Characterization of late-diagenetic calcites of the Devonian Southesk-Cairn Carbonate Complex (Alberta Basin): constraints from petrography, stable and radiogenic isotopes, fluid inclusion and organic matter maturity data Open Access

[摘要] The Alberta Basin has been the subject of various diagenetic studies but the precise understanding of the processes behind deep burial cementation remains unclear. This study investigates late-diagenetic calcites from the Devonian Southesk-Cairn Carbonate Complex with the purpose of constraining temperature, relative timing and chemistry of the paleo-fluids involved during calcite precipitation. Two types of late-diagenetic calcites were petrographically and geochemically characterized. Whereas calcite-I resulted from thermochemical sulfate reduction, calcite-II precipitated with no or little oxidized organic carbon present. As shown by the Sr isotopic signatures, some reservoirs were exposed to radiogenic Sr-bearing fluids. A slight trend of increasing fluid inclusion homogenization temperatures with depth is only seen in calcite-I, and bitumen reflectance also increases with depth following a normal burial gradient. These results, however, are not conclusive to interpret the influence of tectonically-driven fluids during deep burial.

[发布机构] University of Alberta

[效力级别] Diagenesis