The Rasario Mining District in south-central Honduras is in the highlands of the rugged San Juancito Mountains. This range consists of a thick section of sediments and volcanics, ranging in age from Upper Triassic to Quaternary, which rests on low-grade metamorphic rocks. It is intruded by plugs and dikes of hypersthene andesites, dacite, and granodiorite. Easterly trending arching, north-south and east-west intrusive trends, and blocks faulting are the dominant structural features.
The extensive, steeply dipping, westerly and northerly trending vein systems, consisting of some 85 veins and splits, have developed largely in the major dacite intrusive body of the district and in the adjacent andesitic tuffs and clastic sediments. The mineralization consists of free gold, sulfides and sulfosalts of silver, and the sulfides of lead, zinc, and copper and related oxidation products. The gangue is largely quartz, rhodonite, carbonates, and country-rock fragments.
The Rosario mines have produced over $93,000,000.00 in silver and gold from some 7,000,000 tons of ore mined since 1883.