The Gippsland Basin of southeastern Australia is the most energy-rich basin of Australia producing petroleum, gas and brown coal. Three-quarters of the Basin lies offshore and the rest onshore. The basin was initiated as a rift valley, caused by the separation of the Australian continent from the Antarctic followed by a number of tectonic events throughout the basin history. Early Cretaceous sedimentary rocks form the basement, which is in turn covered with Late Cretaceous to Recent sediment of sand, clay, limestone, and brown coal seams. The total thickness of the in-filling sediments offshore attains up to 6000 m, but onshore is up to 1200 m. There are three main acquifer systems, the Hydrostratigraphic Units 2, 4, and 7, all of which are confined. The two lower aquifer systems, Units 4 and 7, contain high temperature groundwater. It is generally agreed that the hydrocarbons offshore have been derived from terrestrial matters including brown coal and ligneous clay offshore. In the present study, the author has developed a case that hydrocarbons offshore being derived not only from the offshore source but also from onshore brown coals and coaly matter and in this hydrocarbon forming processes, groundwater has played a significant role. The Central Deep, in particular, provides favourable conditions for hydrocarbon maturation. Throughout the basin history, the Central Deep has experienced the oil window temperatures. In supporting this hypothesis, geochemical studies on groundwater, brown coal, and hydrocarbons as well as hydrodynamics are presented.

This practice based project presents the story of my research journey, as Ganai man. The exegesis documents my life journey, from a young boy to adulthood on traditional country, in the Gippsland region. The stories reveal my experiences of country, identity, racism, family and language as an indigenous male. The content of this project is significant, because it reveals the importance of Indigenous local Ganai connection to country, identity, and the revival of traditional language. I have used multi-disciplinary materials, such as adobe photoshop, film and sound recordings in the making of work. My work examines and engages with personal history, culture and the revival and resounding of Ganai language. My aim is that the research and arts practice discussed in this document encourages future research, steered by Indigenous education and community initiatives. Such initiatives, may both build on my research, and provide an avenue for our younger generation to continue with the re-claiming and resounding of traditional languages.

Deep seismic exploration in the Gippsland Basin is hindered by strong, unidentified noise below the Latrobe Group coal sequence. Low velocity events that appeared in field data semblance analyses suggested that an elastic wave modelling study was required to understand the subcoal reflection response. The modified reflectivity method (Kennet, 1980) provided a means for constructing detailed and accurate synthetic seismograms from realistic depth models, under the assumption of an isotropic, plane-layered earth. A study into the effect of each part of an elastic depth model (upon an elastic depth model (upon an elastic synthetic seismogram) resulted in a set of guidelines for obtaining a field data comparison. Excellent ties were obtained at several wells, often using little more than a partial sonic log. The noise contributions to the synthesis were interpreted using additional synthetics computed from variations upon the depth model and by exercising control over the wave types modelled. Subsequent processing of the synthetics revealed three types of persistent noise in progressively deeper parts of the subcoal image: 1) mode converted interbed multiples (generated within the coal sequence); 2) S-wave reflections and long period multiples (generated between the coal sequence and the Miocene carbonates and 3) surface related multiples.

Deep seismic exploration in the Gippsland Basin is hindered by strong, unidentified noise below the Latrobe Group coal sequence. Low velocity events that appeared in field data semblance analyses suggested that an elastic wave modelling study was required to understand the subcoal reflection response. The modified reflectivity method (Kennet, 1980) provided a means for constructing detailed and accurate synthetic seismograms from realistic depth models, under the assumption of an isotropic, plane-layered earth. A study into the effect of each part of an elastic depth model (upon an elastic depth model (upon an elastic synthetic seismogram) resulted in a set of guidelines for obtaining a field data comparison. Excellent ties were obtained at several wells, often using little more than a partial sonic log. The noise contributions to the synthesis were interpreted using additional synthetics computed from variations upon the depth model and by exercising control over the wave types modelled. Subsequent processing of the synthetics revealed three types of persistent noise in progressively deeper parts of the subcoal image: 1) mode converted interbed multiples (generated within the coal sequence); 2) S-wave reflections and long period multiples (generated between the coal sequence and the Miocene carbonates and 3) surface related multiples.

This thesis reports the results obtained, and conclusions made regarding research into the hydrochemistry of a small impounded karst area in southeastern Australia. Water samples were collected from a variety of sites over a period of approximately six years and include samples that are representative of baseflow (drought conditions) and flood (high flow conditions) the two extremes of the flow regime. Four distinct water types were found to be associated with the karst spring and cave water sites sampled. In terms of physical, chemical and computed parameter values these have been classed as TYPE 1 water (median parameter values similar to those noted for the surface stream sites sampled with catchments of non-carbonate material); TYPE 2 water (catchment predominantly of limestone); TYPE 3 water (catchment predominantly of dolomite); TYPE 4 water (high median chemical concentrations). Spatial variation within the study area is considerable and intrinsic factors such as catchment lithology, the residence time of recharge, aspect and vegetation cover are the major natural controls in determining physical and chemical characteristics.

Bibliography: leaves 135-143. An anthropological analysis of an industrial dispute that occurred within the East Gippsland forest industry, 1997-1998 and how the workers strove to acheive better working conditions for themselves, and to share in the wealth they had created.

This thesis consists of six published papers. The present-day stress tensor has been determined using petroleum well data in the Gippsland and Otway Basins in Southeast Australia (Papers 1 and 4) and the Cooper Basin in Central Australia (Paper 5). In the Gippsland Basin, the present-day stress regime is transitional between one of reverse and strike-slip faulting and the maximum horizontal stress (SHmax) is oriented ~139°N. The present-day stress regime in the Victorian sector of the Otway Basin is also transitional between one of reverse and strike-slip faulting and SHmax is oriented ~135°N. Horizontal stresses are lower in the South Australian sector of the Otway Basin where the stress regime is one of strike-slip faulting and SHmax is oriented ~124°N. The orientations of SHmax in Southeast Australia are consistent with focal mechanism solutions, neotectonic structures and modelling of plate-boundary forces (Paper 4). Closure pressures from mini-frac injection tests are commonly used to determine the minimum horizontal stress (Shmin) magnitude. However, in high stress basins such as the Cooper and Gippsland Basins, these pressures may not reliably yield Shmin (Papers 2 and 5). In the Cooper Basin, high closure pressures (>18 MPa/km) were observed in tests where pressure-declines indicated complex hydraulic fracture growth. Closure pressures in these injections are unlikely to be representative of Shmin. They are believed to reflect the normal stress incident on pre-existing planes of weakness that are exploited by hydraulic fluid during the mini-frac injection (Paper 5). Sub-horizontal fabrics that are open at the wellbore wall were observed on image logs in the Cooper and Gippsland Basins (Papers 2 and 5). This fabric is believed to be at least partially responsible for the complex growth of hydraulic fractures observed in the Cooper Basin. The occurrence of these sub-horizontal fabrics and knowledge of rock strength have been used to constrain the magnitudes of SHmax and Shmin independently of mini-frac injections in the Cooper and Gippsland Basins (Papers 2 and 5). The present-day stress tensor is often quoted as a single gradient at a sedimentary basinor petroleum field-scale. Image logs and mini-frac data from Central and Southeast Australia indicate significant stress differences between stratigraphic units (Papers 3 and 5). Finite element modelling of the stress distribution between interbedded sands and shales in the Gippsland Basin indicates that stress is ‘partitioned’ to ‘hard’ lithological units in high stress areas. This accounts for the observation that borehole breakout only occurs in hard, cemented sandstones in the Gippsland Basin (Paper 3). A generic ‘mechanical stratigraphy’ derived from knowledge of wellbore failure (from image logs), rock strength and rock properties in individual rock units in the Cooper Basin allows an approximation of the present-day stress-state to be made directly from image-logs for individual rock units prior to mini-frac injection (Paper 6). This is important for predicting and understanding hydraulic fracture growth and containment. When considered together, the papers comprising this thesis provide significant new data on the orientation and magnitude of present-day stresses in Central and Southeast Australia. They also provide insight into the tectonic origin of those stresses and their distribution within sedimentary basins. In particular the papers develop and use new methods for constraining the present-day stress in regions of high tectonic stress. They also discuss implications for problems in petroleum development including wellbore stability and hydraulic fracturing. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1283781 / Thesis(Ph.D.) -- Australian School of Petroleum, 2007

This study developed a heirarchical approach to improve the efficiency and reliability of surveys for stream-breeding frogs in the montane forests of south-eastern Australia. Areas with suitable climate for some of these species were first determined by bioclimatic modelling. Landscape and habitat preferences were then determined for the four species commonly found in far East Gippsland, along with an assessment of survey techniques from which effective survey protocols were developed. The climate of localities at which five stream-breeding species had been previously found was modelled using BIOCLIM, and maps of the predicted potential distributions having similar climate were developed. Litoria phyllochroa was found to occur in coastal to alpine areas from Melbourne to Nowra, and potentially further inland, in areas with relatively low temperatures and low summer rainfall. Litoria lesueuri had a slightly larger known and predicted distribution, covering a wide range of values for the temperature and precipitation parameters. Both species had predicted areas inland from Melbourne and the Blue Mountains where they had never been recorded, probably largely due to land clearing. The rare Heleioporus australiacus had a slightly more northerly distribution, closer to the coast and adjacent ranges from Central Gippsland to just north of Sydney, with a generally warmer climate and large range of average annual precipitation values. Litoria citropa occupies an even narrower area along the coast, extending slightly further north again, with a climatic profile of few extremes but with relatively high rainfall particularly in summer. The rare Mixophyes balbus had a more northerly known and predicted narrow range along the NSW coast, just extending into Victoria and Queensland, characterised by the subtropical influence of higher summer rainfall. The southern extension into far East Gippsland appears to have an extreme sub-climate, and is hence considered highly susceptible to climate change. Future monitoring sites for these species can now be systematically chosen to include their full climatic range, so that any negative effects of climate change on amphibian populations may have a greater chance of detection. Four species were found commonly enough in the far East Gippsland study area for more detailed study - the three stream-breeding specialist species, L. phyllochroa, L citropa, and L. lesueuri, along with Crinia signifera which was not restricted to streams but commonly found along them. Three species, L. phyllochroa, L citropa and L. lesueuri, were not found at the few higher altitudes sites on the Errinundra Plateau, however they may have been restricted by habitat requirements other than altitude. Litoria phyllochroa was otherwise widespread, but preferred larger in-stream pools and backwaters for breeding with overhanging vegetation for perch and call sites. The other three species preferred stream reaches characterised by wide bedrock outcrops and associated wide break in the tree canopy, which may allow their preferred perch sites on rocky substrates to retain heat after sunset. Litoria lesueuri tadpoles were found in both unconnected and connected pools, and the common association of this species with bedrock outcrops may explain its range being largely restricted to granitic substratum where these outcrops mostly occurred. Litoria citropa preferred reaches with bedrock and boulder outcrops, although frogs used both rocky and vegetative substrates as perch sites, with tadpoles caught in both unconnected pools and backwaters. Crinia signifera tadpoles were mostly restricted to unconnected pools, with frogs generally only detected within or very close beside these. Habitat models varied in their predictive ability, from 67.5% for L. phyllochroa frogs to 92.7% for L. lesueuri tadpoles. Models developed from normally-distributed habitat variables by discriminant function analysis were generally more predictive than those from logistic regression analysis. The occurrence of frogs and tadpoles of L. phyllochroa, L. citropa and L. lesueuri can be predicted by the measurement of five habitat variables along a 50m reach: average width between the banks, average channel width, an average of the maximum depth of channel cross-sections along the reach, channel slope, and proportion of the stream length as pools. The occurrence of C. signifera along reaches can be predicted with the additional measurement of the proportion of the banks covered in ferns, the maximum cross-sectional channel depth along the reach, and the number of unconnected pools. Several different techniques for surveying frogs were compared for the four species commonly found along the streams. Probability of detection models were derived for each species for each technique, which allowed calculation of the statistical confidence of detecting a species that actually occurred at a site for any given number of surveys. For transect-based techniques, models were also developed which allowed determination of the minimum number of surveys required without detecting a species to be 95 percent statistically confident that the species did not occur there, for various transect lengths. This level of confidence can be obtained for the four common species by four surveys using the reliable night encounter technique along 500m stream transects, during the period from Ocotber to March, with air temperatures above 10°C. The application of habitat models to select favourable 50m reaches for survey also generally improved the detectability of each species. Timer-activated tape recorders, which automatically recorded the calls of frogs for many consecutive nights at a site, were very efficient at detecting all species except the quietcalling L. lesueuri. Night encounter surveys along stream transects detected all species from a reasonable effort, and dip-netting for tadpoles was also effective for most species. Active visual encounter surveys were less reliable, and day encounter surveys detected few frogs but provided some additional data when other activities were being performed along the streams. The findings of this study have important implications for future amphibian surveys and monitoring undertaken in East Gippsland and the south coast of New South Wales. If the standardised survey techniques recommended by this study are used in Environmental Impact Assessments, their results can be objectively assessed and defended. The use of habitat modelling and improvement in survey reliability can also be used more efficiently to find sites with populations suitable for monitoring. The likely amount of effort required by a long-term monitoring program can also be determined so as to largely overcome daily variations in the detection of each species.

There is a need for ecological modelling to help understand the dynamics in ecological systems, and thus aid management decisions to maintain or improve the quality of the ecological systems. This research focuses on non linear statistical modelling of observations from an estuarine system, Gippsland Lakes, on the south-eastern coast of Australia. Feed forward neural networks are used to model chlorophyll time series from a fixed monitoring station at Point King. The research proposes a systematic approach to modelling in ecology using feed forward neural networks, to ensure: (a) that results are reliable, (b) to improve the understanding of dynamics in the ecological system, and (c) to obtain a prediction, if possible. An objective filtering algorithm to enable modelling is presented. Sensitivity analysis techniques are compared to select the most appropriate technique for ecological models. The research generated a chronological profile of relationships between biophysical parameters and chlorophyll level for different seasons. A sensitivity analysis of the models was used to understand how the significance of the biophysical parameters changes as the time difference between the input and predicted value changes. The results show that filtering improves modelling without introducing any noticeable bias. Partial derivative method is found to be the most appropriate technique for sensitivity analysis of ecological feed forward neural networks models. Feed forward neural networks show potential for prediction when modelled on an appropriate time series. Feed forward neural networks also show capability to increase understanding of the ecological environment. In this research, it can be seen that vertical gradient and temperature are important for chlorophyll levels at Point King at time scales from a few hours to a few days. The importance of chlorophyll level at any time to chlorophyll levels in the future reduces as the time difference between them increases.

Nodularia spumigena is an estuarine cyanobacteria that produces the toxin nodularin. This toxic cyanobacteria is known to have caused death to domestic and wild animals and is recognised as dangerous to human health. N. spumigena causes harmful algal blooms in many parts of the world including Australia. The toxic solutes of N. spumigena are potentially dangerous when contact is made to contaminated water bodies or is ingested by primary consumers. In Australia blooms of N. spumigena are common in the Gippsland Lakes in South-eastern Victoria and cause socio - economic hardships to the local communities. This PhD investigates the toxic effects of N. spumigena and its solutes to a range of aquatic life. A method known as SPME - HPLC showed promise in environmental monitoring of N. spumigena toxins by measuring nodularin from water samples. Other research presented study into the lethal and sublethal effects of on an extract from N. spumigena to aquatic fauna. Resu lts showed the N. spumigena extract was not lethal to many aquatic fauna although zooplankton from the Gippsland Lakes showed mortality at environmental relevant levels. Biochemical studies focusing on animal detoxification and antioxidation enzymes and DNA integrity showed sublethal effects to the N. spumigena extract. Results presented in this thesis show that an extract of N. spumigena elicited detoxification and antioxidation responses in animals tested. Furthermore, the use of the COMET assay showed increased damage to DNA of animals tested. Results also showed that different organs in animals tested responded differently to the aqueous extract, suggesting mode of uptake maybe important in toxicosis. Further, feeding studies with N. spumigena help elucidate mode of uptake using enzyme response biomarkers. The overall results of this research provided an assessment of the toxic affects of N. spumigena on aquatic fauna with special reference to the Gippsland Lakes, Victoria, Australia.