La Formación Ayabacas (~Turoniano) es una unidad resedimentada que se observa sobre un área superior a 50000 km2 en el Altiplano y la Cordillera Oriental del sur del Perú (Sempere et al., 2000). Su génesis fue explicada de maneras muy diferentes: fallamiento de bloques y erosión intensa (Heim, 1947), tectónica con pliegues y cabalgamientos (Newell, 1949; Chanove et al., 1969), deformación disarmónica y/o polifásica, fracturación causada por karstificación y/o diapirismo de yesos, intrusiones hipovolcánicas (Audebaud, 1971), caos producido por deslizamientos subaéreos (De Jong, 1974) o submarinos (Audebaud, 1967; Sempere et al., 2000). El estudio en curso soporta esta última interpretación, describiendo la Fm Ayabacas como una megabrecha (u olistostromo), es decir el resultado de deslizamientos submarinos de gran amplitud (Spence and Tucker, 1997). Aunque las interpretacion...

La región de Puno cubre partes del Altiplano peruano y de la Cordillera Occidental, y presenta una estratigrafía original, así como una distribución de unidades estrechamente controlada por la estructura tectónica regional.

Although Andean southern Peru forms the northwestern termination of the Bolivian Orocline, knowledge of its geology has little progressed in the last 20 years, partly due to the civil war that spread in the region during the 1980s and early 1990s. As a consequence, outdated information and concepts are generally still used in current assessments and syntheses, and updated data are needed. This short descriptive contribution presents the principal tectonic elements we currently recognize in southern Peru, and their relationships with syntectonic sedimentary basins. We observe that the most prominent deformational systems in this part of the Bolivian Orocline are dominantly transcurrent, and that many magmatic manifestations are associated with them.

[ENG] Three large transcurrent systems, with related magmatism, are identified in southern Peru. A ∼40-80km-wide, N150-trending, dextral corridor (CECLLA =Cusco-Lagunillas-Laraqueri-Abaroa structural corridor) is characterized by thick Oligocene basic lavas and numerous intrusions. The other two systems are oriented ∼N125-130 and sinistral, and cartographically related to the CECLLA. Miocene to Quaternary basic magmas are associated to the northeastern system (SFUACC = Urcos-Ayaviri-Copacabana-Coniri fault system). In the southwestern region, the abundant Late Cretaceous-Paleocene arc magmatism seems related to the Incapuquio-El Castillo fault system (SFIEC).