SHRIMP zircon U-Pb age and tectonic significance of the Palaeoproterozoic Boolaloo Granodiorite in the Ashburton Province, Western Australia
Titel:
SHRIMP zircon U-Pb age and tectonic significance of the Palaeoproterozoic Boolaloo Granodiorite in the Ashburton Province, Western Australia
Auteur:
Krapez, B. McNaughton, N. J.
Verschenen in:
Australian journal of earth sciences
Paginering:
Jaargang 46 (1999) nr. 2 pagina's 283-287
Jaar:
1999-04
Inhoud:
The age of the Ashburton Province, comprising an older divergent-margin megasequence and a younger convergent-margin megasequence, is poorly constrained. The Boolaloo Granodiorite, which intruded the divergent-margin megasequence on the western margin of the Ashburton Province, has given a SHRIMP zircon U-Pb age of 1786 ± 5 Ma, and therefore post-dates convergent-margin, backarc basin sequences, with established conventional zircon U7sbnd;Pb ages of ca 1843-1828 Ma. However, it pre-dated deformation of convergent-margin, remnant-ocean sequences. Similarly aged (ca 1797-1791 Ma) granitoids are present in the adjacent Gascoyne Province, thereby identifying a magmatic fold-thrust belt that abutted a remnant ocean in the Ashburton Province.
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