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GEM: Granite related mineralization of strategic metals – conditions of mineralization and search criteria for hidden ore bodies

The distribution of Phanerozoic granite resulted mineralization in space and time is the result oft he superposition of several first-order processes that include intense chemical alteration on the stable continent, the sedimentary and tectonic accumulation of the intensely altered sediments, and the high-temperature melting of these rocks. In the project, geochemical and structural studies are combined with thermal modeling to identify those factors that are critical for the formation of mineral deposits, which are the transfer of ore metals from the protolith to the melt, the thermal evolution of the crust that controls conditions of melting and melt fractionation, the structural controls of heat and melt distribution, and the focused metal deposition by fluid-rock interaction. Two subprojects headed by Section 3.1 contribute to this theme: 1) Intense chemical alteration results in lithologies that have a reduced metamorphic phase assemblage (relative to non-altered rocks) and therefore show contrasting melting behavior. As metals are redistributed between melt and restite phases, melting history (as function of protolith chemistry, temperature, and melt extraction history) controls whether melts are enriched in ore metals or not. 2) Fluid-rock reaction changes the fluid composition and may induce phase separation, both of which may reduce the solubility of ore metals. Thus, reaction fronts may be particularly enriched in economically interesting metals. Reaction fronts that develop after metal precipitation, however, are barren. The reaction history and fluid-flow history are key parameters for describing the distribution of ore elements within a deposit.

Project details

Duration of project: 2015 - 2018 

Funding: BMBF

Cooperation partner: TU Bergakademie Freiberg, BEAK consulting (Freiberg), GEOS (Freiberg)

Link: For further information please click here.

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