The Kangaroo Caves zinc-copper deposit in the Archaean Panorama District in the northern Pilbara Craton, Western Australia contains an Indicated and Inferred Mineral Resource of 6.3 million tonnes at 3.3% zinc and 0.5% copper. The Kangaroo Caves area is characterised by predominantly tholeiitic volcanic rocks of the Kangaroo Caves Formation, which is overlain by turbiditic sedimentary and volcanic rocks of the Soanesville Group. Zinc-copper mineralisation is hosted mainly by the regionally extensive Marker Chert, the uppermost unit of the Kangaroo Caves Formation, and structurally controlled by D1 synvolcanic faults. The upper area of the deposit is characterised by quartz-sphalerite ± pyrite ± baryte ± chalcopyrite, whereas the lower area contains mainly chlorite-pyrite-quartz-carbonate-sericite ± chalcopyrite ± sphalerite. Laser ablation inductively coupled plasma mass spectrometry analyses show that cobalt-nickel ratios in pyrite are significantly greater in the upper, zinc-rich area (median copper/nickel = 0.4) of the deposit than the lower, zinc-poor area (median copper/nickel = 5). Structural analysis of the Kangaroo Caves area combined with Leapfrog modelling of ore and trace element distribution shows that the deposit is predominantly an elongate sheet of zinc mineralisation (-1%), which plunges ~30° to the northeast and is approximately 1000 metres in length. The morphology of the Kangaroo Caves deposit was retained from its original formation, despite rotation during the D2 event. Variations in hydrothermal alteration assemblages, including the copper and nickel contents of pyrite within the deposit and underlying dacite, are interpreted to be the result of variations in the influx and mixing of seawater with upwelling volcanogenic fluids during zinc-copper mineralization. At the Kangaroo Caves area the cobalt-nickel ratio of pyrite can be used as an exploration vector towards high-grade zinc-copper mineralization.

At the request of Mr. G. Lindesay Clark, Deputy Controller of Minerals Production, estimates have been made of the grade of ore likely to be delivered to the mill during the next two years under conditions of half-scale production. The methods of estimating tonnage and grade, as well as the resultant estimates, are discussed in this report.

Sediment-hosted Pb-Zn (SH Pb-Zn) deposits can be divided into two sub-types: 'clastic-dominated lead-zinc' (CD Pb-Zn) ores hosted in shale, sandstone, siltstone, mixed clastic or as carbonate replacement within a clastic dominated sedimentary sequence and Mississippi Valley-type (MVT Pb-Zn) ores that occurs in platform carbonate sequences, typically in a passive margin tectonic setting. The emergence of CD and MVT deposits in the rock record between 2.02 Ga, the age of the earliest known deposit of these ores, and 1.85-1.58 Ga, a major period of CD Pb-Zn mineralization in Australia and India, corresponds to a time after the 'Great Oxygenation Event' (GOE) ca 2.4 to 1.8 Ga. Contributing to the blooming of CD deposits at ca 1.85-1.58 Ga was the following: a) enhanced oxidation of sulfides in the Earth's crust that provided sulfate and lead and zinc to the hydrosphere; b) development of major redox and compositional gradients in the oceans; c) first formation of significant sulfate-bearing evaporites; d) formation of red beds and oxidized aquifers: e) evolution of sulfate-reducing bacteria; and f) the formation of large and long-lived basins on stable cratons. A significant limitation imposed on interpreting the secular distribution of the deposits is that presently, there is no way to quantitatively evaluate the removal of deposits from the rock record through tectonic recycling. Considering that most of the sedimentary rock record has been recycled, probably most SH Pb-Zn deposits have also been destroyed by subduction and erosion or modified by metamorphism and tectonism so that they are no longer recognizable. Thus, the uneven secular distribution of SH Pb-Zn deposits reflects the genesis of these deposits, linked to Earth's evolving tectonic and geochemical systems, as well a record severely censored by an unknown amount of recycling of the sedimentary rock record.

The analyses of some Australian iron ores was undertaken. The results of these analyses are set down in this report. Results are given for each deposit by state.

Details concerning the reserves of iron ore in Australia have been tabulated in this report. The report provides estimates of the grade and probable reserves of ore for the known Australian deposits.

The geology and ore reserves of the dolomite deposit near Wall's Siding are discussed in this report. The report should be read in conjunction with the report on "Limestone and Dolomite Deposits at Cow Flat and Wall's Siding, New South Wales" (Record 1947/090).

The object of this tour was to study ore deposits and methods of exploration in Africa and North America as well as to attend, as Official Delegate of the Commonwealth of Australia, the 19th International Geological Congress held at Algiers in September, 1952. A considerable amount of information was gained concerning ore deposits in the countries visited and this information should be of assistance in the search for further metal deposits in Australia. At the international Congress useful work was achieved and contact was made with a large number of geologists in various parts of the world. These contacts will facilitate the exchange of information between Australia and foreign geologists. The itinerary followed the attached as an Appendix to this report.

The Treasure Mine, Hatches Creek, is believed to have been discovered in 1914 and has been one of the most consistent producers of wolfram to the present time. This report gives an account of the economic geology of the mine. The ore type, reefs and workings, ore localization, and ore reserves are described.

Ore reserves in the Geiger-Main and Whip Lodes at Radium Hill have been calculated from up-to-date plans and assay data provided by the South Australian Mines Department and results obtained agree closely with estimates made by the Mines Department. Tonnage of ore (not including dilution) to 600 feet depth on Geiger-Main and Whip Lodes and to 400 feet in Main Lode South block is estimated at 337,500 tons containing 938 tons U3O8, corresponding to an approximate average of 160 tons U3O8 per 100 feet of vertical depth. The data used, method of calculation, and results, are discussed at length in this report.

The area was geologically investigated at the request of the Director of Mines, Alice Springs, by A.D.M. Bell and J. Firman. Mapping was by chain and compass traverse during periods 29th to 31st October, 1952; 4th to 6th November, 1952 and 19th December, 1952. Previous geological reconnaissance was made by B. Thompson of the Enterprise Exploration Company in 1948.