@article{GuzmanPetrinovicBrodetal.2011, author = {Guzman, S. and Petrinovic, I. A. and Brod, J. A. and Hongn, Fernando D. and Seggiaro, R. E. and Montero, C. and Carniel, Roberto and Dantas, E. L. and Sudo, Masafumi}, title = {Petrology of the Luingo caldera (SE margin of the Puna plateau) a middle Miocene window of the arc-back arc configuration}, series = {Journal of volcanology and geothermal research}, volume = {200}, journal = {Journal of volcanology and geothermal research}, number = {3-4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0377-0273}, doi = {10.1016/j.jvolgeores.2010.12.008}, pages = {171 -- 191}, year = {2011}, abstract = {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.}, language = {en} } @article{delPapaHongnPowelletal.2013, author = {del Papa, C. and Hongn, Fernando D. and Powell, J. and Payrola, P. and Do Campo, M. and Strecker, Manfred and Petrinovic, I. and Schmitt, A. K. and Pereyra, R.}, title = {Middle Eocene-Oligocene broken-foreland evolution in the Andean Calchaqui Valley, NW Argentina: insights from stratigraphic, structural and provenance studies}, series = {BASIN RESEARCH}, volume = {25}, journal = {BASIN RESEARCH}, number = {5}, publisher = {WILEY-BLACKWELL}, address = {HOBOKEN}, issn = {0950-091X}, doi = {10.1111/bre.12018}, pages = {574 -- 593}, year = {2013}, abstract = {Two end-member models have been proposed for the Paleogene Andean foreland: a simple W-E migrating foreland model and a broken-foreland model. We present new stratigraphic, sedimentological and structural data from the Paleogene Quebrada de los Colorados (QLC) Formation, in the Eastern Cordillera, with which to test these two different models. Basin-wide unconformities, growthstrata and changes in provenance indicate deposition of the QLC Formation in a tectonically active basin. Both west- and east-vergent structures, rooted in the basement, controlled the deposition and distribution of the QLC Formation from the Middle Eocene to the Early Miocene. The provenance analysis indicates that the main source areas were basement blocks, like the Paleozoic Oire Eruptive Complex, uplifted during Paleogene shortening, and that delimits the eastern boundary of the present-day intraorogenic Puna plateau. A comparison of the QLC sedimentary basin-fill pattern with those of adjacent Paleogene basins in the Puna plateau and in the Santa Barbara System highlights the presence of discrete depozones. These reflect the early compartmentalization of the foreland, rather than a stepwise advance of the deformation front of a thrust belt. The early Tertiary foreland of the southern central Andes is represented by a ca. 250-km-wide area comprising several deformation zones (Arizaro, Macon, Copalayo and Calchaqui) in which doubly vergent or asymmetric structures, rooted in the basement, were generated. Hence, classical foreland model is difficult to apply in this Paleogene basin; and our data and interpretation agree with a broken-foreland model.}, language = {en} }