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Abstract
275 igneous zircon grains were dated using U/Pb analyses from 12 different basement rock samples in the Central Merida Andes of Venezuela. The data suggests that this region underwent two separate igneous events during the Ordovician-Silurian and also the Triassic. The Ordovician-Silurian ages represent either rift magmatism that opened the Rheic Ocean or orogenesis from the closure of the Iapetus Ocean. The Triassic igneous ages represent continental collision and resulting post-orogenic collapse of the Hercynian Orogeny. 41 metamorphic hornblende grains were dated using 40Ar/39Ar analyses from two different hornblende-rich samples, which were found to be Triassic in age. Two separate metamorphic events in the Triassic along with one Triassic deformational event were recorded in this region. These events likely took place synchronously with the Triassic igneous activity related to the syn and post-collisional granites of the Hercynian Orogeny.