Please use this identifier to cite or link to this item: http://hdl.handle.net/2440/101297
Type: Thesis
Title: The geology of Wardang Island, Yorke Peninsula, South Australia
Author: Bone, Y.
Issue Date: 1978
School/Discipline: School of Physical Sciences
Abstract: The crystalline basement consists of porphyritic rhyo-dacite, with minor latite, conglomerates and metasediments. Geochemistry indicates possible affinities with the Gawler Range Volcanics and the Moonta Porphyry. The sequence is intruded by amphibolite dykes. Metamorphic and tectonic events have modified the rocks, destroying primary textures. These events may be related to the Olarian orogeny. The figure of 1735 m.y. obtained on the rhyo-dacite probably represents a re-setting event. Permian glacigene sediments unconformably overlie the acid volcanics. These sediments consist of mottled clays and quartz arenites, and contain heavy mineral grains the surfaces of which show well-defined chattermark trails. Erratics are numerous. Grooved bedrock surfaces indicate a 340° ice movement direction, as does the Cape Willoughby source for the largest granite erratic. A richly-fossiliferous Pliocene sequence - the Hallett Cove Sandstone - overlies the Permian and the Basement. The 4 m thick sequence shows ten distinct horizons, reflecting differing environmental conditions. The Quaternary cover shows evidence of Holocene sea-level changes in the form of stranded shingle beach ridges, aeolianite wave-cut platforms and undersea calcrete reefs. These also record palaeoclimatic changes, as do the fossil soils, calcretes and aeolianite dunes. The geochemistry of the calcretes reflects that of the underlying bedrock, and places constraints on the calcrete-formation model postulated. A salt-marsh-prograding barrier beach couplet shows the classic features of such an environment. Palaeontological analyses of the Recent sands indicates a diverse death assemblage, the dominance differences probably resulting from life-assemblage environmental differences, particularly depth and bottom. The presence of Marginopera vertebralis in the tidal detritus between Wardang Island and Goose Island indicates that this species may still be extant in this locality. MgC03 analyses support this hypothesis.
Dissertation Note: Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 1978
Where: Spencer Gulf, South Australia
Keywords: Honours; Geology; Gawler Craton; Permian glacigenes; Pliocene; Recent
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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02wholeGeoHon.pdf7.47 MBAdobe PDFView/Open
Fig 1_geological map.pdf122.49 kBAdobe PDFView/Open


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