Measurements of water turbidity, currents, seafloor sediment samples and geophysical data document the sedimentary processes and the Late Quaternary sedimentary history of a continental shelf valley system on the East Antarctic continental margin.

Recent improvements to Australian apparent polar wander paths for the different geological periods allow palaeomagnetic analysis to contribute increasingly to reconstruction of mineralisation environments and the study of ore formation processes. This paper looks at the application of palaeomagnetism to the timing of regional chemical alteration, mapping of hydrothermal fluid flow paths, identification and timing of intraplate tectonism (which controls the evolution of sedimentary basins that host mineralisation as well as the circulation of mineralising fluids in the upper crust), location of displaced metallogenic provinces of formerly single tectonic units, and dating of strata. Numerous examples are available of the application of palaeomagnetism to mineralisation studies, especially in North America. An Australian example is the discovery in the southeastern McArthur Basin of magnetic overprint signatures that suggest wide-spread circulation of fluids during the general period when the HYC Pb-Zn deposit formed. Another Australian example is the dating of the Au-bearing Quamby Conglomerate in the Cloncurry region: the date is substantially older than the earlier, tentatively estimated ages, opening the possibility that the mineralisation occurred within a large fluid circulation system that existed at the time of intrusion of late Palaeoproterozoic granites. Palaeomagnetism has also been used to establish a geological framework that integrates tectonic, magmatic and mineralisation events in northern Australia. A recent palaeomagnetic reconstruction suggests the proximity during the Palaeoproterozoic of the Pacific margins of the Australian and North American cratons, with implications for mineral exploration in both continents.

Outcrop and core gamma-ray logs have been successfully used to correlate Proterozoic units in northern Australia. This paper highlights the benefits of integrating gamma-ray data and traditional sedimentology for defining large-scale depositional cycles and depositional geometry. Gamma-ray logs of outcrop and cored intervals provide excellent stratigraphic and sedimentological information for areas where conventional down-hole geophysical surveys are lacking. Both total count (scintillometer) gamma-ray profiles and spectral gamma-ray profiles enable recognition of subtle changes in lithology and sedimentary cyclicity that might have been missed during customary section measuring. Lithofacies described from measured sections and core may be characterised by their gamma-ray signatures, and the signatures may then be used as proxies for down-hole gamma-ray logs obtained from the subsurface where direct lithological information is sparse or absent. The integration of traditional lithostratigraphic descriptions with surface and subsurface gamma-ray logs results in a more robust and sophisticated stratigraphic framework than either data set can yield independently. Use of sequence stratigraphic principles enables gamma-ray log trends and their stacking patterns to be interpreted as part of larger sedimentary cycles that reflect changes in sediment supply and relative sea level. Abrupt shifts in gamma-ray values occur at important stratigraphic surfaces that define sedimentary sequences of various scales. Systematic variations in sedimentary thickness and gamma- ray stacking patterns between areas are related to changes in depositional geometry of sequences. Regional mapping of stratigraphic surfaces and sequences by the correlation of vertical gamma-ray profiles and corresponding descriptive logs allows a predictive chronostratigraphic framework to be constructed for a region.

In many ore-forming and surficial environments, fluid-rock interaction can be identified using isotopic methods, especially H, O, C and S stable isotopes. The isotopic fingerprint or halo related to fluid-rock or fluid-ore interaction can be used in mineral exploration. Three examples demonstrating different mineral exploration scenarios in Australia are presented.

Victoria provides the only well-exposed section across the southern part of the Lachlan Fold Belt and the easternmost Delamerides. Although the plate tectonic setting of this region in the Palaeozoic is still uncertain, the exposure provides important insights into its depositional, magmatic and structural evolution from the Cambrian to the end of the Devonian. The oldest known rocks are Late Proterozoic or Cambrian and either calc-alkaline arc-type volcanics (mainly in the west) or MORB-types (mainly in central Victoria). The MORB-types host small copper-gold deposits and may be the source for the turbidite-hosted gold. The arc-type volcanics have potential for major VHMS deposits. The volcanics are overlain by an extensive turbidite sheet, which is Cambrian in the west and Early Ordovician in central and eastern Victoria; in east-central Victoria the turbidites may be absent. The Delamerian Deformation affected rocks in the far west; the Benambran Deformation affected the east and the Bendigo and Stawell Zones in west-central Victoria. In the Bendigo and Stawell Zones, late phases of the Benambran Deformation coincided with the formation of the world-famous turbidite-hosted gold deposits. There was no Benambran Deformation in the Melbourne Zone in central Victoria, where marine deposition continued without interruption from the Cambrian to the early Middle Devonian. In the Silurian, the partly fluvial, partly shoreline facies Grampians Group was laid down on cratonic crust in western Victoria, at what may have been the western shoreline of the Melbourne Trough in central Victoria. This was followed in the Late Silurian by eruption of the subaerial Rocklands Rhyolite. In eastern Victoria, there are two cycles of rifting in transtensional rift-like grabens into which voluminous silicic volcanics and marine sediments were deposited. The first, Silurian, cycle formed the Cowombat Rift, host to significant base-metal deposits. Away from this rift, there seems to have been a shallow sea during most of the Silurian in eastern Victoria, into which a very condensed limestone seems to have been deposited; however, the limestone is mainly known from olistoliths in the rift sequence. A second cycle of transtension in the Early Devonian formed the Buchan Rift and smaller basins, into which volcanics and/or marine sediments were deposited. In western Victoria, numerous I-type granites were intruded. In eastern Victoria, mixed I-, S- and A-type granites were intruded; several broke through to the surface and formed calderas. The Middle Devonian Tabberabberan Deformation affected most rocks in central and eastern Victoria. It was rapidly followed by intrusion of several granites and the Woods Point Dyke Swarm in central Victoria, which hosts the large Woods Point-Walhalla gold province in the Melbourne Zone. In the Late Devonian, a molasse-type sequence, mainly fluvial redbed sediments and silicic pyroclastics and lavas, was deposited in the Howitt Province in east-central Victoria, from where the rivers probably flowed to the east coast via Gippsland. The Howitt Province overlaps with the Central Victorian Magmatic Province, where many more granites were intruded with, again, some rising to the surface to form calderas into which thick sequences of silicic volcanics were erupted. The last significant Palaeozoic deformation was the Kanimblan, in the Carboniferous, during which the Upper Devonian and Lower Carboniferous redbeds were mildly to strongly folded and faulted.

The folded Proterozoic and Palaeozoic rocks of Tasmania are host to a wide variety of mineral deposits, some of which are of world-class significance. The Proterozoic sequences host known iron ore, gold, copper and non-metallic mineralisation, but have not been intensively explored and have considerable potential for further discoveries, of both the known deposit types and a number of other sediment-hosted mineralisation types. Early Cambrian ultramafic/mafic complexes, now thought to be allochthonous, have historically given platinum-group minerals, chromite and nickel. The Middle- Late Cambrian Mt Read Volcanics, host to known world-class VHMS- gold deposits and intensively explored, are still considered to represent a prime exploration target. Disseminated zinc-lead mineralisation of possible Irish style has recently been recognised in Ordovician platform carbonate sequences in western Tasmania. Widespread mineralisation related to the intrusion of Middle Devonian- early Carboniferous granitoids includes tin-tungsten, silver-lead and slate-belt gold, and there is considerable potential for the discovery of further similar deposits. Recent advances in the recognition of structural complications caused by major thrust faulting have in some cases increased the known and perceived possibilities for potential sites of mineralisation. The late Carboniferous and younger cover rocks have traditionally been a barrier to mineral exploration, but geophysical flagging of favourable host sequences in the basement below these rocks, together with the discovery of mineralisation in basement inliers, suggests considerable mineral potential in the basement.

The Early to Middle Cambrian Stansbury Basin preserves a palaeogeographic zonation, from shallow shelf carbonates in the west (Spencer and Ardrossan Shelves) through extensional siliciclastic rift facies (Kanmantoo Trough) and volcanogenically influenced back-arc basin environments (Murray Basin basement). Sedimentation occurred from about 540 Ma to at least 510 Ma, with a distinctive phase of thick rift sedimentation in the Kanmantoo Trough from 526 Ma. Sedimentation continued beyond the 510 Ma onset of compressional orogenesis, in back-arc basin environments east of the Padthaway Ridge and, possibly, in a foreland setting now occupied by Gulf St Vincent. Granitoid emplacement accompanied both the main compressive deformation (syntectonic 1- and S-type c.51 0- 500 Ma) and subsequent relaxation and extension (post-tectonic A-type granitoids and mantle-derived mafics c.480-490 Ma). Variably deformed, syn- to post-orogenic acid volcanics occur along the Padthaway Ridge. Listric faults associated with extensional rift development along the southeastern margin of the Gawler Craton were inverted during the Delamerian Orogeny as preferential zones of shearing and thrusting. The change from rift basin to platform sequence is now marked by a discrete shear zone on Kangaroo Island and a broader zone of imbricate thrusting on western Fleurieu Peninsula. There was little detachment between basement and cover, with most thrusts rooted in southeast-dipping shear zones within the basement. Cambrian carbonates of the Ardrossan and Spencer Shelves have potential for epigenetic, structurally modified Mississippi Valley-type (MVT) mineralisation associated with basin dewatering along major structures. Key areas for mineralisation are unconformities, karst and porous carbonates around the margins of the basin and near reactivated thrusts and fractures that acted as conduits for fluid movement. There is also potential for stratabound Cu mineralisation at redbed-to-marine stratigraphic transitions on the shelf. Many base-metal deposits with stratiform or structurally modified genetic characteristics have been discovered in outcrop in the Kanmantoo Trough. A syngenetic association with flooding surfaces (sequence boundaries) and manganiferous sea-floor exhalites has been recognised. Varying degrees of structural control or structural modification of originally stratiform and sedimentary exhalative mineralisation are evident. Recent sub-economic discoveries at the Angas and Mt Torrens prospects are significant and encouraging for undiscovered economic syn-sedimentary lead- zinc- silver- gold deposits. Beneath the Murray Basin, there is potential for volcanogenic massive sulphide mineralisation analogous to the Mt Read Volcanics. Recent drilling on the northern flank of the Padthaway Ridge encountered a number of anomalous Zn, Pb, Cu and Au intervals associated with post-collisional lavas, intrusives and pyroclastics. Extensive syn- and post-tectonic granitoids near the southern and eastern limits of Kanmantoo Group exposure are potential sources for porphyry Cu-Mo, epithermal Cu-Au and skarn deposits. Platinum-group element mineralisation is also evident in post-orogenic, mantle-derived mafic intrusives.

The Proterozoic Curnamona Province extends across northeastern South Australia and western New South Wales, with exposures in the Willyama, Mount Painter and Mount Babbage Inliers, but much of it is obscured by younger sedimentary cover. Curnamona Province rocks comprise a late Palaeoproterozoic metasedimentary and metavolcanic succession (Willyama Supergroup) with some meta-intrusives and early Mesoproterozoic volcanics, sediments and granitoid intrusives. The Willyama Supergroup in South Australia is divided into the Olary and Broken Hill Domains on the basis of lithological and geophysical character, with a strong linear magnetic feature marking the boundary. A tentative lithostratigraphy has been established for the Olary Domain, in parallel with the Broken Hill Domain. Limited geochronology indicates broad contemporaneity, but the Olary Domain differs in the apparent dominance of shallow-water or evaporitic sediments, the relative paucity of volcanics, the presence of widespread metasomatism, particularly albitisation and associated brecciation, and abundant Mesoproterozoic granitoids. Current mapping of the Broken Hill Domain in South Australia has identified lithologies comparable with the Thorndale Composite Gneiss, Thackaringa Group, Broken Hill Group and Sundown Group. The Benagerie Ridge, known only from limited drilling, contains lower metamorphic grade metasediments consistent with the northwards decrease of grade observed in the Olary Domain. Further north on the ridge, essentially flat-lying Mesoproterozoic sediments and acid and basic volcanics may overlie Willyama Supergroup. The Willyama Inliers in South Australia have widespread base-metal, gold and uranium occurrences, although total production has been very small, except for the Radium Hill uranium mine. In the Broken Hill Domain, known mineralisation includes a copper sulphide resource at the Mutooroo Mine and several large, low-grade bodies of disseminated copper and zinc sulphides. The Olary Domain has numerous occurrences of copper, zinc, lead and gold associated with sulphidic, calc-silicate and albitic units. Copper and gold are also associated with stratabound quartz- magnetite bodies lower in the sequence. Discordant, epigenetic, base metal- and gold-bearing veins are also widespread in the Willyama Supergroup, related particularly to the retrogressive phase of the Mesoproterozoic Olarian Orogeny and to the Cambro-Ordovician Delamerian Orogeny. Significant intersections of copper, zinc, molybdenum and gold mineralisation have been found in ?Willyama Supergroup metasediments in the southern Benagerie Ridge. In general, the Curnamona Province is prospective for stratiform and stratabound lead- zinc and Olympic Dam and Cloncurry Belt style copper- gold(- uranium) mineralisation.

The evolution of the geology and mineral deposits of the Proterozoic in Western Australia can be described in terms of episodes of continental breakup, terrane accretion and plate aggregation. The Hamersley Basin represents breakup of an Archaean continent in the late Archaean to earliest Palaeoproterozoic (2800-2300 Ma). A period of plate aggregation occurred in the Palaeoproterozoic between 1900 and 1750 Ma with the formation of the North, South, and West Australian Cratons, probably as parts of larger continents. A period of intracratonic basin formation followed in the earliest Mesoproterozoic, around 1600 Ma. A second period of terrane accretion and plate aggregation took place in the late Mesoproterozoic between 1300 and 1000 Ma, during which the main crustal components of Proterozoic Australia were assembled as part of the Rodinian supercontinent. Proterozoic Australia remained essentially intact during Neoproterozoic continental breakup at ~750 Ma. Old Palaeoproterozoic and Mesoproterozoic sutures were reactivated as intracratonic orogenic belts between 560 and 540 Ma, during the late Neoproterozoic assembly of a new supercontinent. Two broad groups of mineral deposits, related to different tectonic regimes, can be recognised: volcanogenic massive sulphide deposits, stratiform sediment-hosted deposits, and hydrothermal vein systems related to rifting and basin formation; and mesothermal lode mineralisation, formed from magmatic, deformational, and metamorphic events linked to compressional tectonics. Although there are similarities, the geological evolution and mineralisation of individual orogenic belts and basins do not conform simply to models developed in the Proterozoic of northern and northeastern Australia. Given the low level of exploration activity and poor exposure in many areas, and recognising that mineralisation related to large-scale hydrothermal systems has occurred at various times throughout the Proterozoic, the potential exists for the further discovery of large-scale mineralisation.

There are two Archaean cratons in Western Australia, the Pilbara Craton and the Yilgarn Craton. Although tectonic models for each are controversial, there are clear differences between the two cratons in terms of age, relative abundance of rock types and structure. There are also contrasting ranges of mineral deposits. The Yilgarn Craton is the more prospective, especially for nickel, gold and tantalum. It contains world-class deposits of each of these commodities and many other small to medium-sized deposits of nickel and gold. A vigorous approach to exploration in the Yilgarn Craton over the past fifteen years has been rewarded with a steady stream of discoveries and conversion of prospects to mines. The Archaean rocks of the Yilgarn have also given rise to large deposits of bauxite and heavy-mineral sands, as a result of Tertiary weathering processes. The Pilbara Craton appears to be less well-endowed with mineral wealth, but contains some large sub-economic deposits of platinum-group elements, molybdenum and barite, as well as several clusters of volcanogenic base-metal sulphide deposits. Some of these deposits may become operating mines in the medium term and indicate the potential for more, possibly higher grade deposits in the Pilbara Craton.