Dept. of Geosciences Colloquium: Beyond geochronology: The use of grain morphology and early Precambrian zircon age spectra as tools for provenance study and terrane analysis
Dr. Uri Shannan, Geological Survey of Israel
Detrital zircon geochronology is a powerful tool for investigating sedimentary provenance and for terrane analysis, but the traditional use of U-Pb zircon ages cannot distinguish between mixed sources or between source terranes with resembling prominent age components. Using examples from eastern Australia and the SW Pacific region, two new data handling approaches that permits more insightful interpretations of detrital zircon data are demonstrated and their wide applicability is explained. The first method relies on the comparison of multiple single-grain parameters (such as grain morphology, Hf isotopic data or Th/U ratios) to determine the modality of specific age populations and to yield additional insights into the geological provenance (e.g., transportation span of detritus, and tectonic setting of source terranes). The second tool is using the early Precambrian zircon age spectra as unique identifiers of Phanerozoic terranes (detrital fingerprint). This fingerprinting approach enables the determination of relationships between terranes (i.e., connectivity, recycling of detritus, or disjunction).
Event Organizer: Dr. Roy Barkan