|Title||Multivariate statistical analysis of trace element compositions of native gold from orogenic gold deposits: implication for mineral exploration|
|Author||Liu, H; Beaudoin, G; Makvandi, S; Jackson, S E; Huang, X|
|Source||Ore Geology Reviews vol. 131, 104061, 2021 p. 1-17, https://doi.org/10.1016/j.oregeorev.2021.104061|
|Alt Series||Natural Resources Canada, Contribution Series 20200777|
|Media||paper; on-line; digital|
|Subjects||economic geology; geochemistry; mineralogy; Science and Technology; Nature and Environment; mineral exploration; mineral deposits; gold, native; ore mineral genesis; crystallization; precipitation;
electron probe analyses; mass spectrometer analysis; microscopic analyses; trace element geochemistry; statistical analyses; minor element geochemistry; inclusions; mineral associations; textures; gangue minerals; host rocks; paragenesis;
hydrothermal systems; fluid flow|
|Illustrations||location maps; histograms; photomicrographs; plots; schematic diagrams|
|Released||2021 02 11|
|Abstract||The mineralogy and chemical composition of native gold from twenty-seven representative orogenic gold deposits were investigated using optical microscopy, electron probe microanalysis (EPMA), and laser
ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Minor elements, such as Ag and Cu, occur in solid solution, while trace elements, such as Fe, As, S, Hg, form impurities or micro inclusions in native gold. Partial least
squares-discriminant analysis (PLS-DA) has identified compositional characteristics based on mineral association, gold texture and dominant country rocks. Gold grains are commonly associated with pyrite, arsenopyrite, chalcopyrite, pyrrhotite, and
tourmaline in the studied orogenic deposits. Chemical variations in gold with different associated mineral assemblages are related to the partitioning of trace elements between co-crystalizing minerals and gold during precipitation. Gold inclusions
in gangue minerals are discriminated from later gold in fractures based on contents of Ag, Fe, Pb, and Bi, which indicates that gold in different paragenetic stages of mineralization can be identified using its trace element signature. Gold hosted in
different regional country rocks can be discriminated by Ag, Cu, Pd, Sb, and Hg, likely because of reactions of hydrothermal fluids with the regional country rocks along the fluid flow paths. |
|Summary||(Plain Language Summary, not published)|
In this study, researchers explored the characteristics of native gold found in twenty-seven different orogenic gold deposits. They examined the
mineralogy and chemical composition of the gold using various techniques like electron probe microanalysis and laser ablation-inductively coupled plasma-mass spectrometry.
They discovered that native gold can contain minor elements like silver
(Ag) and copper (Cu) within its structure, while trace elements like iron (Fe), arsenic (As), sulfur (S), and mercury (Hg) can form impurities or micro-inclusions in the gold.
The researchers used a method called partial least squares-discriminant
analysis (PLS-DA) to identify specific characteristics of the gold based on factors like the minerals it's associated with, its texture, and the rocks it's found in.
They found that the chemical variations in gold were related to how it interacted
with other minerals and elements during its formation. This information can help scientists distinguish between different types of gold based on their trace element signatures.
Understanding the composition and characteristics of native gold is
essential for the mining industry, as it can aid in the identification of potentially valuable gold deposits and the development of more efficient extraction methods.