An orogenic surge model for the eastern Yilgarn Craton: Implications for gold mineralising systems  

Authors / CoAuthors

Blewett, R.S. | Cassidy, K.F. | Champion, D.C. | Henson, P.A. | Goleby, B.R. | Kalinowski, A.A.

Abstract

Orogenesis in Phanerozoic systems is rapid, diachronous, episodic, and involves the switching of tectonic modes (extension-compression). In contrast, many Archaean orogens have traditionally been viewed as having developed by relatively simple, long-lived, mono-mode deformational processes. New results, however, reveal that the late Archaean eastern Yilgarn Craton (EYC) evolved episodically and rapidly, with a diachronous series of approximately E?W coaxial switches in tectonic mode. Tectonic mode switching changed stress regimes and resulted in the development of `late basins?, the emplacement of granites, and early orogenic gold mineralisation diachronously from east to west (NE?SW). Fluids were driven from the lower crust (and below) via large-scale crustal imbricating thrust faults. These fluids promoted the passage of a compression-extension couplet along a basal detachment by successively `lubricating? faults (preparing the ground), and facilitating a propagating wave of foreland surge (D2a) and hinterland extension (D2E) followed by inversion, uplift and annealing (D2b). In this way, orogenic Au and westward orogenic surge with associated tectonic mode switches are linked. We predict that the compres-sion-extension couplets and early orogenic gold mineralisation propagated from the east to the west diachronously at a rate of ~3-5 m.y. between domains from ~2670 Ma to ~2650 Ma. Multiple mineralising episodes are also a predicted consequence of the orogenic surge model.

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nonGeographicDataset

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61345

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• External PublicationConference Paper

( Theme )

• structural geology

( Theme )

• metallogenesis

• AU-WA

Australian and New Zealand Standard Research Classification (ANZSRC)

• Earth Sciences

• Published_Internal

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2004-01-01T00:00:00

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Australian Government Security ClassificationSystem    

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Creative Commons Attribution 4.0 International Licence    

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geoscientificInformation

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[-32.0, -24.0, 120.0, 125.0]

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