Environmental Isotopes of Pampa de Gan Gan. North Patagonian Massif. Chubut.

DAPEÑA, CRISTINA; PARICA, CLAUDIO A.; BECHIS, FLORENCIA; REMESAL, MARCELA B.

Salvador-BA, Brazil

Simposio; IV South American Symposium on Isotope Geology; 2003

Comité SSAGI Brazil

The area is located in the centre north of the Patagonian Massif. The studies presented in this paper are part of the University of Buenos Aires projects UBACYT X 164 and X 628. The aim of these  investigations is to gain a better comprehension of the hydrological system in the area of the Pampa de Gan Gan and the surrounding ranges using environmental stable isotopes (2H and 18O), and to make a first approach to the origin of natural Chubut province, Argentina (42°00?-42°30? S; 69°00?- 67°15? W). We propose that the main sources of recharge are related of the phreatic level in Gan Gan are related to meteoric waters, which isotopic composition represents the mixing of snowfall or rainfall in the higher levels of the surrounding ranges. The different values obtained for different points of the hydrological system are closely related to ?Altitude Effect? and ?Latitude Effect?. Evaporation is mainly represented in lakes by large isotopic enrichment.