SHRIMP U-Pb zircon age constraints on the Late Archaean tectonostratigraphic architecture of the Eastern Goldfields Superterrane, Yilgarn Craton, Western Australia

Reassessment of Late Archaean tectonostratigraphic architecture of the Eastern Goldfields Superterrane is based oil 35 new SHRIMP U-Pb zircon ages of supracrustal sequences. The Superterrane comprises at least five terranes with similar to 2810 to 2715 to similar to 2692 Ma plume-influenced, but deep-marine, mafic-ultramafic succession (Kambalda Sequence) overlain unconformably by a 2686 +/- 5 to 2740 Ma volcanic sequences that are remnants of autochthonous basement to the Kambalda Sequence.Arc-related bimodal and intermediate volcanic rocks of the Gindalbie Terrane, ranging in age from 2693 +/- 14 to 2676 +/- 5 Ma, are coeval with but geochemically distinct from the Kalgoorlie Sequence. They overlie sequences similar in age and composition to volcanic rocks of the Kurnalpi Terrane. The Kurnalpi Terrane comprises deep-marine, calc-alkalic mafic and intermediate volcanic rocks (Kurnalpi Sequence) ranging in age from 2715 +/- 5 to 2704 +/- 4 Ma, overlain conformably by mafic to ultramafic lavas (Minerie Sequence). Although of overlapping age, arc-related rocks in the Kambalda and Kurnalpi-Minerie Sequences are geochemically different. SHRIMP dating has identified older volcanic sequences in the Laverton ( 3400 Ma. Many zircon age-populations correspond to known supracrustal and crustal rocks in the Yilgarn Craton, but some have no known Source in the Eastern Goldfields Superterrane. Superterrane-wide distribution and evidence for erosion of all crustal and supracrustal rocks >= 2660 Ma in age requires deposition of these sequences after terrane amalgamation, most likely synorogenic to collision between the Eastern 41 Goldfields Superterrane and the Yilgarn Craton. (C) 2007 Elsevier B.V. All rights reserved.