A fluid inclusion and light element stable isotope study of the gold-bearing quartz vein system,Falun, Sweden |
| |
| Authors: | A Åberg A E Fallick |
| |
| Institution: | 1. Mineral Resources Information Office, Geological Survey of Sweden, Skolgatan 4, S-930 70, Mal?, Sweden
2. Isotope Geology Unit, Scottish Universities Research and Reactor Centre, East Kilbride, G75 0QU, Glasgow, UK
|
| |
| Abstract: | The Falun gold quartz vein mineralization is located ca 230 km NW of Stockholm, Sweden, within the Early Proterozoic volcano-sedimentary sequence of Bergslagen. The mineralization consists of a system with subparallel quartz veins that crosscut the alteration zone to the Falun massive sulphide deposit. Early barren and late gold-bearing quartz veins follow tectonic structures postdating the formation of the massive sulphide ore. Both generations of veins are epigenetic to the massive sulphide ore and were formed by hydrothermal processes. Fluid inclusion study of the gold-bearing quartz veins indicates a low-moderately saline fluid (0.3 to 17.4 equiv wt% NaCl). Heterogeneous trapping is indicated by coexisting inclusions showing a variable CO2 content from 100% CO2 ± CH4 to 100% aqueous fluid. Temperatures of total homogenization also show a wide spread from 116–350°C with a slightly bimodal distribution with peaks at ca 180°C and 280°C. MeasuredδD values — 69 to — 63%0 (SMOW), of inclusion fluid and calculatedδ 18O values of hydrothermal fluids — 7.5 to — 1.4%0 (SMOW), strongly suggest a meteoric origin for the fluids. The quite consistentδD values and the range inδ 18O values indicate that major water-rock interaction led to the evolution inδ18O of the hydrothermal fluids. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
