ENVIRONMENTAL ISOTOPES OF PAMPA DE GAN GAN, NORTH PATAGONIAN MASSIF, CHUBUT

DAPEÑA, C.; PARICA C A,; BECHIS, F. ,; REMESAL, M. B

Salvador de Bahia

Simposio; IV South American Symposium on Isotope Geology; 2003

South American Symposium on Isotope Geology

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) (Fig. 1). The region is formed by several elevated ranges and displays a typically broken morphology, dissected by ephemeral streams and creeks (?arroyos?). The surface waters formed temporary and permanent lakes. The highest points are Sierra de Chacays (1400 m), Sierra de Talagapa (1600 m) and Sierra Pire Mahuida (close to 2000 m) (Fig. 1). Gan Gan town is located over an old depressed plain surrounding by those highest ranges. The water circulation from the higher to lower altitudes flows through the fractures in hard rocks and alluvial fans close to the border of the ranges.