Maars, tuff rings, tuff cones and scoria cones in Payenia Volcanic Province, Mendoza, Argentina

MORALES VOLOSÍN, SOLEDAD; RISSO, CORINA

Congreso; 27th IUGG General Assembly; 2019

The Southern Volcanic Zone of the Andes has a Quaternary basaltic province along the retroarc known as Payenia Volcanic Province (PVP). The PVP covers an area larger than 40000 km2, with an estimated volume of about 8387 km3 erupted around 960 volcanic centers in the last ~2 Ma. In the SE of Mendoza province, the PVP could be divided into 4 volcanic fields: Diamante (DVF), Llancanelo (LVF), Nevado (NVF) and Payún Matru (PMVF). Among them, around 749 monogenetic centers are recognized, most of which are red and black scoria cones. At least 34 centers show evidence of explosive eruptions with varying degrees of water-magma interaction. To the north, at the DVF, 7 phreatomagmatic centers are described: 4 maars (El Pozo and Arroyo Hondo) and 3 tuff-cones. The other 27 phreatomagmatic centers are distributed in the LVF and NVF (central part), being mainly tuff-cones and only 2 tuff-rings described at LVF (Piedras Blancas and Carapacho). On the other hand, in the PMVF (southern part) no evidence of significative water-magma interaction is found. This particular distribution of monogenetic volcanoes, with maars only present in the northern part (DVF) is remarkable, pointing us that the substrate below them exert some kind of control in it. Therefore, the purpose of our work is trying to understand the subsurface geology and determine the factors that controlled this distribution, with the leading hypothesis that the subsurface permeable conglomerates to the north allowed the maars? generation.