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

    Evaluating the temporal link between the Karoo LIP and climatic–biologic events of the Toarcian Stage with high-precision U–Pb geochronology

    Access Status
    Fulltext not available
    Authors
    Sell, B.
    Ovtcharova, M.
    Guex, J.
    Bartolini, A.
    Jourdan, Fred
    Spangenberg, J.E.
    Vincente, J.
    Schaltegger, U.
    Date
    2014
    Type
    Journal Article
    
    Metadata
    Show full item record
    Citation
    Sell, B. and Ovtcharova, M. and Guex, J. and Bartolini, A. and Jourdan, F. and Spangenberg, J.E. and Vincente, J. et al. 2014. Evaluating the temporal link between the Karoo LIP and climatic–biologic events of the Toarcian Stage with high-precision U–Pb geochronology. Earth and Planetary Science Letters. 408: pp. 48-56.
    Source Title
    Earth and Planetary Science Letters
    DOI
    10.1016/j.epsl.2014.10.008
    ISSN
    0012-821X
    School
    Department of Applied Geology
    URI
    http://hdl.handle.net/20.500.11937/47427
    Collection
    • Curtin Research Publications
    Abstract

    The Karoo Large Igneous Province (K-LIP) is considered to have substantially influenced global warming, marine anoxia, and concomitant marine extinction in the Toarcian (Lower Jurassic). The sequence and duration of these events has been uncertain thus precluding direct comparison between sedimentary successions and the K-LIP. Two relatively narrow time intervals of the Early Toarcian, one approximately within the lower portion of the H. falciferum ammonite zone and the other near the Pliensbachian–Toarcian boundary (PL–TO-B), have received much attention because they are associated with carbon isotope excursions (CIEs) and marine extinctions. Potential causal mechanisms have been proposed, such as the release of massive amounts of carbon to the atmosphere via a catastrophic magmatic intrusive episode related to the K-LIP. Here we test the timing with four new high-precision (CA-ID-TIMS) U–Pb zircon ages from the Toarcian stage, collected from tephra interstratified with ammonite-bearing carbonates in southernmost Peru. We also present new U–Pb zircon and baddeleyite data from three sills and one rhyolite of the K-LIP in South Africa. Our new data permit a substantial reinterpretation of the Toarcian timescale: The Pliensbachian–Toarcian boundary (PL–TO-B), a prominent global extinction level, must be older than 183.5 Ma on the basis of our oldest tephra. The H. falciferum CIE (equivalent to the so-called Toarcian oceanic anoxic event) is bracketed by two ash-fall bed dates between 183.22±0.26183.22±0.26 and 181.99±0.13 Ma181.99±0.13 Ma (all 2σ analytical and tracer errors); the CIE duration is estimated at approximately 300 ka on the basis of minimum error interpolation of ammonite zone boundaries. The base of the H. falciferum CIE appears to correlate in time with the onset K-LIP sill emplacement dated by the oldest sill at 183.014±0.072 Ma183.014±0.072 Ma. However, sill emplacement appears to have lasted for a minimum of 2 million years, at least until 181.31±0.19 Ma181.31±0.19 Ma, which is in disagreement with a short duration of the H. falciferum negative CIE. Furthermore, our data suggest that the timing of the main volume of the K-LIP may have been approximately 4–5 Ma. This prolonged and possibly pulsed magmatic activity of the K-LIP may be correlated with extinction pulses and climate changes in the Middle and Late Toarcian Stage, each event occurring within a unique set of global environmental conditions.

    Related items

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

    • 40Ar/39Ar ages of the sill complex of the Karoo large igneous province: implications for the Pliensbachian-Toarcian climate change.
      Jourdan, Fred; Fraud, G.; Bertrand, H.; Watkeys, M.; Renne, P. (2008)
      Reliable geochronological results gathered so far (n = 76) have considerably constrained the timing of the emplacement of the Karoo large igneous province (LIP). Yet strikingly missing from this dating effortis the huge ...
    • Biomarker distributions and stable isotopes (C, S, H) to establish palaeoenvironmental change related to the end-Permian mass extinction event
      Nabbefeld, Birgit (2009)
      Extinction, the irreversible loss of species, is perhaps the most alarming symptom of the ongoing biodiversity crisis. Some of the most significant changes in evolution throughout Earth’s history have coincided with ...
    • Primary hydrous minerals from the Karoo LIP magmas: Evidence for a hydrated source component
      Ware, Bryant; Jourdan, Fred; Tohver, E.; Fernandes, K.; Chiaradia, M. (2018)
      © 2018 Elsevier B.V. Large Igneous Provinces mark important and consequential events that span almost the entirety of the Earth's history. These punctuated geologically significant events that include earth processes from ...
    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.