Jose Roberto Ferreira

Located in the northeast of Brazil, Maranhão has a GDP around 23 billion dollars, and an important need of energy for industry (20% of the GDP) and agriculture (12.6%). Steel mill, cellulose factory, beverage factory, ethanol factory, chemical products factory and alumina factory, as well as field irrigation uses today a significant amount of energy. Another important aspect to highlight is that Maranhão is a large exporter of iron ore, grains, alumina and cellulose, due to the fact that it has an access channel to the ports with a natural depth of approximately 23 meters. Expectation for new sources of energy exploited locally and with low carbon emissions is high, and natural hydrogen may be considered as a promising option. A first attempt for exploring this natural resource has been performed, and the surface measurements are encouraging in several areas of the state. The main geological formation outcropping in Maranhão is the Paleozoic basin of Parnaiba, covering an Archean basement. A lot of fairy circles could be observed in the Eastern part of the state and in the center of the basin. These structures are aligned along large lineation, including the continental sized TransBrasiliana tectonic suture. Some of these structures present weak hydrogen signal in soils. But other ones, mainly located along the Parnaiba River, show concentrations higher than 1000 ppm, and a recharge in hydrogen after several minutes, indicating that hydrogen is actively seeping, and does not correspond to human artefact. Areas with extremely soft soils present also hydrogen anomalies, whereas the weakness of sandy soils prevents generally any hydrogen preservation. More studies are now necessary to confirm the potential of this area. Other surface measurements as gamma spectrometry and radar interferometry may add valuable insights for the recognition of the natural hydrogen potential in Maranhão.