Caracterización geoquímica y petrográfica de la Super Unidad Catahuasi y Unidad Tupe para la evaluación del potencial de exploración de yacimientos tipo pórfido de Cu en el valle de Lunahuaná, Cañete, Lima

Abstract

The study area is located in the Cañete river valley, Yauyos, Lima. The lithogeochemical characterization of the Catahuasi Super Unit and the Tupe Unit was carried out through the use of major and trace elements. Major elements allow rocks to be classified by assigning lithologies, magmatic series and tectonic origin. Trace elements are useful in identifying petrogenetic processes that major elements can´t, despite the presence of alteration in rocks. The petrographic characterization was carried out based on the QAPF diagrams. The samples identified with high Cu values are sample GR50A-19-020 (Cu: 2935 ppm) belonging to the Catahuasi Super Unit and sample GR50A-19-037 (Cu: 999 ppm) belonging to the Tantará Formation. The rare earth elements diagrams indicate a crust enriched in amphiboles (Hydrated). samples GR50A-19-020 and GR50A-19-037 show null or positive Eu anomalies (Hydrated). In the spider diagrams, the characteristic anomalies are from subduction zones and contamination with primitive magmas. The bivariate diagrams show that samples GR50A-19-020 and GR50A-19-037 present greater control of hydration (NbN/TaN and Sc parameters) and volatile content (U/Th parameter) instead of redox state (Parameters Eu/Eu*, Ce/Ce* and V), thermal rejuvenation (Parameters ThN, K/Rb and Ca/Sr) and cortical thickness (Parameters Sr/Y and LaN/YbN), likewise, the sample GR50A- 19-037 is associated with the occurrence of a late porphyry compared to the porphyry associated with sample GR50A-19-020, the two samples are linked to the rise of the Catahuasi Super Unit.