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Distribution of Hydrothermal Alteration associated with High and Low Sulfidation Deposits

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Distribution of Hydrothermal Alteration associated with High and Low Sulfidation Deposits. High Sulfidation Epithermal Gold Deposits form in geothermal systems where hot acidic hydrothermal fluid directly from the intrusion, remains undiluted by ground water. Low Sulfidation Deposits on the other hand, from a geothermal system in which the magmatic fluid is cooled and diluted by groundwater and the pH is neutralized at depth. White, N. C., & Hedenquist, J. W. (1995). Epithermal gold deposits: styles, characteristics, and exploration. SEG Discovery, (23), 1-13.
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Boron isotope variations in a single monogenetic cone: La Poruña (21°53′S, 68°30′W), Central Andes, Chile

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  Benigno Godoy a.  .,F rances M. Deegan b  ., Osvaldo González-Maurel c .,Petrus le Roux c .,Dieter Garbe-Schönberg d e ., Inés Rodríguez f g .,Gabriela Guzmán-Marusic g .,Carolina Marín h La Poruña is a monogenetic volcano located within the Altiplano-Puna Volcanic Complex (21°-24°S) in the Central Andean subduction zone. Since crustal contamination of Andean magmas is ubiquitous, and because extensive geochemical data exist for La Poruña, we employ this volcano as a case study to examine the behavior of boron isotopes during crustal assimilation. We present whole-rock boron concentration and   11 B/ 10 B ratios (as δ 11 B values) for La Poruña lava samples that were prepared as nano-particulate pressed pellets. La Poruña B contents range from 14 to 20 μg/g and δ 11 B values range from −1.39 ± 0.54 ‰ (2σ) to +0.94 ± 0.30 ‰ (2σ), which overlap with the range of available whole-rock data for Central Andean lavas. Moreover, La Poruña δ 11 B va...
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