Showing results for: [ Exploration Geochemistry ]
Supplementary files which accompany the CRC LEME Open File Report 87 and CSIRO Division of Exploration Geoscience Report 296R, 2nd Impression.
Legacy data - CRC LEME Open File Report Series - Published 27 Jul 2020
The Capricorn hydrogeochemistry study builds on previous work in the Yilgarn Craton, creating a seamless dataset that covers much of Western Australia. This study has developed a provisional review of... more the mineral prospectivity of the region using groundwater geochemistry, defining areas of interest requiring further investigation.
In the Capricorn Orogen, groundwater samples were collected from 1035 wells and bores, in most cases the water table was within 20 m of the surface. Samples were also taken from known mineral deposits to provide examples of the geochemical signature associated with mineralisation in the region. Field measurements included pH, Eh, EC and temperature. Separate field prepared sub-samples were collected for cation, anion, alkalinity, and Au/PGE analysis. Robust statistical methods were applied to combine bailed and flowing samples using a derived contamination factor that is tailored to the individual measured parameters. Rescaling normal or log-normal data and the creation of indices for lithology discrimination, Au, U and sulfide mineralisation improved the utility of hydrogeochemical data. All samples were analysed for δ18O, δ2H and selected samples were analysed for δ34S and associated δ18O from SO42.
A number of different parameters can be used to indicate rock types from hydrogeochemical data even when there is deep weathering or transported cover. Higher dissolved concentrations of elements can indicate mafic (Cr, V) or granitic (U, F) rocks and ratios between elements (e.g. K excess, relative to Rb) can differentiate between granitic and sedimentary terrains. These determinations are improved by multi-element indices.
The work tests the utility of previously derived mineral exploration indices, and has resulted in the creation of new indices designed for the geology of the Capricorn Orogen. Hydrogeochemical exploration for Au using Au, Ag, As and combined element indices such as AuMin was able to delineate areas of known mineralisation and target new areas of interest. The FeS index developed in the north Yilgarn Craton did not prove to be very effective in the Capricorn Orogen, but the AcidS index has anomalism linked to most of the known deposits and provides new areas of interest. There are several areas in the Capricorn Orogen that have U concentrations greater than those in close proximity to known deposits in the north Yilgarn. Spatially, the carnotite saturation index predicts most of the known U prospects and provides new targets in the Capricorn Orogen.
The utility of groundwater as a sample medium able to ‘see through’ cover was tested in two case study regions. In the Bryah Basin, groundwater possesses the chemical signature of mafic rocks but due to the thickness of transported cover soil sample chemistry does not reflect the underlying lithologies. At the polymetallic Abra deposit groundwater possesses anomalous Pb and W concentrations related to the buried deposit, whilst soil samples are proven to be an ineffective at targeting mineralisation.
Oxygen and hydrogen isotopes highlight groundwater samples that have a composition suggestive of a water source other than meteoric water. This water source has mixed with meteoric water and may be linked to faults, mineralisation or hydrothermal alteration. Light δ34S values and associated light δ18O successfully identified mineralisation at Paulsens Au deposit and have the potential to target new areas of mineralisation.
This research further demonstrates the value of groundwater chemistry for defining lithology, hydrothermal alteration and mineralisation in areas with and without cover. Stable isotopes have been used systematically across the region to assist in delineating new areas of interest.less
SIEF Distal Footprints - Geochemical Analysis of Groundwater - Published 24 Jun 2020
The Rocklea Dome 3D Mineral Mapping project was conducted by the Western Australian Centre of Excellence for 3D Mineral Mapping from 2009 to 2012 to showcase the opportunities offered by existing hype... morerspectral remote and proximal sensing technologies for comprehensive minerals systems analyses.
Key achievements of the Rocklea Dome 3D Mineral Mapping project are (Haest et al., 2012 a,b; 2013):
•Quantification of iron oxide phases and associated mineralogy derived from hyperspectral data and validated using X-ray diffractometry and geochemistry:•iron (oxyhydr-)oxide content: RMSE of 9.1 wt % Fe
•Al clay content: RMSE 3.9 wt % Al2O3
•hematite/goethite ratio: RMSE 9.0 wt % goethite
•Spatial characterisation of vitreous vs. ochreus goethite
•Defining the Tertiary channel boundary using key mineralogical parameters, such as the kaolin crystallinity
•Modelling the iron ore resource of the Rocklea Dome CID
•Identification of drill holes that were sunk into barren (i.e. bedrock) lithologies, suggesting that about a third of drill holes could have been saved
•Detailed characterisation of clay mineralogy that is associated with distinct domains of the CID and its cover (i.e. kaolin group vs. Al-smectites vs. Fe-smectites)
•Characterisation of mineral assemblages in the Quaternary cover of the Tertiary channel (e.g. calcrete)
•Improvement of quality of mineral maps by application of vegetation unmixing methods
All of the above points showcase how hyperspectral data can be used for the whole of mine life cycle, from exploration to resource characterisation.
COE - 3D Mineral Mapping - Exploration Through Cover - Published 04 Jun 2020
Hyperspectral (VNIR/SWIR/TIR) drill core data set collected using HyLogger3 at GSSA's NVCL node at the Tonsley Core Library in Adelaide
AuScope NVCL FY20 - NVCL - Published 01 May 2020
A data collection that accompanies the paper.
Group Management - Exploration Through Cover - - Published 29 Apr 2020
The digital 3-dimenional (3D) mineral mapping suite of Queensland comprises ~20 “standardized” products at the spectral resolution of the ASTER (Advanced Space-borne Thermal Emission and Reflection Ra... morediometer) sensor and generated from publicly-available satellite, airborne, field and drill core spectral data spanning the visible near infrared (VNIR; 0.4 to 1.0 µm), shortwave infrared (SWIR; 1.0 to 2.5 µm) and thermal infrared (TIR; 7.5 to 12.0 µm) wavelength regions, including:
1. Satellite ASTER maps at both 30 m and 90 m pixel resolution with complete coverage of the state of Queensland, i.e. 1.853 million km²;
2. Airborne HyMap maps at ~5 m pixel resolution with a coverage of ~25,000 km2 from areas across north Queensland;
3. Field point samples (~300) from the National Geochemical Survey of Australia (NGSA) collected from a depth of 0-10 cm of flood overbank sediments;
4. Drill-core profiles (~20) of the National Virtual Core Library (NVCL) selected from the area around the Georgetown seismic line (07GA-IG2).
Key to the processing of the remote sensing data-sets (ASTER and HyMap) was the implementation of unmixing methods to remove the effects dry and green vegetation. This unmixing was not applied to the Australian ASTER geoscience maps released in 2012 (called here Version 1 or V1) resulting in extensive areas with little/no mineral information because of the need to apply masks. The vegetation unmixing methods used in the Version 2 (V2) processing of the ASTER and HyMap imagery has resulted in very few areas without coherent mineral information.
The resultant V2 “mineral group” products were designed to measure mineral information potentially useful for mapping: (i) primary rock composition; (ii) superimposed alteration effects; and (iii) regolith cover. These V2 products may assist in mapping soil properties and groundwater conditions. However their relatively low spectral resolution (based on ASTER’s 14 VNIR-SWIR-TIR bands) means that they do not provide the high level of mineralogical detail available from hyperspectral systems (>100 spectral bands), like HyMap and the HyLogger. Nevertheless, the relatively low spectral resolution of ASTER means that all other sensor data can be spectrally resampled to that resolution. Furthermore, the ASTER global data archive, which now spans entire Earth’s land surface <80degrees latitude, means that it can be used as global base-map for integrating all other spectral data.
3D Mineral Map of Queensland - Stage 1 - mineral mapping - Published 06 Dec 2019
Spreadsheet of soils and regolith data from orientation sites and regional map sites analysied with the UltraFine+ method developed as part of the M462 project
Reference sites for method development d... moreata on Au and Cu by size fractions and Spectral and XRD analysesless
MRIWA M462 -Ultrafine Au for exploration - - Published 24 Jun 2019
Field and laboratory hydrogeochemical data for the SIEF and MRIWA Capricorn Distal Footprints project.
MRIWA M436: Distal Footprints of Giant O - Hydrogeochemical survey - Published 04 Dec 2018
Supplementary files which accompany CRC LEME Open File Report 99.
Legacy data - CRC LEME Open File Report Series - Published 30 Sep 2018
Supplementary files which accompany CRC LEME Open File Report 107.
Legacy data - CRC LEME Open File Report Series - Published 26 Sep 2018
Supplementary files which accompany CRC LEME Open File Report 105.
Supplementary files which accompany CRC LEME Open File Report 108.
Supplementary data from CRC LEME open file report 94.
Legacy data - CRC LEME Open File Report Series - Published 25 Sep 2018
Supplementary files which accompany CRC LEME Open File Report 92.
Supplementary files which accompany CRC LEME Open File Report 85.
(CSIRO Exploration and Mining Report 332R, 1992.2nd Impression 2001)
Legacy data - CRC LEME Open File Report Series - Published 13 Sep 2018
Supplementary files which accompany CRC LEME Open File Report 84.
Legacy data - CRC LEME Open File Report Series - Published 22 Aug 2018
Supplementary files which accompany CRC LEME Open File Report 83.
Supplementary files which accompany CRC LEME Open File Report 82.
Legacy data - CRC LEME Open File Report Series - Published 20 Aug 2018
Supplementary files which accompany the CRC LEME Open File Report 8. (CSIRO Division of Exploration Geoscience Report 2R, 1988. Second Impression 1998)
Legacy data - CRC LEME Open File Report Series - Published 10 May 2018
Supplementary files which accompany CRC LEME Open File Report 79.
PIRSA Report Book 2000/00003.
Supplementary files which accompany CRC LEME Open File Report 78.
PIRSA Report Book 98/10.
Supplementary files which accompany the CRC LEME Open File Report 18. (CSIRO Division of Exploration Geoscience Report 68R, 1989. Second Impression 1998)
Supplementary files which accompany CRC LEME Open File Report 232.
PIRSA Mineral Resources Report Book RB 2007/14.
Legacy data - CRC LEME Open File Report Series - Published 03 May 2018
Supplementary files which accompany CRC LEME Open File Report 113.
(CSIRO Exploration and Mining Report 794R, CRC LEME Report 156R, 2001, 2nd Impression 2001)
Supplementary files which accompany CRC LEME Open File Report 221.
(CRC LEME Restricted Report 118R / E&M Report 649R, 1999, 2nd Impression 2008)
Legacy data - CRC LEME Open File Report Series - Published 30 Apr 2018