Traditional economic geologists focus on the primary magmatic or sedimentary signature of ore deposits, neglecting the key secondary orogenic processes that may upgrade the initial CRM budget.
Indeed, many deposits – in particular in Europe – are located in orogens.
This project aims at filling the fundamental gaps in knowledge on CRM (like Ga, Ge, In) mobility during orogenic process. Our recent work has proposed a new paradigm by which CRM get concentrated into critical minerals in a different way from how base ores are formed (Fig. below), highlighting the role of metamorphic and tectonic processes to form economic deposits.
While this finding opens new avenues to fundamentally change the approach to target and explore for CRM, significant questions remain before the knowledge can be operationalized to the mining industry.
We will revisit existing ore-deposits sampling different crustal levels that record different degrees of metamorphic and tectonic processes from the large tectonic-scale to the mineral-scale.
Through detailed mineralogical and in situ chemistry studies, we will evaluate the potential secondary gains in existing ores and abandoned mine wastes. In order to test the project hypothesis and ensure the reproducibility of our results, we have chosen a large number of targets that have been differently affected by orogenic processes in Europe and France.
A sequence of four work-packages will be applied to each of these case studies, from the regional structural setting to the mineral-scale.