Cartography and reconstruction of the eruptive history of Cueros de Purulla volcano, Southern Puna, province of Catamarca

Abstract

Rhyolitic domes usually represent effusive phases related to explosive eruptions within the evolution of polygenetic volcanoes, or monogenetic eruptions forming part of volcanic fields. However, some rhyolitic domes not associated with polygenetic volcanoes can develop complex eruptive histories, including multiple effusive-explosive events separated by long-term repose periods (in the scale of ky). One of the least studied aspects of the Neogene-Quaternary volcanism of the Southern Puna is the occurrence of rhyolitic domes apparently not associated with any major polygenic volcanic centre (e.g. Cueros de Purulla and Chascón Volcanoes). This contribution presents a new cartography and detailed stratigraphy of the Cueros de Purulla Volcano together with complementary morphometric, textural, petrographic and geochemical data of mapped units. The results obtained allow us to classify the Cueros de Purulla Volcano as a dome complex with associated explosive activity, although the lack of absolute ages and/or stratigraphic markers of hiatues prevent to define a monogenetic or polygenetic character. All Cueros de Purulla Volcano products are crystal-poor rhyolites. The eruptive evolution of the Cueros de Purulla Volcano was divided into 3 phases: i) pre-collapse effusive phase represented by domes and coulées, ii) explosive syn-collapse phase represented by a debris avalanche, pyroclastic flow and pyroclastic fall deposits and iii) post-collapse effusive phase represented by domes and coulées.