Sedimentación sintectónica en la base del Grupo Payogastilla (¿Paleógeno?-Neógeno), Valle Calchaquí norte, Salta

HONGN, F.; DEL PAPA, C.E; PETRINOVIC, I.; MON, R.; POWEL, J

Revista de la Asciación Geológica Argentina

Año: 2006 vol. 6 p. 84 - 90

0004-4822

ABSTRACT. Syntectonic sedimentation in the base of Payogatilla Group (Paleogene?-Neogene), north Calchaquí Valley, Salta. The Salta (Cretaceous-Eocene) and Payogastilla (Paleogene?-Neogene) Groups include respectively successions filling basins related to the Mesozoic rifting and the Andean shortening. This change in the tectonic conditions means that both stratigraphic discontinuities and angular discordances should be present in between. Previous works have addressed the stratigraphic discontinuities but it is worth considering the scarce evidences for angular discordances. This paper shows angular discordance between both Groups as well syntectonic sedimentation in the basal levels of the Payogastilla Group (Quebrada de los Colorados Formation) in the northern portion of the Calchaquí Valley. The lower section of the Quebrada de los Colorados Formation preserves both progressive and angular syntectonic discordances related to fault-related folds whose geometry suggests a tectonic transport from east-northeast for the main deformation. The age of deformation is unknown. Correlations with sections exposed in the south portion of the Calchaquí Valley indicate that the growth structures occurred before 13 Ma. The initial successions of the foreland basin in south Puna (Geste Formation) and eastern border of north Puna (Casa Grande Formation) contain vertebrate fossils of Eocene-Oligocene age. If it were the age of the Quebrada de los Colorados Formation, the angular discordance separating it from Salta Group and the growth strata in its lower part would mark the start of the foreland basins in the Paleogene in the Puna-Cordillera Oriental transition south of 24ºS. Salta (Cretaceous-Eocene) and Payogastilla (Paleogene?-Neogene) Groups include respectively successions filling basins related to the Mesozoic rifting and the Andean shortening. This change in the tectonic conditions means that both stratigraphic discontinuities and angular discordances should be present in between. Previous works have addressed the stratigraphic discontinuities but it is worth considering the scarce evidences for angular discordances. This paper shows angular discordance between both Groups as well syntectonic sedimentation in the basal levels of the Payogastilla Group (Quebrada de los Colorados Formation) in the northern portion of the Calchaquí Valley. The lower section of the Quebrada de los Colorados Formation preserves both progressive and angular syntectonic discordances related to fault-related folds whose geometry suggests a tectonic transport from east-northeast for the main deformation. The age of deformation is unknown. Correlations with sections exposed in the south portion of the Calchaquí Valley indicate that the growth structures occurred before 13 Ma. The initial successions of the foreland basin in south Puna (Geste Formation) and eastern border of north Puna (Casa Grande Formation) contain vertebrate fossils of Eocene-Oligocene age. If it were the age of the Quebrada de los Colorados Formation, the angular discordance separating it from Salta Group and the growth strata in its lower part would mark the start of the foreland basins in the Paleogene in the Puna-Cordillera Oriental transition south of 24ºS. Salta (Cretaceous-Eocene) and Payogastilla (Paleogene?-Neogene) Groups include respectively successions filling basins related to the Mesozoic rifting and the Andean shortening. This change in the tectonic conditions means that both stratigraphic discontinuities and angular discordances should be present in between. Previous works have addressed the stratigraphic discontinuities but it is worth considering the scarce evidences for angular discordances. This paper shows angular discordance between both Groups as well syntectonic sedimentation in the basal levels of the Payogastilla Group (Quebrada de los Colorados Formation) in the northern portion of the Calchaquí Valley. The lower section of the Quebrada de los Colorados Formation preserves both progressive and angular syntectonic discordances related to fault-related folds whose geometry suggests a tectonic transport from east-northeast for the main deformation. The age of deformation is unknown. Correlations with sections exposed in the south portion of the Calchaquí Valley indicate that the growth structures occurred before 13 Ma. The initial successions of the foreland basin in south Puna (Geste Formation) and eastern border of north Puna (Casa Grande Formation) contain vertebrate fossils of Eocene-Oligocene age. If it were the age of the Quebrada de los Colorados Formation, the angular discordance separating it from Salta Group and the growth strata in its lower part would mark the start of the foreland basins in the Paleogene in the Puna-Cordillera Oriental transition south of 24ºS. Salta (Cretaceous-Eocene) and Payogastilla (Paleogene?-Neogene) Groups include respectively successions filling basins related to the Mesozoic rifting and the Andean shortening. This change in the tectonic conditions means that both stratigraphic discontinuities and angular discordances should be present in between. Previous works have addressed the stratigraphic discontinuities but it is worth considering the scarce evidences for angular discordances. This paper shows angular discordance between both Groups as well syntectonic sedimentation in the basal levels of the Payogastilla Group (Quebrada de los Colorados Formation) in the northern portion of the Calchaquí Valley. The lower section of the Quebrada de los Colorados Formation preserves both progressive and angular syntectonic discordances related to fault-related folds whose geometry suggests a tectonic transport from east-northeast for the main deformation. The age of deformation is unknown. Correlations with sections exposed in the south portion of the Calchaquí Valley indicate that the growth structures occurred before 13 Ma. The initial successions of the foreland basin in south Puna (Geste Formation) and eastern border of north Puna (Casa Grande Formation) contain vertebrate fossils of Eocene-Oligocene age. If it were the age of the Quebrada de los Colorados Formation, the angular discordance separating it from Salta Group and the growth strata in its lower part would mark the start of the foreland basins in the Paleogene in the Puna-Cordillera Oriental transition south of 24ºS. Salta (Cretaceous-Eocene) and Payogastilla (Paleogene?-Neogene) Groups include respectively successions filling basins related to the Mesozoic rifting and the Andean shortening. This change in the tectonic conditions means that both stratigraphic discontinuities and angular discordances should be present in between. Previous works have addressed the stratigraphic discontinuities but it is worth considering the scarce evidences for angular discordances. This paper shows angular discordance between both Groups as well syntectonic sedimentation in the basal levels of the Payogastilla Group (Quebrada de los Colorados Formation) in the northern portion of the Calchaquí Valley. The lower section of the Quebrada de los Colorados Formation preserves both progressive and angular syntectonic discordances related to fault-related folds whose geometry suggests a tectonic transport from east-northeast for the main deformation. The age of deformation is unknown. Correlations with sections exposed in the south portion of the Calchaquí Valley indicate that the growth structures occurred before 13 Ma. The initial successions of the foreland basin in south Puna (Geste Formation) and eastern border of north Puna (Casa Grande Formation) contain vertebrate fossils of Eocene-Oligocene age. If it were the age of the Quebrada de los Colorados Formation, the angular discordance separating it from Salta Group and the growth strata in its lower part would mark the start of the foreland basins in the Paleogene in the Puna-Cordillera Oriental transition south of 24ºS. Salta (Cretaceous-Eocene) and Payogastilla (Paleogene?-Neogene) Groups include respectively successions filling basins related to the Mesozoic rifting and the Andean shortening. This change in the tectonic conditions means that both stratigraphic discontinuities and angular discordances should be present in between. Previous works have addressed the stratigraphic discontinuities but it is worth considering the scarce evidences for angular discordances. This paper shows angular discordance between both Groups as well syntectonic sedimentation in the basal levels of the Payogastilla Group (Quebrada de los Colorados Formation) in the northern portion of the Calchaquí Valley. The lower section of the Quebrada de los Colorados Formation preserves both progressive and angular syntectonic discordances related to fault-related folds whose geometry suggests a tectonic transport from east-northeast for the main deformation. The age of deformation is unknown. Correlations with sections exposed in the south portion of the Calchaquí Valley indicate that the growth structures occurred before 13 Ma. The initial successions of the foreland basin in south Puna (Geste Formation) and eastern border of north Puna (Casa Grande Formation) contain vertebrate fossils of Eocene-Oligocene age. If it were the age of the Quebrada de los Colorados Formation, the angular discordance separating it from Salta Group and the growth strata in its lower part would mark the start of the foreland basins in the Paleogene in the Puna-Cordillera Oriental transition south of 24ºS. Syntectonic sedimentation in the base of Payogatilla Group (Paleogene?-Neogene), north Calchaquí Valley, Salta. The Salta (Cretaceous-Eocene) and Payogastilla (Paleogene?-Neogene) Groups include respectively successions filling basins related to the Mesozoic rifting and the Andean shortening. This change in the tectonic conditions means that both stratigraphic discontinuities and angular discordances should be present in between. Previous works have addressed the stratigraphic discontinuities but it is worth considering the scarce evidences for angular discordances. This paper shows angular discordance between both Groups as well syntectonic sedimentation in the basal levels of the Payogastilla Group (Quebrada de los Colorados Formation) in the northern portion of the Calchaquí Valley. The lower section of the Quebrada de los Colorados Formation preserves both progressive and angular syntectonic discordances related to fault-related folds whose geometry suggests a tectonic transport from east-northeast for the main deformation. The age of deformation is unknown. Correlations with sections exposed in the south portion of the Calchaquí Valley indicate that the growth structures occurred before 13 Ma. The initial successions of the foreland basin in south Puna (Geste Formation) and eastern border of north Puna (Casa Grande Formation) contain vertebrate fossils of Eocene-Oligocene age. If it were the age of the Quebrada de los Colorados Formation, the angular discordance separating it from Salta Group and the growth strata in its lower part would mark the start of the foreland basins in the Paleogene in the Puna-Cordillera Oriental transition south of 24ºS.