A magnetic survey of the Kunimo creek area near Kuta in the Central Highlands of New Guinea was carried out between July 17th and July 28th, 1950. It was hoped that the survey would trace the course of the auriferous wash originally laid down in the bed of a former creek but now concealed by overburden of soil and unconsolidated volcanic ash. This report gives an account of the magnetic survey and its results.

Gold Mining Lease 1075 is situated at the head of Rowlands Creek, a tributary of Barola Creek. The workings are on the hillside just south of the head of Rowlands Creek and approximately five miles west-south-west from Kainantu Sub-District Office and Airstrip in the Eastern Highlands of New Guinea. The elevation of the workings is approximately 6,200 feet above sea-level. The area was examined by the writer in April, 1953. [The history and development of the lease, transport and resources, general geology, ore geology, the occurrence of the gold, and further prospects, are discussed in this report].

Map showing distribution of a selected range of mineral deposits, operating mines and historic mines for selected commodities.

This investigation was undertaken primarily to assess the importance of a discovery of gold in the tributaries of the Porgera River west of Mt. Hagen, Mandated Territory of New Guinea. Two patrols were carried out. The first patrol was from Wabag to Mongureba. The purpose of the patrol was to inspect the main gold find in the vicinity of Mongureba. The occurrence of alluvial gold was also reported from the River Timen area, and consequently a patrol from Wabag to Mt. Hagen Police Post by way of the River Timen was undertaken. This report gives an account of the geological reconnaissance and its findings. The physiography, geology, geomorphology, and economic geology of the area are described. Accompanying maps and photographs are included.

At the Sandpiper gold deposit in the Tanami region of northern Australia sericite is intimately intergrown with arsenopyrite in gold-bearing quartz veins and breccias, suggesting sericite crystallisation synchronous with gold-bearing fluid flow. This ore-stage sericite yields a 40Ar/39Ar plateau age of 1785 ± 16 Ma (1?? including all known systematic uncertainties). Recalculation using revised and more precise values for the 40K decay constants and the age of the Fish Canyon Sanidine standard shifts the age to 1792 ± 6 Ma (1???including all known systematic uncertainties). Given the possibility of post-mineralization isotopic resetting this age can be conservatively interpreted as a minimum constraint on the timing of gold deposition although, given local geological relationships and estimates for the argon retentivity of white mica, we consider complete isotopic resetting to be unlikely. The preferred interpretation is, therefore, that the sericite 40Ar/39Ar age indicates the timing of gold mineralization. The sericite age accords with a limited dataset of 207Pb/206Pb xenotime ages of ~1800 Ma from other gold deposits in the Tanami region, interpreted as mineralization ages. The agreement between independently-derived ages from several gold deposits lends support for a widespread gold-mineralizing event at ~1800 Ma in the Tanami region.

Geological regions with abnormally high endowment in metals appear to have resulted from the fortunate juxtaposition in space and time of numerous, possibly exceptional, processes. The gold mineral system of the Eastern Goldfields Superterrane (EGST) is an example. In order to understand why this is so, we have taken an approach that considers the mineral system as a series of integrated components known as the Five Questions: viz 1) geodynamics; 2) architecture; 3) sources & reservoirs; 4) drivers & pathways; and, 5) depositional mechanisms. In order to better understand these components and the geological processes that define them, a range of scales needs to be considered. However at each scale the relative benefits of considering any one of the five components varies. Ultimately the aim is to use this scale-integrated process-based understanding for prediction. Understanding why a region is particularly endowed or a deposit so rich is important but only half the question. The other half is where is the next favourable region and/or camp and deposit? In this regard, we 'Answer' the Five Questions.

Extended abstract describing metallogenic significance of georgina-Arunta seismic line. The abstract discusses mainly the Neoproterozoic and Phanerozoic mineral potential, including implications to U, Cu-Co, Au, Cu-U and energy.

A map showing the distribution of selected mines and mineral depsosits for a range of commodities. It also shows the distribution of petroleum resources in basic form. The map base is the Gravity Map of the Australian Region.

The Archean Yilgarn Craton of Western Australia, is not only one of the largest extant fragments of Archean crust in the world, but is also one of the most richly-mineralised regions in the world. Understanding the evolution of the craton is important, therefore, for constraining Archean geodynamics, and the influence of such on Archean mineral systems. The Yilgarn Craton is dominated by felsic intrusive rocks - over 70% of the rock types. As such these rocks hold a significant part of the key to understanding the four-dimensional evolution of the craton, providing constraints on the nature and timing of crustal growth, the role of the mantle, and also the timing of important switches in crustal growth geodynamics. The granites also provide constraints on the nature and age of the crustal domains within the craton. Importantly, this crustal pre-history appears to have exerted a significant, but poorly understood, spatial control on the distribution of mineral systems, such as gold, komatiite-associated nickel sulphide and volcanic-hosted massive sulphide (VHMS) base metal systems

The development of a regional stratigraphy in Palaeoproterozoic basins within the Tanami region, Northern Australia has been hindered by the difficulty of discriminating sedimentary units and facies across isolated and poorly exposed basins. A regional stratigraphy is important as it provides constraints on sedimentary basin evolution and assists in gold exploration, as mineralisation is more abundant in certain rock formations. Based on geochemistry, five main sedimentary basin events have been identified in the Tanami region, ranging from poorly mixed local sedimentary sources to well mixed distal sources. Within the basins, major gold bearing lithologies are characterised by mafic source indicators: (1) high Cr/Th ratios; (2) low Th/Sc ratios; (3) low (La/Yb)N ratios relative to Post-Archaean Average Shale; (4) Eu anomaly equal to ~1 and, (5) distinctive ranges in initial Nd values, which together define vertical stratigraphic position. Potential future exploration target areas have been identified in the Tanami region at the Cashel and Sunline prospects using these geochemical parameters.