Geochemical Modeling of the Zoned Footwall Alteration Pipe,Hellyer Volcanic-Hosted Massive Sulfide Deposit, Western Tasmania,Australia
| Autor: | Christian Schardt, David R. Cooke, Ross R. Large, J. Bruce Gemmell |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
geography
geography.geographical_feature_category Andesite Geochemistry Geology engineering.material Hematite Sericite Hydrothermal circulation chemistry.chemical_compound Geophysics chemistry Volcano Geochemistry and Petrology visual_art engineering visual_art.visual_art_medium Economic Geology Pyrite Chlorite Geochemical modeling |
| Zdroj: | Economic Geology. 96:1037-1054 |
| ISSN: | 0361-0128 |
| DOI: | 10.2113/gsecongeo.96.5.1037 |
| Popis: | The mineralogy of hydrothermal alteration assemblages (siliceous core, chlorite zone, sericite zone) in the footwall pipe of the Hellyer volcanic-hosted massive sulfide (VHMS) deposit is controlled mainly by the temperature, pH, and redox state of the hydrothermal fluids. Based on the results of our numerical modeling, the zoned alteration system could have formed by a combination of water-rock interaction and cooling, with a siliceous core predicted to form at the center of the conduit, passing outward to a chlorite-dominated zone, a sericite-rich zone, and finally grading out to unaltered andesite. These mineralogical changes relate to a gradual evolution of fluid chemistry, water/rock ratio, pH, and temperature from the core to the margin of the system. Initial temperatures were probably close to 350 degrees C, and the hydrothermal fluids were reduced (H2S dominated). At low temperatures ( |
| Databáze: | OpenAIRE |
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