In situ U-Pb dating and Hf isotope geochemistry of zircons from granites and related rocks of the Garzon area, eastern Cordillera of Colombia: timing and source of the magmatism on the Northwestern Andes, preliminary insights - Garcia Chinchilla, Daniel Alejandro; Vlach, Silvio Roberto Farias (South American Symposium on Isotope Geology, 2016)