Metallurgy in pre-Columbian America

Further information: Metallurgy in pre-Columbian Mesoamerica

Sican tumi, or ceremonial knife, Peru, 850–1500 CE

Metallury 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 centuries. 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.^[1] and North American copper finds dated to approximately 5000 BCE.^[2] 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 the metal 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."^[3] In South America the case is quite different. Indigenous South Americans had full metallurgy with smelting and various metals being purposefully 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 and Bolivia with gold being hammered and shaped into intricate objects, particularly ornaments.^[4] Recent finds date the earliest metal work to 2155 to 1936 BCE.^[5] It was found in the context of a society undergoing social and economic changes but still very much small food producer and not quite sedentary yet. This breaks away from the idea that this type of metal work developed in societies with enough food surplus to support an elite. Rather than being a product of a hierarchical society gold might have been meshed in the creation of it. Further evidence for this type of metal work comes from the sites at Waywaka, Chavin and Kotosh (^[6]), 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 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 (this not to say that some more functional objects were not being produced). It is during the Early horizon that 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 along side 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,^[7] with the ore itself possibly coming from the south Chilean-Bolivian border.

Evidence for fully developed smelting however only appears with the Moche culture (northern coast, 200 BCE—600 CE). The ores were being extracted at shallow deposits in the Andean foothill, 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 artefacts and from ceramic vessels depicting the process, which is believed to have been occurring in adobe brick furnaces with at least 3 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 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.

It is really only with the Incas that metals gain a more utilitarian use. Nonetheless, it remained a material 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). Metal other than gold also had an intrinsic value with the axe pieces being of particular note in this regard. With the spread of metal tools being championed by the Incas it is thought possible that a more Old World use of metals would have become more common. In any case "Bronze can be seen as an expensive substitute for the equally efficient stone."^[8]

Mesoamerica

Mixtec gold pendant representing a snailshell, ca. 900—1520 CE

Main article: Metallurgy in pre-Columbian Mesoamerica

Metallurgy only appears in Mesoamerica in 800 CE with the best evidence from west Mexico. Much like in South American, fine metals were seen as a material for the elite. Metal's special qualities of colour and resonance seemed to have appealed most and then led to the particular technological developments seen in the region.^[9]

Exchange of ideas and goods with peoples from today’s region of Ecuador and Colombia (likely via a maritime route) seems to have fueled early interest and development. Similar metal artefact types are found in West Mexico and the two regions: copper rings, needles and tweezers being fabricated in the same ways as in Ecuador and also found in similar archaeological contexts. There is also a multitude of bells found, but in this case they were cast using the same lost-wax casting method as seen in Colombia.^[10] During this period, copper was being used almost exclusively.

Continual contact kept the flow of ideas from that same region and latter, coinciding with the development of Andean long distance maritime trade, influence from further south seems to have reached the region and lead to a second period (1200-1300 CE to the Spanish arrival).^[11] By this time, copper alloys were being explored by West Mexican metallurgists some because the different mechanical properties were needed to fashion specific artefacts like particularly axe monies - further evidence for contact with the Andean region - but in general developed the new properties such alloys introduced to match their own regional representations - specially wirework bells, which at times had such high tin content in the bronze that it was irrelevant for its mechanical properties, but gave it a golden colour.

The actual artifacts and then techniques were imported from the south, but west Mexican metallurgists worked ores from the abundant local deposits- the metal was not being imported. Even when the technology spread from West into north-eastern, central and southern Mexico, artifacts that can be traced back to West Mexican ores are abundant, if not exclusive. It is not always clear if the metal reached its final destination as an ingot, an ore or a finished artifact. Provenance studies on metal artifacts from southern mesoamerica cast with the lost-wax technique and dissimilar to west Mexican artefacts have shown that there might have been a second point of emergence of metallurgy into mesoamerica there since no known source could be identified.^[12]

The Aztecs did not initially adopt metal working, even if they had acquired metal objects from other people. However, as conquest gained them metal working regions, the technology started to spread. By the time of the Spanish conquest, a blooming bronze smelting technology seemed to be nascent.

North America

Hopewell copper falcon, ca. 200 BCE—1 CE, Ohio^[13]

Archaeological evidence has not revealed metal smelting or alloying of metals by pre-Columbian indigenous peoples north of the Rio Grande River; however, they did use native copper extensively.^[14]

As widely accepted as this statement might be it should not be considered synonymous with a lack of metal objects, as it points out native copper was abundant particular in the Great Lakes region and "overlooks the simple fact that there was really very little to be gained by smelting..."^[15] The latest glacial period had resulted in the scouring of copper bearing rocks. Once the ice retreated, these were readily available for use in a variety of sizes.^[16] Copper was shaped via cold hammering into objects from very early dates (Archaic period in the Great Lakes region: 8000-1000 BCE). There is also evidence of actual mining of copper veins(Old Copper Complex), but disagreement exists as to the dates.^[17]

Unlike their Southern counterparts, North American metallurgy had a more utilitarian purpose from very early on, with losing sight of the prestige attached to the metal artifacts (knifes, fishhooks, bracelets).

Extraction would have been extremely difficult. Hammerstones may have been used to break off pieces small enough to be worked. This labor intensive process might have been eased by building a fire on top of the deposit, then quickly dousing the hot rock with water, creating small cracks. This process could be repeated to create more small cracks.

The copper could then be cold-hammered into shape, which would make it brittle, or hammered and heated in an annealing process to avoid this. The final object would then have to be ground and sharpened using local sandstone. Numerous bars have also been found, possibly indicative of trade for which their shaping into a bar would also serve as proof of quality.

Great Lake artifacts found in the Eastern Woodlands of North America seem to indicate there were widespread trading networks by 1000 BCE. Progressively the usage of copper for tools decreases with more jewellery and adornments being found. This is believed to be indicative of social changes to a more hierarchical society.^[18]

However this Great Lake model as a unique source of copper and of copper technologies remaining somewhat static for over 6000 years has recently come into some level of criticism, particularly since other deposits seem to have been available to ancient North Americans, even if a lot smaller.^[19][20]

See also

• Native copper
• Copper Inuit
• Cape York meteorite

Notes

1. ^ Aldenderfer et al. 2008
2. ^ Beukens, R.P. et al., 1992
3. ^ Martin 1999) pp 136
4. ^ Bruhns 1994
5. ^ Aldenderfer et al. 2008
6. ^ Bruhns 1994
7. ^ Keatinge 1988
8. ^ Bruhns 1994, p. 183
9. ^ Hosler 1988
10. ^ Hosler 1988
11. ^ Hosler 1988
12. ^ Hosler 1999
13. ^ "Falcon-shaped Cut-Out." Ohio Pix. (retrieved 12 July 2011)
14. ^ Geoge Rapp, Jr. et al., pp 26
15. ^ Martin 1999
16. ^ Martin 1999
17. ^ Martin 1999
18. ^ Martin 1999
19. ^ Levine 2007b
20. ^ Levine 2007a

References

• Aldenderfer, M., Craig, N.M., Speakman, R.J. & Popelka-Filcoff, R., 2008. "Four-thousand-year-old gold artifacts from the Lake Titicaca basin, southern Peru." Proceedings of the National Academy of Sciences of the United States of America, 105(13), pp. 5002–5.
• Beukens, R.P., Pavlish, L.A., Hancock, R.G.V., Farquhar, R.M., Wilson, G.C., Julig, P.J.,, 1992, Radiocarbon dating of copper-preserved organics, Radiocarbon, 34, pp. 890–7.
• Bruhns, K.O., 1994, Ancient South America, Cambridge University Press,.
• G. Horz, M.K., 2000, The treasure of gold and silver artifacts from the Royal Tombs of Sipa n, Peru Ð a study on the Moche metalworking techniques, Materials Characterization, 45, pp. 391–420.
• George Rapp Jr, Guy Gibbon & Kenneth Ames Archaeology of Prehistoric Native America: an Encyclopedia, Taylor & Francis, .
• Gordon, R. & Knopf, R, Metallurgy of Bronze used in tools from Machu Picchu, Peru, Archaeometry, 48, pp. 57–76.
• Gordon, R. & Knopf, R., 2007, Late horizon silver, copper, and tin from Machu Picchu, Peru, Journal of Archaeological Science, 34(1), pp. 38–47.
• Hosler, D. & Macfarlane, A., 1996, Copper Sources, Metal Production, and Metals Trade in Late Postclassic Mesoamerica, Science, 273(5283), p. 1819.
• Hosler, D., 1988, Ancient West Mexican Metallurgy: South and Central American Origins and West Mexican Transformations, American Anthropologist, 90(4), pp. 832–55.
• Hosler, D., 1999, Recent insights into the metallurgical technologies of ancient mesoamerica, JOM Journal of the Minerals, Metals and Materials Society, 51(5), pp. 11–4.
• Keatinge, R.W., 1988, Peruvian Prehistory: An Overview of Pre-Inca and Inca Society, Cambridge University Press,.
• La Niece, S. & Meeks, N., 2000, Diversity of goldsmithing traditions in the Americas and the Old World, Precolumbian Gold: Technology, Style and Iconography, British Museum Press, London, pp. 220–39.
• Lechtman, H. & Klein, S., The Production of Copper–Arsenic Alloys (Arsenic Bronze) by Cosmelting: Modern Experiment, Ancient Practic, Journal of Archaeological Science, 26, pp. 497–526.
• Lechtman, H., 1991, The Production of Copper-Arsenic Alloys in the Central Andes: Highland Ores and Coastal Smelters? , Journal of Field Archaeology, 18(1), pp. 43–76.
• Levine, M.A., 2007a, Determining the Provenance of native copper artifacts from Northeastern North America: evidence from instrumental neutron activation analysis, Journal of Archaeological Science, 34(4), pp. 572–87.
• Levine, M.A., 2007b, Overcoming Disciplinary Solitude: The Archaeology and Geology of Native Copper in Eastern North America, Geoarchaeology: An International Journal, 22(1), pp. 49–66.
• Martin, S.R., 1999, Wonderful Power: The Story of Ancient Copper Working in the Lake Superior Basin, Wayne State University Press,.
• Martinón-Torres, M., Rojas, R.V., Cooper, J. & Rehren, T., 2007, Metals, microanalysis and meaning: a study of metal objects excavated from the indigenous cemetery of El Chorro de Maita, Cuba, Journal of Archaeological Science, 34(2), pp. 194–204.
• Mulholland, S.C. & Pulford, M.H., 2007, Trace-Element Analysis of Native Copper: The View From Northern Minnesota, USA, Geoarchaeology: An International Journal, 22(1), pp. 67–84.
• Pero-Sanz, J.A., Asensio, J., Verdeja, J.I., & Sancho, J.P., 1998, Calcolithic Coppers of Peru, Materials Characterisation, 41, pp. 1–9.