<div>Alkaline and related rocks are a relatively rare class of igneous rocks worldwide. Alkaline rocks encompass a wide range of rock types and are mineralogically and geochemically diverse. They are typically though to have been derived by generally small to very small degrees of partial melting of a wide range of mantle compositions. As such these rocks have the potential to convey considerable information on the evolution of the Earth’s mantle (asthenosphere and lithosphere), particularly the role of metasomatism which may have been important in their generation or to which such rocks may themselves have contributed. Such rocks, by their unique compositions and or enriched source protoliths, also have considerable metallogenic potential, e.g., diamonds, Th, U, Zr, Hf, Nb, Ta, REEs. It is evident that the geographic occurrences of many of these rock types are also important, and may relate to presence of old cratons, craton margins or major lithospheric breaks. Finally, many alkaline rocks also carry with them mantle xenoliths providing a snapshot of the lithospheric mantle composition at the time of their emplacement.</div><div><br></div><div>Accordingly, although alkaline and related rocks comprise only a volumetrically minor component of the geology of Australia, they are of considerable importance to studies of lithospheric composition, evolution and architecture and to helping constrain the temporal evolution of the lithosphere, as well as more directly to metallogenesis and mineralisation.</div><div><br></div><div>This contribution presents data on the distribution and geology of Australian alkaline and related rocks of Proterozoic age. Proterozoic alkaline and related rocks are primarily restricted to the western two-thirds of the Australia continent, congruent with the distribution of Proterozoic rocks more generally. Proterozoic alkaline rock units are most abundant in Western Australia and the Northern Territory, with minor occurrences in South Australia, and the western regions of Queensland, New South Wales and Tasmania.</div><div><br></div><div>The report and accompanying GIS document the distribution, age, lithology, mineralogy and other characteristics of these rocks (e.g., extrusive/intrusive, presence of mantle xenoliths, presence of diamonds), as well as references for data sources and descriptions. The report also reviews the nomenclature of alkaline rocks and classification procedures. GIS metadata are documented in the appendices.&nbsp;</div>

Herein we present the results of a national compilation of mineral deposits (available in Excel or CSV format) for Australia. The deposits were selected as they have substantial endowment (i.e. pre-mining mineral resource) and/or detailed geological information is available. For each deposit (or, in some cases, district) the dataset includes information on: 1. Name (including synonyms), location and GA identifying numbers; 2. Tectonic province that hosts the deposit; 3. Type(s) and age(s) of mineralising events that produced/affected the deposit (including metadata on ages); 4. The metal/mineral endowment of the deposit; 5. Host rocks to the deposit; 6. Spatially and/or temporally associated magmatic rocks; 7. Spatially and temporally associated alteration assemblages (mostly proximal, but, in some cases, regional assemblages); 8. The Fe-S-O minerals present in the deposit and relative abundances where known; 9. Sulfate minerals present; 10. Peak metamorphic grade; 11. Data sources; and 12. Comments. This document presents more detailed descriptions of the metadata presented in the compilation. The dataset is presented in Appendix A. Appendix B presents a national classification of geological provinces based mostly on existing State survey classifications; Appendix C presents a deposit classification based on the classification proposed by Hofstra et al. (2021); and Appendix D presents mineral abbreviations used in the dataset.

Geoscience Australia, in collaboration with State and Territory Geological Surveys, began a geochronology program in the mid-2000’s to determine the age of mineralising events in Australia. It began with the Paterson Project in the mid-2000’s and continued with the Onshore Energy Security program and the current Exploring for the Future program. Some of the results were published, either as formal publications or in abstracts, however, much of the analytical data collected have never been formally published. This report aims to formally publish all the data from these past projects and programs. Geochronology analyses for this program have been carried out by Geoscience Australia, the Australian National University, the University of Alberta, the University of Melbourne, the University of Queensland and the United States Geological Survey. The first part of this report summarises the analytical procedures and uncertainties of all laboratories used. The second part presents the results of the analyses along with brief descriptions of the deposit studied and an interpretation of the significance of the results. Molybdenite Re–Os results from 22 deposits that are considered to have geological significance include: Strelley greisen – ca 3230 Ma, Jupiter – ca 2683 Ma, Mulgine Hill – ca 2740 Ma and Katanning – ca 2617 Ma (Western Australia); Molyhil – ca 1720 Ma (Northern Territory); Kaiser Bill – ca 1524 Ma, Greenback – ca 426 Ma, Gromac – ca 426 Ma, Chloe – ca 413 Ma, Mount Specimen – ca 318 Ma, Anthony – ca 310 Ma, Black Mountain – ca 301 Ma and Whitewash – ca 244 Ma (Queensland); Cowal Central – ca 451 Ma and Whipstick – ca 389 Ma (New South Wales); Unicorn – ca 412 Ma, Everton – ca 380 Ma, Monkey Gully – ca 371 Ma, and Myrtle Creek – Scorpion Hill – 370 Ma (Victoria); and Mount Stronach – ca 393 Ma, Squib – ca 383 Ma, and King Island – ca 358 Ma (Tasmania). In each case, the age is placed in context with the geological history of the deposit and compared with other relevant ages (e.g. the age(s) of spatially associated granites). We report apparent ages from two other deposits (Mount Moliagul, Victoria and Mount Killiecrankie, Tasmania) that are geologically implausible. At Molyhil, the molybdenite Re–Os age agrees within error of previously reported xenotime U–Pb (Cross, 2009) and muscovite 40Ar–39Ar age (Reno and Fraser, 2021; using new (Kwon, 2002) K-Ar decay constants) ages, and all three ages agree within uncertainty with a SHRIMP U–Pb zircon age of the spatially associated Marshall Granite (Kositcin et al., 2018). 40Ar–39Ar ages reported include ages of muscovite intergrown with Zn-Cu-Sn veins at the Wallabadah prospect (Queensland: ca 285 Ma) and ages of various minerals from the Magnum Au-Cu prospect (Western Australia: ca 637 Ma). The Magnum age agrees within error with the age previously reported (Maidment et al., 2010) for the Telfer Au-Cu deposit, indicating a widespread granite-related Au-Cu event in the Paterson Province.