserves of southern Saskatchewan is discussed in relationship to the Tertiary stratigraphy developed in the Williston Basin. An economic evaluation was conducted of the underclays associated with the Ravenscrag lignites, as well as other industrial mineral resources in the area.
A twelve-foot thick column sample from the Utility Coal Company strip mine west of Estevan was collected and analyzed petrographically. In addition, trace elemental analysis, X-ray diffraction, infrared spectroscopy and differential thermal analyses provided detailed information on the petrographic relationships among the macerals in the Ravenscrag lignite. The authors also developed a new means of identifying leonarditic alterations of lignite.
High concentrations of fusinite characterize the lower middle section of the seam and are indicative of forest-moor origin. This concentration in the lower and middle sections develops into higher clarite concentrations in the upper portion of the seam. The highest inorganic concentration is in the lowest one foot of the seam. Thirty-one trace elements with concentrations greater than 10 ppm were detected in the column sample.
The major detection limits are in the following minerals, identified by X-ray diffraction in the shale partings and in the ash: kaolinite, montmorillonite, illite, muscovite, pyrite, marcasite, thenardite, gypsum and calcite. Low-angle X-ray scattering of leonardite provides a new and efficient non-chemical means of determining its presence. Apparently the higher peak intensity of lignite and lower intensity of the leonardite peak is correlated with the high concentration of aromatic structures with increasing rank from leonardite to lignite.
A paleoenvironmental analysis indicates a forest-moor origin, but the autochthonous nature of the deposit is questioned. Possible marine influences at this time are discussed, particularly in reference to the Cannonball Sea intrusion into Canada during Paleocene time.