14C Analyses of Groundwater from the Botucatu Aquifer System in Brazil
KeywordsBotucatu Aquifer System
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CitationSilva, A. A. K. E., da Cunha Rebouças, A., & Freitas Santiago, M. M. (1989). 14C analyses of groundwater from the Botucatu aquifer system in Brazil. Radiocarbon, 31(3), 926-935.
DescriptionFrom the 13th International Radiocarbon Conference held in Dubrovnik, Yugoslavia, June 20-25, 1988.
AbstractMeasurements of 14C activity as well as determinations of the stable isotope composition (18O, 2H and 13C) of groundwater samples were made to investigate the flow path, origin, recharge and age of the Botucatu Aquifer System in Brazil, between 1984 and 1987. The stable oxygen isotope composition reflects infiltration during several climatic recharge conditions. Measured 14C activities range from 0.4 to 94.2% modern. delta-13C values enable us to distinguish two groundwater types of different origins. There is a gradual increase of 14C ages from the outcrop area towards the central part of the basin, associated with a progression of the confining conditions. Anomalous fluoride contents seem to be correlated with high 14C ages of the groundwater. The reliability of the 14C data is discussed.