Age and palaeomagnetism of the Mundine Well dyke swarm, Western Australia: implications for an Australia-Laurentia connection at 755 Ma

Michael Wingate, J.W. Giddings

    Research output: Contribution to journalArticle

    276 Citations (Scopus)

    Abstract

    Integrated U-Pb geochronology and palaeomagnetic studies of the Mundine Well dyke swarm (MDS) of the Pilbara Craton, Western Australia, are employed to test the hypothesis that Australia and Laurentia were joined as part of the Rodinia supercontinent. Ion microprobe U-Pb dating of zircon and baddeleyite indicates that the MDS was emplaced at 755 +/- 3 Ma (95% confidence interval) and palaeomagnetic results confirm that the swarm is equivalent in age to dykes of the Northampton Inlier. A positive contact test between an MDS dyke and an older dolerite sill indicates that the MDS magnetisation dates from the time of dyke emplacement and cooling at 755 Ma. Combining new palaeomagnetic data for eight MDS dykes with previous results for six Northampton dykes yields a palaeopole for Australia at 135 degrees E, 46 degrees N (A(95) = 4 degrees). The MDS palaeopole lies 30 degrees away from the 780 to 740 Ma APW path segment for Laurentia, indicating that, if the Rodinia reconstruction is correct, breakup between Australia and Laurentia occurred prior to 755 Ma. It has been suggested elsewhere that the Sturtian glaciation in Australia preceded or accompanied breakup. If so, the Sturtian rocks should be older than 755 Ma and hence may not be coeval with glaciogenic rocks of the post-755 Ma Rapitan Group in Laurentia. Crown copyright (C) 2000 Published by Elsevier Science B.V. All rights reserved.
    Original languageEnglish
    Pages (from-to)335-357
    JournalPrecambrian Research
    Volume100
    Issue number1
    DOIs
    Publication statusPublished - 2000

    Fingerprint Dive into the research topics of 'Age and palaeomagnetism of the Mundine Well dyke swarm, Western Australia: implications for an Australia-Laurentia connection at 755 Ma'. Together they form a unique fingerprint.

    Cite this