Quartz textures in epithermal veins, Queensland; classification, origin and implication

Then, in the Cretaceous, and primarily in the Cenozoic, tectonic discontinuities filled with neptunian dykes were penetrated by karst waters and by hydrothermal solutions, which partly silicified the carbonate material infilling the dykes. The formation of dykes is genetically related to the Late Jurassic, Pan-European stress-field reorganization caused by the opening of the Northern Atlantic and Tethys Oceans.

show abstract

“…Sporadically, the internal sediment infillings contain fine (up to 1 mm across) aggregates of microflamboyant quartz ( Fig. 5c; Dong et al 1995).…”

Section: The Młynka Quarrymentioning

confidence: 99%

Oxfordian neptunian dykes with brachiopods from the southern part of the Kraków-Częstochowa Upland (southern Poland) and their links to hydrothermal vents

Matyszkiewicz

Krajewski

Kochman

et al. 2016

Facies

View full text Add to dashboard Cite

show abstract

“…Fluids that are slightly saturated may cool slowly to produce well-crystallised quartz, whereas extremely oversaturated fluids tend to produce colloidal aggregates or gels. Numerous quartz and silica textures have been reported from different deposits and a summary of these and their mode of occurrence has been described by Adams (1920), Sander and Black (1988), Dong et al (1995), and Moncada (2012aMoncada ( , 2012b. These studies provide a description of how the initial conditions of silica deposition relate to the final structure of the different silica forms observed in the epithermal environment.…”

Section: Silica Depositionmentioning

confidence: 99%

The importance of supersaturated silica deposition for base-metalAu–Ag mineralisation in western Turkey

Bozkaya¹,

Banks²

2015

Turkish J Earth Sci

View full text Add to dashboard Cite

In the Arapuçandere LS-IS epithermal deposit in western Turkey, either well crystallised euhedral quartz or milky amorphous silica occurrences are associated with the precious and base-metal mineralisation. This study has determined the relative importance of the processes precipitating both of these in relation to the deposition of the ore. Analysis by LA-ICPMS of euhedral quartz and amorphous silica show that the latter is associated with much higher metal concentrations and suggests that the process responsible is more important for deposition of ore in the deposit. Mineralisation at Kumarlar and Koru may be similar. Slow cooling precipitates euhedral quartz and some ore but flashing of hydrothermal fluids causes drastic decreases in both T and P, sufficient to quantitatively deposit base metals and Au. In amorphous silica bands base metals reach concentrations of 1000's of ppm compared with a few 10's ppm in euhedral quartz; Au can reach over 1 ppm compared with a few 10's ppb in quartz. The drastic pressure change from lithostatic to sub-hydrostatic could reasonably be caused by opening of faults and fractures by seismic events.

show abstract

“…Les fluides sont typiquement saturés en silice et le quartz est le minéral de gangue dominant dans les veines, représentant souvent la seule phase à s'y être déposée tout au long de l'évolution du système (Dong et al 1995;Groves et al 1998). Ses caractéristiques peuvent refléter les différentes conditions durant la croissance des veines, incluant celles favorables à la précipitation de l'or (Dong et al 1995).…”

Section: Mode De Formation Des Minéralisations Filoniennesunclassified

“…Ses caractéristiques peuvent refléter les différentes conditions durant la croissance des veines, incluant celles favorables à la précipitation de l'or (Dong et al 1995). Outre sa structure cristalline, sa composition chimique et ces propriétés physico-chimiques, la morphologie du quartz et sa direction de croissance (ex.…”

Section: Mode De Formation Des Minéralisations Filoniennesunclassified

“…crustiforme, colloforme) et radiales sont caractéristiques des dépôts formés près de la surface où la pression des fluides s'approche d'un régime hydrostatique, tandis que les textures sans contrôle directionnel ou contrôlées par le déplacement sont associées à des dépôts intermédiaires (faciès des schistes verts et amphibolites) où la pression des fluides s'approche d'un régime lithostatique (Cox et Etheridge 1983;Vearncombe 1993). En somme, la reconnaissance de ces textures, qu'elles soient primaires, recristallisées ou en remplacement peut représenter un outil privilégié pour certaines interprétations des conditions de pression et température du milieu et des fluides (Dong et al 1995). Ceci met donc l'emphase sur la nécessité d'étudier les gisements orogéniques non seulement à l'échelle du gisement mais aussi à l'échelle des veines et des textures internes avec des analyses structurales et pétrographiques détaillées.…”

Section: Mode De Formation Des Minéralisations Filoniennesunclassified

See 1 more Smart Citation

Contrôles structuraux de la minéralisation aurifère de la veine Consuelo, Pataz, La Libertad, Pérou /

Tremblay¹

2012

View full text Add to dashboard Cite

Quartz textures in epithermal veins, Queensland; classification, origin and implication

Cited by 257 publications

References 0 publications

Oxfordian neptunian dykes with brachiopods from the southern part of the Kraków-Częstochowa Upland (southern Poland) and their links to hydrothermal vents

Oxfordian neptunian dykes with brachiopods from the southern part of the Kraków-Częstochowa Upland (southern Poland) and their links to hydrothermal vents

The importance of supersaturated silica deposition for base-metalAu–Ag mineralisation in western Turkey

Contrôles structuraux de la minéralisation aurifère de la veine Consuelo, Pataz, La Libertad, Pérou /

Contact Info

Product

Resources

About