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Metallurgy in pre-Columbian America is the extraction and purification of metals, as well as creating metal alloys and fabrication with metal by Indigenous peoples of the Americas prior to European contact in the late 15th century. Indigenous Americans have been using native metals from ancient times, with recent finds of gold artifacts in the Andean region dated to 2155–1936 BCE. and North American copper finds dated to approximately 5000 BCE. The metal would have been found in nature without need for smelting techniques and shaped into the desired form using heat and cold hammering techniques without chemically altering it by alloying it. To date "no one has found evidence that points to the use of melting, smelting and casting in prehistoric eastern North America." In South America the case is quite different. Indigenous South Americans had full metallurgy with smelting and various metals being purposely alloyed. Metallurgy in Mesoamerica developed from contacts with South America. ==South America== South American metal working seems to have developed in the Andean region of modern Peru, Bolivia, Ecuador, Chile, and Argentina with gold and copper being hammered and shaped into intricate objects, particularly ornaments.〔 Recent finds date the earliest gold work to 2155–1936 BCE.〔 and the earliest copper work to 1432–1132 BCE.〔〔(Boletín del Museo Chileno de Arte Precolombino. Volumen 15, Nº 1, 2010 ) - more articles in Spanish in regard to ancient metalwork from the same period〕 These works originated in the context of a society undergoing social and economic changes but still very much a small food producer and not yet quite sedentary. This contrasts with the idea that this type of metal work developed in societies with enough food surplus to support an élite. Rather than being a product of a hierarchical society, gold might have been meshed in the development of such a society. Further evidence for this type of metal work comes from the sites at Waywaka, Chavín and Kotosh, and it seems to have been spread throughout Andean societies by the Early horizon (1000–200 BCE). Unlike in other metallurgy traditions where metals gain importance due to their widespread use in fields ranging from weaponry to everyday utensils, metals in South America (and later in Central America) were mainly valued as adornments and objects representative of a high status (though some more functional objects might have been produced). During the Early horizon, advancements in metal working result in spectacular and characteristically Andean gold objects made by the joining of smaller metal sheets, and also gold-silver alloy appears. Two traditions seem to have developed alongside each other – one in northern Peru and Ecuador, and another in the Altiplano region of southern Peru, Bolivia and Chile. There is evidence for smelting of copper sulphide in the Altiplano region around the Early horizon. Evidence for this comes from copper slag recovered at several sites, with the ore itself possibly coming from the south Chilean-Bolivian border. Extensive use of "portable" smelting kilns in the vicinity of Puma Punku, Bolivia and at three additional sites in Peru and Bolivia to manufacture, ''in situ'', "I" beams as connectors to large stone blocks during the construction process represent a seemingly anomalous function for metal smelting. The reported chemical analysis of these metal pours is 95.15% copper, 2.05% arsenic, 1.70% nickel, .84% silicon and .26% iron. The estimated date of these pours lies between 8000 BCE–500 CE. Evidence for fully developed smelting, however, only appears with the Moche culture (northern coast, 200 BCE–600 CE). The ores were extracted at shallow deposits in the Andean foothills, whether by specialised workers or slaves/prisoners is unclear. In any case the ores are believed to have been smelted at nearby locations, evidenced in the actual metal artifacts and from ceramic vessels depicting the process, which is believed to have occurred in adobe brick furnaces with at least three blow pipes to provide the air flow needed to reach the high temperatures. The resulting ingots would then have been moved to coastal centres where shaping of the object would occur in specialised workshops. Both of the workshops found and studied were located near the administrative sections of the respective towns – again indicative of the high value placed upon metal. The objects themselves were still mainly adornments, now often being attached to beads. Some functional objects were fashioned but they were elaborately decorated and often found within high-status burial contexts. For this reason, it is believed that they were still being used more for symbolic purposes. The appearance of gold or silver seems to have been important, with a high number of gilded or silvered objects as well as the appearance of Tumbaga, a copper/gold and sometimes also silver alloy. Arsenic bronze 〔 〕 was also being smelted from sulphidic ores, a practice either independently developed or learned from the southern tradition. This technology gradually spread north into Colombia, Panama and Costa Rica, reaching Guatemala and Belize by 800 CE. Only with the Incas did metals really come into more utilitarian use. Nonetheless, they remained materials through which to display wealth and status. The characteristic importance placed on colour, which had led to some of the earlier developments, was still present (sun/moon association with gold/silver). Metals other than gold also had an intrinsic value, with axe pieces being of particular note in this regard. With the spread of metal tools being carried out by the Incas, it is thought possible that a more Old World use of metals would have become more common. In any case, as Bruhns notes, "Bronze can be seen as an expensive substitute for the equally efficient stone".〔p. 183〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Metallurgy in pre-Columbian America」の詳細全文を読む スポンサード リンク
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