Physical and chemical processes in a large magma chamber: The Bjerkreim-Sokndal Intrusion

Physical and chemical processes that take place in magma chambers are of fundamental importance for magma differentiation, mixing and contamination as well as the nature and products of volcanic activity. Despite considerable research effort over many yea rs there is currently little concensus among petrologists concerning the nature and significance of many of the processes that may take place in magma chambers and much still remains to be learnt about their evolution. One approach to the evaluation of p rocesses in magma chambers is through the study of layered intrusions, i.e. solidified magma chambers that contain rock series that crystallised sequentially. These intrusions contain layered series composed of rocks that crystallised successively on the roof, walls and, most commonly, on the floor of the respective magma chamber. Layered Series form a record of temporal and spatial changes in the composition and temperature of the magma that occupied the chamber as well as transient processes that took p lace during their crystallisation. The study of layered series can make an important contribution to the identification and evaluation of the processes and events that took place during the evolution of magma chambers . The proposed project aims to compl ete the current partial documentation of the field relations, mineralogy and geochemistry of the Bjerkreim-Sokndal Intrusion, the largest and compositionally most unusual of the Norwegian layered intrusions, and infer the physical and chemical processes t hat occurred in a specific magma chamber.