Wed 30th November 2022 @ 12:00 nn, 312.222 and online via Webex (meeting #: 2655 735 2039 and password: rZQ77e7XU8W)

Abstract:

Detrital zircons collected from Earth`s modern rivers provide a representative sample to study the evolution of the continental crust on a global scale. This is because most of the eroded material in modern rivers has experienced long-time sediment-sediment recycling, and thus they contain detrital zircons from source rocks of diverse origins, including the crustal segments that are currently inaccessible by surface geology.

In this talk, I will present three projects of my PhD research, which focus on using large data sets of zircon geochronology and isotope geochemistry to track a range of crustal processes throughout Earth’s history. In the first project, I used trace element geochemistry of 6911 detrital zircons from worldwide major rivers, together with their U-Pb isotopic ages, to document the relative abundance of zircons from S-type granites, which gives new quantitative insights into sediment melting in the different supercontinent cycles. In the second project, I used lutetium (Lu) content in zircons to identify those that came from the high-pressure zones of deep roots that underlie high mountains. The results of mountain-building history were compared with the variations in atmospheric oxygen levels and biological evolution. For my third project, combined zircon U-Pb, O and Hf isotopes are used to constrain the evolution and growth rate of the European continental crust.

Short bio:

I am a PhD candidate at the Australian National University working with Prof. Ian Campbell. I obtained my undergraduate degree at China University of Geosciences (Wuhan) in resource exploration engineering in 2017, after which I went to ANU for a PhD. My PhD projects focus on using large data sets of zircon age, isotopes and trace element compositions to infer Earth’s crustal evolution, including the formation of S-type granites, the growth of the continental crust, mountain-building events and the supercontinent cycles throughout Earth’s history. I am currently doing a  3-month internship project at CSIRO about “visualising Earth’s evolution with isotopic systems”, in which I am using combined geochronological and Sm-Nd isotopic data to visualise the continental evolution of Australia.