N2CH4z.sbnd;CO2 fluids during formation of the Dôme de l'Agout,France |
| |
Authors: | R Kreulen RD Schuiling |
| |
Institution: | Institute of Earth Sciences, Dept. of Geochemistry, University of Utrecht, P.O. Box 80.021, 3508 TA Utrecht, The Netherlands |
| |
Abstract: | The Dôme de l'Agout consists of an ellipsoidal mass of gneisses and migmatites emerging from a large area of chlorite-sericite schists. Fluid inclusions in syn-metamorphic quartz segregations are typically one-phase at room temperature. Analyses by gas chromatography indicate that their main constituents are N2, CH4 and CO2; such compositions are confirmed by freezing studies on individual inclusions. Nitrogen contents of the inclusions range from 2 to 72 mol% and tend to increase with increasing degree of metamorphism. CH4 and CO2 show an erratic distribution with the exception of the lowest grade samples, which invariably have very high CO2 contents. The origin of the nitrogen remains unsolved; however, it seems likely that the nitrogen was not produced by mineral reactions in the presently exposed rocks but came from an external source and moved from the centre of the dome outwards. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|