Authors / CoAuthors
Miller, J.M. | Blewett, R.S. | Tunjic, J. | Connors, K.
Abstract
Early formed rift architecture has a major control on the subsequent compressional and strike-slip fault systems that host the world class St Ives Goldfield in the Yilgarn Craton, Western Australia. The current topography of the faults, at both a camp and regional scale, is a reflection of the geometry of the early rifts and old basement boundaries. Early structures have been physically mapped and identified in potential field data sets, isopach thickness variations and by the distribution of dolerite and basalt units. The early rift geometry is interpreted to have been a series of early WNW-trending normal faults and breached relay ramps associated with oblique rifting along an older NNW-trending basement boundary. Strike changes on major regional faults, such as the Boulder-Lefroy Fault, correlate with the location of major early formed WNW-trending faults. These control dilational and contractional fault segments associated with several world class gold fields. Within the St Ives Goldfield a series of N-trending linking thrusts developed during D2 inversion that are bounded by WNW-trending faults. During gold mineralization these linking thrusts became contractional jogs that now host several gold ore bodies. The WNW-trending relay faults acted as transfer faults syn-gold mineralization, although only discrete segments of these transfer faults were active during gold mineralization. They transferred strain from a complex combination of block on block movement associated with thrusting and strike-slip movement on NW- and N-trending faults. The WNW-trending faults were also a focus of intrusive dykes and larger scale intrusions that are inferred to have produced the pronounced WNW-trending gravity trends in regional potential field data sets.
Product Type
nonGeographicDataset
eCat Id
69466
Contact for the resource
Custodian
Point of contact
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Keywords
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- External Publication
- ( Theme )
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- economic geology
- ( Theme )
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- structural geology
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- AU-WA
- Australian and New Zealand Standard Research Classification (ANZSRC)
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- Earth Sciences
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- Published_Internal
Publication Date
2009-08-31T00:00:00
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unknown
Topic Category
geoscientificInformation
Series Information
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Unknown
Parent Information
Extents
[-31.0, -30.0, 120.0, 121.5]
Reference System
Spatial Resolution
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