Regional mapping (1:50,000) and U-Pb and K-Ar geochronology in the El Indio region refines the knowledge of the distribution, lithostratigraphy, and age of the sedimentary, volcanic, and intrusive rocks that comprise the regionally extensive Pastos Blancos Group which is equivalent to the Choiyoi Group of the Argentine Frontal Cordillera. The Pastos Blancos Group (which we elevate to Group status herein) includes at least two diachronous volcanic-sedimentary sequences: an older felsic volcanic and volcaniclastic unit, the Guanaco Sonso sequence, that is Permian in age, and a younger bimodal volcanic and volcaniclastic unit, the Los Tilos sequence that is Middle Triassic to Early Jurassic. Sedimentary rocks of the Los Tilos sequence are transitional upward into the overlying Early to Middle Jurassic shallow marine limestones of the Lautaro Formation.Intrusions that make up the regionally extensive Permian to Early Jurassic plutons of the Chollay and Elqui-Limar batholiths that were previously mapped as a single plutonic association, the Ingaguas Complex, include in the El Indio region at least three discrete intrusive units. These include: Early Permian (280-270 Ma) biotite granites, Early to Middle Triassic (242-238 Ma) silica-rich leucocratic granites and rhyolitic porphyries that made up the bulk of the Chollay Batholith, and a younger Late Triassic-Early Jurassic unit (221-200 Ma) of mainly intrusive rhyolitic porphyries, extrusive domes, and subordinate mafic intrusions and both felsic and mafic dikes, which are coeval with volcanic rocks of the Los Tilos sequence.Our data show that latest Paleozoic to Early Jurassic intrusive, volcanic, and sedimentary rocks in the El Indio region of the High Andes of Chile between 29-30 o S likely formed during extension driven processes after the cessation of Carboniferous-Early Permian subduction along the western edge of Gondwana. These processes began by Late Permian time, but instead of recording a single and protracted magmatic event, as has been previously suggested, rocks that belong to the Pastos Blancos Group and the Ingaguas Intrusive Complex record at least three discrete periods of silicic to bimodal magmatism which occurred during the Middle Permian to Early Jurassic interval.Nuevos antecedentes geologicos (mapeo regional a escala 1:50.000) y geocronologicos (U-Pb y K-Ar) de la zona de El Indio, en los Andes des centro-norte de Chile, han permitido mejorar el conocimiento de la distribucion, litoestratigrafa y edad de las rocas sedimentarias, volcanicas e intrusivas que conforman el Grupo Pastos Blancos, equivalente al Grupo Choiyoi de la Cordillera Frontal argentina. El Grupo Pastos Blancos, elevado al status de Grupo en este trabajo incluye, al menos, dos secuencias volcano-sedimentarias diacronicas: una unidad volcanica y volcanoclastica permica (secuencia Guanaco Sonso), y una unidad volcanica bimodal y volcanoclastica del Triasico Medio a Jurasico Inferior (secuencia Los Tilos), la que pasa transicionalmente a calizas marinas someras de la sobreyacente Formacion Lautaro del Jurasico Inferior a Medio.Junto con ello, se ha reconocido, al menos, tres distintas unidades intrusivas en plutones del Permico a Jurasico Inferior de los batolitos Chollay y Elqu-Limar, previamente incluidos dentro del Complejo Ingaguas. Estas incluyen: granitos de biotita del Permico Inferior (280-270 Ma), granitos leucocraticos silceos y porfidos riolticos del Triasico Inferior a Medio (242-238 Ma) que forman gran parte del Batolito Chollay, y una unidad mas joven del Triasico Superior-Jurasico Inferior (221-200 Ma) constituida por porfidos riolticos, domos riolticos intrusivos maficos subordinados y diques felsicos y maficos, equivalentes subvolcanicos de las rocas extrusivas de la secuencia Los Tilos.Estos datos demuestran que las rocas intrusivas, volcanicas y sedimentarias del Paleozoico Superior-Jurasico Inferior de la zona de El Indio en los Andes de Chile entre los 29-30 o S se formaron a raz de fenomenos de extension posteriores al cese de la subduccion a lo largo del borde occidental de Gondwana en el Carbonfero-Permico Inferior. Estos comenzaron en el Permico Superior, pero en lugar de generar un unico y prolongado evento magmatico, como haba sido sugerido previamente, las rocas del Grupo Pastos Blancos y del Complejo Intrusivo Ingaguas revelan, al menos, tres distintos perodos de magmatismo silceo a bimodal ocurridos entre el Permico Medio y el Jurasico Inferior.