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, Indiana Galena, Indiana Galena is a census-designated place (CDP) in Floyd County, Indiana, United States. The population was 1,818 at the 2010 census. The CDP includes the town of Galena as well as the nearby town of Floyds Knobs and their immediate surroundings. Galena was originally called Germantown, and under the latter name was platted in 1837. A post office was established as Galena in 1843, and remained in operation until it was discontinued in 1933. Galena is located at (38.350585, -85.940435). According to the United States Census Bureau, the CDP has a total area of , of which is land