School of Earth Sciences - Theses
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ItemStudies in Victorian Tertiary foraminifera neogene planktonic faunas( 1977)Planktonic foraminiferal faunas are described for the interval late Early Miocene to the Pleistocene, in the Tertiary basins along the southern margin of Victoria, including the Otway Basin, the Port Phillip Embayment, and the Gippsland Basin. Ninety-two foraminiferal taxa are identified. The faunas are dominated in the Early Miocene by globigerinid and globigerinoidid species, by unkeeled globorotalids in the Middle Miocene, and by keeled globorotalids for most of the Late Miocene. Unkeeled globorotalids are again important in the Early Pliocene, but keeled species again reappear in the Late Pliocene and the Early Pleistocene. One Pleistocene, two Pliocene, two Late Miocene, and two Middle Miocene planktonic foraminiferal zones are recognised on the first appearance of the following species: Orbulina suturalis, Globorotalia mayeri, Globorotalia acostaensis, Globorotalia conomiozea, Globorotalia puncticulata, Globorotalia viola, Globorotalia truncatulinoides. Subzones are identified by the extinction of Globorotalia peripheroronda, and by the appearance of Globigerina nepenthes and Globorotalia plesiotumida. Foraminiferal datum levels are used to correlate the Victorian sections with the Italian stratotype sections, the New Zealand late Tertiary, and the N-zonation of Blow, and hence into the palaeomagnetic and radiometric time scales. In the Tertiary basins, the maximum extent of marine deposition occurred in the Early Miocene, and despite subsequent sea level falls, continuous marine deposition is found through the Middle Miocene and most of the Late Miocene in the Otway Basin and the Port Phillip Embayment. Shallowing within the Middle Miocene is reflected by breaks in the Gippsland Basin sections, and lithological changes in other basins. A major sea withdrawal occurred near the top of the Miocene. Small scattered Pliocene deposits indicate short high sea level phases at the base of the Pliocene, in the middle of the Pliocene, and about the Pliocene - Pleistocene boundary.
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ItemMineralogy, geochemistry and origin of the Kalgoorlie gold deposits, Western Australia( 1978)Rich gold-telluride lodes (steeply dipping and flatly dipping) and minor gold-quartz stockwork mineralization characterize the Kalgoorlie gold-field. The origin of these gold deposits, the relationship between deposits and then nature of the host rocks are the major problems considered in this thesis. Extensive diamond drilling at the essentially unmineralized southern end of the field provided excellent material for stratigraphic studies and for country rock analysis whilst ore samples were obtained from both mines and drill core.
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ItemStructural analysis of selected duplex soils( 1971)The profile characteristics, geographical extent and general environmental relationships of duplex soils are described. They are shown to be an important group in Australia and particularly in Victoria. The variety of approaches and definitions employed by investigators of soil structure are discussed. These are contrasted with the definition used in this thesis which incorporates the concepts of spatial distribution and orientation of vectorial fabric elements in the soil. The importance of describing structural features at a number of scales is emphasized. At each scale an attempt is made to quantitatively describe (where possible) the three or two-dimensional geometrical properties of the soil components. A structural classification of duplex soils that incorporates a number of descriptive geometrical elements is proposed. A detailed study is made of the structure and related chemical, physical and mineralogical properties at an undisturbed site (Boorook) in Western Victoria. The ground surface at the Boorook site is described as being deformed into gilgai microrelief. It is demonstrated that soil structural analysis can be usefully employed to develop a swelling mechanism that explains how the Boorook gilgai probably formed. The data and subsequent analysis tends to place some doubt on mechanisms proposed by past workers. A detailed study is also reported from a site (Hartwell) near Melbourne. The site is described as being illustrative of profiles that show little or no internal and ground surface deformation. An unfolded stoneline is considered to be the principal structural feature. The mechanism for the formation of the stoneline is shown to probably involve gravitational settling of the grains in a fluid-like medium. Regional investigations of profiles throughout Western and Central Victoria and New Guinea are also described. It has been found that the principles and techniques of soil structural analysis can also be applied to buried soil structures. By these means it has been possible to establish that buried fold-like structures seen in section in a road cutting at Terang, are in fact relics of gilgai. Experimental models have assisted the investigations into the structure of duplex soils and have provided additional information on the dynamic interaction of moisture with the soil components. The main processes and sequences in the genetic development of structure of duplex soils as discussed in the light of observations of natural structures and experimental results. Attention is drawn to the differences between the dominant structural processes in the two main horizons of the profile. The approach of soil structural analysis is formalized for profile studies into the discipline of Structural Pedology. The principles of Structural Pedology threaded through the body of the thesis are summarized and shown to be very similar to those of Rock Fabric Analysis. The need for an interdisciplinary approach in this field is emphasized. It is shown that soil structural analysis is not limited to Pedology but rather can be applied to a number of academic and applied problems in a variety of disciplines that include Engineering (Soil Mechanics), Earth Sciences, Agriculture, Soil Erosion and Conservation.