The deposit is composed of numerous fissure-filling quartz veins contained within Precambrian granitic gneiss adjacent to a contact with a granitic stock of Mesozoic age. delta 34 S values of 2.4 to 4.4 per mil suggest that the source of sulfur was igneous. Carbon and oxygen isotopic analyses suggest that the hydrothermal system was dominated by meteoric fluids at temperatures below 240 degrees C. Mineralizing fluids ranged from 2.6 to 14.4 equivalent weight percent NaCl. Color zoning in large scheelite crystals. Hydrothermal tungsten deposits in Korea are genetically related to shallow granitic volcanism of Cretaceous age.--Modified journal abstract.