Stratigraphy of the Coranzulí caldera

SEGGIARO, RAÚL; GUZMÁN, SILVINA; MONTERO, CAROLINA; LÓPEZ, MARÍA ELENA

Lisboa

Congreso; Strati: 1st International Congress on Stratigraphy; 2013

The Coranzulí caldera (23ºS-66º15´W) is one of the largest volcanic complexes located in the eastern part the Northern Puna, Central Andes. Its location was controlled by the intersection of two lineaments with NW-SE and NE-SW strike. The Coranzulí caldera emitted three major and a smaller pyroclastic units related to the caldera formation and three lava flows that represent the final stages of the caldera cycle. The pyroclastic sequences are dacitic and crystal-rich, they are moderately to intensely welded and the pumice fragments are highly vesiculated. The ages obtained for the ignimbrites range between 6.8 ± 0.15 Ma and 6.45 ± 0.15 Ma. The absence of fall-out deposits indicates that a relatively low-height eruptive column fed the pyroclastic sequences. The deposits cover an area of 1,900 km2 and have 400 km3 (DRE).