📋 Tender Overview
As part of the program to update the National Geological Chart at 150 000 scale the Geological Mining and Metallurgical Institute Ingemmet carried out the geological mapping of the San Francisco quadrangle located between the departments of Ayacucho and Cusco. A better determination of stratigraphy has been achieved that ranges from the Proterozoic to the recent and two zones are clearly distinguished the Pichari-Cielo Punko anticlinorium with a metamorphic basement of gray-green gneiss quartzitic gneiss with chlorites migmatites and granulites to the northeast of the quadrangle encompassing the valley of the Apurmac river and the axis of the Eastern Cordillera to the southwest whose basement is made of green schists of mica and chlorites greenish-gray phyllites quartz-silty metarenstone outcrops in the Huaytapallana Metamorphic Complex. In the quadrangle the entire sequence of the upper and lower Paleozoic is exposed mainly sedimentary with an upper level volcano-sedimentary exposed in a restricted way in the extreme SW of the quadrangle while only the lower Paleozoic is concentrated to the northeast of the quadrangle. On the other hand intrusive rock outcrops are divided into three major events Carboniferous-Permian intrusions Permo-Triassic intrusions and Cenozoic rhyolites. The study area is not characterized by the presence of important mineralized areas However there is the potential to contain them with the presence of metallotects in the Eastern Cordillera related to metallogenetic bands such as Au in Paleozoic-Proterozoic rocks. In the investigation 808 geological observation points were taken 117 rock samples were collected for petromineralogical and paleontological studies and geochemical analysis a total of 2500 km2 of the 3000 km2 was covered and stratigraphic columns were erected in the study area. The study is part of the bulletin 20 L Geology of the San Francisco Quadrangle sheets 26o1 26o2 26o3 26o4 and is accompanied by four 150 000 scale maps of the San Francisco Quadrangle.
