Zircon U-Pb geochronology of the Chimpa volcano (Central Andes, Puna plateau, NW Argentina): Inferences on the temporal evolution of the magmatic system

BUSTOS, E.; BARDELLI, L.; ARNOSIO, M.; BECCHIO, R.A.

Geosystems and Geoenvironment

Elseiver

Año: 2024

2772-8838

We investigated the temporal evolution of the andesitic Chimpa volcano of the northern Puna plateau, Central Andes, situated at the geological boundary between the plateau and the Eastern Cordillera domains. The volcanic activity consisted in three constructive volcanic cycles (Basal, Cajon, and Chimpa units) showing complex eruptive behaviors (ignimbrites, lava domes. block-and-ash flows, lava flows). We present new U-Pb analyses conducted on the zircon crystals from the Chimpa volcanic rocks. These analyses provide constraints on the magmatic/volcanic tempos and offer insights into the Th and U (and Th/U ratios) systematics of the analyzed zircon crystals. The results suggest a lifespan for volcanism ranging 7.5 to