Provenance of the Ben Nevis Formation sandstones, White Rose Field, Jeanne d' Arc Basin, Newfoundland, Canada

• Main Author: Dearin, Angela
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 2007
• Subjects: Canada; Ben Nevis; Newfoundland
• Online Access: https://research.library.mun.ca/6965/; https://research.library.mun.ca/6965/1/Dearin_Angela.pdf; https://research.library.mun.ca/6965/3/Dearin_Angela.pdf

This study focuses on the changes of sediment provenance with time, within and adjacent to selected reservoir intervals of the Aptian Ben Nevis Formation in the White Rose Field, Jeanne d'Arc basin. The field contains both oil and gas, and the reservoir rock is a very-fine- to fine-grained, generally well-sorted sandstone with variable thicknesses of up to 300 m. Average QFL ratios for Ben Nevis sandstones are Q₈₉F₃L₈, with the major lithic components being detrital carbonate grains and chert. Based on subcrop patterns and relative grain sizes, the Tithonian-Berriasian Hibernia Formation sandstones and the Barremian-Aptian Avalon Formation sandstones are thought to be possible sediment sources. -- Tectonic discriminative diagrams as well as petrographic descriptions give evidence of a very small amount of feldspar and indicate that the Ben Nevis Formation is not a first cycle sediment; rather, abraded quartz overgrowths indicate that Ben Nevis Formation sandstones are polycyclic and were sourced from recycled sediments. In addition, the Chemical Index of alteration (CIA) diagram can be used to show that the original basement of igneous and/or metamorphic rocks that acted as sediment source for the Ben Nevis Formation must have been of granodiorite composition. -- The Avalon Formation is petrographically and geochemically similar to the Ben Nevis Formation. Cuttings samples show a similar grain size and chemical composition to the Ben Nevis Formation, indicating that the Avalon Formation is a plausible source for the Ben Nevis Formation without requiring significant reworking or alteration. -- Possible sources with a higher lithic component, such as the Hibernia Formation, imply geochemical alteration with only limited physical reworking of the rock, which removed a large portion of unstable lithic grains and increased the quartz content relative to feldspars and lithic grains, leading to the quartz-rich composition of the Ben Nevis Formation. This process is supported by trace element data and plots of SiO₂ ...