Study of the mineralogy of lower cretaceous Mannville Group oil sand deposits, Alberta and west central Saskatchewan
Lower Mannville sediments are composed of detrital quartz (41-97%) with minor amounts of potash feldspar (0-16%) and muscovite (0-8%). Siderite1 pyrite, and marcasite are connnon components, whereas calcite, dolomite, gypsum, and glauconite are sporadic in occurrence. Kaolinite (1-27%) and degraded illite (trace-10%) are the most abundant clay minerals. Kaolinite is enriched in sands compared to associated· finer-grained sediments. Random mixed-layer clay rninerals are common in fine-grained sediments. Plagioclase and biotite are present and chlorite and montmorillonite are generally. confined to sediments deposited near the close of Lower Mannville time. Upper Mannville sediments are composed of quartz (17-98%), potash feldspar (0-42%), and plagioclase (0-41%). There is a general increase in feldspar content from Lower Mannville to the close of Upper Mannville deposition. Siderite, pyrite, calcite, and dolomite are sporadic in occurrence, however glauconite distribution is widespread in basal Upper Mannville sediments. Muscovite and biotite are common components. Kaolinite (0-18%) and degra~1ed illite/illite (trace-15%) are the most abundant clay minerals. Chlorite (0-7%) and rnontmorillonite (0-17%) are common in occurrence and there appears to be a general increase in content of these clay minerals from Lower Mannville to the close of Upper Mannville tirnt~. Source rock composition is the dominant factor controlling the mineralogical distribution of Mannville Group sediments. Lower Mannville sediments were derived from igneous and metamorphic rocks of the Canadian Shield or from sediments which had a Canadian Shield source. Near the close of Lower Mannville time an influx of sediments from a western source area probably occurred. Plagioclase, biotite, and montmorillonite first appeared and chlorite content increased in the sediments deposited at this time. Upper Mannville sediments have increased volcanic rock fragments, plagioclase, potash feldspar, chlorite, and montmorillonite contents throughout Upper Mannville time which indicates increased influence on the sediments by the western source area. Tectonic framework, climatic conditions, basin configuration, sea level movements, depositional environments, and diagenesis modified the mineralogy of the Mannville sediments which was originally and primarily controlled by source rock composition.
Bibliography: p. 127-134.
Schooley, J. V. (1975). Study of the mineralogy of lower cretaceous Mannville Group oil sand deposits, Alberta and west central Saskatchewan (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/19924