Ore genesis accumulation of hematite gravels called "pisolites" which form channel-iron deposits. These are preferred because they are cheap to mine. Lead-zinc deposits are generally accompanied by silver, hosted within the lead sulfide mineral galena or within the zinc sulfide mineral sphalerite. Lead and zinc deposits are formed by discharge of deep sedimentary brine onto the sea floor (termed "sedimentary exhalative" or SEDEX), or by replacement of limestone, in skarn deposits, some associated with submarine volcanoes (called volcanogenic massive sulfide ore deposits or VMS), or in the aureole of subvolcanic intrusions of granite. The vast majority of SEDEX lead and zinc deposits
Galena, South Dakota A Bear Butte Creek runs beside the town, which is located in a meadow in the middle of a gulch. Galena, South Dakota Galena (also Galena City) is an unincorporated community in Lawrence County, South Dakota, United States. It is often considered to be a ghost town, even though a few families still live in the area. It is not tracked by the U.S. Census Bureau. The town was named after the galena found in the ore in the surrounding mines. In 1875, gold was discovered in the Black Hills and drew settlers to the area. The mines in the