Constraints on the timing and genetic link of scheelite- and wolframite-bearing quartz veins in the chuankou W ore field, South China

Fluid Processes of Wolframite-Quartz Vein Systems: Progresses and Challenges

“…Subsequently, the application of infrared technology in the geological field provides a window for the direct testing of fluid inclusions in wolframite [22,[117][118][119][120][121]. Since then, intensive comparative studies have been carried out on the fluid inclusion of wolframite and quartz, and the results show that the homogenization temperature of fluid inclusions in wolframite are mostly higher than those in quartz, i.e., the Dajishan, Pangushan, Piaotang and Maoping tungsten deposits from the tungsten belt in southern Jiangxi, China [4,23], the Yaogangxian, Chuankou tungsten deposit in southeastern Hunan, China [6,21] and the St. Michael's Mount and Cligga Head deposits, Cornwall, England [22]. Combining these results with the field observation that most wolframite crystals grow from the edges of quartz veins, it is suggested that most of the quartz crystals were formed after precipitation of the coexisting wolframite [4,6,17].…”

“…Based on a large number of comprehensive research studies, the widely accepted precipitation mechanism of wolframite in quartz vein includes fluid boiling or immiscibility, fluid-rock interaction, simple cooling and meteoric water mixing [4,6,13,15,17,21,111,144,[146][147][148]. However, which precipitation mechanism plays the key role in certain W deposits formation has been a matter of dispute for decades.…”

“…Via a geochemical analysis of both fluid inclusion and wall rock, Lecumberri-Sanchez et al (2017) [13] proposed that the addition of Fe provided by fluid-rock interaction is the main controlling factor of wolframite precipitation at Panasqueira, Portugal. Similarly, quantitative analysis of fluid inclusion and wall rock alteration suggest that wall rocks are possible sources of Fe required for the precipitation of wolframite in the Chuankou tungsten deposit, South China [21]. On the contrary, Yang et al (2019) [16] reported very high Mn (up to 6.7 wt%) and Fe (up to 44.4 wt%) concentrations in quartz-hosted fluid inclusions from the Piaotang deposit in southern Jiangxi and suggested that the magmatic-hydrothermal fluids themselves contain enough Fe and Mn for wolframite deposition.…”

“…A close temporal and spatial relationship generally exists between the wolframitequartz vein-type tungsten deposits and granitic intrusion. However, the genetic link between granitic magma and associated wolframite-bearing quartz veins is still controversial (e.g., [5,11,16,21,23,74,80,153,154]). Two well-known genetic models have been proposed: The "orthomagmatic hypothesis" emphasizes that granitic magma is the direct source of W-bearing fluid, and ore-forming fluid is directly separated during the cooling and crystallization of granitic magma [11,80,85,155].…”

“…130 years with a total production of 76,000 metric tons of W since 1934 [8]. Because of its important economic significance, a significant number of studies on the fluid processes of wolframite-quartz vein-type W deposits have been carried out all over the world [4,5,[10][11][12][13][14][15][16][17][18][19][20][21]. However, preliminary reviews on their global distribution, fluid processes and metallogenic mechanism are relatively scarce.…”