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, Oregon office moved from the current site of Galena two miles up Elk Creek to their mine. The new post office was named for a body of galena ore in the area, and the town was renamed as well. The mines were worked extensively in the 1860s and were still active in 1940. Galena, Oregon Galena is an unincorporated community in Grant County, Oregon, United States, about from Austin Junction in the Blue Mountains. It is on the Middle Fork John Day River in the Malheur national forest. The former gold mining camp is considered a ghost town. The locale was