Guatemela: Preliminary Zircon Ages from Central Cordillera

Science  04 Oct 1968:
Vol. 162, Issue 3849, pp. 121-122
DOI: 10.1126/science.162.3849.121


Concordia resolution of uranium-lead analyses of zircons from rocks of the Guatemalan Cordillera indicates a period of plutonism, and perhaps metamorphism, in late Paleozoic times (345 ± 20 million years). Gneisses of the Chuacus Series yield an age of 1075 ± 25 million years which may be either the age of a source terrain for the original sediments, or the age of principal metamorphism. Zircons from a Paleozoic granite intruding the gneisses appear to contain inherited or contaminating material acquired during the process of magma generation or emplacement, or both.