Hydrothermal alteration of surficial rocks at Los Humeros geothermal field, Mexico: a magnetic susceptibility approach

Abstract Utility of the geothermal surface manifestations (GSMs; thermal springs, geysers, fumaroles, and zones hydrothermal alteration) in studies related to exploration is widely recognized. The identification hydrothermally altered rocks alteration very important because their presence indicates type size reservoir existing conditions. use traditional methods (i.e., geochemistry, mineralogy, petrography) requires expensive equipment, time-consuming, laborious sample preparation methods. Some rock magnetic parameters, like susceptibility (χlf) percentage frequency-dependent (χfd%), are potential become effective additional tools during initial stages exploration. Three chemical methods, Chemical Index Alteration (CIA), loss-on-ignition (LOI), binary plot (CaO + Na 2 O K O) vs. (Fe 3 MnO MgO), along with two χlf (χlf χfd%), applied nine intensively andesite reference rocks. All five have correctly identified that 99 out total 350 studied altered. More distributed surrounding several faults study area. Various (e.g., Los Humeros fault Loma Blanca fault) favor fluid flow present strong at surface. However, there no on region between E-W trending Las Papas Viboras faults. only deeper pathway toward east surroundings these result into almost absence strike Consequently, not many observed These features suggest Geothermal Field (LHGF) controlled by χfd% reliable, simple measure, fast, cost-effective, reliable for future studies.