Genesis and evolution of granitoids from the Patagonian Batholith (42º40'-42º50' S)

GHIARA MR; BARBIERI M; CASTORINA F; HALLER MJ; TRUDU C

Beijing

Congreso; XXX International Geological Congress; 1996

IUGS

Twenty two samples of granitoids from the Patagonian Batholith (42.40º-42.50º S) have been analyzed. major and trace elements distribution suggests that the observed chemical variations are realted to a process of fractional crystallization. Chemical and Petrographical data allow to classify the plutonic rocks woth a silica content higher than 60% as I-type granitoids, which plot in the field of volcanic arc syncollisional granites. The 87Sr/86Sr initial ratio suggests that the granite magma derived from melting of a relatively primitive source. Analytical data are discussed an compared with the data referred in the literature for rocks from the Patagonian Batholith.