Active metal deposition in a giant geothermal system

Abstract

Metallogenic models are vital to mineral exploration. However, there is debate concerning the origin of hydrothermal-type ore deposits such as vein-type U and W deposits. The formation, migration, heating and controls on the composition of metal-fertile fluids in active geothermal systems provide insights into the formation of ore-forming fluids. Fluid's metal contents are relatively high in the Yadong-Yangbajing-Naqu (YYN) geothermal belt of South Tibet, and a similar association of enrichment has been found in saline lakes of the region. This study analysed major ions and trace metal contents together with stable (O, H) isotopes of water samples from geothermal springs and wells and regional saline lakes and rivers along the Beng and YYN fault systems. Results demonstrate that metal-fertile geothermal brines, were sourced from the Bangor saline lake. This study highlights the role of evaporation of saline lake water in the formation of metal-fertile brines and the contrasting behaviors of U and W in hydrothermal conditions.

Climate Affects Global Basin-Related Metallogeny

“…The metal-fertile saline brines that are contemporaneous with evaporites are probably the initial oreforming fluid of basin-related ore deposits (e.g., Zhang et al, 2022Zhang et al, , 2023aZhang et al, , 2023b. This view comes from current research on saline lakes.…”

“…The factor that controls the formation of initial ore-forming fluid also influences the formation of basin-related ore deposits (Zhang et al, 2022(Zhang et al, , 2023a(Zhang et al, , 2023b. The ancient metal-rich saline lakes have disappeared, but they have left evidence of their existence, such as evaporites, fossils, and residual metal-fertile brines (Ba˛bel and Schreiber, 2014).…”

“…A rising mountain range, which is the direct result of tectonic activity, is a barrier to atmospheric circulation, especially if perpendicular to the incoming circulation (Sun et al, 2008). Tectonic activity is one dominant factor that influences the formation of hydrological closed basins which are home to metal-rich saline brines (Zhang et al, 2022(Zhang et al, , 2023a(Zhang et al, , 2023b. Therefore, in addition to climate, tectonic activity is the second prime factor that influences the formation and distribution of continental and marine saline brines (Warren, 2010).…”

“…However, there continues to be one significant gap in our understanding of the secular distribution of many types of ore deposits in time and space (e.g., Robb, 2005;Goldfarb et al, 2010). If we shift our perspective from ore-deposit centric to one centered on ore-forming fluids (e.g., Richard et al, 2013Richard et al, , 2014Zhang et al, 2022Zhang et al, , 2023aZhang et al, , 2023b, the global distribution pattern of basin-related mineral deposits (e.g., SEDEX and MVT Pb-Zn deposits, sediment-hosted stratiform Cu deposits, Unconformity related U deposits) in time and space would be understood more easily. Recently, some researchers have begun to study the metal-rich fluids in developing basins, so as to reveal the formation processes of paleo-ore-forming fluids for the basin-related ore deposits (e.g., Li and Barnes, 2019;Zhang et al, 2022Zhang et al, , 2023a.…”

“…If we shift our perspective from ore-deposit centric to one centered on ore-forming fluids (e.g., Richard et al, 2013Richard et al, , 2014Zhang et al, 2022Zhang et al, , 2023aZhang et al, , 2023b, the global distribution pattern of basin-related mineral deposits (e.g., SEDEX and MVT Pb-Zn deposits, sediment-hosted stratiform Cu deposits, Unconformity related U deposits) in time and space would be understood more easily. Recently, some researchers have begun to study the metal-rich fluids in developing basins, so as to reveal the formation processes of paleo-ore-forming fluids for the basin-related ore deposits (e.g., Li and Barnes, 2019;Zhang et al, 2022Zhang et al, , 2023a. The goal of this paper is to provide a new perspective into the climate controls on the formation of metal-rich fluids, and therefore controls the formation of basin-related ore deposits.…”