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, Illinois city was $24,117. About 5.9% of families and 7.9% of the population were below the poverty line, including 13.8% of those under age 18 and 7.0% of those age 65 or over. Galena is a popular tourist destination hosting well over one million visitors each year. Galena is also popular with Chicagoans, many of whom keep second homes in the area. 85 percent of the structures in Galena are within the Galena Historic District, which is listed on the National Register of Historic Places and greatly contributes to the city's popularity. The Old Market House State Historic Site, built in