Please use this identifier to cite or link to this item: http://hdl.handle.net/2440/119992
Type: Thesis
Title: Structural, geochemical and isotopic investigation of granitoids within the central area of the eastern Weekeroo Inlier, Olary Domain, South Australia
Author: Brett, D.
Issue Date: 1998
School/Discipline: School of Physical Sciences
Abstract: In the central part of the eastern Weekeroo Inlier, Olary Domain, two types of granite have been identified. This thesis explores both granite types in order to explain possible tectonic environments and geological evolution during the Proterozoic. The A-type Walter Outalpa granite is characterised by high Si02, Zr, Nb, Y, rare earth elements (REE) and low MgO, CaO, Ti02, P205 and light field strength elements (LFSE). High zircon saturation temperatures differentiate this fractionated A-type granite from potential fractionated I-type granites. The peraluminous granite is characterised by high Si0, Al203, Rb, U, Th, and low MgO, CaO, Ti02, Sr and light REE. It displays strong geochemical similarities to the Bimbowrie S-type granite. Consistent geochemical and isotopic characteristics for the Walter Outalpa granite and other similar A-type granites across the Olary Domain indicate a single regional crustal plus mantle source. Partial melting of lower Archaean crust due to lithospheric thinning is proposed. Geochemistry and isotopic analysis of the peraluminous granites suggest varying infracrustal sources for loosely grouped S-type granites in the Olary Domain. Previous interpretations for the depositional environment of the Willyama Supergroup metasediments in a continental rift setting are supported by comagmatic A-type volcanics and granites within the central part of the eastern Weekeroo Inlier. An extensional environment during emplacement is consistent with evidence for shallow level emplacement such as graphic texture, and the absence of a contact aureole for the Walter Outalpa granite. There is foliation development and evidence of folding for three deformation events during the Proterozoic Olarian Orogeny. Timing relationships between granitoids and metasediments in this area have constrained relative timing of emplacement. Low temperature solid state deformation affected the A-type Walter Outalpa granite after emplacement into Willyama Supergroup metasediments. Crosscutting relationships between the peraluminous granite and adjacent deformed metasediments imply a late to post D2 emplacement for this granite.
Dissertation Note: Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 1998
Where: Weekeroo Inlier, Olary Domain, Curnamona Province, South Australia
Keywords: Honours; Geology; Weekeroo Inlier; Olary Domain; Curnamona Province; granites; geochemistry; geochronology; structure; source environments
Description: This item is only available electronically.
Provenance: This electronic version is made publicly available by the University of Adelaide in accordance with its open access policy for student theses. Copyright in this thesis remains with the author. This thesis may incorporate third party material which has been used by the author pursuant to Fair Dealing exceptions. If you are the author of this thesis and do not wish it to be made publicly available, or you are the owner of any included third party copyright material you wish to be removed from this electronic version, please complete the take down form located at: http://www.adelaide.edu.au/legals
Appears in Collections:School of Physical Sciences

Files in This Item:
File Description SizeFormat 
01frontGeoHons.pdf187.04 kBAdobe PDFView/Open
02wholeGeoHons.pdf8.77 MBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.