Departamento de Geologia e Recursos Naturais
Uranium anomaly in groundwater of the hard rock aquifer system in southeast Brazil
This study presents a hydrogeological characterization that fills knowledge gaps in an area where a complex geological scenario connects two fractured (granite/metamorphic rocks and diabase) and one porous (sedimentary rocks) aquifer systems. Previous groundwater studies from the four local deep supply wells suggested the sedimentary aquifer as the source of uranium (∼60 μg/L) in one of the wells. Despite the water extraction interruption from this well, this finding needed to be supported by evidence provided by the geological and structural characteristics of the aquifers.
Use of low-cost accelerometers for landslides monitoring: results from a flume experiment
Early Warning Systems (EWS) are non-structural measures for landslides disaster prevention. They are based on the detection of impending failure signals. The results of a landslide simulation experiment where accelerometers were used to identify pre-failure signals are presented in this paper. Landslide was simulated in a tilting flume filled with sandy soil. During the experiment, the flume was fixed at 30° inclination and water percolated through the soil until it slid.
Within-plate magmatism in the southern Borborema Province (NE Brazil): Mantle plumes associated with the Nuna-Columbia and Rodinia breakup?
Formation and fragmentation of landmasses, such as the Nuna/Columbia and Rodinia supercontinents, are influenced by mantle plume activity during rifting and breakup. In the Borborema Province, NE Brazil, within-plate magmatism at ca. 1.6 and at ca. 0.8 Ga is evidenced by the formation of mafic-ultramafic volcanic and plutonic rocks, mafic-ultramafic layered intrusions, and A-type granite intrusions.
Zircon U–Pb geochronology of manganese-rich rocks from the Borborema Province, Northeast Brazil: adding a new piece to the global inventory of Paleoproterozoic manganese mineralization
The Borborema Province hosts several Mn-rich metasedimentary sequences, containing up to 40 wt% MnO(total). These sequences are composed of Mn oxide and Mn silicate lenses that alternate with spessartite quartzite layers. They are also spatially associated with graphite-bearing gneissic and granitic rocks.
