Please use this identifier to cite or link to this item: http://hdl.handle.net/2440/115883
Type: Thesis
Title: Amphibolite and metasediments of the northwest Weekeroo Inlier, Olary Province
Author: Taylor, G. J.
Issue Date: 1985
School/Discipline: School of Physical Sciences
Abstract: The northwest Weekeroo Inlier, Olary, consists of Lower Proterozoic, Willyama Supergroup metasediments and amphibolites. Upper Proterozoic cover metasediments of the Adelaide Supergroup overly these basement rocks. The basement rocks of the area are dominated by structures of the third Olarian event. Macrosocopic anticlines and synclines are open to tight, easterly plunging with a southerly dipping axial surface. The third generation penetrative schistosity cross-cuts a former schistosity (S1 or S2) which is parallel or oblique to layering. Abundant crenulations and kinkbands are likely to belong to the first Delamerian folding event which reactivated many basement structures of the Weekeroo Inlier. A stratigraphic sequence is recognized whereby pelites ('Mica Schists') overly psammo-pelites and quartz-albite rocks ('Bedded Schists'). A very broadly conformable sequence of massive, brecciated and layered amphibolite is "stratigraphically positioned" at the top of the Bedded Schists. From consideration of abundant sedimentary structures, together with facies changes and overall stratigraphic relations, likely depositional models include a very shallow marine shelf, a broad shallow inland lake-alluvial fan toe complex, and a river dominated, regressive deltaic-sabkha situation. Olarian metamorphic conditions ranged from those characteristic of the upper greenschist facies to those typical of the mid-amphibolite facies. These were followed by strongly retrogressive metamorphism (lower greenschist facies grade) associated with the cover deformation events during the Delamerian Orogeny. The Olarian metamorphism is manifested by paragenetic relations between actinolite, hornblende, epidote, albite, opaques and sphene in amphibolites and between fibrolite, chloritoid, almandine, biotite, muscovite, sericite, quartz, minor staurolite and minor chlorite in pelites. Closely associated with the amphibolite bodies of the Weekeroo Inlier are albitites and calc-albitites. Previously, a metasomatic origin was proposed for these albite rich rocks. An evaporitic sediment with a possible tuffaceous component is now considered more likely. The Weekeroo amphibolites are chemically similar to ferro-tholeiites of ocean floor/mid oceanic ridge transitional to continental origin.
Dissertation Note: Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 1985
Where: Olary Domain, Curnamona Province, South Australia
Keywords: Honours; Geology; Proterozoic; Weekeroo Inlier; Olary Province; stratigraphy; structure; metamorphism; metasediments; pegmatites; amphibolites
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

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