In autumn 2024, an expedition to Rwanda was undertaken within the framework of the research project “CRM-geothermal”. 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. The eastern and western branches of the EARS host juvenile sectors with promising geothermal potential related to hot fluids migrating along permeable faults.
The expedition began in the Virunga Volcanic Province in north-western Rwanda and continued all along Lake Kivu to Kamembe Further, along the Nyakabuye-Ruhwa Valley, in the area of Bugarama, Ruhwa and Mashyuza, gas, water, rock and sediment associated with natural hot springs but also cold springs were collected. On site, physical and chemical parameters were measured in-situ and documented together with the geology, infrastructure and domestic use of the hot site. At Ruhwa borehole, southern Rwanda, the hot water (66°C) emerges as an artesian spring at the surface. Drilling sites for geothermal water and energy extraction in Karisimbi were not visited because no economically viable geothermal system was found. Gisenyi and Bugarama are in the focus of the authorities, but funding for drilling at these sites was not yet achieved. We visited these sites to monitor the physicochemical parameters and to highlight the importance of their usage.
This dataset presents the raw data of an experimental series of analogue models performed to investigate the influence of inherited brittle fabrics on narrow continental rifting. This model series was performed to test the influence of brittle pre-existing fabrics on the rifting deformation by cutting the brittle layer at different orientations with respect to the extension direction. An overview of the experimental series is shown in Table 1. In this dataset we provide four different types of data, that can serve as supporting material and for further analysis: 1) The top-view photos, taken at different steps and showing the deformation process of each model; they can be used to interpret the geometrical characteristics of rift-related faults; 2) Digital Elevation Models (DEMs) used to reconstruct the 3D deformation of the performed analogue models, allowing for quantitative analysis of the fault pattern. 3) Short movies built from top-view photos which help to visualize the evolution of model deformation; 4) line-drawing of fault and fracture patters to be used for fault statistical quantification. Further details on the modelling strategy and setup can be found in Corti (2012), Maestrelli et al. (2020), Molnar et al. (2020), Philippon et al. (2015), Zwaan et al. (2021) and in the publication associated with this dataset. Materials used for these analogue models were described in Montanari et al. (2017) Del Ventisette et al. (2019) and Zwaan et al. (2020).
This dataset shows the original data of a series of enhanced-gravity (centrifuge) analogue models, which were performed to test the influence of the pre-existing fabrics in the brittle upper crust on the evolution of structures resulting from oblique rifting. The obliquity of the rift (i.e., the angle between the rift axis and the direction of extension) was kept constant at 30° in all the models. The main variable of this experimental series was the orientation of the pre-existing fabrics (indicated as the angle between the trend of the fabric and the orthogonal to extension), which varied from 0° to 90° (i.e., from orthogonal to parallel to the extension direction). The inherited discontinuities were reproduced by cutting with a knife through the top brittle layer of models. An overview of the experimental series is shown in Table 1. In this dataset, four different data types are provided for further analysis: 1) Top-view photos of model deformation, taken at different time intervals and showing the deformation process of each model; they can be used to interpret the geometrical characteristics of rift-related faults; 2) Digital Elevation Models (DEMs) used to reconstruct the 3D deformation of the analogue models, allowing for quantitative analysis of the fault pattern. 3) Movies of model deformation, built from top-view photos, which help to visualize the evolution of model deformation; 4) Faults line-drawings to be used for statistical quantification of rift-related structures. Further information on the modelling strategy and setup can be found in the publication associated to this dataset and in Corti (2012), Philippon et al. (2015), Maestrelli et al. (2020), Molnar et al. (2020), Zwaan et al. (2021), Zou et al. (2023). Materials used to perform these enhanced-gravity analogue models were described in Montanari et al. (2017), Del Ventisette et al. (2019) and Zwaan et al. (2020).