4:00 PM - 4:15 PM
[SCG55-03] Constraints on continental growth models from isotope geochemistry
Keywords:continental crust, supercontinent cycle, crustal recycling
Previously proposed models of continental growth are quite diverse, ranging from early establishment with little subsequent growth (e.g., Armstrong, 1981; Fyfe, 1978) to progressive growth with a nearsteady rate (e.g., Hurley and Rand, 1969; Moorbath, 1978; O'Nions et al., 1979) or with pulses at a high rate (e.g., Condie, 1998; McCulloch and Bennett, 1994; McLennan and Taylor, 1982; Patchett and Arndt, 1986).
Here I use the compiled detrital zircon U-Pb age and Hf isotope data to set constraints on the timing of continental crust generation and the mode of continental crust evolution in relation to supercontinent cycle. Further, by taking into account the crustal residence times of continental crust recycled back into the mantle, I propose a model of net continental growth that stable continental crust was firstly established in the Paleo- and Mesoarchean and significantly grew in the Paleoproterozoic.