EVALUATION OF GROUNDWATER AGES AND ISOTOPIC COMPOSITION ALONG DEFINED FLOW PATH IN THE NORTHEASTERN SECTOR OF GUARANI AQUIFER SYSTEM (GAS) - BRAZIL

摘要

Guarani Aquifer System (GAS) represents one of the most important groundwater reservoirs in South America, constituting a typical example of transboundary aquifer, which extends for about 1,100,000 km~2 over the territory of: Argentina (228,255.26 km~2), Brazil (735,917.75 km~2), Paraguay (87,535.63 km~2) and Uruguay (36,170.51 km~2). In this continental scale aquifer groundwaters aged over 30,000 years, based on ~(14)C determinations, were recognized in confined portion of the aquifer during isotopic studies carried out by several authors (Gallo and Sinelli, 1980; Silva, 1983; Kimmelman et al., 1989 and OAS, 2009).