To establish the conditions under which fluids are present in the upper crystalline crust, and to investigate their source and the nature, timescale and dynamics of their interactions with host rocks.
The work will pay particular attention to the relationship between tectonics and crustal fluids, and the role of fluids in heat and mass transfer. It will address the discrepancies between geophysical and petrogeological interpretations of the importance of fluid in crystalline rocks in stable crustal areas, using textural studies to investigate the relative timing and continuity of fluid flow episodes. This will be achieved primarily by integrating the study of palaeofluids preserved as inclusions in mineral veins with geochemical modelling of fluid-rock interactions.
The project will investigate examples of rocks from a variety of tectonic settings, including both systems in which contemporary activity is continuing and fossil systems. The work will include investigation of the structural controls on the development of veins and other fluid flow pathways, textural studies of mineral growth and fluid trapping, measurement of fluid density and, hence, estimation of depths and temperatures of trapping. Chemical studies will be aimed at defining individual fluid zones and equilibria with different mineral phases at different times in the system.
The work will draw on drill cores from Soultz (France) and Larderello (Italy), and on outcrop material from Portugal and Spain. Other field areas will be selected as work proceeds.
Funding SchemeCSC - Cost-sharing contracts