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, Alaska The City of Galena is incorporated as a first-class city, governed by a city council. The city's mayor is Jon Korta. The Louden Tribal Council is elected to represent the local Athabascan Native community. The council's tribal chief is Jenny Pelkola. The City of Galena operated a full-time police department. There is an Alaska State Troopers post in Galena with two troopers and a trooper-pilot. Galena has a volunteer Rescue Squad composed of Alaska Emergency Trauma Technicians (ETT) and Emergency Medical Technicians (EMT), and a volunteer fire department which recently received new advanced firefighting apparatus from the U.S. Air Force