Curtin University Homepage
  • Library
  • Help
    • Admin

    espace - Curtin’s institutional repository

    JavaScript is disabled for your browser. Some features of this site may not work without it.
    View Item 
    • espace Home
    • espace
    • Curtin Research Publications
    • View Item
    • espace Home
    • espace
    • Curtin Research Publications
    • View Item

    Paleomagnetism of the Jurassic Transantarctic Mountains revisited - Evidence for large dispersion of apparent polar wander within less than 3Myr

    Access Status
    Fulltext not available
    Authors
    Lemna, O.
    Bachtadse, V.
    Kirscher, Uwe
    Rolf, C.
    Petersen, N.
    Date
    2014
    Type
    Journal Article
    
    Metadata
    Show full item record
    Citation
    Lemna, O. and Bachtadse, V. and Kirscher, U. and Rolf, C. and Petersen, N. 2014. Paleomagnetism of the Jurassic Transantarctic Mountains revisited - Evidence for large dispersion of apparent polar wander within less than 3Myr. Gondwana Research. 31: pp. 124-134.
    Source Title
    Gondwana Research
    DOI
    10.1016/j.gr.2015.01.002
    ISSN
    1342-937X
    School
    Department of Applied Geology
    URI
    http://hdl.handle.net/20.500.11937/42455
    Collection
    • Curtin Research Publications
    Abstract

    The Transantarctic mountains predominantly consist of Jurassic continental flood basalts (Kirkpatrick) and sills (Ferrar) emplaced during the earliest phase of the break-up of Pangea. Published ages, based on a variety of geochronological methods all agree rather well and cluster around 180 Ma suggesting emplacement during a rather short time interval of not more than 3 Myr. Paleomagnetic studies, mostly carried out between the 60s and 90s of the last century, however, yield two well defined but significantly different groups of paleomagnetic pole positions plotting either in intermediate latitudes (A) or at latitudes exceeding 60°S (B). Pole positions belonging to group A are generally interpreted to be of primary origin whereas the significance of group B poles remains unclear. Here we report new data from the Kirkpatrick basalts of Northern Victoria Land, Antarctica, where 157 oriented paleomagnetic samples were taken, covering about 800 m of stratigraphy and 23 volcanic flows in Gair Mesa (73.4666°S; 162.8666°E). After removal of a steep magnetic overprint with rather low coercivities straight linear segments of exclusively normal polarity trending toward the origin of projection are identified in 151 samples from 22 sites. Maximum unblocking temperatures do not exceed 580 °C and maximum coercivities not 60 mT. The resulting mean virtual geomagnetic pole (VGP) for the Gair Mesa plots at 66.4°S; 227.7°E (α95 of 6.2°, k = 25.7) comparable to group B poles. Reflecting light microscopy reveals that the magnetic inventory of all samples analyzed is dominated by magnetite showing shrinking cracks and broad ilmenite lamellae, the latter being diagnostic for high temperature oxidation. Analysis of the distribution of the 22 pole positions obtained here shows that secular variation has successfully been averaged (Sb = 15.9°) suggesting that the rocks studied here have recorded the time averaged geomagnetic field during early mid Jurassic times. Based on these new results we postulate that both clusters A and B of pole positions reflect primary magnetizations and that the Kirkpatrick basalts of Gair Mesa have been emplaced in a rather short normal polarity time interval of 3 Myr. If our reasoning is correct, the apparent polar wander path for the latest early Jurassic might be more complex than previously thought. Whether this complexity is evidence for massif True Polar Wander remains speculative.

    Related items

    Showing items related by title, author, creator and subject.

    • Paleomagnetism of Jurassic carbonate rocks from Sardinia: No indication of post-Jurassic internal block rotations
      Kirscher, Uwe; Aubele, K.; Muttoni, G.; Ronchi, A.; Bachtadse, V. (2011)
      Several paleomagnetic studies on Carboniferous and Permian sedimentary and volcanic rocks from Sardinia and Corsica have recently demonstrated (1) the tectonic coherence between southern Corsica and northern Sardinia and ...
    • Pre-Rodinia supercontinent Nuna shaping up: A global synthesis with new paleomagnetic results from North China
      Zhang, S.; Li, Zheng-Xiang; Evans, D.; Wu, H.; Li, H.; Dong, J. (2012)
      The existence of a pre-Rodinia Precambrian supercontinent, variously called Nuna or Columbia, has been widely speculated in the past decade, but the precise timing of its existence and its configuration have been uncertain ...
    • Paleomagnetism and rock magnetism of the ca. 1.87 Ga Pearson Formation, Northwest Territories, Canada: A test of vertical-axis rotation within the Great Slave basin
      Gong, Z.; Xu, X.; Evans, D.; Hoffman, P.; Mitchell, Ross; Bleeker, W. (2018)
      A geometrically quantitative plate-kinematic model, based on paleomagnetism, for the initial assembly of Laurentia has taken form in the past few decades. Within this framework, there remains but one problematic interval ...
    Advanced search

    Browse

    Communities & CollectionsIssue DateAuthorTitleSubjectDocument TypeThis CollectionIssue DateAuthorTitleSubjectDocument Type

    My Account

    Admin

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Follow Curtin

    • 
    • 
    • 
    • 
    • 

    CRICOS Provider Code: 00301JABN: 99 143 842 569TEQSA: PRV12158

    Copyright | Disclaimer | Privacy statement | Accessibility

    Curtin would like to pay respect to the Aboriginal and Torres Strait Islander members of our community by acknowledging the traditional owners of the land on which the Perth campus is located, the Whadjuk people of the Nyungar Nation; and on our Kalgoorlie campus, the Wongutha people of the North-Eastern Goldfields.