There are many modern and ancient opinions on the origin of dolomite, and the general opinion on the geological and geochemical side is that the origin of the dolomites is not yet clear enough. That there are different sorts of dolomites is generally agreed. [Five different kinds of dolomite are defined and described. The possible origins and formation of dolomite are discussed.]

The aim of the study was to determine the geochemical characteristics of a number of intrusive and extrusive lithologies from the Boddington gold mine and surrounding prospects. A number of suites have been delineated on the basis of their petrography, timing relations and wholerock geochemistry.

Dr Andy Barnicoat's presentation at the China Mining Conference 2012 in Tianjin.

The occurrence of radioactive minerals with cobaltiferous deposits in the Carcoar area has been known since 1894, but until recently they have not received much attention. The present geological survey has been carried out following the discovery of three rather significant radioactive anomalies in the north-eastern part of the mined area, during radiometric surveys in 1950 and 1951. The geological survey has shown that the cobaltiferous-uranium deposits occur in strong north-south shears in an area of Silurian slates and volcanic rocks intruded by diorite sills and dykes, close to the south-eastern boundary of a large mass of hornblende diorite. Opportunities occur for the discovery of other uranium deposits in parallel shears outside the area, in which radioactive anomalies have already been found. This report gives a detailed account of the geological survey. Geology, geological structure, the workings, deposits, and mineralization are discussed, and recommendations are made for future testing and surveying of the area.

This report comprises notes concerning the situation, occurrence, analysis, and production of dolomite at Cow Flat.

A report on the testing of bauxite deposits in the Tasmanian districts of Ouse, Launceston, Rosevale and Myalla. This report is supplementary to Mr. Owen's report (1946/2).

Increases in atmospheric CO¬2 cause the oceanic surface water to continuously acidify, which has multiple and profound impacts on coastal and continental shelf environments. Here we present the carbonate mineral composition in surface sediments from a range of continental shelf seabed environments and their current and predicted stability under ocean acidifying conditions. Samples come from the following four tropical Australian regions. 1. Capricorn Reef (southern end of the Great Barrier Reef). 2. The Great Barrier Reef Lagoon. 3. Torres Strait. 4. The eastern Joseph Bonaparte Gulf. Outside of the near-shore zone, these regions typically have a carbonate content in surface sediments of 80 wt% or more. The abundance of high magnesium-calcites (HMC) dominates over aragonite (Arag) and low magnesium-calcite (LMC) and makes up between 36 and 50% of all carbonate. HMC is significantly more soluble than Arag and LMC and the solubility of HMC positively correlates with its magnesium concentration. Using the solubility data by Plummer and Mackenzie (1974) (1), 96% of HMC in the four regions is presently in thermodynamic equilibrium or slightly supersaturated relative to global mean tropical sea surface water. When the modelled saturation state for aragonite in equatorial areas for this century (2) is converted into HMC saturation state curves, HMC is predicted to become undersaturated in the four regions between 2040 to 2080 AD with typical HMC decline rates between 2 and 5% per year. The range of respective estimated carbonate dissolution rates is expected to exceed current continental shelf carbonate accumulation rates leading to net dissolution of carbonate during the period of HMC decline. In a geological context, the decline in HMC is a global event in tropical continental shelf environments triggered by reaching below-equilibrium conditions. The characteristic change in carbonate mineral composition in continental shelf sediments will serve as a geological marker for the proposed Anthropocene Epoch.

Two samples of diatomite were recently received from Broken Hill Pty. Co. Limited for microscopic examination. They were from Nettle Creek, 9 miles north-east of Mt. Garnet and near Innot Hot Springs. The results of the microscopic examination are given in this report.

Quartz crystals occur in the county of Dampier near the head of Tuross River 13 miles east-southeast from Countegany and about 5 miles east-southeast from Tuross Post Office. The presence of small quartz crystals in this locality has been known to Mr. L.W. Schaeffer of Tuross for many years, but only recently has he found larger crystals and undertaken more systematic prospecting. This report comprises notes on the quartz crystals, following an examination of the locality, 1944.

The beach sands on which investigations were carried out, were mainly from beaches along the eastern coast of Australia and from islands adjacent to this coast. A high percentage of the mineral grains of the heavy mineral fraction in these sands have grain sizes within the range -100 to +200, referred to British Standard Sieves. The grain size of the minerals, combined with the fact that the grains are quite well rounded, makes the heavy mineral sands an ideal subject for separation using the inclined method with the Isodynamic Separator. The use of this method, and the results obtained, are described in this report.