Sulfur radical species form gold deposits on Earth

Abstract

Current models of the formation and distribution of gold deposits on Earth are based on the long-standing paradigm that hydrogen sulfide and chloride are the ligands responsible for gold mobilization and precipitation by fluids across the lithosphere. Here we challenge this view by demonstrating, using in situ X-ray absorption spectroscopy and solubility measurements, coupled with molecular dynamics and thermodynamic simulations, that sulfur radical species, such as the trisulfur ion S − 3 , form very stable and soluble complexes with Au + in aqueous solution at elevated temperatures (>250°C) and pressures (>100 bar). These species enable extraction, transport, and focused precipitation of gold by sulfur-rich fluids 10-100 times more efficiently than sulfide and chloride only. As a result, S − 3 exerts an important control on the source, concentration, and distribution of gold in its major economic deposits from magmatic, hydrothermal, and metamorphic settings. The growth and decay of S − 3 during the fluid generation and evolution is one of the key factors that determine the fate of gold in the lithosphere.gold | sulfur | ore deposit | hydrothermal fluid | trisulfur ion

Acidity constants and redox potentials of uranyl ions in hydrothermal solutions

“…ref. [27][28][29][30][31][32][33][34][35][36][37]. As a hard acid, uranyl ions favor complexing with hard base ligands, e.g.…”

CuCl Complexation in the Vapor Phase: Insights from Ab Initio Molecular Dynamics Simulations

“…Enabled by advances in computing power and algorithms, molecular dynamics simulations have been applied increasingly to the study of metal speciation in hydrothermal liquids (e.g., Cu(I)-Cl -, [13,14]; Au(I)-HS -, [15]; Ag(I)-Cl -, [16,17]; Au(I)-HS -/OH -/S 3 -, [18,19]; Cu(I)-HS -/Cl -, [20]; Au(I)-Cl -, [14]; Pd(II)-Cl -/HS -, [21]; Zn(II)-Cl -/HS -, [22,23]; Ag(I)-HS -/OH -, [24]; Cu(I)-Ac -, [25]). These studies have demonstrated the importance of MD in understanding metal complexation at the molecular-level and, in some cases, have provided complementary information that helped resolve apparent discrepancies in the interpretation of experimental results [13,22].…”

Process and Mechanism of Gold Mineralization at the Zhengchong Gold Deposit, Jiangnan Orogenic Belt: Evidence from the Arsenopyrite and Chlorite Mineral Thermometers

“…At the early stage, free elements sulfur, arsenic and gold precipitated from the gold-bearing fluids when fluid-rock reaction occurred [28], which promoted the deposition of arsenopyrite and pyrite with the invisible gold, disseminated in the altered slates at a temperature of 322-397 • C and the lgf (S 2 ) from −8.5 to −6.7 (Figure 10a). Arsenic of the arsenopyrite has negative correlation with sulfur ( Figure 7), indicating that S could be substituted by As [47]; therefore, Au could enter into the arsenopyrite by substituting Fe to maintain the electric balance [10,48,49]. Subsequently, because of shortening event, the euhedral arsenopyrite underwent minor crystal plastic deformation (Figure 10b).…”