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
Mineral industry of Peru privatization process in the minerals sector and FDI in every sector of the Peruvian economy, particularly in the banking and energy industries are expected to continue to generate additional investments. Higher demand for copper, gold, iron ore, and silver and high metal prices are likely to encourage mining companies to invest in expanding and modernizing their operations. The liquefaction of Camisea's natural gas for export to China, MERCOSUR, North American Free Trade Agreement (NAFTA), and other trading partners is expected to increase Peru's mineral exports further. The transportation phase of Camisea's pipelines for natural gas (714 km) and for natural