LA-ICP-MS Trace-Element Analysis of Pyrite from the Huanxiangwa Gold Deposit, Xiong’ershan District, China: Implications for Ore Genesis

Abstract

The Huanxiangwa deposit is a major gold deposit in the Xiong’ershan district, which is the third-largest gold-producing district in China. Pyrites from the Huanxiangwa deposit were investigated using ore microscopy and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Pyrite is the dominant Au-bearing mineral in the Huanxiangwa deposit and can be divided into two types: medium- to fine-grained subhedral-anhedral pyrite (Py1) disseminated in altered rocks and coarse-grained subhedral-euhedral pyrite (Py2) hosted in auriferous quartz veins. LA-ICP-MS time-resolved depth profiles show that invisible gold occurs primarily as solid solution or as homogeneously distributed nanoparticles of native gold, electrum, or Au-Ag-Te minerals in Py1, whereas it is present mainly as nano- to submicron-sized inclusions of complex Au-Ag-Cu-Pb-Zn domains in Py2. The presented data indicate that the Huanxiangwa deposit resulted from two episodes of hydrothermal mineralization associated with two distinct source reservoirs. The first episode of mineralization was linked to the dehydration of deep-seated mafic-ultramafic metamorphic rock during the Triassic collision of the North China Craton with the Yangtze Craton. The second episode of mineralization was related to hydrothermal activity resulting from Early Cretaceous I-type granitic magmatism.

Types of Tellurium Mineralization of Gold Deposits of the Aldan Shield (Southern Yakutia, Russia)

“…Numerous studies show the presence of gold of three varieties: invisible in pyrite or arsenopyrite, native gold and gold tellurides. With the advent in recent decades of the highly sensitive inductively coupled plasma mass spectrometry (LA-ICP-MS) method and, especially, the local version of this method with laser ablation of the substance directly from the sample, it became possible to determine gold and other trace elements in pyrite [45][46][47][48][49].…”

Disseminated Gold–Sulfide Mineralization in Metasomatites of the Khangalas Deposit, Yana–Kolyma Metallogenic Belt (Northeast Russia): Analysis of the Texture, Geochemistry, and S Isotopic Composition of Pyrite and Arsenopyrite

“…Elevated As content is characteristic of pyrite with excess iron (S/Fe = 1.9-1.98). In the pyrite structure, As isomorphically replaces S (Fe 1.00 (S 1.98 As 0.02 ) 2.00 ) to form, in some cases, arsenian pyrite (As > 1.7 %), which is typical for reducing conditions (see [60,77], etc.). Reich et al [60] noted for epithermal and Carlin-type deposits increased Au solubility in the pyrite structure with increasing As content: C Au = 0.02 • C As + 4 × 10 −5 .…”

Structural and geochemical ore-forming processes in deformed gold deposits: towards a multiscale and multimethod approach

“…Similarly to what has been widely documented for sulphide-bearing ore deposits (e.g. Sung et al, 2009;Zhao et al, 2011;Peterson and Mavrogenes, 2014;Velasquez et al, 2014;Genna and Gaboury, 2015;Belousov et al, 2016;Salvi et al, 2016;Augustin and Gaboury, 2018;Kerr et al, 2018;Gao et al, 2019;Wu et al, 2019a), the coupling between deposit-scale petrological-structural study, textural characterisation and LA-ICP-MS analyse of pyrite helps tracking gold endowment steps resulting in the formation of the GSS gold deposit (Fig. 11):…”