Go to  Advanced Search

Architecture of the Silurian sedimentary cover sequence in the Cadia porphyry Au-Cu district, NSW, Australia : implications for post-mineral deformation

Show full item record

Files in this item

Files Size Format Description   View
ubc_2008_fall_washburn_malissa.pdf 13.73Mb Adobe Portable Document Format   View/Open
 
Title: Architecture of the Silurian sedimentary cover sequence in the Cadia porphyry Au-Cu district, NSW, Australia : implications for post-mineral deformation
Author: Washburn, Malissa
Degree Master of Science - MSc
Program Geological Science
Copyright Date: 2008
Publicly Available in cIRcle 2008-07-22
Subject Keywords Cadia, New South Wales; Structural geology; Waugoola group; Basin inversion; Rift-sag sequence; Fold and thrust belt; Tabberabberan Orogeny
Abstract: Alkalic porphyry style Au-Cu deposits of the Cadia district are associated with Late-Ordovician monzonite intrusions, which were emplaced during the final phase of Macquarie Arc magmatism at the end of the Benambran Orogeny. N-striking faults, including the curviplanar, northerly striking, moderately west-dipping basement thrust faults of the Cadiangullong system, developed early in the district history. NE-striking faults formed during rifting in the late Silurian. Subsequent E-W directed Siluro- Devonian extension followed by regional E-W shortening during the Devonian Tabberabberan Orogeny dismembered these intrusions, thereby superposing different levels porphyry Au-Cu systems as well as the host stratigraphy. During the late Silurian, the partially exhumed porphyry systems were buried beneath the Waugoola Group sedimentary cover sequence, which is generally preserved in the footwall of the Cadiangullong thrust fault system. The Waugoola Group is a typical rift-sag sequence, deposited initially in local fault-bounded basins which then transitioned to a gradually shallowing marine environment as local topography was overwhelmed. Basin geometry was controlled by pre-existing basement structures, which were subsequently inverted during the Devonian Tabberabberan Orogeny, offsetting the unconformity by up to 300m vertically. In the Waugoola Group cover, this shortening was accommodated via a complex network of minor detachments that strike parallel to major underlying basement faults. For this reason, faults and folds measured at the surface in the sedimentary cover can be used as a predictive tool to infer basement structures at depth.
URI: http://hdl.handle.net/2429/1064

This item appears in the following Collection(s)

Show full item record

All items in cIRcle are protected by copyright, with all rights reserved.

UBC Library
1961 East Mall
Vancouver, B.C.
Canada V6T 1Z1
Tel: 604-822-6375
Fax: 604-822-3893