SHRIMP U-PB Zircon age of the la Cruz granite, eastern precambrian of Bolivia: implications for the lomas manechis orogeny in SW Amazonian Craton - Matos, Ramiro; Teixeira, Wilson; Geraldes, Mauro Cesar; Bettencourt, Jorge Silva; Cordani, Umberto G. (Simpósio 45 anos de Geocronologia no Brasil: CPGEO 1964-2009, 2009)