Isabelle Moretti1, Alejandra Carrillo 1&2, Felipe Gonzalez Penagos 3, German Rodriguez 3
1 UPPA, rue de l’université, Pau, France
2 University nacional, Colombia
3 Atlas research Group, Colombia
The exploration of natural H2or white hydrogen has started in various geological settings. Ophiolitic nappes are already recognized as one of the promising contexts. In South America, the only data available so far concerns the Archean iron rich rocks of the Mina Gerais in Brazil or the subduction context of Bolivia. In Colombia, despite government efforts to promote white hydrogen, data remain limited. We will present the first dataset gathered from soil gas sampling within the Cauca-Patia Valley and Western Cordillera whose the basement is an accreted oceanic lithosphere. In this valley, promising areas with H2potential were identified using remote sensing tools, in particular vegetation anomalies. The Atmospherically Resistant Vegetation Index (ARVI) appears to be well adapted for this context and the field data collection confirmed the presence of H2 in the soil in all pre-selected structures. The valley is heavily cultivated, primary for sugar cane production, and H2emissions cause changes in vegetation but not its complete disappearance, as reported in other countries. Soil gas measurements along the thrusts bordering the Cauca Valley also show high H2 content in the fault zones. The highest values where found on the Guadas-Pradera Fault Zone. In the valley, the presence of sedimentary cover above the ophiolites which are presumably the H2 generating rocks, allows addressing the possible presence of reservoirs and seals to define potential plays. By analogy to the Malian case, the intrusive could potentially be one of the seals.