Fluid Inclusion Studies in Opaque Ore Minerals: I. Trace Element Content and Physical Properties of Ore Minerals Controlling Textural Features in Transmitted Near-Infrared Light Microscopy

Ortelli, Mélissa; Kouzmanov, Kalin; Wälle, Marküs; Ubrig, Nicolas; Casanova, Vincent

doi:10.5382/econgeo.2018.4615

Cited by 12 publications

(4 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Before the 1980s, fluid inclusions trapped within gangue minerals, i.e., quartz and topaz, were used for the investigation of ore-forming fluids [107,[110][111][112][113][114][115][116], with the hypothesis that the crystallization of quartz (or topaz) and wolframite occurs simultaneously. 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].…”

Section: Fluids Forming Ore and Gangue Mineralsmentioning

confidence: 99%

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

Pan

et al. 2022

Minerals

View full text Add to dashboard Cite

Wolframite-quartz vein-type tungsten deposits constitute the world’s major tungsten resources and are integral to tungsten production. A major share of this mineralization product is found in Southeast China, with other significant resources in the Central Andean belt, the East Australian belt, the Karagwe-Ankole belt and the European Variscan belt. In the past few decades, extensive studies on wolframite-quartz vein-type tungsten deposits have been conducted, but many key questions concerning their ore-forming fluid and metallogenic mechanism remain unclear. Additionally, a summary work on the global distribution and fluid characteristics of these wolframite-quartz vein-type tungsten deposits is still lacking. In this contribution, recent progress regarding several major issues related to the fluid processes involved in the forming of these veins are overviewed, and challenges in terms of future research are proposed. These issues include the nature of ore-forming fluids, their sources, and their transportation and wolframite deposition mechanisms. In particular, the affinity between veins and the exposed granitic intrusion from the Zhangtiantang-Xihuashan ore district, where an as-yet undiscovered deep intrusion, rather than the exposed granitic intrusion, was probably responsible for the formation of the wolframite-quartz veins, is reevaluated. This study also reviews the existing fluid and melt inclusion data from several tungsten deposits to address whether the mineralization potential of the magmatic-hydrothermal systems was directly correlated with the metal contents in the granitic melts and the exsolving fluids.

show abstract

Section: Fluids Forming Ore and Gangue Mineralsmentioning

confidence: 99%

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

Pan

et al. 2022

Minerals

View full text Add to dashboard Cite

show abstract

“…The stage was calibrated at -56.6°C, 0.0°C, and 374.1°C using pure H2O and H2O-CO2 synthetic fluid inclusion standards. Petrography and microthermometry of wolframite-hosted fluid inclusions were carried out at the University of Geneva (Switzerland) using a Linkam FTIR 600 stage mounted on an Olympus BH-51 microscope equipped with an Olympus XM-10 near-infrared (NIR) camera (Ortelli et al, 2018). Calibration of the heating-cooling stage was performed regularly using SynFlinc standards at -56.6°C, 0.0°C, and 374.1°C (Sterner and Bodnar, 1984).…”

Section: Fluid Inclusion Analysismentioning

confidence: 99%

“…The visible light absorbed by opaque minerals is partially converted into heat in proportion to the opacity and this could potentially preclude accurate microthermometric measurements (Moritz, 2006). To avoid this problem, a voltmeter was connected directly to the lamp of the microscope to control the power of the incident light following the procedure described by Ortelli et al (2018). Sample heating is not high enough to affect microthermometric measurements if a 90% closed diaphragm, a condenser at 0.3, and a power of <4 V depending on the transparency of the different zones of the crystals are used (Casanova et al, 2018).…”

Section: Fluid Inclusion Analysismentioning

confidence: 99%

Multistage development of a hydrothermal W deposit during the Variscan late-orogenic evolution: the Puy-les-Vignes breccia pipe (Massif Central, France)

Harlaux¹,

Marignac²,

Poujol

et al. 2021

BSGF - Earth Sci. Bull.

View full text Add to dashboard Cite

The Puy-les-Vignes W deposit, located in the northwestern French Massif Central (FMC), is a rare occurrence worldwide of a wolframite-mineralized hydrothermal breccia pipe hosted in high-grade metamorphic gneisses. We present here an integrated study of this deposit aiming to characterize the ore-forming hydrothermal system in link with the Variscan late-orogenic evolution of the FMC. Based on a set of representative samples from the host rocks and mineralization, we describe a detailed paragenetic sequence and we provide the major and trace element geochemistry of the host rocks and W-Nb-Ta-Sn-Ti oxide minerals, in situ U-Pb and 40Ar/39Ar geochronology, and a fluid inclusion study in quartz and wolframite. We demonstrate that the formation of this W-mineralized breccia pipe results from a multistage development between ca. 325 and 300 Ma related to four major episodes during the late Carboniferous. The first episode corresponds to the emplacement of an unexposed peraluminous granite at ca. 325 Ma, which generated microgranite dykes exposed at the present-day surface. The second episode is the formation of the quartz-supported breccia pipe and wolframite mineralization at ca. 318 Ma at a paleodepth of 7 km. The mineralizing fluids have a H2O-NaCl-CO2-CH4-N2 composition, a moderate-salinity (<9 wt.% NaCl eq) and were trapped at high-temperatures (400-450°C) during lithostatic to hydrostatic pressure variations caused by intense hydraulic fracturing of the host rocks. Wolframite deposition is interpreted to result from the mixing between a W-rich intermediate-density magmatic fluid exsolved from an evolved leucogranite and low-salinity volatile-rich metamorphic fluids of distal origin. The third episode corresponds to a magmatic-hydrothermal Nb-Ta mineralization overprinting the W-mineralized system and related to the intrusion at ca. 314 Ma of a rare-metal granite, which is part of a regional peraluminous rare-metal magmatism during the 315-310 Ma period. Finally, the last episode corresponds to the formation of a disseminated Bi±Au-Ag mineralization at ca. 300 Ma, which shares similar textural and mineral features with orogenic gold deposits in the FMC. The Puy-les-Vignes W deposit records, therefore, a multistage and long-lived development that extends over a timespan of 25 million years in a regional setting dominated by protracted peraluminous magmatism and HT-LP metamorphism. Although the local environment of ore deposition is atypical, our results show that the mineral assemblages, alteration styles, and fluid characteristics of the Puy-les-Vignes breccia pipe are similar to those of other peri-granitic W deposits in the FMC.

show abstract

“…Element distribution maps (e.g., SEM-EDS or µXRF) can be also used to target internal zones, or to exclude samples for ID-TIMS analyses. Near-infrared microscopy (e.g., Ortelli et al 2018;Harlaux et al 2021) and X-ray computed tomography (CT; Harlaux et al 2018a) are also promising tools to investigate the textures of wolframite and to provide 3D information about the relative proportions and the spatial distribution of micro-inclusions and/or alteration zones.…”

Section: Assessment Of Commonmentioning

confidence: 99%