Combined study of Au-bearing arsenopyrite of orogenic gold deposits (NE Asia): High resolution 3D X-ray computed tomography, LA-ICP-MS, and EMPA data
Year: 2024
Type: article
Abstract: • High-resolution X-ray microtomography (HRXCT) reliably identified dense mineral phases. • HRXCT study is most effective when it is used together with SEM, EMPA, LA-ICP-MS. • HRXCT allow to estimate amount of gold grains in rocks and evaluate the gold content. • HRXCT provide data on the distribution pattern of gold inclusions. The distribution of gold in small acicular arsenopyrite of a pyrite-arsenopyrite association from Suzdal (Eastern Kazakhstan), Olympiada (Yenisei Ridge, Russia) and large pseudorhombic arsenopyrite crystals from Bazovskoe (Yakutia, Russia) orogenic-type deposits were investigated. On orogenic gold deposits in NE Asia, occurring mainly in black shales, two productive stages of ore deposition are distinguished, which correspond to two morphological varieties of arsenopyrite. At the early stage, fine-grained acicular-prismatic arsenopyrite with invisible gold was deposited; at the late stage, tabular arsenopyrite in association with free visible gold was formed. The samples of gold-bearing arsenopyrite were analyzed using Scanning Electron Microscopy, Electron Microprobe Analyses, Atomic Absorption and Laser Ablation Inductively Coupled Plasma Mass Spectrometry in combination with High Resolution 3D X-ray Computed Tomography (HRXCT). HRXCT does not destroy the studied mineral during the investigation. That technique permits to do an estimation of the amount of gold inclusions in minerals or host rocks and draw reasonable conclusions about the gold content of the ores, to study in detail the distribution patterns of metal inclusions (associated with certain minerals, cracks, crystal growth faces, etc.) and to determine the form of the gold. It can be used to understanding of the genesis of productive mineral associations, and to developing optimal technological schemes for gold extraction.
Source: Geoscience Frontiers
Authors: Evgeny Naumov, Yuri Kalinin, Galina Palyanova, Lyudmila Kryuchkova, Viacheslav Voitenko, Vera Abramova, Franco Pirajno
Institutions: Central Research Institute of Geological Prospecting for Base and Precious Metals, V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, St Petersburg University, Russian Academy of Sciences, Institute of Geology of Ore Deposits Petrography Mineralogy and Geochemistry, The University of Western Australia
Language: English
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,000
OpenAlex ID: W4403539651