Origin and composition of hydrothermal fluids related to the formation of granite-related Sn-W deposits in SW England.
Final Report Abstract
Samples from five plutonic complexes related to diverse magmatic to hydrothermal stages of the Cornubian Batholith (SW England) have been investigated with a special emphasis on tourmaline. A comprehensive data set on major, minor and trace element concentrations as well as Fe3+/ƩFe ratios of texturally different tourmaline groups has been acquired applying electron microprobe analyses (EPMA), Laser ablation ICP-MS and Mössbauer spectroscopy. The details of this comprehensive study have been published in Ore Geology Reviews (Duchoslav et al., 2017). The detailed search for fluid inclusions in the studied samples revealed a similar or even more complex picture and microthermometric for fluid inclusions in selected samples exhibit an enormous range in ice melting, hydrohalite melting and and homogenization temperatures. Fluid inclusions in selected samples where analyzed by LA-ICP-MS and quantified by a Pitzer ion interaction approach in the system H2O- NaCl-KCl-CaCl2-MgCl2-FeCl2. This approach has particular potential in the application to magmatic-hydrothermal or pegmatitic systems, in which NaCl cannot be readily assumed to dominate the chloride budget. It is anticipated to complete the fluid inclusion investigation including the analysis of fluid inclusions via LA-ICP MS as described above in a follow-up project.
Publications
- Changes in tourmaline trace element geochemistry during magmatic fractionation and hydrothermal ore deposition. DMG conference 2014, FLU-T09
Duchoslav, M., Marks, M., Wenzel, T., Markl, G.
- Changes in tourmaline trace element geochemistry during magmatic differentiation and hydrothermal ore deposition. Goldschmidt conference 2015, Prague
Duchoslav, M., Marks, M.A.W., McCammon, C., Marschall, H., Wenzel, T., Markl, G.
- Major-, minor and trace element variations in tourmaline as monitors for magmatic differentiation, fluid un-mixing and associated ore precipitation. DMG conference 2015, Berlin
Duchoslav, M., Marks, M.A.W., McCammon, C., Marschall, H., Wenzel, T., Markl, G.
- (2017): Changes in tourmaline composition during magmatic and hydrothermal processes leading to tin-ore precipitation: The Cornubian Batholith, SW England. Ore Geology Reviews 83, 215-234
Duchoslav, M., Marks, M.A.W., Drost, K., McCammon, C., Marschall, H.R., Wenzel, T., Markl, G.
(See online at https://doi.org/10.1016/j.oregeorev.2016.11.012)
