The extensive research into satellite data technology that followed the launch of Landsat-1 (ERTS-1) in 1972 has resulted in progressive improvements to product quality and digital data analysis techniques. Improved image quality has direct significance to the many mineral and petroleum exploration organisations that are now routinely applying conventional photogeological interpretation techniques to Landsat multispectral scanner imagery. Photogeological techniques will continue to be the main means of Landsat interpretation, however, even the best quality imagery may contain less than one quarter of the total data recorded and computer techniques offer the only adequate means of analysing all the data in a Landsat scene. Considerable progress has been made with computer analysis of Landsat digital data and some techniques have definite application to mineral and petroleum exploration. In specific environments direct detection of iron weathering products associated with both hydrothermal alteration and uranium deposits has been achieved. Various computer-enhancement techniques have also been employed to reveal structural and lithological information not obvious on conventional Landsat imagery or aerial photography.

Geoscience Australia contributed a multi-satellite, multi-year weekly time series to the International DORIS Service combined submission for the construction of International Terrestrial Reference Frame 2008 (ITRF2008). This contributing solution was extended to a study of the capability of DORIS to dynamically estimate the variation in the geocentre location. Two solutions, comprising different constraint configurations of tracking network, were undertaken. The respective DORIS satellite orbit solutions (SPOT-2, SPOT-4, SPOT-5 and Envisat) were verified and validated by comparison with those produced at the Goddard Space Flight Center (GSFC), DORIS Analysis Centre, for computational consistency and standards. In addition, in the case of Envisat, the trajectories from the GA determined SLR and DORIS orbits were compared. The results for weekly dynamic geocentre estimates from the two constraint configurations were benchmarked against the geometric geocentre estimates from the IDS-2 combined solution. This established that DORIS is capable of determining the dynamic geocentre variation by estimating the degree one spherical harmonic coefficients of the Earth's gravity potential. It was established that constrained configurations produced similar results for the geocentre location and consequently similar annual amplitudes. For the minimally constrained configuration Greenbelt - Kitab, the mean of the uncertainties of the geocentre location were 2.3, 2.3 and 7.6 mm and RMS of the mean uncertainties were 1.9, 1.2 and 3.5 mm for the X, Y and Z components respectively. For GA_IDS-2_Datum constrained configuration, the mean of the uncertainties of the geocentre location were 1.7, 1.7 and 6.2 mm and RMS of the mean uncertainties were 0.9, 0.7 and 2.9 mm for the X, Y and Z components respectively. The mean of the differences of the two DORIS dynamic geocentre solutions with respect to the IDS-2 combination were 1.6, 4.0 and 5.1 mm with an RMS of the mean 21.2, 14.0 and 31.5 mm for the Greenbelt - Kitab configuration and 4.1, 3.9 and 4.3 mm with an RMS 8.1, 9.0 and 28.6 mm for the GA_IDS-2_Datum constraint configuration. The annual amplitudes for each component were estimated to be 5.3, 10.8 and 11.0 mm for the Greenbelt - Kitab configuration and 5.3, 9.3 and 9.4 mm for the GA_IDS-2_Datum constraint configuration. The two DORIS determined dynamic geocentre solutions were compared to the SLR determined dynamic solution (which was determined from the same process of the GA contribution to the ITRF2008 ILRS combination) gave mean differences of 3.3, -4.7 and 2.5 mm with an RMS of 20.7, 17.5 and 28.0 mm for the X, Y and Z components respectively for the Greenbelt - Kitab configuration and 1.1, -5.4 and 4.4 mm with an RMS of 9.7, 13.3 and 24.9 mm for the GA_IDS-2_Datum configuration. The larger variability is reflected in the respective amplitudes. As a comparison, the annual amplitudes of the SLR determined dynamic geocentre are 0.9, 1.0 and 6.8 mm in the X, Y and Z components. The results from this study indicate that there is potential to achieve precise dynamically determined geocentre from DORIS.

A number of empirical laws which state that a simple relationship exists between the size and ranking of objects have been used in assessing undiscovered petroleum and minerals resources. The most well known of these, the log-log and log-linear laws, are described and compared with log-normally distributed statistics which I have assumed give a good description of sizes of petroleum and mineral deposits. The log-log law, which states that the log of size of a mineral deposit plots as a straight line against the log of the rank of the deposit sizes, was found to give a fair fit for the bigger deposit sizes, but the smaller sizes would be over-estimated. The log-linear law which states that the log of size of a deposit plots as a straight line against the rank of the deposit sizes was found to give a poor fit for both the big and small sizes. The log-log law may be useful for assessing undiscovered resources where geological analogues exist and the largest deposit can be assessed by other means.

The tectonic evolution of the fault-bounded volcanic-sedimentary Leichhardt River fault trough is reinterpreted in the light of detailed mapping of a part of this structure. Two major unconformities are indicated, the first above the Kalkadoon-Leichhardt acid igneous complex, and the second at the base of the ore-bearing Mount Isa Group and its equivalents - the Mingera and Surprise Creek Beds. A complex succession of movements is indicated, involving (1) early faulting of the Kalkadoon-Leichhardt acid igneous complex; (2) long-acting penecontemporaneous faulting; (3) folding and uplift accompanying or post-dating emplacement of Sybella Granite, and (4) a younger major faulting phase. During phase (2) syndepositional block movements resulted in differential accumulation of volcanic flows and of sediments, reflected by abrupt thickness changes across faults. In other instances the observed thickness variations can be explained by strike faulting of lenticular sedimentary units. Basic dyke swarms which intrude the volcanic- sedimentary sequence of the Leichhardt River fault trough have postdated the folding and predated the major faulting event defined as phase (4). The Sybella Granite, thought by some workers to be younger than the Mount Isa Group on the basis of structure and lead isotope ratios, is considered by us to be older than this unit. The ore lead in the Mount Isa deposit could be related to erosion or leaching of lead from older rocks such as the Kalkadoon-Leichhardt basement complex and the Eastern Creek Volcanics. An age of between I500-1600 m.y. is indicated for the syngenetic lead deposit at Mount Isa. The Eastern Creek Volcanics show very high Pb relative to average basalt, and high Cu, Zn and Pb levels relative to other basic volcanic rocks in this region, and may have a genetic relation to the Mount Isa Cu and Ag-Pb-Zn ore deposits. Geochemical features of basalts of the Eastern Creek Volcanics are consistent with those of continental flood tholeiites, showing high FeO, FeO/ MgO ratios, TiO2, K2O, P2O5, Ba and Rb and low Al2O3. Structural, sedimentological and geochemical changes between the Mount Isa area and the CIoncurry area to the east - where ocean floor type tholeiites occur - can be interpreted in terms of a transition into a continental margin environment in this direction.

A new rock unit, the Bullara Limestone, is proposed for a Late Oligocene bioclastic limestone, which is probably restricted to the subsurface of Rough Range. The Bullara Limestone is a lateral equivalent of the lower part of the Mandu Calcarenite, and contains a Tertiary lower e stage larger foraminiferal fauna and a Zone N.3 planktic fauna.

Q-mode factor analysis classified the estuarine samples from Broad Sound into two main geologically distinct groups representing intertidal and supratidal deposition. This classification was supported statistically by stepwise discriminant analysis, and mathematically by Q-technique canonical correlation analysis. Analysis of variance was useful in identifying significant error with some of the measured variables, and proving the stability of the pH and Eh readings over time. Using R-mode factor analysis, with the associated correlation coefficients, and stepwise regression analysis, the various processes controlling the concentration of P2O5, Cu, Pb and Zn, in the supratidal and intertidal sediments are identified. Although Cu, Pb, and Zn are mainly deposited in both supratidal and intertidal zones adsorbed onto iron hydroxide colloids, the three trace elements (but especially Pb) are released with decreasing pH and Eh in the intertidal zone and form metal sulphides or metallo-organic complexes. The reduced iron is also redeposited as iron sulphide. Under supratidal oxidizing conditions the Cu and Zn remain attached to the iron colloids but Pb is released with increasing acidity. The absorption of P2O5 on clay particles increases with acidity in the intertidal zone, but P2O5 is mainly associated with organic carbon in the supratidal sediments.

Seismic reflection profiles over the southwestern margin of the Exmouth Plateau, which have been tentatively tied to the Northwest Shelf stratigraphic sequence, indicate that rocks of probable Permian to Early Tertiary age form bedrock on the lower continental slope and probably crop out in places. Water depths range from 1400 to 4000 m. It is surmised that the rocks present include pre-Late Jurassic fluvial, deltaic and shallow marine sandstone, siltstone and shale; Late Jurassic to Neocomian deltaic sandstone, siltstone and shale; mid Cretaceous shallow marine shale; Late Cretaceous shelf limestone and Cainozoic foraminiferal ooze. The Exmouth Plateau is cut by normal faults which are predominantly downthrown oceanwards and trend north-northeasterly across most of the area, except near the southwestern margin where they trend northwesterly. Faulting occurred primarily in the Middle to Late Jurassic and led to formation of the north-western and northern margins by seafloor spreading. A major anticline, which parallels the southwestern margin, has one limb truncated by the lower continental slope, probably resulting in older rocks cropping out in places. Deep Sea Drilling Project results on the Cuvier Abyssal Plain indicate that the southwestern margin formed in the Late Cretaceous, either as a transcurrent fault associated with seafloor spreading or by collapse along normal faults. Sampling of outcrops along the southwestern margin would enable the sequence to be dated more reliably and this would permit the theories of geological evolution and favourable petroleum potential of the Exmouth Plateau to be tested.

Geological and soils mapping and an assessment of groundwater conditions has been carried out to assist development planning in the new town of Tuggeranong, in the Australian Capital Territory. The rocks of the area are mainly volcanic rhyodacites and the depth of weathering is generally less than 15 m. Residual soils are mainly podzolic clays; transported soils range from partly cemented gravelly, sandy silts (slope- wash) to complex layered clays (alluvium). Foundation conditions are generally expected to be satisfactory in most areas for single-storey structures, and large buildings are expected to be founded within 5-10 m of the surface in the town centre area. Excavation conditions will be variable because of the irregular weathering profiles characteristic for the volcanic rocks. Groundwater occurs in fractured rock, colluvial, and alluvial aquifers, and could be used for irrigation in places. Groundwater seepage problems are associated with the pediplain basins, and some remedial drainage works are necessary. Sand deposits in the bed of the Murrumbidgee River constitute a major resource but supplies of rock aggregate will have to come from outside the area. The location of sanitary landfill sites will require detailed study to evaluate the risk of surface water and groundwater pollution.

The Kuta Formation is mainly a limestone deposit which crops out on the flanks of the Kubor Anticline in the Central Highlands of Papua New Guinea. It has been variously regarded as Cainozoic, Permian and Permo-Triassic in age, but is now positively dated as late Norian or Rhaetian (Late Triassic) on the basic of conodonts, molluscs and brachiopods. The Kuta Formation is thus the youngest known Triassic formation in Papua New Guinea. Interpretation of the local stratigraphy is simplified by this dating. It is now apparent that the marine Triassic sedimentation in Papua New Guinea commenced no later than the Anisian (Middle Triassic) and continued, probably uninterrupted, until Rhaetian time. The fossils identified and described include the conodont Misikella posthernsteini Kozur and Mock, 1974, the ammonite Arcestes (Arcestes) cf. sundaicus, Welter, 1914, and some bivalves. The brachiopods Clavigera, Zugmeyerella, Sinucosta, Robinsonella, ?Hagabirhynchia are equally important in dating the assemblage, but will be described in detail separately. All the more closely identified fossils have a Tethyan Provincial aspect except Clavigera which was previously known only from New Zealand and New Caledonia.

One Tree Reef is one of fourteen reefs in the Capricorn Group, southern Great Barrier Reef. The reef has an asymmetrical triangular shape, 5.5 km long and 3 km wide, with a small coral shingle cay on the southeastern corner. One Tree Reef evolved from a karst carbonate platform, now 10 to 25m below sea level, but emergent during the last sea-level low before 9600-9000 years B.P. With rising sea level, vertical organic accretion was dominant, although there was some lateral accretion on the higher southeastern corner. By 4400 years B.P. the reef grew up into the influence of the present wind-induced southeasterly wave regime. Present reef shape approximates a bow of a ship facing into wind, with the resultant wave refraction and diffraction producing a symmetrical energy pattern which has influenced the present sediment pattern. This pattern is symmetrical about a lagoonal axis of interaction of wave fronts. Present lagoonal sedimentation is controlled by flood tide and swash or wave surge transport, swash sorting and slack water periods when sediment in suspension is deposited.