Metallurgical Control And Social Power. The Bronze Age Communities Of High Guadalquivir (Spain)

METALLURGICAL CONTROL AND SOCIAL POWER. THE BRONZE AGE COMMUNITIES OF IDGH GUADALQUIVIR (SPAIN) Auxilio MORENO ONORATO*, Francisco CONTRERAS CORTÉS', Juan Antonio CÁMARA SERRANOY José Luis SIMÓN GARCÍA'- -Departamento de Prehistoria y Arqueología. Universidad de Granada (Espaila) .- Departamento de Prehistoria y Arqueología. Universidad de Alicante (España) ABSTRACT This research project is centered on lbe archaeometallurgic process lbat was developed by Bronze Age communities in tbe High Guadalquivir (Spain). Copper, bronze and silver mining and metallurgic transformations constitute one of tbe bases of tbe historie develapment of tbese communities.· Such activity implies tbe use of more complex technologies and lbe control of tbe distribution of tbese new products by tbe aristoeratic groups. The fieldwork carried out in lbe site of Peilalosa (Bailos de la Encina, provinee of Jaen, Spain) has produced a great deal of archaeologieal n';mains showing tbe complexity of tbe metallurgical process in Recent Prehistory. Excavations at Peilalosa have allowed us to carry out archaeometaJlurgical research in relation to: 1. The sequence ofmelallurgical aetivity. 2. The ascription ofthis activity and its different phases to different vilJage areas. 3. Use of different stone raw materials to creale lbe necessary tools for lbe metallurgical process and differenl minerals (malachile, azurile, galena, etc.) to be fused. 4. General aecess to metallurgieal pracesses (found in al! tbe dwellings) and tbeir praduels (presenl in a great number of tombs, especially in relation to daggers and swords). 5. Differenees in tbe size of tbe weapons located in tbe differenl lombs. 6. Restricted access to non-copper minerals and, overall, lo items made witb preciaus metals. KEYWORDS Bronze Age, High Guadalquivir, ArchaeometaJlurgical, Mining, Social Hierarchization INTRODUCTlON AND GOALS This study is par! of two Research Projects: Archeometallurgical Project: Bronze Age Communities 01 the High Guadalquivir (BHA2000-1512), funded by tbe Ministry of Seience and Teehnology, and tbe Peñalosa Projecl, funded by tbe Ministry of Culture of !he Autonomaus Cammunity of Andalusía. The data were obtained fram tbe excavation of tbe last stratigraphieal phases (1800-1500 cal BC) oftbe Peñalosa site (Baños de la Encina, Jaén) (Contreras & Cámara, 2002). The goals are: 1. To determine how tbe cornmunities of lhe mining areas of tbe High Guadalquivir functianed and evolved during tbe second. millennium B.C., by analyzing ecanomie produetion and its dominant sector, metallurgical productian. 625 2. To evaluate some proposed hypotheses on tbe evolution of pIehistoric socielies based upon tbree aspects: metalluIgy as support and justification for social hierarchization, the role of contacls in social change and tbe ideologieal factor in tbe development of social inequality. In this study, we are Fig. 1. Peñalosa site concerned only wifu tbe metallurgical factor as a driving force behind social change. METHODOLOGY The fmt step was macros copie descriplion and determination,. using a binocular magnifying glass, of aU tbe elemenls related to metallurgical activity. Bas ed upon this analysis, we selecled samples for microscopic study. The nexl step was the application of a series of analyses according lo fue different remains involved in eaeh of the metallurgieal phases, sueh as XRF, AAS, SEM and lead isotope testing. PRELIMINARY ANALYTICAL RESULTS Peñalosa, on fue eastem edge of Sierra Morena (Andalusia), Jies in !he middle of a broad territory witb numerous polymetallic sites. Its most eommon mineralizations are lead, argentiferous lead and copper, with the site's greatest concentration being of copper in the form of sulfides, especiaUy easily exploitable pyrites and carbonates.' Archaeologieal survey has shown a strong concentration of settlemenls with metallurgical activity across a wide belt running in a longitudinal direction along the Rumblar river (Contreras & Cámara, 2002). The minerals exploited were mainly oxides (cuprite, tenorite) and eopper sulfides (ehalcopyrite) in eomplex paragenesis with otber sulfides, in !he case of pyrite, or with galena. As detailed below, in Peñalosa arehaeometaUurgieal samples have been galhered !hat represent eaeh of fue phases of fue metaUurgical proeess, from extraction of tbe mineral to tbe final manufactured product, passing tbrough roasting and reducing (depending on !he material being trealed) and smelting. In the area ofthe settlement, cupriferous minerals generally appear in very small fragments, at times grouped together in relatively abundant quantities and having similar size. Minerals have also been found in the process of transformation, where a heat source was used to ready fuem for tbe fusion proeess. lt is difficult at this time to explain the abundant presenee oflead (galena), both in and near 626 .....----- --- -- - _ .- - - tbe domestic areas, botb because of tbe charaeteristics of tbe remains analyzed and because we have little evidence regarding tbeir use and, further, they have not yet been sufficiently studied. This is tbe case witb tbe crucible fragments witb interior pieces of slag of a whitish color. However, it would be strange to have such a quantity of stored galena if it were not used for metallurgical tash. There are remains of galena witb tbe green coloring corresponding to their cupriferous content, although we do not know what was gained from tbese associations. We do know that there are plenty of lead Fig. 2. Galena storage room seams wilb important quantities of copper in the region we are studying. In light of the existence of objects made of silver, it is conceivable to think Ibat the galeoa was used to extraet silver, but there are 00 clear indicatioos tha! the Pedalosa metallurgists were familiar with tbe process of cupelatioo. It may be!hat tbe galeoa was used to smelt tbe copper (Moreno, 2000). Four types of slag were reeovered from tbe site: 1.- Slags oí a globular shape, brilliant black or flat dark gray, with metallic copper inclusions. There are secoodary products made of copper in their interior. Z.- Tree-shaped slaga, not as compact as those aboye, black in color, witb cavities rangiog from elongated to elliptic aod numerous gases, witb a large oumber oí impurlties (graios oí quartz and otber mineral s, small pieces of carboo, remains of sediment and some green remains, tbe product oí tbe oxidization of tbe copper). They are lighter Iban Ibose in the fust group and tbere are residual remains of smelting inside. In some cases, tbey have dark brown inclusions possibly due to their iron conten!. 3.- Tree-shaped slags, whitish-yellowish, no! very heavy and wilb few inclusions of olber mineral compounds. Their shape !ends to be fluid witb a fair number of sponge-type eavities. This type has not yet been analyzed. 4. -Slags found on the interior wall of a few fragments of flat crueibles tbat are off -white, compact and globular. Their points ofbreakage bave a bright dark gray color. The analytical results of tbe study of Ibe slags indicate tbat Ibe majority belong to Ibe smelting process. 1t is likely !hat Ibe reduction was performed away from tbe domestic area of the settlement, which is why hardly any slags related 10 this fus! step in tbe process have appeared. Most oí tbe slags analyzed are !he result of the Irealment of both sulfides (chalcopyrite, chalcosine) and copper carbonates (malachite) 'and oxides (cuprite and tenorite). With the carbonates, a roasting temperature of 600-700 oC transforms malachíte into copper oxide, releasing COl, wbile if copper oxides are used, the temperature must be higher, around 900 oC. Here, reduction to metallic copper is produced because of the presence of carbon monoxide (created in the combustion of the carbon added in a low oxygen environment). 627 The metallurgy of iron sulfides consists of roasting fue ores io a highly oxygenated environmeot to eliminale fue sulfur, which gives rise to fue fonnation of copper oxide wifu an abWldant release of sulfurous anhydrate. Tbe temperalure in fue fust stage mus! be rela tiv ely low, around 600 oc so fua! the copper oxide fuat is formed wil! laler react wifu more copper sulfur 10 cre a!e metallic copper with Ihe release of sulfurous anhydrate. During fue reduction of fue oxide, fue !emperalure io !he oven mus! be 900 oC or slightly higher. The entire process would produce a low yield, wifu part of fue copper being lost in fue matle, particularly in !he case ofusing eomplex ores witb arsenic and antimooy, so fual fue copper standard in Ibis copper malles was usuaJly rafuer high allhough it was oot always recovered. Finally, we mus! bear in mind lbal fue arsenic detected in sorne of tbe mineral sarnp1es is eonsistent witb tbe production of arsenica! eopper, alfuough more data is oeeded to support this relationship scieotifically. Production of Ihis type during tbe Chalcolithic has beeo wide ly debated, rejectiog oc aecepting it based 00 tbe differential presenee of arsenic in fue instruments produced, although fuis should imply more fuan fue addition of arsenic in itself, fue choice of copper minerals rieh in arsenic, or perhaps, fueir being alloyed wifu ofuer metals in fue same smelting (Moreno, 1993). The ceramie elements present in fue metallurgieal process at Pefialosa have been typologically divided into four morphometrie groups: flat erueibles, deep crucibles (vessel oveos), moulds and circular pieees. To fuese we must add p os sible fragments of oven wall and sorne pieces fuat can be eonsidered nozzles. The first furee typological groups have been sampled and examined wifu a binocular magnifying glass to obtaio a reliable eharacterization of fuem. Fil!. 3. Sherds of a vessel oven The analysis of fue slag from one of fue flat crucibles indieates fu~ presenee oí arsenic and copper, whieh implies fueir use in tbe smelting of arsenieal copper just as we have " , • documented wifu some oí fue metallie " .' ' .. , ' pieces analyzed. Generally, fuey are , " ',' highly vitrified ceramics wifu wide ,," " .. - pores fua! have borne high temperatures, above 11 00 o C. Sorne flal crucibJes have compact, offwhite intemal slags !hat sometimes contain some copper inclusion. Until we have fue analytieal series, it does not seem hasty to indicate fuat fuese are crucibles Ihal contaio lead as a principal componen!. Fil!. 4. Flal crucibles lnside !he deep crucibles, !here are residual remains of vitrification wifu an irregular whitish-yellowish-greenish color 00 fue surfa ce , and there is praclically none conserving any real melallie slag. This suggesls for 628 now the possibility of lhe crucibles having been coated with a type of insulation to make it easier to loosen lhe resulting slag mass. They were frred from inside (vessel ovens). Anolher peculiarity wilh this type of fragment is !hat lhey show remains of lhe slag on lhe fracture even when lhe interior part has none. This suggests !hat lhey are broken inrrnediately upon fmishing lhe process. The qualitative analysis carried out on a srunple from !he bottom of a deep crucible wilh a relatively abundant layer of slag reveals sorne runple copper and arsenic contents and a lesser quantity of tin and lead on !he inner surfaee near tbe bóttom of lhe crucible. The sample is overall very heterogeneous, but the data from lhe analysis may indicate lhat lhis crucible was used to smelt lrue bronze (wilh tin), altbough new analyses must be performed. The archaeological register shows many ceramic moulds. They have a trapezoidal forro, flat bottom and straight walls and trapezoidal ingots were obtained from tbem. They are dark brown in color and have remains of an off-white, grayish color on lheir inner surface, a type of smoking. This would be a substance applied to make it easier to extract lhe ingots. Fig. 5. Ceramic ingot moulds Fig. 6. Sandstone moulds The stone chosen for lhe manufacture of the moulds in tbe Peñalosa register is generally sandstone. Found in lhe area around tbe settlement, it is easily worked and makes it possible to obtain smooth and homogenous surfaces. The surfaces are reddish in color. Allhough lhe majority of tbe moulds are univalve, it is likely Ihat bivalve moulds eKÍsted. In one case, a two-hoop mould, it is possible to see tbat tbere were feeding canals or grooves to stabilize tapping and to release tbe gasses. Regarding Ihe implements. we have found punch tools and awls, chisels, daggers, arrowheads and ingots in domestic contexts, while weapons and adornments are almost exc1usively found in funerary contexls. Two of lhe ingots were analyzed based upon with Iheir composition in lead isotopes and Ihey display what seeros likely lo be a different geographical origin. One of Ihem had alead isotope composition unique among the mineral ores and artifacts in lhe srunples Ihat have been analyzed in !he Iberian Peninsula lo lhis point. The olher, on Ihe otber hand, had alead isolope composition Ihat is characteristic of tbe ores of soulhwestem Spain, included in lhe same orographic unit as Peñalosa (Sierra Morena) bul very distant, allhough none shows Ihe same combination (Moreno, 2000). In Tomb 7 four silver bracelels have appeared along wilh a dagger wilh two rivets and a punch tool. The AAS analysis of one of Ihe bracelets shows a high silver content and smal! indications of eopper and lead, bul no tino 629 The on1y gold object is an earring from a funeraly offering, associated with a child. It is very s mal! and is made of a string o~ gold with a semicircular section, wilh overlapping end s. ; - '. ' " .. There is an important contradietion between tbe high number ofaxe moulds and tbe absence ofaxes in domestic and funerary contexts. In tbe first case, it can be argued that tbe inhabitants of tbe settlement took Ibe axes witb tbem when Ibey abandoned Ibe Fig. 7. Metallie grave goods from tomb 7 settlemeo!. But this does not solve !he problem of their absence in lhe tombs. Perhaps !hey were distributed among olber settlements or swords were used as substitutes in the offerings of high prestige. In any case, the preliminary results of the analysis of the pieces indicates !hat lhe majority of!he artifaets analyzed were made of arsenical copper, typologically and technologically characteristie of the Full Bronze Age. The arsenic content of these alloys is generalIy between 3-4%, suffieient to produce a more durable aUoy!han pure copper iflhe metal was worked correctly. One of the dagger blades had a significantly higher quantity of arsenie lhan its associated rivet, which lhe analytical results of similar pieces has established as normal (Harrison & Craddock, 1981). This tends to show that lhe metaUurgists knew how to reeognize alloys of different degrees of hardoess and used !he harder metal to make !he blade. However, and contrary .... " .. ,. . . . . ' .. '. .. to this , the rivet analyzed ~. , ~': .. ": ,, :v-:¿ .~>;. ",. J ~ ' ~ '. ", ," ~;~ ~ .~. r~~~:~~::~:allb;~ . :' ~;:0;t r' , ,: eorresponding blade. .:: :;e .. ;: ~ ; ~ Generally speaking, the eontents of trace elements of arsenica! copper are low, which is also eommon in olher metal!urgieal ana1yses of tbe Bronze Age in lhe lberian Peninsula (Hook el al., 1990). This, combined wilb tbe low iron content, could indicate that al tbis site lhe process of reduction was not very complex and was earried out using relatively low temperatures and witb little production of slag. :. :' > ~ -: f· ~}' · :;~F~· , ~ - ', ,- , :,'0, " . ' .. ; ... : .:., .' .'- ;. ',; .. ,'~. '. '': ,. ' . :' .. .... -.-. , ;' ¡ : '~ .. ~ .. . , .;> ' Fig. 8. Swords and daggers 630 .. ' ~(~ \ ' ll ··; ~ '- . '. : " . , ~ . ' o·.;' • ':. SPACIAL RESULTS The distribution of archaeometallurgical materials in the Peñalosa settlement indicates that metallurgy is present in almost all of the spaces, although the proportion varies widely, with most of the items, except implements, concentrated in or near open spaces. These open spaces either form authentic workshops or are small open patios in the interiors of the dwellings. le n CEMl<11C ~l)LDS I ~t'l l\ L 01IJK C7S n l"M (l fll<J.lO$ .. I'OUstlrcllSTO/i1::'l :;¡ I'IA T otll l' U¡¡ ..f5 lI. COrrli,kílkE' u I) U l'l:lt 1! CJlIL~S IJ LllAf)OlUl .0 MI I' m<ilLU,I!tI[ !t."" OGKIM)Cifi llm:'<f-,1 • STOHl,MOUtOS Fig. 9. Archaeometallurgical items from the Structural Group 1 It is in these spaces that the activities of smelting/refinement took place, as documented especially by the remains of heated mineml, smelting drops, metallic remains and even fine layers of slag adhered to sorne of the clay platforrns and/or the soi! itself and the slags. Next to many of these spaces, in the areas giving access to them, we have identified fragments of oven vessels brought to the settlement from nearby places to be smelted in this area. The pouring into the moulds also seeros to have been spatially separated from the smelting activities, although the majority of the moulds -both ceramic and of sandstone -are located in spaces very close to the spaces deseribed above. The greatest concentrations of oven vessels appear in the oldest levels of the outside areas of the settlement. Numerous crucibles related to smelting have been documented in this old phase in the interior ofthe settlement. With respect lo the distribution of the artifacts found in living quarters, they are present in all the rooms, both those related to metallurgy and those where subsistence activities predominated. \. CONCLUSIONS. DIFFERENT FORMS OF CONTROL AND APPROPRIATION OFMETAL During the Chaleolitbic, both in the High Guadalquivir and in the Southeastern lberian Peninsula, there was relative specialization oC activities among the different settiements, with documentation of the following: mines intended solely for the extraction of raw material, whether metallic minemls (Alearaz el al., 1994) or other types of rocks and 631 minerals (Carrión el al., 1993), settlements near fue mines where some or all phases of Ihe metallurgical process were carried out, distribution settlements and central settlements, far from Ihe searos of ore in most cases, where metallurgical activity has also been documented, like Los Millares (Santa Fe de Mondújar, Almena) (Arribas el al., 1987). Ibis structuring of fue population into settlements wifu some being intended for extraction of raw material and sorne for metallurgical transformalion implies, fust, fue circulation ofraw materials from mines lo certain political centers or dependent transformation centers and, second, control from fue large settlements of fue transformalion of the metal and its distribution. During the Bronze Age, the process became more complicated in bofu areas. In the High Guadalquivir, !he hierarchical centers controlled!he movement oflhe finished products and established secondary centers, true colonies, !hat controlled !he mineral coming from the mine and conveI:led it into metal (ingot and objects) (Contreras & Cámara, 2002) . Vb ~ . Ve • • :;(,; EMMK:!MOOlOSl /o.n!.TAL C)RJu.~ -; CRUCIRl.FJ¡ • 'EAII;R.JNGCi 'FL,T<ltUCI81.l$ .\ corPtltOJt.E m:I-JlCk lJ CUlU :S 1> t.EADQRE d"llNIK:O 11A1I.fM F. R:"i ' c:;A 1 NIHNIj SfOHfS .S1t) :' m MOVl.Il5 ~ POllSlII:D STONI!S . , ...... .. ,. ¡ • I I :: I V. Fig. 10. Archaeometallnrgical items from fue Structural Group V 632 In the Southeast, il has been sug¡¡ested that there was a more eomplex system where seeondary settlements like Fnente A1amo (Cuevas de A1manzora, Almeria) did nol perform all of Ihe phases of the metallurgieal process. The analyses eamed out on the melallie materials of the Gatas site (Turre, Almería) suggest that the source of the raw material, or of the finished produet, was the Sierra Morena area (Castro el al., 2001), whieh implies interregional eirculation. Different authors have suggested tha! the dependent organization in the settlement pattem of this area implies the circulation of subsistence products from the smaller settlements in the flat areas to secondary centers, perhaps with the centralizing and redistributing involvement of the large settlement of El Argar (Antas, A1mería), which shows signs ofthe last phases oflhe melallurgical process (Sehubart el al., 2000). Generally speaking, the Culture of Argar verifles a non-generalized aecess lo metal, even in the top-Ievelmetallurgical eenters like Peñalosa where eertain people did not have access lo metallic elements at the time of their buria!' The greater part of the maseuline populalion, with exeeptions, only had aecess to a dagger, which would beeoroe a syrobol of social position and only a certain sector, a restricted minority, had access lo preeious metal adornments, which, in the case of men, usually appear with larger daggers or Ime swords (Cámara, 200 1). These differences eorrespond strongly with those documented among the dwellings sinee, although metallurgical activity has been doeumented in all of thero, onIy sorne show signs of mineral storage areas, consumption of large animals (bovine and equine) and an abundanee of deeorated eeramies (Contreras & Cámara, 2002). In the social context of Peñalosa, where we can distingwsh aristocratic elites, peasantwamors and servants (Contreras & Cámara, 2002), metal beeame a syrobol of sla/us, either beeause weapons became the attribute of the cornmunity's Ime membership or beeause only eertaín people had aeeess to certain metallic elements. However, we can also confmn the use of metal to create the ínslmments that facilitated productive activities, since, in addition to the punch tools, needles and awls documented in the dwellings, which must be related to textile activity because oftheir association with other elements (bone punch tools and needles, 100m weights, etc.), the presence of cutting eIemenls used in the quartering of animals has also been indirectly documented. Weapons were no! only syrobols, but also a means of production because they were used in the acquisition of wealth through war and piUage (Cámara, 2001). Finally, the importance of metallurgical activity in Peñalosa ín relation lo the movement discussed above is shown in Ibe documentation of real ingots intended for accumuIation and circulation. REFERENCES ALCARAZ, F.M., CASTILLA, J., HITOS, M.A., MALDONADO, G., MÉRlDA, V., RODRÍGUEZ, F.J. and RUIZ, Mi.V., Prospección arqueológica superficial en el Pasillo de Tabernas. Primeros resultados y perspectivas metodológicas, Origens. estruturas e relaróes das Culturas calco líticas da Península Ibérica (Actas das I Jornadas Arqueológicas de Torres Vedras 3-5 Abril 1987), (M. Kunst. Coord.), Traba/has de Arqueologia 7, Lisboa, 1994, pp. 217-223. 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