The cartographic collection of the Doc Fisher Geoscience Library consists of the maps and air photos created or acquired by agency staff since the formation of BMR in 1946. This includes maps produced by agencies which have merged with these over the years, such as AUSLIG. Maps held include: Australian geological map series (1:250,000, 1:100,000 and the 1 mile series); topographic maps produced by NATMAP and its predecessors (1:250,000, 1:100,000 and 1:50,000) - latest editions only; various Australian geochemical, geophysical and other thematic maps; geoscience map series from other countries acquired on an exchange basis, including some with accompanying explanatory notes; Non-series maps acquired by donation or exchange; atlases. The Air photos are predominantly those used for mapping Australia and, to a lesser extent, Papua New Guinea and Antarctica, by BMR/AGSO from the 1940s to the 1980s. Geographical coverage of the sets is not complete, but many individual photos are unique in that they have pin points, overlays or other markings made by teams in the field. The Papua New Guinea photographs in the collection may, in many cases, be the only existing copies. Flight diagrams are also held for many (but not all) sets of air photos. Some other related materials, such as montages of aerial photographs (orthophotos), are also represented in the collection.

No abstract available

Victorian geology, mine data and deep leads GIS database (June 1998)

The effect of increased nutrient loads on biogeochemical processes in macrotidal, mangrove-lined creeks was studied in tropical Darwin Harbour, Australia. Water quality and sediment composition, benthic and pelagic metabolism and benthic nutrient and gas fluxes were studied during three field surveys to compare nutrient transformation and retention processes in three tidal creeks receiving different loads of sewage discharge. There were marked differences in process rates between Buffalo Creek (hypertrophic), which receives the largest sewage loads; Myrmidon Creek (oligotrophic-mesotrophic) which receives smaller sewage inputs; and Reference Creek (oligotrophic) which is comparatively pristine. Net benthic nutrient fluxes in Buffalo Creek were more than an order of magnitude higher than in Myrmidon and Reference Creeks, which have similar and low benthic fluxes during the wet and dry seasons. Similarly, net pelagic primary production rates were much higher in Buffalo Creek and respiration exceeded primary production resulting in severe drawdown of O2 concentrations at night. In Buffalo Creek, anoxic sediments released oxide-bound phosphorus and inhibited coupled nitrification-denitrification, enhancing benthic nitrogen and phosphorus fluxes. Light limitation of primary production resulted in build-up of excess nutrients in the water column, further stimulating primary production. Poor water quality in Buffalo Creek was exacerbated by poor tidal flushing imposed by a narrow meandering channel and sandbar across the mouth. In contrast to Buffalo Creek, the effect of the sewage load in Myrmidon Creek was confined to the water column, and the impact was temporary and highly localized. This study has identified pelagic primary production, benthic nutrient fluxes and denitrification efficiency as the biogeochemical processes most affected by nutrient loading in tidal creek systems. The serious deterioration of water quality impacts on the functioning of the whole ecosystem, with potential for detrimental effects on higher trophic levels.

Legacy product - no abstract available

Understanding the hydrology of cold seep environments is crucial to perform accurate estimates of fluid and chemical fluxes at sedimentary wedges. Shallow convection processes may affect fluid flux estimates and could favor the destabilization of gas hydrate accumulations, increasing the sediment-ocean methane flux. Evidence for the occurrence of convection at cold seeps, however, is still limited. We use the concentration of 14C (D14C) in carbonate crusts formed at cold seeps of the eastern Mediterranean Sea as a tracer for convective recirculation of seawater-derived fluids. A numerical model is applied to investigate the controls on 14C incorporation in cold seep carbonates. Our simulations show that increased amounts of CH4 in the expelled fluids result in elevated crust D14C, while high Ca2+ and HCO3 concentrations produce the opposite effect. Convection is the only transport process that can significantly increase crust D14C. Advection, bioirrigation, eddy diffusion and bioturbation instead, have little effect on, or produce a decrease of, crust D14C. In addition, the presence of old or modern carbon (MC) in host sediments prior to cementation and the 14C-decay associated to the time needed to form the crust contribute in defining the D14C of carbonate crusts. We then use the model to reproduce the 14C content of the eastern Mediterranean Sea crusts to constrain the chemical and hydrological conditions that led to their formation. Some crusts contain relatively low amounts of 14C (-945.0<D14C - <-930.2) which, assuming no ageing after crust formation, can be reproduced without considering convection. . Other crusts from two sites (the Amsterdam and Napoli mud volcanoes), instead, have a very high 14C-content (-899.0<D14C - <-838.4) which can only be reproduced by the model if convection mixes deep fluids with seawater.

Using geophysical-geochemical spatial data to map of hydrothermal footprints in the Eastern Fold Belt of the Mount Isa Inlier

The absence of basement outcrop and the nearly complete lack of surface expression of mineralisation in the Olympic Cu-Au province is the major impediment to mineral exploration in the province. In such circumstances, analysis of potential field data is one of the usual ways of inferring hidden geology, as high-quality datasets, especially aeromagnetic data, are available for most of the actively explored areas of Australia. Quantitative interpretation of potential field data principally involve 2D forward modelling of profiles, or sections, by skilled interpreters but it can be difficult, and time-consuming, to correctly track structure and geology from one section to the next should one wish to create a 3D model of the geology. To alleviate this problem, we have used a modification of the methods of Li and Oldenburg (1996 & 1998), constrained by known geological information, to give geologically and geophysically consistent solutions to the possible distributions of sources giving the magnetic and gravitational fields observed in a region about Olympic Dam.

In late 2006, the Australian Government announced its Energy Security Initiative, allowing Geoscience Australia to initiate, among others, a major program of onshore activities [1]. An ambitious National Geochemical Survey of Australia (NGSA) project was launched in January 2007 as part of this program because until then Australia lacked a complete geochemical data coverage. Such a dataset informs on the concentrations and distributions of chemical elements in the near-surface environment. Building on methods developed during precursor pilot projects [2], NGSA targets catchment outlet (overbank) sediments as a uniform sampling medium. A shallow and a deeper level are being collected in 1390 catchments covering 91% of the country. Sampling is carried out by State and Northern Territory geoscience agencies following protocols described in a detailed Field Manual [3] and practiced during in-field training; all equipment and consumables are provided centrally. Dry and moist Munsell colours, soil pH, digital photographs and GPS coordinates are recorded in the field. In the laboratory, these transported, fine-grained regolith materials are dried and a split is archived for future use. Electrical conductivity and pH of 1:5 (soil:water) slurries, laser particle size distribution and infrared spectroscopy are measured on the remaining split. This split is further sieved into two grain-size fractions (<2 mm and <75 mm) for analysis by x-ray fluorescence (XRF), inductively-coupled mass spectrometry (ICP-MS) after total digestion (multi-element) as well as after aqua regia digestion (multi-element, including low level gold), and by specialised methods for platinum group elements, fluorine and selenium. As at February 2009, 78% of the samples have been collected and most analyses have been completed for the first 25% of samples. The project will contribute fundamental knowledge to the energy and mineral resources exploration industry by its completion in June 2011. This pre-competitve knowledge, used in combination with other datasets, can reduce exploration cost/risk by helping target more detailed activities. Spin-offs into other applications are also expected.

This data package comprises the following data sets covering the state of Victoria: GIS MapInfo and MapInfo Export format files containing geographically referenced information. MapInfo Export files can be imported into ArcView software. Vicmine Microsoft Access and ASCII text format files containing detailed mineral resource information. Geochemistry ASCII text format files containing geochemical sample data. The data is only available in this data package in text format because of disk space limitations. It is available in other formats through GSV.