Haematite pigmentation events and palaeomagnetic recording: Implications from the Pilbara Print Stone, Western Australia

Alexandra Abrajevitch*, Brad J. Pillans, Andrew P. Roberts

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    18 Citations (Scopus)

    Abstract

    Haematite pigment is a common constituent of sedimentary rocks, but its contribution to the natural remanent magnetization of rocks is poorly understood. Here, we describe magnetic properties of two distinct pigment types that produce a characteristic decorative 'print stone' found in the~2.5 Ga Mount McRae Shale Formation, Hamersley Province, Western Australia. Distinct magnetic remanence directions observed in the Print Stone can be correlated to each pigment type. By comparison with the Australian apparent polar wander path, the remanence carried by uniformly distributed pigment can be dated to ~15-25 Ma, while two age options, the Mesoproterozoic (~1.5 Ga) or the middle Carboniferous (~320-310 Ma), are permissible for the remanence carried by the pigment responsible for the distinctive 'newsprint' pattern. Magnetic properties and demagnetization characteristics of the different pigment types overlap significantly, and thus are not predictive of the dominant remanence carrier. Magnetic characteristics of the uniformly distributed pigment vary significantly on short spatial scales. Strong local control on pigment formation raises the possibility that a primary remanent magnetization may survive locally in pockets within sedimentary red bed formations.

    Original languageEnglish
    Pages (from-to)658-672
    Number of pages15
    JournalGeophysical Journal International
    Volume199
    Issue number2
    DOIs
    Publication statusPublished - 1 Nov 2014

    Fingerprint

    Dive into the research topics of 'Haematite pigmentation events and palaeomagnetic recording: Implications from the Pilbara Print Stone, Western Australia'. Together they form a unique fingerprint.

    Cite this