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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Granitic and migmatitic rocks of the Cooke Hill area, South Australia, and their structural setting

Abbas, Syed Abdul Fazlil January 1975 (has links)
4 fold. maps in end pocket of v.2 / 2 v. : ill., photos., maps, diags. (some fold) ; 26 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Geology and Mineralogy, 1975
2

The geology of the Adelaidean - Kanmantoo group sequences in the eastern Mount Lofty Ranges

Toteff, Stephen January 1977 (has links)
The metamorphosed sedimentary sequence of the Precambrian Adelaide Supergroup in the eastern Mt. Lofty Ranges closely resembles its lower grade stratotype in the western Mt. Lofty Ranges. Although rocks have been metamorphosed from biotite to high andalusite grade, the nature of the original succession can still be deduced. Stratigraphic thicknesses in the eastern and western sequences differ, however. The thickness of the Torrens Group metasediments in the eastern sequence above the Stoneyfell Quartzite equivalent is over four times that found in its type area. In contrast, the overlying Sturt Group is less than half the thickness of the stratotype whilst the Marino Group is only slightly thinner in the eastern sequence. In the region between Birdwood and Mt. Barker Creek, the Lower Cambrian Kanmantoo Group is in fault contact with the Adelaide Supergroup, the lower levels of the basal unit of the Kanmantoo Group ( the Carrickalinga Head Formation ) being absent. A conformable succession of Kanmantoo Group strata, closely resembling the lithologies in the type area on the south coast of Fleurieu Peninsula, occurs to the east of this contact. Evidence for a fault contact disproves earlier interpretations that the Kanmantoo Group unconformably overlies older strata in parts of this region and confirms the existence of the Nairne Fault. Furthermore, it is doubtful whether the Kanmantoo Group unconformably overlies older strata elsewhere in the eastern Mt. Lofty Ranges. Where there is a break in the normal Kanmantoo Group succession ( which exhibits a remarkable constancy of facies ), faulting is probably the cause. A well developed penetrative schistosity ( S2 ) occurs throughout the Nairne - Mt. Barker Creek area, being related to a deformation phase F2 which produced tight assymetric folds with easterly - dipping axial planes ( paralleled by S2 ) during the Early Palaeozoic Delemarian Orogeny. An earlier deformation ( F1 ) with accompanying metamorphism, earlier than generally recognized in the Mt. Lofty Ranges is evident in the schists. Metadolerite dykes in the area were probably emplaced pre - S2 to early syn - S2. Petrological examination of the metasediments in the Nairne - Mt. Barker Creek area revealed that critical minerals present in metashales of appropriate bulk composition are andalusite, staurolite and almandine whereas cordierite is absent. The origin of andalusite and staurolite is unresolved. Fibrolite ( + minor coarse sillimanite ) is present in all andalu - site - bearing rocks. The sillimanite problem is examined through the well developed textures in peraluminous schists. Green hornblende, diopside and scapolite occur in calc - silicates. Green hornblende, high - An plagioclase and minor epidote are present in the metadolerite dykes. P - T conditions at the peak of metamorphism ( based on mineral assemblages and metamorphic textures ) were probably around 3.5 to 3.75 kb and 500 to 550 ° C ( close to the andalusite - sillimanite phase boundary and near the Al2 SiO5 triple - point ). Temperatures of metamorphism deduced from the garnet - biotite geothermometer and more generally from muscovite compositions are compatible with this range. Fibrolite probably formed just within the upper limits of the andalusite stability field. It is uncertain, however, if fibrolite formed as a stable mineral under these P - T conditions or whether it formed metastably, perhaps as a result of rapid reactions induced by sudden temperature increases. / Thesis (Ph.D.)--Department of Geology and Mineralogy, 1977.
3

Conservation assessment of remnant vegetation in the Mount Lofty Ranges, South Australia

Mitchell, Leslie Howard, n/a January 1983 (has links)
This study is concerned with programs to conserve remnant stands of native vegetation in the agricultural regions of South Australia and concentrates on the development of explicit evaluation procedures which reflect stated conservation objectives. As botanical data are available for stands of native vegetation in most of the agricultural regions, stands in a particular region are able to be compared rather than assessed in isolation. Based on a review of conservation evaluation schemes in Australia and overseas, a hierarchical evaluation procedure using multiple criteria to compare stands was applied to stands of vegetation in the Mount Lofty Ranges. The conservation objective, of preserving samples of all plant communities in a region, led to the analysis of existing botanical data from two surveys of the Mount Lofty Ranges, to provide the basis for an inventory of regional plant communities. These surveys included 52 remnant stands of native vegetation and employed a point-centred quarter plotless sampling technique to summarise the vegetation. Numerical classificatory analysis of the raw sampling point data produced a more comprehensive floristic summary than the results from the plotless sampling. These floristic groups were correlated with physical environmental variables to produce an inventory of 45 regional vegetation types, as the first stage in the conservation evaluation of stands. Evaluation criteria of size, species richness and species rarity were quantified and used to select examples of each vegetation type on the basis of overall satisfaction of the criteria. In addition, the smallest suite of stands, in which all the vegetation types were represented, was determined, and was shown to be 24 stands. All of these were included in the 37 stands chosen using the three criteria. A third evaluation stage used stand parameters such as plant community richness to give a priority ranking of the 37 stands. A polythetic divisive classification of the vegetation types was developed to provide a means of evaluating communities in stands of native vegetation yet to be sampled in the region, and of comparing the vegetation types with communities in existing reservesr Examination of species-sampling area relationships led to recommended plot sizes for such future vegetation surveys in the Mount Lofty Ranges. The ease of collecting floristic data and the extensive time involved in quantitative measurements suggest that all perennial plant species be recorded and only estimations be made of vegetation quantity and structure for each sampling plot. This study demonstrates the usefulness of numerical classification techniques for conservation evaluation, and of continuous variables to quantify criteria of conservation value; and the application of those criteria in an explicit, hierarchical conservation evaluation procedure.
4

Strategic revegetation planning in an agricultural landscape: A spatial information technology approach

Bryan, Brett A January 2000 (has links)
Revegetation is required to conserve the biological diversity of over-cleared and fragmented agricultural regions. This dissertation represents an application of spatial information technologies to environmental management. It makes a significant contribution to the integration of general landscape-scale principles into restoration ecology. New and established quantitative, spatial analytical techniques are used in environmental modelling, ecological assessment and in setting geographic priorities for strategic revegetation planning in the Mt. Lofty Ranges in South Australia. This is one of the first assessments of the adequacy and representativeness of remnants in an agricultural region and one of the first attempts to apply these landscape-scale conservation principles to the field of restoration ecology. The adequacy of the remnant ecological system is assessed in terms of the landscape structure. Landscape ecological principles provide a basis for setting geographic priorities for the revegetation of an adequate remnant ecological system. Although seldom quantified, it is often thought that remnants in agricultural regions are not representative of the regional physical environmental heterogeneity. The representativeness of remnant vegetation is assessed in the study area and a complex effect of land clearance and reserve selection on representativeness is revealed which has significant implications for strategic revegetation planning. Land clearance has precluded the use of information on the spatial distribution of biological diversity in agricultural regions. Hence, a surrogate is required in strategic planning for the restoration of a representative regional ecological system. The degree of vegetation/environment convergence is assessed to investigate the viability of using the physical environment as a surrogate for the distribution of biological diversity. An index of coincidence is developed specifically for this purpose. An environmental classification is then derived for use in setting geographic priorities for the restoration of a representative regional ecological system. Three complementary techniques are used to find the simplest classification possible that does not have overly broad environmental classes. Geographic priorities are suggested according to the distribution and representativeness of environment types in the study area. In the light of the results of this dissertation, a research direction for restoration ecology in agricultural landscapes is mapped out. / Thesis (Ph.D.)--Department of Geographical and Environmental Studies; Department of Applied and Molecular Ecology, 2000.
5

Sedimentology of the late Precambrian Mundallio Subgroup : a clastic - carbonate ( Dolomite, Magnesite ) sequence in the Mt. Lofty and Flinders Ranges, South Australia

Uppill, Robin K January 1980 (has links)
During deposition of the mixed carbonate - clastic sequence of the Mundallio Subgroup, the " Adelaide Geosyncline " was a very shallow, elongate sedimentary basin, flanked to the west and east by older Precambrian basement. In much of the southern and northern Flinders Ranges, clastic deposition predominated in the lower Mundallio Subgroup. In the north, alternating development of shallow mudflats and sandflats ( Nankabunyana Formation ) depended on the interplay between the sediment supply and winnowing processes, while dolomite mudstones were locally deposited in the shallowest areas. In the eastern half of the Willouran Ranges, massive shales were deposited as the environment remained persistently below wave base ( Camel Flat Shale ), but a renewed sand influx led to deposition of the Tilterana Sandstone. In the southern Flinders Ranges, terrigenous clay and silt were deposited on submergent mudflats which shallowed into intermittently exposed dolomite mudflats ( Nathaltee Formation ). Dolomite mudflats were a more persistent feature in areas more distal from the terrigenous source, and sometimes contained isolated, ephemeral lakes which were sites of magnesite deposition ( Yadlamalka Formation ). Dolomite and magnesite mudstone deposition of the Yadlamalka Formation became wide spread in the northern and southern Flinders Ranges in the upper Mundallio Subgroup, as shallowing and retreat of the basin margin led to the formation of semi - isolated lakes, separated and enclosed by exposed carbonate mudflats. The elastics deposited in association with these carbonate mudstones consisted largely of sand sized detritus, probably derived from the reworking of aeolian deposits. In the eastern Willouran Ranges, the greater influx of sand and the slightly deeper, largely submergent environments, led to the deposition of the sandstones, dolomites and siltstones of the Mirra Formation. Because of little clastic influx into the northern Mt. Lofty Ranges, shallow to occasionally exposed environments were largely sites of dolomite deposition ( Skillogalee Dolomite ). To the south, shales were deposited in slightly deeper environments ( Woolshed Flat Shale ), although local dolomite deposition occurred in the Adelaide region ( Castambul Formation, Montacute Dolomite ). In the uppermost part of the subgroup, the area of shale deposition extended northward, encroaching over the dolomite mudflats of the upper Skillogalee Dolomite. Dolomite, occurring largely as mudstones, is the major carbonate mineral present in the Mundallio Subgroup, but magnesite is also widespread. Limestones are not present. The carbonates experienced minor replacement by early diagenetic chert, initially precipitated as both crystalline and amorphous phases. Within the upper Mundallio Subgroup, the preservation of fine details of the detrital texture of dolomite mudstones and peloidal dolomites, and the high Sr contents of dolomites ( largely in the range of 400 - 650 ppm ), suggest that these sediments consisted of Ca - Mg carbonates ( protodolomite, Mg - calcite ) at the time of deposition. Slightly greater recrystallisation of dolomites in the lower Mundallio Subgroup resulted in their lower Sr and higher Mn and Fe contents. Magnesite mudstones may have initially precipitated as hydrated Mg - carbonates. Lithification of surface sediments as a result of subaerial exposure, led to the formation of micritic magnesite. Much of this magnesite was subsequently reworked into intraclastic beds. The carbonate mineralogy of this sequence, and the evidence of only rare sulphates, indicate that the carbonates were precipitated from alkaline, Mg - Ca - C03 waters, with a higher carbonate and lower sulphate content than seawater. / Thesis (Ph.D.)--Department of Geology and Mineralogy, 1980.
6

Sedimentology of the late Precambrian Mundallio Subgroup : a clastic - carbonate ( Dolomite, Magnesite ) sequence in the Mt. Lofty and Flinders Ranges, South Australia

Uppill, Robin K January 1980 (has links)
During deposition of the mixed carbonate - clastic sequence of the Mundallio Subgroup, the " Adelaide Geosyncline " was a very shallow, elongate sedimentary basin, flanked to the west and east by older Precambrian basement. In much of the southern and northern Flinders Ranges, clastic deposition predominated in the lower Mundallio Subgroup. In the north, alternating development of shallow mudflats and sandflats ( Nankabunyana Formation ) depended on the interplay between the sediment supply and winnowing processes, while dolomite mudstones were locally deposited in the shallowest areas. In the eastern half of the Willouran Ranges, massive shales were deposited as the environment remained persistently below wave base ( Camel Flat Shale ), but a renewed sand influx led to deposition of the Tilterana Sandstone. In the southern Flinders Ranges, terrigenous clay and silt were deposited on submergent mudflats which shallowed into intermittently exposed dolomite mudflats ( Nathaltee Formation ). Dolomite mudflats were a more persistent feature in areas more distal from the terrigenous source, and sometimes contained isolated, ephemeral lakes which were sites of magnesite deposition ( Yadlamalka Formation ). Dolomite and magnesite mudstone deposition of the Yadlamalka Formation became wide spread in the northern and southern Flinders Ranges in the upper Mundallio Subgroup, as shallowing and retreat of the basin margin led to the formation of semi - isolated lakes, separated and enclosed by exposed carbonate mudflats. The elastics deposited in association with these carbonate mudstones consisted largely of sand sized detritus, probably derived from the reworking of aeolian deposits. In the eastern Willouran Ranges, the greater influx of sand and the slightly deeper, largely submergent environments, led to the deposition of the sandstones, dolomites and siltstones of the Mirra Formation. Because of little clastic influx into the northern Mt. Lofty Ranges, shallow to occasionally exposed environments were largely sites of dolomite deposition ( Skillogalee Dolomite ). To the south, shales were deposited in slightly deeper environments ( Woolshed Flat Shale ), although local dolomite deposition occurred in the Adelaide region ( Castambul Formation, Montacute Dolomite ). In the uppermost part of the subgroup, the area of shale deposition extended northward, encroaching over the dolomite mudflats of the upper Skillogalee Dolomite. Dolomite, occurring largely as mudstones, is the major carbonate mineral present in the Mundallio Subgroup, but magnesite is also widespread. Limestones are not present. The carbonates experienced minor replacement by early diagenetic chert, initially precipitated as both crystalline and amorphous phases. Within the upper Mundallio Subgroup, the preservation of fine details of the detrital texture of dolomite mudstones and peloidal dolomites, and the high Sr contents of dolomites ( largely in the range of 400 - 650 ppm ), suggest that these sediments consisted of Ca - Mg carbonates ( protodolomite, Mg - calcite ) at the time of deposition. Slightly greater recrystallisation of dolomites in the lower Mundallio Subgroup resulted in their lower Sr and higher Mn and Fe contents. Magnesite mudstones may have initially precipitated as hydrated Mg - carbonates. Lithification of surface sediments as a result of subaerial exposure, led to the formation of micritic magnesite. Much of this magnesite was subsequently reworked into intraclastic beds. The carbonate mineralogy of this sequence, and the evidence of only rare sulphates, indicate that the carbonates were precipitated from alkaline, Mg - Ca - C03 waters, with a higher carbonate and lower sulphate content than seawater. / Thesis (Ph.D.)--Department of Geology and Mineralogy, 1980.

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