In autumn 2022, an expedition to Tanzania was undertaken within the framework of the research project “CRM-geothermal” and Scintific Priority Program (SPP) 2238 “Dynamics of Ore Metal Enrichment”. Within „CRM-geothermal“ we are looking for an environmentally friendly co-production of critical raw materials together with the provision of geothermal energy. In the EARS, high levels of rare earth elements (REE), Sr, Ba and Mg are expected in waters and solids in areas with alkaline volcanic rocks, while other critical elements, including helium, have been sought in other localities. In particular, the eastern branch is the most juvenile sector and has increased geothermal potential related to hot fluids migrating along permeable faults.
Tanzania was crossed from north to south, along the eastern arm of the EARS, to collect gas, water, rock and sediment samples associated with natural hot springs, lakes and vents. On site, physical and chemical parameters were measured in-situ and documented together with the geology, infrastructure and the domestic use of the hot site. In the south, existing drill sites and geothermal development areas were visited and gas and water samples were taken from boreholes and rocks sampled from drill cores. The survey covered 13 sites, from Lake Natron in the north to Lake Malawi in the south (see map).