Geochronology and geochemistry of Grenvillian igneous suites in the northern Oaxacan Complex, southern Mexico: tectonic implications

Chemical and U–Pb isotopic analyses of metaigneous rocks in the northern Oaxacan Complex in southern Mexico indicate that they form part of two granitic–gabbroic suites intruded at ∼1157–1130 and ∼1012 Ma, which were metamorphosed under granulite facies conditions between ∼1004 and 980 Ma. Although the older suite has both within-plate and arc geochemical signatures, the arc characteristics (enrichment of La and Ce relative to Nb, Ta, and Th)...