Episyenites—Characteristics, Genetic Constraints, and Mineral Potential

  title={Episyenites—Characteristics, Genetic Constraints, and Mineral Potential},
  author={Einari Suikkanen and O. Tapani R{\"a}m{\"o}},
  journal={Mining, Metallurgy \& Exploration},
Episyenites are sub-solidus, quartz-depleted alkali-feldspar-rich rocks. They form veins and lenticular bodies in granitoid rocks and migmatites in a late- to post-orogenic or anorogenic setting. Leaching of quartz is usually a response to a flux of weakly saline hydrothermal solution in circulation cells above cooling intrusions, where sufficient fluid-rock ratios and thermal gradients are achieved. Fluid Si-undersaturation is achieved by rapid cooling within the field of retrograde Si… 
Alteration of Granitoids and Uranium Mineralization in the Blatná Suite of the Central Bohemian Plutonic Complex, Czech Republic
The Bohemian magmatic complex belongs to granitoid plutons of the Central European Variscides. Hydrothermal uranium mineralization evolved in the small uranium deposits Nahošín and Mečichov is
An Archean Porphyry-Type Gold Deposit: The Côté Gold Au(-Cu) Deposit, Swayze Greenstone Belt, Superior Province, Ontario, Canada
The Archean low-grade, large-tonnage Côté Gold Au(-Cu) deposit is the first large gold deposit discovered in the Swayze greenstone belt, Ontario, Canada. The deposit is hosted by the Chester


Episyenite formation in the Toki granite, central Japan
Episyenite is a quartz-depleted vuggy rock resulting from hydrothermal alteration of granitic rocks. This is the first report of its existence in an island arc, which is identified in a deep drill
Mineralogical and geochemical characteristics of hydrothermal alteration and episyenitization in the Königshain granites, northern Bohemian Massif, Germany
Abstract The late-Hercynian granites of Königshain underwent multistage hydrothermal processes. Extensive high-temperature late-magmatic alteration is, for example, indicated by low Zr/Hf and an REE
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Late Paleozoic fluorine-rich granites and their host metasediments in the Emuford district of the Herberton tin field contain small zones of intense albitization that host cassiterite mineralization.
The replacement of plagioclase feldspars by albite: observations from hydrothermal experiments
Oligoclase and labradorite crystals have been experimentally replaced by albite in an aqueous sodium silicate solution at 600°C and 2 kbars. The replacement is pseudomorphic and is characterised by a
Evolution of High-Temperature Hydrothermal Fluids Associated with Greisenization and Feldspathic Alteration of a Tin-Mineralized Granite, Northeast Queensland
Greisenization, albitization, and K-feldspathization occur as pervasive (background) alteration and fracture-controlled (selvage-style) alteration in the Go Sam granite in the Herberton-Mount Garnet
Hydrothermal processes related to movement of fluid from plastic into brittle rock in the magmatic-epithermal environment
Repeated intrusions of magma to depths of 2 to 6 km beneath a volcanic complex result in a large body of surrounding rock attaining temperatures sufficiently hot (>400 degrees C) for crustal rocks to