Compilation of new and existing data can be used to show systematic variations in initial ore-related Pb isotope ratios and derived parameters for the Lachlan and Delamerian orogens of southeast Australia. In addition to mapping tectonic boundaries and providing genetic context to mineralising processes, these variations map mineralised provinces at the orogenic scale and can provide vectors to ore at the district scale. In New South Wales and Victoria, mapping using a parameter termed the 'Lachlan Lead Index' (LLI), which measures relative mixing between crustal- and mantle-derived Pb using the curves of Carr et al. (1995, Economic Geology 90:14671505), clearly demarcates the boundary between the Eastern and Central Lachlan provinces, and seems to identify boundaries between zones within the Western Lachlan Province of Victoria. The LLI also maps the extent of the isotopically juvenile Macquarie 'Arc' in New South Wales. However, rocks in the Rockley-Gulgong Belt, initially mapped as part of the Macquarie Arc, have a more evolved isotopic character, suggesting that these rocks are not part of the Macquarie Arc. This interpretation supports recent mapping that casts doubt on the attribution of this belt to the Macquarie Arc (Quinn, et al., 2014, Journal of the Geological Society of London 171:723736). The LLI has also identified small exposures of Ordovician volcanic rocks, well removed from the main Macquarie Arc, as possible correlates to this arc, with potential to host porphyry and epithermal deposits. Metallogenically, porphyry Cu-Au deposits in the Macquarie Arc are characterised by juvenile Pb. In contrast, Sn and Mo deposits in the Central Lachlan Province (i.e., the Wagga tin belt) are characterised by highly evolved Pb even though these deposits formed over 30 million years. Moreover, the Pb isotope data suggest that the original interpretation that copper deposits in the Girilambone district are volcanic-associated massive sulfide deposits was correct and that these deposits formed in a back-arc to the Macquarie Arc at ~480 Ma. In the Mount Read Volcanics of western Tasmania, all deposits appear to cluster along the same growth curve. However, when divided according to age (i.e., Cambrian (~500 Ma) versus Devonian (~360 Ma)), spatial patterns are visible in 206Pb/204Pb data. For Cambrian deposits 206Pb/204Pb decreases overall to the southeast, although low values are also present in the far south (i.e., Elliott Bay) and northeast. The most highly mineralised central part of the belt seems to be broadly associated with the zone of highest 206Pb/204Pb. Variations in 206Pb/204Pb for Devonian deposits broadly mimic the patterns seen for the Cambrian deposits. More importantly, a district-scale pattern in 206Pb/204Pb is present in the Zeehan district. Isotopically, the Sn-dominated core of the Zeehan district (e.g. Queen Hill and Severn deposits) is characterised by high 206Pb/204Pb, which decreases outward into the Zn-Pb-Ag-dominated peripheries. Lead isotope distribution patterns can potentially be used as an ore vector in this and other intrusion-centered mineral systems.

Measurements of maximum trace amplitudes from 181 short- period vertical seismograms recorded at hypocentral distances of 3-1500 km from 36 earthquakes in the magnitude range 0.8 - 4.3 were used to derive a new preliminary ML scale for southeastern Australia ML = log A + (1.34±0.09)log(R/100) + (0.00055±0.00012)(R-100) + 3.13 + S where ML is local magnitude, A (mm) is equivalent Wood-Anderson trace amplitude not corrected for the measurement having been made on a vertical component, R (km) the hypocentral distance and S the station correction.

The largest southeastern Australian earthquake this century occurred in the West Tasman Sea, 100 km east of Flinders Island, at 1948 UTC on 14 September 1946. Its epicentre was at 39.97°S, 149.35°E and its Richter magnitude ML 6.0. It was felt strongly throughout Tasmania and Gippsland, Victoria, and caused minor damage in Launceston. The isoseismal map of the earthquake is consistent with lower strong ground motion attenuation in Tasmania than in mainland southeastern Australia, and the macroseismic effects suggest amplification of seismic shaking by Tertiary lake sediments in Hobart and Launceston.

The Bremer Basin underlies part of the upper continental slope of offshore southwest Australia. It occupies an area of 9000 km2, and contains a sedimentary pile probably 10 km thick in water depths of 200-3000 m. Though not tested by drilling, the basin is covered by a grid of seismic data. By analogy with the Eyre Sub-basin to the east, the Bremer Basin probably contains Late Jurassic to Barremian continental deposits overlain by Albian and Late Cretaceous marine deposits with a veneer of Tertiary open-marine carbonates of variable thickness. The Bremer Basin formed during the period of continental extension that preceded the breakup of Australia and Antarctica in the mid-Cretaceous. However, Triassic (?and older) extension and spreading events in the Perth Basin, a short distance to the west, are likely to have influenced its evolution. Basement structural trends in the basin indicate an old east-west-trending (?Palaeozoic) fabric that has been overprinted by north-northwesterly oriented Jurassic-Cretaceous extension and wrenching. The resultant structure is complex, particularly where the Palaeozoic and Mesozoic trends intersect. The hydrocarbon potential of the Bremer Basin is currently unknown. However, by analogy with the Eyre Sub-basin, potential source and reservoir sections can be inferred to exist, although the presence of a regional seal and a heatflow regime adequate for the generation of hydrocarbons is less certain. Potential trapping mechanisms for hydrocarbons include wrench-induced anticlines, clastic aprons adjacent to boundary and transfer faults, and stratigraphic traps within dipping Neocomian rocks beneath a major angular unconformity.

Sediments on the continental shelf of eastern Australia increase in carbonate content away from the present shoreline. However, the high values of the outer shelf sands show little latitudinal variation, both tropical and temperate continental shelves being mantled with sediments which are relatively pure carbonates. Thus a high calcimass productivity is not restricted to tropical regions. However, the types of carbonate-secreting organisms do show marked latitudinal variations. North of latitude 24°S the outer continental shelf is dominated by the Great Barrier Reef, and inter-reef and outer shelf sediments contain the remains of hermatypic corals and calcareous green algae, mainly Halimeda, together with varying amounts of foraminifera, Mollusca, Bryozoa, and calcareous red algae. Corals and Halimeda are not present in the sediments south of 24°S, which consists of foraminifera, mollusca, bryozoa and calcareous red algae. The bryozoan content of the sediments increases to the south, and between 38° and 44°S bryozoans become the dominant component of the outer shelf sands. Present-day sea-surface temperature and salinity data have been analysed to predict the distribution of carbonate particle associations. The observed distribution agrees with the predicted one, but the presence of relict carbonate sediments must be taken into account.

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.