Sequence stratigraphy, chemostratigraphy and facies analysis of Cambrian Series 2 – Series 3 boundary strata in northwestern Scotland

FAGGETTER, LUKE E.; WIGNALL, PAUL B.; PRUSS, SARA B.; RAINE, ROBERT J.; NEWTON, ROBERT J.; JOACHIMSKI, MICHAEL M.; SMITH, PAUL M.; WIDDOWSON, MIKE; Faggetter, Luke; Joachimski, Michael; Pruss, Sara; Raine, Robert; Smith, Paul; SUN, YADONG; Wignall, P B

Abstract

Globally, the Series 2 – Series 3 boundary of the Cambrian System coincides with a major carbon isotope excursion, sea-level changes and trilobite extinctions. Here we examine the sedimentology, sequence stratigraphy and carbon isotope record of this interval in the Cambrian strata (Durness Group) of NW Scotland. Carbonate carbon isotope data from the lower part of the Durness Group (Ghrudaidh Formation) show that the shallow-marine, Laurentian margin carbonates record two linked sea-level and carbon isotopic events. Whilst the carbon isotope excursions are not as pronounced as those expressed elsewhere, correlation with global records (Sauk I – Sauk II boundary and Olenellus biostratigraphic constraint) identifies them as representing the local expression of the ROECE and DICE. The upper part of the ROECE is recorded in the basal Ghrudaidh Formation whilst the DICE is seen around 30m above the base of this unit. Both carbon isotope excursions co-occur with surfaces interpreted to record regressive–transgressive events that produced amalgamated sequence boundaries and ravinement/flooding surfaces overlain by conglomerates of reworked intraclasts. The ROECE has been linked with redlichiid and olenellid trilobite extinctions, but in NW Scotland, Olenellus is found after the negative peak of the carbon isotope excursion but before sequence boundary formation.

Citation

FAGGETTER, L. E., WIGNALL, P. B., PRUSS, S. B., RAINE, R. J., NEWTON, R. J., JOACHIMSKI, M. M., SMITH, P. M., WIDDOWSON, M., Faggetter, L., Joachimski, M., Pruss, S., Raine, R., Smith, P., SUN, Y., & Wignall, P. B. (2018). Sequence stratigraphy, chemostratigraphy and facies analysis of Cambrian Series 2 – Series 3 boundary strata in northwestern Scotland. Geological magazine, 155(04), 1-13. https://doi.org/10.1017/s0016756816000947

• Acceptance Date: Sep 5, 2016
• Online Publication Date: Nov 4, 2016
• Publication Date: 2018-05
• Deposit Date: Jan 12, 2017
• Publicly Available Date: Jan 12, 2017
• Journal: Geological magazine
• Print ISSN: 0016-7568
• Publisher: Cambridge University Press
• Peer Reviewed: Peer Reviewed
• Volume: 155
• Issue: 04
• Pages: 1-13
• DOI: https://doi.org/10.1017/s0016756816000947
• Keywords: Durness Group, ROECE, DICE, Trilobite extinction, Scotland
• Public URL: https://hull-repository.worktribe.com/output/472288
• Publisher URL: https://www.cambridge.org/core/journals/geological-magazine/article/div-classtitlesequence-stratigraphy-chemostratigraphy-and-facies-analysis-of-cambrian-series-2-series-3-boundary-strata-in-northwestern-scotlanddiv/C34BD618A3A3D0810CC7DF0567990704
• Additional Information: This article has been published in a revised form in Geological magazine http://dx.doi.org/10.1017/S0016756816000947 . This version is free to view and download for private research and study only. Not for re-distribution, re-sale or use in derivative works. © copyright holder.
• Contract Date: Jan 12, 2017