Volcanología y geocronología de extensos flujos basálticos neógeno cuaternarios del sureste de Payenia, centro-oeste de Argentina

BERTOTTO GUSTAVO WALTER; PONCE, ALEXIS DANIEL; ORIHASHI YUJI; BERNARDI MAURO; SUMINO HIROCHIKA

ANDEAN GEOLOGY

SERVICIO NACIONAL GEOLOGIA MINERVA

Lugar: Santiago de Chile; Año: 2019 vol. 46 p. 490 - 525

0718-7092

ABSTRACT. Volcanology and geochronology of very long Neogene-Quaternary basaltic flows from southeast Payenia, central-west Argentina. The basaltic lava flows located in the southeast of Payenia Volcanic Province, Argentina, show lengths between 40 and 181 km. These flows have transversal sections characterized by external vesicular crusts that surround a massive core hosting vesiculated structures. These characteristics defined them as P-type pahoehoe flows. Based on their surface topography, 2 types of flows were determined: sheet flows and hummockyflows. The first were emplaced through inflation and lateral coalescence of lobes in the front of the flow, giving rise to flat roofs and large lateral width. The second ones exhibit a microrelief given by local inflation structures (e.g., tumuli). It is proposed that the lava flows were initially emplaced as sheet flows on low angle slopes (