Correlation between the Wonominta and the Broken Hill Blocks in western New South Wales: Evidence from Nd isotope studies of metasediments |
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| Authors: | B Zhou K J Mills |
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| Institution: | 1. Department of Geology and Geophysics , University of Sydney , NSW, 2006, Australia;2. Department of Applied Geology , University of New South Wales , Kensington, NSW, 2033, Australia;3. Department of Geology and Geophysics , University of Sydney , NSW, 2006, Australia |
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| Abstract: | Nd isotope studies of the oldest metasedimentary rocks from the Wonominta Block, western New South Wales reveal that these samples have a model age (TDM) of 1780–2010 Ma, slightly younger than that of low‐grade Willyama Supergroup metasediments (1920–2160 Ma), and significantly younger than those ages previously reported from high‐grade rocks of the Broken Hill Block (2200–2300 Ma). These differences have important implications for tectonic reconstruction in this region and support a model of transitional tectonics from the Broken Hill to Wonominta Blocks, as suggested by earlier geochemical studies of mafic rocks. Those studies revealed that the mafic rocks from the basal sequence of the Wonominta Block may have formed in a back‐arc basin, developed from a propagating rifting, an environment contiguous to that in which Willyama Supergroup was deposited. These results also carry significant implications for tectonic reconstruction of eastern Australia. |
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| Keywords: | Broken Hill Block model ages Nd isotope Wonominta Block |
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