Geochronology and facies analysis of subaqueous volcanism of lower ordovician, Famatinian arc, Argentina

摘要: Abstract The Chuschin formation is a sedimentary-volcanic succession of the Famatina System subduction-related arc magmatism. This developed along western margin Gondwana during early and middle Ordovician. interpretation significant for understanding Famatinian arc. study provides detailed facies analysis, which allows characterizing deposits as well defining some characteristics volcanism sedimentation. Coherent, autoclastic, peperitic, pyroclastic volcaniclastic were recognized between different volcanic facies. relationships these indicate events effusive subaqueous explosive showing predominantly high temperature features. Both types are interbedded with volcanogenic epiclastic sediment that associated mainly turbidity currents. magmatic rocks dominantly subalkaline, weakly peraluminous silicic. Two new U-Pb zircon crystallization ages on from Formation show this section formed 463 469 Ma (Middle Ordovician).