2019. Geological and mineralogical characterization of “San José” and “La Arenosa” veins, in Santa Marianita mine of Malvas parish, Zaruma district El Oro province. Revista Científica Ciencias Naturales y Ambientales. 13, 2 (Dec. 2019). DOI:https://doi.org/10.53591/cna.v13i2.1195.