TY  - JOUR
A1  - Guzman, S.
A1  - Petrinovic, I. A.
A1  - Brod, J. A.
A1  - Hongn, Fernando D.
A1  - Seggiaro, R. E.
A1  - Montero, C.
A1  - Carniel, Roberto
A1  - Dantas, E. L.
A1  - Sudo, Masafumi
T1  - Petrology of the Luingo caldera (SE margin of the Puna plateau) a middle Miocene window of the arc-back arc configuration
JF  - Journal of volcanology and geothermal research
N2  - We describe the petrographic characteristics, whole-rock geochemistry and mineral chemistry of rocks from the Pucarilla-Cerro Tipillas Volcanic Complex with emphasis on the rocks belonging to the middle Miocene Luingo caldera, located in the south-eastern portion of the Central Volcanic Zone (CVZ) of the Andes. We modelled the petrogenesis of the Luingo caldera rocks as a mixture of ca. 20% crustal magmas and 80% of mantle magmas by AFC with recharge processes. A comparison of Luingo geochemical data with the composition of Miocene-Pliocene volcanic rocks from the broad area, points to major thickening events during the middle Miocene for the western portion and during the upper Miocene for the eastern portion of the Southern CVZ. In the eastern sector (similar to 66 degrees W) the mantle source appears to change from a spinel-lherzolite type for the middle Miocene to a garnet-lherzolite type for the upper Miocene-Pliocene magmas. The areal distribution of the volcanic products led to the recognition of approximately equivalent areas covered by volcanic rocks both in the eastern and in the western Puna borders. This indicates a broad arc, which was structurally controlled at the proto-Puna/Puna margins, whose geochemical differences are related with variations in crustal thicknesses and heterogeneous mantle sources from west to east.
KW  - Luingo caldera
KW  - Central Andes
KW  - Miocene volcanism
KW  - Southern Central Volcanic Zone
KW  - crustal thickness
Y1  - 2011
U6  - https://doi.org/10.1016/j.jvolgeores.2010.12.008
SN  - 0377-0273
VL  - 200
IS  - 3-4
SP  - 171
EP  - 191
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Aramayo, Alejandro
A1  - Guzman, Silvina
A1  - Hongn, Fernando D.
A1  - del Papa, Cecilia
A1  - Montero-Lopez, Carolina
A1  - Sudo, Masafumi
T1  - A Middle Miocene (13.5-12 Ma) deformational event constrained by volcanism along the Puna-Eastern Cordillera border, NW Argentina
JF  - Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth
N2  - The features of Middle Miocene deposits in the Puna-Eastern Cordillera transition (Valles Calchaquies) indicate that Cenozoic deformation, sedimentation and volcanism follow a complex spatiotemporal relationship. The intense volcanic activity recorded in the eastern Puna border between 14 and 11.5 Ma coincides with the occurrence of one of the most important deformation events of the Neogene tectonic evolution in the region. Studies performed across the Puna-Eastern Cordillera transition show different relationships between volcanic deposits of ca. 13.5-12.1 Ma and the Oligocene-Miocene Angastaco Formation. In this paper we describe the ash-flow tuff deposits which are the first of this type found concordant in the sedimentary fill of Valles Calchaquies. Several analyses performed on these pyroclastic deposits allow a correlation to be made with the Alto de Las Lagunas Ignimbrite (ca. 13.5 Ma) of the Pucarilla-Cerro Tipillas Volcanic Complex located in the Puna. Outcrops of the ca. 13.5 Ma pyroclastic deposits are recognised within the Puna and the Valle Calchaqui. However, in the southern prolongation of the Valle de Hualfin (Tiopampa-Pucarilla depression) that separates the Puna from the Valle Calchaqui at these latitudes, these deposits are partially eroded and buried, and thus their occurrence is recorded only by abundant volcanic clasts included in conglomerates of the Angastaco Formation. The sedimentation of the Angastaco Formation was aborted at ca. 12 Ma in the Tiopampa-Pucarilla depression by the Pucarilla Ignimbrite, which unconformably covers the synorogenic units. On the contrary, in the Valle Calchaqui the sedimentation of the Angastaco Formation continued until the Late Miocene. The different relationships between the Miocene Angastaco Formation and the ignimbrites with ages of ca. 13.5 and ca. 12 Ma reveal that in this short period (-1.5 m.y.) a significant deformation event took place and resulted in marked palaeogeographic changes, as evidenced by stratigraphic-sedimentological and chronological records in the Angastaco Formation. (C) 2017 Elsevier B.V. All rights reserved.
KW  - Angastaco Formation
KW  - Miocene deformation
KW  - Alto de Las Lagunas Ignimbrite
KW  - Luingo caldera
KW  - Foreland
Y1  - 2017
U6  - https://doi.org/10.1016/j.tecto.2017.02.018
SN  - 0040-1951
SN  - 1879-3266
VL  - 703
SP  - 9
EP  - 22
PB  - Elsevier
CY  - Amsterdam
ER  -