How fluids infiltrate through fractures and change metamorphic rocks - a case study from northern Spitsbergen

Abstract

Metasomatism is a process that involves changes in mineralogical and chemical composition of rocks or their portions due to interaction with fluids. In metasediments from northern Spistbergen clear zonation of metasomatic changes occur. Biotite break downs to chlorite, K-feldspar, titanite and/or rutile. Different mass balance calculations were applied in order to examine element redistribution during chloritization reaction. Textural evidence point out to isovolumetric replacement with H2O, FeO and MgO introduced to the system and K2O and TiO2 removed. Differences in calculated chloritization reactions equations suggest fluid heterogeneity on micro scale and control of local chemical composition on the progress of reaction and final product phases.