Isotopic study of the Laguna Mar Chiquita, Córdoba, Argentina and its hydrogeological and paleoclimatological implications.

C DAPEÑA,; PANARELLO, H.0.

Iaea Technical Document Tecdoc

International Atomic Energy Agency

Lugar: Viena-Austria; Año: 2001 vol. 1206 p. 7 - 16

ABSTRACTThis work presents the results obtained during the first stage of the investigations carried out in the Mar Chiquita lake (Córdoba Province, Argentine Republic) within the framework of the Coordinated Research Program (CRP) on "Isotope Techniques in Lake Dynamics Investigations" of the International Atomic Energy Agency. The main objectives are to contribute to the study of this huge water body that in the past two decades increased its size almost three folds, to establish its water balance and to asses the influence of the climatic changes on the waterbudget. This water body is the final receptacle of a large closed basin formed mainly by the rivers Dulce, Suquía and Xanaes. During 1890-1973 it occupied 1800 to 2000 km2 with a salinity of 310-250 g/L. At present, it has around 5000 km2, a maximum depth of 10-12 m and a salinity rounding 42 g/L. The changes in salinity and size are related to an increase in precipitation which, at the same time, depends on different palaeoclimatic conditions. From a scientific point of view it is also important to study the lake hydrological balance, its groundwater input and output aswell as the evaporation rate and the mean residence time. These latter considerations are the object of the present isotopic research. Future studies will consider a palaeoclimatic approach..