Periodically Released Magmatic Fluids Create a Texture of Unidirectional Solidification (UST) in Ore-Forming Granite: A Fluid and Melt Inclusion Study of W-Mo Forming Sannae-Eonyang Granite, Korea

The Upper Cretaceous Sannae-Eonyang granite crystallized approximately 73 Ma and hosted the Sannae W-Mo deposit in west Eonyang amethyst east. contained textural zones of miarolitic cavities unidirectional solidification texture (UST) quartz. UST rock sampled mine consisted (1) early cavity-bearing aplitic granite, (2) co-crystallization feldspars quartz a granophyric (3) latest growth larger crystals with clear zonation patterns. After was deposited, aplite or porphyritic formed, repeating prior sequence. Fluid melt inclusions occurring phenocrysts were studied to understand magmatic-hydrothermal processes controlling formation mineralization granite. composition suggested that formed by fractionated late-stage Some early-stage associated aqueous inclusions, indicating fluid exsolution from granitic melt. Hypersaline brine allowed calculation minimum trapping pressure 80–2300 bars. Such highly fluctuating might be potentially due lithostatic-hydrostatic transition pressure-attending loss during formation. Highly pressures created shifting stability field quartz-feldspar cotectic single-phase compositions assemblages deviated fluids trapped quartz, especially regarding Rb/Sr Fe/Mn ratios W Mo concentrations. study sample showed magmatic periodic. A single pulse variable salinities/densities have sequence, new batch would required create next