Gold exploration in two and three dimensions : improved and correlative insights from microscopy and X-Ray computed tomography
Date
2020
Journal Title
Journal ISSN
Volume Title
Publisher
MDPI
Abstract
Abstract: In this contribution, we highlight a correlative approach in which three-dimensional
structural/positional data are combined with two dimensional chemical and mineralogical data to
understand a complex orogenic gold mineralization system; we use the Kirk Range (southern
Malawi) as a case study. Three dimensional structures and semi-quantitative mineral distributions
were evaluated using X-ray Computed Tomography (XCT) and this was augmented with textural,
mineralogical and chemical imaging using Scanning Electron Microscopy (SEM) and optical
microscopy as well as fire assay. Our results detail the utility of the correlative approach both for
quantifying gold concentrations in core samples (which is often nuggety and may thus be
misrepresented by quarter- or half-core assays), and for understanding the spatial distribution of
gold and associated structures and microstructures in 3D space. This approach overlays
complementary datasets from 2D and 3D analytical protocols, thereby allowing a better and more
comprehensive understanding on the distribution and structures controlling gold mineralization.
Combining 3D XCT analyses with conventional 2D microscopies derive the full value out of a given
exploration drilling program and it provides an excellent tool for understanding gold
mineralization. Understanding the spatial distribution of gold and associated structures and
microstructures in 3D space holds vast potential for exploration practitioners, especially if the
correlative approach can be automated and if the resultant spatially-constrained microstructural
information can be fed directly into commercially available geological modelling software. The extra
layers of information provided by using correlative 2D and 3D microscopies offer an exciting new
tool to enhance and optimize mineral exploration workflows, given that modern exploration efforts
are targeting increasingly complex and low-grade ore deposits.
Description
CITATION: Chisambi, J., et al. 2020. Gold exploration in two and three dimensions : improved and correlative insights from microscopy and X-Ray computed tomography. Minerals, 10(5):476, doi:10.3390/min10050476.
The original publication is available at https://www.mdpi.com
Publication of this article was funded by the Stellenbosch University Open Access Fund.
The original publication is available at https://www.mdpi.com
Publication of this article was funded by the Stellenbosch University Open Access Fund.
Keywords
Gold -- Geology, Gold ores -- Tomography, Gold ores -- Assaying, Gold ores -- Mineralization, Imaging systems in geology, Three-dimensional imaging in geology, Orogenic belts -- Malawi
Citation
Chisambi, J., et al. 2020. Gold exploration in two and three dimensions : improved and correlative insights from microscopy and X-Ray computed tomography. Minerals, 10(5):476, doi:10.3390/min10050476