Isotopic Study of the "Laguna Mar Chiquita", Córdoba, Argentina and its hydrogeological and paleoclimatological implications

DAPEÑA, CRISTINA; PANARELLO, HECTOR

IAEA TEC-DOC series

IAEA

Lugar: Viena, Austria; Año: 2001 p. 7 - 15

1011-4289

This work presents the results obtained during the first stage of the investigations carried out in theMar Chiquita lake (Cordoba Province, Argentine Republic) within the framework of the CoordinatedResearch Programme (CRP) on "Isotope Techniques in Lake Dynamics Investigations" of theInternational Atomic Energy Agency. The main objectives are to contribute to the study of this huge waterbody that in the past two decades increased its size almost three folds, to establish its water balance and toasses the influence of the climatic changes on the water budget. This water body is the final receptacle of alarge closed basin formed mainly by the rivers Dulce, Suquia and Xanaes. During 1890-1973 it occupied1800 to 2000 km2 with a salinity of 310-250 g/L. At present, it has around 5000 km2, a maximum depthof 10-12 m and a salinity rounding 42 g/L. The changes in salinity and size are related to an increase inprecipitation which, at the same time, depends on different palaeoclimatic conditions. From a scientificpoint of view it is also important to study the lake hydrological balance, its groundwater input and outputas well as the evaporation rate and the mean residence time. These latter considerations are the object ofthe present isotopic research. Future studies will consider a paleoclimatic approach.