Soil gas geochemistry: significance and application in geological prospectings

摘要: Gas geochemistry has been proven to be a reliable and simple technique apply, at different scales, many geological scenarios (Annunziatellis et al., 2003; Lewicki Baubron 2002; De Gregorio Ciotoli 1998; 1999; Lombardi 1996; Hickman 1995; Duddridge 1991; Durrance Gregory, 1988; Eremeev 1973). The importance of fluid is rooted in the fact that Earth an open system fluid-releasing crustal phenomena are major means for exchange matter energy depths. As such, channels like active faults fractures actually ‘‘window’’ on subterranean physical chemical variations (Ciotoli 2007). study spatial distribution soil gas anomalies surface, can give important interesting information origin processes involving deep superficial species. This applied studied frameworks, example: I) seismic zonation, examining, anomalous concentrations species upraise throughout preferential pathways (faults and/or fractures). Soil distributions directly linked evolution stress regime gases migrate preferentially through fractured zones but only along whose permeability enhanced by activity areas brittle deformation. II) Environmental protection, such as monitoring naturally occurring toxic highlight with high health risks humans. presence magmatic chambers cause accumulation subsurface local structural features favour degassing phenomena. These events particularly dangerous populated it necessary build risk maps define potential hazard terms both short-term long-term risk. III) Radionuclide migration, pollution assessment from abandoned uranium mines high-level radioactive-waste isolation systems. main approach natural migration radiogenic particles or elements clay formations considered excellent sealing material due their ability immobilize water other substance over timescales. evaluation behaviour clays under normal extreme conditions still topic 9