Gold in the Caucasus

Gold in the Caucasus: New Research on Gold Extraction in the Kura-Araxes Culture of the 4th and early 3rd Millennium BC

Gold in the Caucasus: New Research on GoldExtraction in the Kura-Araxes Culture of the 4th and early 3rd Millennium BC

Th. Stllner in collaboration with B. Craddock, I. Gambashidze, A. Hauptmann, A. Hornschuch, F. Klein, M. Jansen, S. Senczek, M. Schaich, G. Steffens and S. Timberlake

With an appendix on recent results by M. Jansen

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Gold in the Caucasus: New Research on Gold Extraction in the Kura-Araxes Culture of the 4th and early 3rd Millennium BC |2 |2

index of contents

Summary 3

Introduction: The Caucasus as a heartland of early mining and metallurgy 3

The ore-deposits of the Bolnissi and a characterization of the Sakdrisi ore-deposit 4

The prehistoric mining of the ore-deposit at the Kachagiani-hillock (Sakdrisi) results of the archaeological research work 7

The chronology of the Kura-Araxes mining galleries 15

Converging to the ancient mining technique: Fire-setting-experiments in Sakdrisi 2011-2013 15

An estimation of the gold contents once being exploited at the ore-deposit of Sakdrisi-Kachagiani The Paravani calculation 21

The Hinterland in MashaweraValley 24

Gold-trade: Provenance studies and a socio-economic model 29

Appendix: Recent results from laboratory work on the gold of Sakdrisi 31

1. Au, Ag and Cu contents from the prehistorically and historically mined ore lodes of Sakdrisi 31

2. Ore fragments in Dzedzwebi 33

3. Gold earrings of Hasansu 33

Literature 34

Photos on first page: View of the Sakdrisi mine; surface-near and subsurface excavation works (photos: DBM/RUB/GNM, Th. Rabsillber; K. Stange, Marienheide).

Deutsches Bergbau-Museum BochumForschungsstelle Archologie und Materialwissenschaften Abteilung Forschung,Forschungsbereich MontanarchologieHerner Str. 45D-44787 [email protected]

Prof. Dr. Thomas Stllner Ruhr-Universitt BochumInstitut fr Archologisches WissenschaftenLehrstuhl Ur- und Frhgeschichte Am Bergbaumuseum 31D-44791 [email protected]


Summary

The Caucasus may be considered one of the most important ore mountains of the ancient world, and in particular of the ancient Near East. As the land of the Golden Fleece, the western part of Georgia, the land of Colchis, was in antiquity a synonym for golden riches.

The discovery of the goldmine of Sakdrisi (ca. 50 km southwest of Tbilisi) leads directly to these issues. Sakdrisi is dated to the 4th and early 3rd millennium B. C. and is one of the oldest known gold-mines in human history; it was worked by miners of the Kura-Araxes Culture. In a total of eight excavation campaigns (20042013) the goldmine and the associated gold district were further investigated. The goldmine of the Kura-Araxes period reached a depth of around 30 m: the ore-body, which is extremely hard especially around the gold-bearing quartz-haematite lodes, was quarried using the fire-setting method and with hammers and was processed on site; stud-ies in experimental archaeology and the detailed study of the tool inventory have made it possible to demonstrate the individual steps of the extraction process right through to the washing of the ore and the associated crucible smelting.

The project also included extensive surveys in the area around the goldmine, with the aim of investigating more closely the ques-tion of an associated settlement landscape. We were able to dis-cover an associated settlement together with contemporary groups of burials and to link it directly to the gold extraction. Evidently a large part of the time-intensive labour of processing the gold ore, the time-intensive milling of the gold ore, was carried out in the settlement. New discoveries also suggest that the groups of craft-spersons engaged in working the gold were largely provided for from outside and did not pursue any agrarian activities. Gold-min-ing and the processing of gold ore, including the gold metallurgy that goes with it, indicate a clear division of the technical processes, but also a society with a division of labour. The burials found in the vicinity show that the gold was not deposited in graves as grave goods, but may have promoted social differentiation in the soci-ety. The focuses of the project are, alongside the archaeological and earth science studies of the terrain, especially on the geochemical laboratory investigations into the source of Caucasian gold: only this will make it possible to establish the economic significance of the reef at Sakdrisi in the 4th and 3rd millennium BC.

Introduction: The Caucasus as a heartland of early mining and metallurgy

The Caucasus is r-enowned for its wealth in natural resources, in particular metal ores: for decades, scholars have surmised causal relationships between the rise of complex, hierarchical societies in the Near East and the development of extractive metallurgy (in general e.g. Strahm 1992; Kienlin 1999). Metallurgy however, is only one among the many innovations that developed in the Caucasus in the course of the 5th until the early 3rd millennia BC (Chernykh 1992; Dschaparidze 2001; Kohl 2007; Courcier 2014): early mining, which is not restricted to metal ore mining, certainly also played a role in the major structural changes at work in the evo-lution of both Caucasian and Near-Eastern societies in Late Prehis-tory, such as work specialisation, rising social inequalities and inter-regional social and economic integration. The Kura-Araxes cultural compound, in particular, is suspected of being one of the driving actors in the introduction and development of this field of socio-economic activity (Sagona 1984; Conti/Persiani 1993; Kushnareva 1997; Akhundov 2004; Magomedov 2006).

However, most of the dynamics that led to the development of mining and its impact in the Caucasus and beyond are far from being understood: what kind of socio-economic, technological and environmental background favoured the rise of systematic mining in the Caucasus at the end of the Chalcolithic? How far early min-ing was linked to the spread of specific subsistence strategies such as pastoral herding? Were mined resources intended for local con-sumption or distributed throughout the Near-East, namely Anato-lia, Northwest-Iran and Mesopotamia?

In contrast to metallurgy, the study of early mining in the Caucasus, its background as well as its impact on Late Prehistoric societies, is still in its infancy. Most of the work done so far has focused on the analysis of ore composition with the view to trac-ing back the geographical origins of artefacts (Selimkhanov 1960; Chernykh 1992, Kavtaradze 1999; Schachner 2002; Bakhshaliyev 2007). Apart from the pioneering work of Mudshiri (1987), early mining as such was seldom studied; it is only recently that thanks to the work conducted by Georgian scientists (Inanishvili et al. 2001; Stllner et al. 2010, 105 ff.) in particular, the first evidence of an incredibly rich mining history was brought to light.

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Th. Stllner in collaboration with B. Craddock, I. Gambashidze, A. Hauptmann, A. Hornschuch, F. Klein, M. Jansen, S. Senczek, M. Schaich, G. Steffens and S. Timberlake


The discovery of the early gold-mine of Sakdrisi and of its hinterland district leads us to these questions1 (Fig. 1): it does not only tell us about technical solutions of gold extraction and gold processing but also it bears information about social complexity and logistic interactions within a landscape. The dwellers of the Maschavera-valley certainly were engaged in this mining enter-prise. But depart from the evidence of interaction between mining and gold ore-processing in the settlement many questions remain open: We still have only a very superficial idea of the social-eco-nomic impact that the gold mining once had to the Kura-Araxes-dwellers in the southern Caucasus? Was it an activity that had been followed by a specialized group within a broader, well organized society or was it a specific ritual and symbolic activity that was carried out on special occasions? The article will try to summarize work that has been carried out since 10 years in Georgia but also tries to give a partial answer at least.

The ore-deposits of the Bolnissi and a characterization of the Sakdrisi ore-deposit

Among the large number of ore deposits of copper, iron, lead, zinc and of other base metals known from the Caucasus, there are several gold districts in Georgia which are located in the Greater Caucasus and in the Transcaucasus as well as in the Lesser Cauca-sus Mountain range (Fig. 2). Both primary gold occurrences and (paleo-) placer gold from various geological epochs were found in these districts; besides the important sources of Svanetia/Racha known particularly from placers in the Enguri and Khrami rivers those of the Bolnissi-zone are of ample importance (Hauptmann 2011). The Bolnissi-metal ore deposits belong to the larger Teth-yan Eurasian Metallogenic Belt (TEMB, Jankovic 1997; Moon et al. 2001) which extends from the Alps in the west over the Balkan Mountains, Anatolia, Armenia, Iran to the Himalayas. The Mad-neuli polymetallic ore-deposit is part of the Artvin-Bolnisi unit of the TEMB. It is a hybride between volcanogenic massive sulfide ore deposits (VMS) and an epithermal (subvolcanic) gold-silver deposit (Migineishvili 2002).

Already in the first half of the last century the gold district of Bolnissi was intensively explored (Godabrelidze 1933). Gold miner-alisations can be found at Mamulo, Dambludka, Bneli Khevi, Tetri Tskaro, Lokchai as well as in the modern open cast mines of VMS-deposits of David Garedji, Madneuli, Tsiteli Sopeli and at Sakdrisi. Numerous rivers in the drainage system of this area are bearing placer gold, e.g., in the Mashavera and its tributes Dambludka,

1 From various publications: Gambashidze et al. 2010; Hauptmann/Klein 2009; Hauptmann et al. 2010; Hauptmann 2011; Stllner et al. 2008; Stllner et al. 2010; Stllner/Gambashidze 2011; Stllner et al. 2012.

Karasu und Moshevani in the area of Pinazauri. Here, the prehis-toric gold mine of Sakdrisi is located (Fig. 3).

Next to placer gold this noble metal occurs in the Bolnissi- district in VMS-deposits and in porphyry copper deposits (Tval-chrelidze 2001). VMS are of major importance. They were formed during the early phase (Jurassic to Cretaceous) of the Alpine met-allogenesis. The ore body of these VSM deposits is bound to a rhy-olithic dome above an intrusion of granodiorite. Kalium-argon-dating of the mineralisation provides an age of 85-93 million years (Moon et al. 2001). The deposit of Madneuli shows verti-cal telescoping of a copper-lead/ zinc-baryte-gold mineralisa-tion (Gogishvili et al. 1976). Due to its geochemical stability gold is enriched in the gossan near the surface, where ancient galler-ies were found: Besides the prehistoric mines of Sakdrisi-Kacha-giani hillock old mining traces could be described from the Mad-neuli-deposit, from the Kvirazchoveli-deposit (Sakdrisi V) as well as from Postiskedi-deposit (Sakdrisi III-IV) (Stllner et al. 2010). Copper is associated in traces with gold, but economic valuable amounts of copper only occur in a depth of ca. 60 m.

The area around Sakdrisi itself consists of several prospects (Sakdrisi I-V). The Kalium-Argon age of this ore deposit is 77.683.5 millionen years (Gugushvili et al. 2002) (Fig. 4). The pre-historic mine Sakdrisi-Kachagiani exploited a swarm of vertical to irregularly formed hydrothermal quartz veins with a thick-ness of only 10 30 cm. In the gossan zone these deposits can be characterized as typical stockwork-mineralisations, what has its consequences also for the prehistoric mining technique (see below). The gangue of the gossan zone is barite and hematite. Hostrocks are ignimbrites and other (pyroclastic) volcanic rocks (tuffs) often intensively affected by tectonic activities and meta-somatism (Fig. 5).

The ore deposit of Sakdrisi was explored and prospected in the 1980ies, when several explorations tunnels had been dug (a description see Omiadze 2007). These tunnels intersected older mining galleries in the underground, an important stratigraphic observation that first was described by Timur Mudshiri, a Geor-gian engineer and geologist (Mudshiri 1987). Intersection cuts with ancient tunnels are reported from the both the exploration horizons, from the 20 m level but also at the 40 m level, where such a site was reported to the research team. A visit in 2005 supplied the evidence of a natural lacuna within the ore vein of the prehistoric mine 1/2; on the contrary to mine 1/2 that once had been exploited to a depth of 24 to 25 m below surface this area never had been touched by this mine2. The deepest vertical extension of prehistoric mining activities can be specified by 31 m below surface in the mining system mine B3/mine 2.

2 Natural lacunas that were not completely filled by ores have been observed also in other parts of the Sakdriss-Kachagiani-deposit.


Fig. 1: Location of the gold-mining district of Sakdrisi within the Transcaucasus region and position within the gold-mining district between Kazreti and Mashavera within the Mashavera-river-stream valley (graphics: DBM/RUB/GNM, A. Hornschuch).

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Fig. 2: Ore deposits and ore occurrences in Georgia and surrounding countries (after Tvalchrelidze 2001).

Fig. 3: Simplified geological map of the copper-gold-district of Sakdrisi-Bolnisi with gold deposits and occurrences as well as associated placers. Modified after the geologic-tectonic map of the Bolnisi-district, Georgia. Internal version, courtesy M. Tshochonelidze, Tbilisi (Ergnzung der Kartierung A. Hornschuch > prhist. Bergbau in Kvemo Bolnissi!) (after Hauptmann 2011, 176 Fig. 3).

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Fig. 4: Simplified geologic-tectonic map of the gold deposit of Sakdrisi-Kachagiani (Sakdrissi I: in the upper right corner) and the other gold-deposits of Sakdrisi II-V. Scale of the map 1 : 10.000 (from Omiadze 2007; Hauptmann 2011, 177 Fig. 4).

Channel samples taken by Georgian geologists gave 23 mt of gold bearing rocks with an average of 1.03 g/t gold (Gugush-vili et al. 2002). However gold enrichments up to 50 g/t and even 500 g/t were also analysed from boreholes (personal communica-tion Malkhaz Natsvishvili). Such enrichments were much more rea-sonable loads for ancient exploitation; as the gold-enrichments are quiet variable within single loads it is difficult to estimate an aver-age gold content of those parts that have been exploited during the prehistoric mining period. The only reasonable approach is to test the ore-veins in those parts that have been exploited in prehistoric times (see below). The gold bearing quartz veins accessible today provide only extremely fine grained flower gold hardly visible with the naked eye: it only can be seen when beneficiating, by washing and panning the ores according to the old techniques (see below).

The prehistoric mining of the ore-deposit at the Kachagiani-hillock (Sakdrisi) results of the archae-ological research work

The prehistoric mine of Kachagiani-hillock was first described by the engineer and geologist T.P. Mudshuri; the site was then called Abulmulg and Mudshiri made valuable observations about the stratigraphic contexts of stone-hammers within refilled min-ing galleries (Mudshiri 1987, 57 pp, 91 pp, 111 pp; commend Stll-ner et al. 2010, 109). He was also the first who hold possible a pre-historic gold mine. In 2004 the ongoing modern research started by a joint Georgian-German team; the group that consisted of

mining archaeologists and archaeometallurgists continued an interdisciplinary field research until 2013 within 8 field seasons; during this period excavations and investigations were carried out at several parts of the ancient mine to clarify questions of ancient mining technology and the chronology of the mining activities as well as further of the logistic and the supply of the ancient mining enterprise (Fig. 6).

The stratigraphy of the mine: Excavations were commenced mainly at two mining structures (mine A and B) (in general already Stllner et al. 2010); these mining structures can be characterized as refilled opencast mines that led once to underground parts; in the case of mine A it was possible to excavate these mining parts also in the underground where the ancient galleries were inter-sected by the galleries of the modern exploration mine; in the course of the excavation and by the subsequent dating of mining debris by archaeological artefacts and radiocarbon-dating of char-coals it turned out that these mines had been used during two phases: the older phase can be dated by several 14C-dates to the 2nd half of the 4th millennium and to the beginning of the 3rd mil-lennium (Fig. 7). It has reached depths of 24 to 31 m below sur-face and was refilled in the lower parts completely by contemporary mining debris; the younger phase in the contrary can be described as a reopening of the old mines: the activities reached depths of around 8 to 9 m below surface; in many cases we found clear strati-graphic evidence of this second phase: in the Kura-Araxes-mine-pocket A9 the younger mine removed parts of the upper hard rock-walls for instance (Fig. 8.a). This mining phase did not carrying out the fire-setting method but used iron-tools in order to widen the

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Fig. 5: Aerial photo of the excavated parts (state of 2008) of the gold mine of the Kachagiani-hillock (Sakdrisi): Note the exploitation of the irreg-ularly and vertically running gold veins of the stockwork-deposit that have been exploited towards to a depth of 27 m (photo: DBM/RUB/GNM, Th. Stllner).

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Fig. 6: General overview of the mining area of Sakdrisi according to the surveys of the DBM between 2004 and 2007, after Stllner et al. 2010, Fig. 14.

old galleries; in mine B3 we clearly found a reopened mine of that period: parts of the older mining debris were stored to side-cham-bers and most of the mine-walls had been re-mined down to a level of nearly 9 meter, where this activities stopped (Fig 8.b-c). At the walls the edge between the prehistorically hammered walls and those wall parts which were laboured by the iron-pick work were still visible (Fig. 8.d). According to the gold contents we measured in the prehistorically mined wall parts it is obvious that the re-min-ing of the ancient wall parts was a profitable task. According to sin-gle charcoal-dating from those younger debris it is likely that this

secondary work step took place between the 5th and beginning of the 7th century AD. The reopening of the mine was probably a dangerous work as we discovered several dislocated human bones and skulls within the refill of the late antique reopening3. According

3 While these human bones were never discovered in situ position one can also interpret a different scenario: they once could have belonged perhaps also to human burials that were dislocated by the younger mining activities at the Kachagiani-hillock. Excavations at the foot of the Kachagiani-hiillock proved the existence of a medieval graveyard which then would be too young (unpublished reports of W. Licheli and K. Kachiani).

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Fig. 7: General overview of AMS-14C-dates from the gold mine of Sakdrissi in 1- and 2 -standard deviation, dating by ETH-Zurich (G. Bonani/I. Hajdas) and B. Kromer (Heidelberg/Mannheim).

Fig. 8: Late Antique reopening of the Sakdrissi-Mine: a: mine A, traces of metal (iron) picks at the eastern wall beyond the mine pockets A3/4; b:Mine pocket A9 with removed upper part of the hard-rock wall (traces of metal tools); c-d: mine B3, waste filling of late-antique period in 8-9 m level, where the mine lamp (8.c) was found; c: (photos: DBM/RUB/GNM, Th. Stllner, drawing: Th. Rabsilber).


to our excavations it became clear that in the upper parts of the mine only very small original parts had survived in smaller side galleries; one of this side-galleries was the mine tunnel A3 that originally was advanced by fire-setting in the Early Bronze Age. But our excavation clearly showed how the younger miners dug into the prehistoric debris but stopped at one point and refilled it (Fig. 9). The whole mine is therefore difficult to understand: it consists of a hard-rock part that first of all was advanced by Kura-Araxes miners in the late 4th mill. BC but later were reused and altered by late antique miners down to a 9 m level. Differen-tiation is possible by careful observation of the different mining traces that originated from different mining techniques (fire-set-ting and pick-mining); besides the hard rock part also the refill of mining debris had to be carefully investigated and differentiated; the upper part mainly consisted of late-antique refills and ero-sion backfill that originally came from tailing that had been re-dumped during the late antique period. Between those layers we

also discovered older erosion soils that can be dated to a longer time period between the late Bronze Age and the late Iron Age; till now there is no indication for mining activities during that period but according to ceramic findings settlement activities can be assumed in the surroundings. Undisturbed stratigraphic relations were detected in all ancient mining galleries deeper than 9 m below ground; in mine 1/1 to 1/3 as well as in mine 2 untouched mining debris was discovered underground; in con-trary to those debris-layers described before the refill here con-sisted of small scale gravel, high amount of charcoal and exclu-sively Kura-Araxes artefacts such as ceramics, stone hammers and stone hammer flakes as well as bone tools (chisels, scrapers), obsidian flakes and tools (Fig. 10). The high amount of charcoal and the burned surfaces of angular rock debris found in those lay-ers gave clear indication for the fire-setting process whose traces also could be seen at all mine-surfaces by typical round shaped cavities. These cavities are covered by millions of small hammer

Fig. 9: Sakdrisi, late antique excavated pit-hole within a Kura-Araxes-stratigraphy, a: features 10080-4 and 10082; b: base map of lower filling 10085 within Kura-Araxes occupation level 10093, photo: DBM/RUB/GNM, Th. Stllner, drawing: J. Garner).

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impacts proving that hammering the walls was a second working step after the first fire-set was done. In general the Kura Araxes debris can be classified into three principle layer types. First of all there were layers that derived directly from the fire-setting pro-cess: angular and reddish/blackish burned volcanic rocks mixed with charcoal and smaller debris. A second layer type consisted of smaller crushed rock debris with a higher amount of sand per-haps the remains of the crushing and selecting work. A third type finally can be characterized as fine crushed and milled debris with a higher amount of quartz-sand; according to our experiments this kind of debris should derive from a more advanced step of ore-crushing and beneficiation.

Considering the fact that nearly all the debris had been refilled after the mining process it is interesting that the Kura-Araxes miners refilled their galleries carefully with different beneficiation debris from up the ground. This conclusion is cogent as the single gallery followed the single ore veins nearly without interconnections so the access once was only possible from the mine mouth.

The shape and structure of the Kura-Araxes mining galler-ies: During the excavations between 2004 and 2013 the research team was able to excavate large parts of the mine A and B (with its related parts underground = mine 1 and mine 2). The reconstruc-tion of the original shape of the mine after the end of the min-ing activities of the Early Bronze Age is possible by using the com-plete 3D-Laser-scan performed in 2011 and 20134. At the current state of evaluation a general 3D model allows to follow the various underground structures (Fig. 11): In principle all the mining cavi-ties had been developed by removing the original ore-body (ores and gangue) and the accompanying host-rocks; the mining tech-nique can be described as a following the vein-system which was advanced in a diagonal way: the underground mines 1 and 2 pro-vide good examples for this technique which mainly applied the principles of fire-setting. The fire always had to be lid at the work-ing-edge within the ore body and as the miners are forced to fol-low the veins to the depth the mining process led to diagonal gal-leries that went down in steps and pedestals; some of the galleries are steeper than others. To arrange the galleries in a more or less diagonal way had its advances for diverting the smoky gases of

4 The full 3D-modelling and GIS-evaluation will be the goal of a future PhD-study that plans to follow the different phases of mining and the process of refilling by regarding all features such as mining traces at the hard-rock surfaces and by the stratigraphic record of the back-fill layers.

Fig. 10: Sakdrisi, typical Kura-Araxes back-fill-stratigraphy from under-ground at mine 1/2 north-extension at the junction between main lode and western side-lode, a-b hammer-stone wall revetting the back-fill-layers (from north, from above), c: S-profile with backfill-layers, pho-tos/drawings: DBM/RUB/GNM, J. Garner, Th. Stllner, P. Thomas.


the fire-setting. According to our experiments it was the easier the steeper the galleries were as the chimney effect allows the divert-ing of the smokes alongside the steep ceiling part. In this respect it is interesting to consider the structure of mine 1/1 that has been laid out nearly vertically. In the lowest part four horizontal pedes-tals/niches were made in opposite directions to each other. It looks like as a zig-zag system at first: but it is likely that these niches can be regarded as first steps of advancing a larger exploitation hori-zontally which ended then in larger cavities (like in mines 1/2 and 1/3). It is likely that the fire-setting most of the time was advanced in horizontal levels in two directions both on the ceiling and on the flour to either reach more depth and to be more effective at the rock-face (Fig. 12).

That the original advancing galleries were driven horizon-tally or slightly inclining most of the time can also be observed

in the lowest and therefore youngest parts of mine 1/2 (the so called North-extension): the southern niche as well as the bot-tom gallery and the northern gallery show such orientations; fur-ther arguments can be found by the observation that parts of the walls show inclining ledges that have lengths of some meters: these can be regarded as part of original advancing galleries that later on were removed when the mining went to a deeper sector.

When analysing all the available mining parts of the Kura Araxes period it is clear that the ancient miners followed most of the richer veins to the depth by creating horizontal and slightly inclining working levels; the most demanding working step was the sinking of the initial gallery part in order to construct a new working level that later could be advanced easier to the lateral.

Fig. 11: Sakdrisi, 3D-model of the Kura-Araxes-mine, performed in 2011 and 2013, by DBM and ArcTron; coloured are the Kura-Araxes-mine parts as well as the late antique parts and the modern exploration tunnels; grey: surface and modern tunnels; turquoise, red and brown colours: prehistoric mining galleries, blue and green: prehistoric mining galleries, reworked in late antique period (DBM/RUB/GNM, F. Klein).

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Fig. 13: Sakdrisi, northern gallery in mine 1/2, N-extension, with fire-setting-traces at the working edge and soot at the ceiling that was hammered down at the stern most part or the gallery, photo: DBM/RUB/GNM, Th. Stllner.

Fig. 14: Sakdrisi, mine 2, deposition of hammer-stones in the lowest northern niche, excavation 2007, photo: DBM/RUB/GNM, Th. Stllner.

Fig. 12: Sakdrisi, reconstruction of the vertical extension of mine galleries 1/1, 1/2 and 1/3 on the base of perpendicular sections (DBM/RUB/GNM, J. Garner).


The chronology of the Kura-Araxes mining galleries

It is always difficult to date a mine; in the case of the Sakdrisi mine we have two possibilities: first to date the hard-rock-structure it-self by its working traces or by help of soot and charcoal coating that still can be found in not altered and untouched parts of the mine (such as mine 1/2 N-extension, northern gallery, Fig.13). The second possibility is to date the backfill by archaeological or by radiometri-cal methods (such as 14C-datings of charcoal or bones). Such dates provide a terminus ante in any case no matter if the refill is from the same mining period itself or even from a later operation period. To qualify the evidence of our dating it is important to understand the refilling process. At Sakdrisi the refilling process was done deliber-ately what easily can be evidenced by installations put in to ena-ble the refilling. In mine 1/2 N-extension we were able to excavate a working platform that was kept open to both sides by the help of two small walls erected with rocks but mostly with hammer-stones already damaged and unusable (Fig. 10). There are other similar observations such as walking steps in mine 2 or a deliberate down-pour of debris-layers. It is also interesting that often deposits of tools were put to the lowest or the stern-most part of mine before it got filled (e.g. Stllner et al. 2010, 30; Fig. 26) (Fig. 14).

As fire-setting was the basic mining technique we decided to date preferably the charcoal after having examined them in regard of the botanical age (especially by selecting the dull edge or young branches) (see Tab. Fig. 7) (Stllner/Gambashidze 2011, 193-194 Fig.6-7). Dating the soot from the walls as well as of the infill stands in accordance to each other. The dates range between the 2nd half of the 4th millennium and the beginning of the 3rd millennium. It is interesting that the older range of dates derives from mine 1/3 and 1/2 lower part as well as mine 2 while mine 1/1 and the upper fill of mine 1/2 belong to the beginning of the 3rd mill. It is fatherly inter-esting that especially mine 1/1 can be regarded also as youngest mine according to the stage of operation and its 14C-dating (sinking the deeper parts but not extending it to the lateral).

This is also in accordance to the archaeological artefacts that were discovered in the debris of the refill: Most of them resemble tools of bone, obsidian and stone (particularly hammer-stones) that only can be dated generally to the 4th and 3rd millennium (Fig. 15): they reflect a prehistoric (chalcolithic to Bronze Age) tool set that is known from Central Asia to Western Europe (e.g. Garner 2013). A better dating can be gained from ceramic pot-sherds found in undis-turbed and also in re-dumped debris; as all of the Kura-Araxes pot-sherds belong to the 2nd stage of the Kura-Araxes chronology (according to Sagona 1984; Kushnareva 1997) it is quite likely that all of them are related with the prehistoric mining process5.

5 One could discuss that some of the Kura-Araxes pot-sherds have been re-dumped and mixed into later contexts (mainly in the late Antique period); so they could derive theoretically from different origin: but there is no evidence for such an assumption because there are enough well stratified potsherds

Converging to the ancient mining technique: Fire-setting-experiments in Sakdrisi 2011-2013

The gold-mining process documented in the Mashavera-valley consisted of several steps that first of all had been docu-mented by archaeological observations, by artifacts and by fea-tures (Stllner/Gambashidze 2011, pp 196; Stllner et al. 2012). According to this evidence our research team was able to recon-struct five distinctive work-steps; each of this general steps can differentiated in further single work procedures of which some are better known than others. The reconstruction of the chane operatoire is still an ongoing process that requires a trans-disci-plinary approach of material sciences, archaeology, ethnology and experimental archaeology. The process reconstructed so far can be compared with techniques described for antique and younger periods (Agricola 1556; see also Tylecote 1987; Bachmann 1999; Craddock 2000). Despite this empirical approach many questions remain open that pertain to technical solutions and quantitative aspects such as the time-span and the yield of different produc-tion steps; together with the estimate of the gold once produced these questions are essential to understand the social impact that the gold exploitation once had (see below). Three of those proce-dural steps mentioned above can be located at the gold mine of Sakdrisi: especially those steps have been also simulated by exper-iments to understand single technical solutions (e.g. Stllner et al. 2012). Experiments were undertaken in 2011 and 2013: the focus was particularly set on the mining, sorting and crushing and mill-ing process of ores as well as the panning of the gold concentrate. In 2011 and 2013 the experiments were carried out by the author in collaboration with S. Timberlake (Cambridge) and B. Craddock6.

1. The ore-mining was carried out by help of fire-setting and extraction work by help of a typical chalcolithic to Bronze Age tool set: hammer-stones often adapted to the very narrow veins as well as bone and antler-chisels were combined to extract gold bearing host rocks and pure quartzite veins. According to broken antler pieces found in the debris we also can assume the usage of antler-picks such of which many had been found in mines between the 5th to 2nd millenniums BC (recently e.g. Groer 2008; Garner 2013). The gold almost was invisible but by testing the gold-content the grade of the ore was determined (see below).

The mining technique experiments had several questions including the question of pebble selection for the stone ham-mers and crushing mallets, the hafting of the tools to the handles, the amount of wood used in relation to the ore produced as well as the progress and efficiency of the ore-producing process. The

which date to the same Kura-Araxes period as the dislocated examples. All the pottery will be examined by N. Otchvani by her Tblissi/Bochum PhD-study.

6 The results of all 11 fire-sets and of all the other details will be published in a separate study; preliminary report: Stllner et al. 2012.

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Fig. 15: Sakdrisi, mine 1/13, pottery (a) and bone tools (b) from the back-fill layers of Kura-Araxes-period, photo: DBM/RUB/GNM, Th. Rabsilber, S. Senczek.

a

b


later question was of special importance as the Sakdrisi hematite-quartz lodes can be regarded as extremely hard.

We worked by using oak wood for fire-setting (the burned wood and charcoal was found in the prehistoric mining debris)7. Hafted hammer-stones and stone tools were prepared of river pebbles (mainly andesite), raw hide and oak handles and twisted hazelnut binding; we utilized hafting methods documented in South America and the Eurasian zone (the strap binding accord-ing to the Chuquicamata-finds, the so called Chuqui-hafting, and the branch-knag hafting, according to the finds of the Mitter-berg, called the Mitterberg-hafting: Craddock 1994; Craddock et al. 2003; Stllner et al. 2012) (Fig. 16.a-b).

Eleven experiments were carried out so far; one of them even underground to test the oxygen and air-circulation. Each of the experiments and fire-sets took several hours and produced ore that finally had been crushed, milled and panned to test the

7 The charcoals were investigated by W. Schoch, Birmenstorf, and N. Boenke, Bochum; a report will be published in a broader version of this article.

Au-grade. It was interesting to learn about the durability of the stone tools which were made according to hafting-evidences from Bronze Age Mining found in Britain, Austria and Central Asia (the so called branch-knag hafting of the Mitterberg-type): this haft-ing type proved successful for smaller hammers that can be used for constant beats to the rock while the twisted strap-hafting seems more useful for heavy hammers: this hafting has both more durability for heavier and intense hits and spares the wrist joints of the miner. Besides the hammer-stones also picks of deer ant-lers were used and proved effective to remove the loosened rock parts after the fire-sets. The tool-kit did perfectly work: after burn-ing the ore-lode it only took us half to one hour to produce an ore volume between 10 and 186 kg (the amount of rock yield depends basically of the amount of fire-wood inserted (see Tab. Fig. 17).

2. Gold-ore testing was presumably undertaken at the site, as the grade of the gold-content cannot be estimated by the naked eye; therefore it was necessary to verify the current gold content of every lode or even the variation of gold-contents within each of

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Fig. 16: Sakdrisi, fire-setting experiments: a. recon-structed stone tools in Chuqui and Mitterberg-hafting type and a deer antler; b. Fire-setting at a steep rift of an ore-lode, at the surface of a lode (pile of wood and fire-set trace after burning and hammering); Photos: DBM/RUB/GNM, K. Stange, Marienheide, Th. Stllner


the profitable lode. It is certainly a difficult task to prove this kind of working step: But there is archaeological evi-dence, that can be interpreted in such a direction: At the mining site a water basin cut out from the rock was discovered during the excavation 2005; this basin may have served once as a cistern and would have provided water for water-sluicing activity to wash and especially to pan gold concentrates. Such concentrates must have been beneficiated before by running through the whole operation chain of crushing and milling. It was therefore striking that the complete set of such tools were found in a prehistoric tailing only some meters in the NW (fea-ture 10042). While crushing anvils were documented everywhere in the mining area of Kachagiani hillock we did find millstones especially concentrated in that area. This speaks for a specialized work-flow that was performed here (Fig. 18). If so, why do we know it was only testing and not the whole process of bene-ficiation that once have been carried out there? This conclusion can only be drawn in a reconstructive way, as a much higher amount of similar mill-stones and milling-anvil were discovered in the set-tlement of Dzedvebi II (Fig. 19). As gold-milling is also evidenced there by the identification of gold bearing sands (see below) it seems most likely that the majority of the time-consuming mill-ing was done in the settlement and not at the mining site. Testing the ores is therefore a logical explanation for the small scaled mill-ing and panning activities in Sakdrisi-Kachagiani.

3. Hand-sorting and crushing of gold ores were the main steps of ore-beneficiation that can be evidenced at the gold mine of Sakdrisi. A first sorting and parting was done even under-ground where simple handheld hammers and dimples in the rock might have served as devices. Anvils with dimples and rock-cut mortars (with dozens of dimples) could be discovered at all

surface parts of the Sakdrisi-mine: Although many anvil-stones were dislocated by the re-flow of the dumps after the Kura-Araxes-mining and by the late antique re-dumping activities the rock-cut mortars (Fig. 20) indicate that most of the crushing work once was done at the edges of the open-cast parts of the galler-ies. The grade of the refilled beneficiation debris crushed down to sizes of about 3 mm to 2 cm still had around 1 ppm of gold but in some cases this grade could even raise up to 6 or even over 20 ppm. It therefore provides a minimum value of gold left in the debris (see below).

4. Once the ore was crushed and sorted most of the high qual-ity gold bearing coarse sands were transported to locations where this material was fine grinded. The results of Dzedzvebi house 3/2009 made apparent that this milling of ore was done in large workshop rooms at the settlement (see below). According to exper-imental results from 2011 and 2013 the milling should not become too fine not to lose the finer grained gold flakes being finely dis-seminated into the ores (Fig. 21). Having found also gold contents of about 1 ppm in this workshop room (and being considerably ele-vated in comparison to the surrounding) proves the workshop and

Fig. 17, Table of 11 fire-setting experiments in regard of time-consumption and rock-wood yield relation.

Fig, 18: Sakdrisi, dump 10042, anvils, milling-plates and handheld rubbers, Photo: DBM/RUB/GNM, Th. Rabsilber.

Gold in the Caucasus: New Research on Gold Extraction in the Kura-Araxes Culture of the 4th and early 3rd Millennium BC 19 |

Fig. 19: Statistical comparison of stone-tools used for mining and beneficiation processes (crushing, milling) in Sakdrisi and Dzedzvebi; note the anomalous statistical representation of dump 10042 that is regarded to be related also with finer beneficiation processes in Sakdrissi.


Fig. 20: Sakdrisi, mine A, dimples of ore-crushing work in the rock-face at the edge of the mine depressions, a. large dimple at mine A6/7, under-ground, b. group of dimples at the edge of mine A and C, photo: DBM/RUB/GNM, Th. Stllner

Fig. 21: Sakdrisi, beneficiation exper-iments (crushing, sorting and mill-ing) 2011, Photo: DBM/RUB/GNM, F. Schapals.

a b

Fig. 22: Crucibles from the Dzedzvebi-settlement, a. crucible-fragment 22434 from Dzedzvebi IV.3, late-chalcolithic feature 36100 and the surface-values of Cu and Ag; b. crucible fragments 9648, 9711 and 12455 from the workshop area Dzedzvebi II.2-3; photos/drawings: DBM/RUB/GNM, A. Kuczminski, Th. Rabsilber.


milling theory. The abundance of mill-stone found there does this also in general. Although we did not experiment the crushing and milling work on a large extend it was interesting to learn about the comparatively high time-consumption during this work: It took four workers and four working days of 7 to 8 hours to prepare around 30 kg of separated ore. This makes clear that even one fire-set plus hammering work of nearly two hours work would have ended in a much higher investment in the ore-beneficiation. Mining the ores stands in relation to ore-preparation at a ratio of 1:32.

5. Whether the sands got washed and fire-assayed in cruci-bles in the end is till now a likely but unproven hypothesis. Proving this needs further fieldwork and perhaps the one or another lucky finding of a gold crucible in the workshop areas of the nearby Balit-shi-Dzedzvebi settlement. 2010 a crucible was found in a pit of the early 4th millennium (together with late chalcolithic pottery). The metallurgical crust of the crucible shows a slight enrichment of silver according to the silver content of the ore-deposit, while the copper is not enriched (Fig. 22).

An estimation of the gold contents once being exploited at the ore-deposit of Sakdrisi-Kachagiani The Paravani calculation

It is certainly one of the most difficult scientific tasks to realis-tically calculate the original gold contents of an ancient gold mine (e.g. Klemm/Klemm 2012): first of all it is apparent that most parts of the original ore body had been exploited in the late 4th and early 3rd mill. Only small remnants of the original ore body have been reserved in the original galleries. Thus only a minimum of the original ore-content has survived: it must have been originally richer in grade and quality. On the other hand it would be also mis-leading to take only the average grade of the gold-content from all the lodes or in general from the whole host rock as it is done by modern mining and beneficiation technology. According to their more selective mining technique ancient miners could easily make a choice and concentrate on the richest lodes.

It was therefore necessary to integrate two different meth-odological approximations: first the minimum level of gold grade that can be calculated from the refills and the original beneficiation debris found above and inside the mine. The second way would be the estimation of an average gold grade of those lodes that had been once exploited. Original ore samples were difficult to achieve: Most of the surface-near parts had been completely exploited by both the mining phases; what the Kura-Araxian miners left behind their late antique colleagues took away by re-mining the lode walls. Best samples were achievable in the underground part that had been not disturbed until the recent years. Despite empirical short-comings there was no doubt that by comparing the averages

of the Au-contents of the prehistoric back-fillings and the average values of Au in prehistorically mined ore-veins it is possible to cal-culate a minimum average of Au that had been extracted in the 4th and early 3rd millennium BC.

At the beginning of the investigations in 2005-2008 several hundreds of kilograms of channel samples from ore veins and from the back-fillings of the prehistoric mine of Sakdrisi were taken. All concentrates obtained were further panned to extract gold grains. In all cases we obtained very fine grained ( 0,1 to 1 mm) flower gold (Hauptmann et al. 2011). From these sam-ples native gold grains were collected and prepared for further analytical investigation. They were studied by scanning elec-tron microscopy (SEM), microprobe analyses (EMPA) and mass spectrometry.

In the first step of investigations we took a channel sample of 175 kg from the gold bearing hydrothermal vein inside the mine of Sakdrisi, and we treated more than 600 kg of backfillings (29 samples) and samples from the nearby Kura-Araxes settlement of Dzedzwebi for fire-assaying. We therefore applied one of the

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b

Fig. 23: a. Gold extracted from c. 50 kg of backfillings in the mine of Sakdrisi by panning (white material), Photo: DBM/RUB/GNM, Alex-andre Omiadze; b. gold bearing lead ingot ready for cupellation to extract the gold-content; c. after cupellation in a porous MgO-crucible the lead oxide is absorbed by the crucible (which is now of yellowish colour), and a gold prill is left. The fire assay was performed by Dr. W. Homann, Dortmund and S. Nadareishvili, Photo: DBM/RUB/GNM, Sergo Nadareishvili, Tbilisi (after Hauptmann 2011, Fig. 7, Fig. 9).

a

b c


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oldest analytical processes8 (Hauptmann 2011, pp 179). Fire assay-ing comprises several steps (cited after Hauptmann 2011):

1. Weighing of the original gold or silver bearing sam-ple. Grinding the material and washing a representative aliquot (Fig.23.a).

2. Roasting of the concentrate to remove sulphide concentra-tions of ores.

3. Smelting of a concentrate together with lead or lead con-taining chemical agents and by adding borax (Na2B4O710H2O). Noble metals will be collected in the lead ingot formed during the smelt (Fig. 23.b).

8 The fire assaying was performed by Dr. Wolfgang Homann, Dortmund. This method is still applied even today in a modern version to determine noble metals in large quantities of noble metal containing ores.

4. The lead ingot will be oxidized by cupellation to lead oxide while the noble metal remains in the metallic state and separates from lead oxide. This will be absorbed by the porous cupel in the liquid state (Fig. 23.c).

5. Weighing the noble metal prill. Calculate metal content of the original sample.

According to these investigations several data could be achieved: first of all there was information about debris ores above ground and refilled mining debris underground (Fig. 24.a); there gold-grade level provided insight into the cut-offs of the gold-pro-ductions; a general mean of 1 ppm Au can be regarded as a min-imum-number of which could not be removed from the deposit.

Further investigations were performed in 2011 by fire-set-ting experiments which delivered ores with partly evaluated gold contents directly from the ore-lodes (Stllner et al. 2012). In 2013

Fig. 24: Contents of noble metals and copper in the back-filling debris and the ores of mine A/mine 1/1-3 below ground (analyses DBM/RUB/GNM, C. Courcier, A. Hauptmann, A. Omi-adze, Th. Stllner).

a


further sampling of the ore deposit was undertaken: the ores were first measured by a portable X-ray spectrometry using a handheld X-ray fluorescence spectrometer (Niton XL.3t, Thermo Scientific) (non-destructive analyses). The XRF is applicable to the determina-tion of main and minor element composition of the elements gold, silver, copper, iridium, osmium, ruthenium, arsenic, tin. While the method is based on the analysis of small spots (diameter of 3 and 8mm) rather than of large parts of the ore-body, it gives the chance to detect even small inclusions or heterogeneities. When sampling the ores we performed several measures of the milled gold-ore of which we took the mean rate (Fig. 24.b); later on these samples have been investigated also in the laboratories of the Ger-man Mining Museum Bochum to control the gold grade9.

In the course of the investigations it turned out to reasona-bly consider the Au-content in respect to each single mining part: A case-example will be given here for the lowest mining part of mine 1/2 (called the North-extension): This area was favourable as it was never disturbed by later mining and as we could system-atically excavate and calculate its 3D-dimensionality. Therefore all the necessary parameters could be achieved: besides the volume and the general ore-content (approximately a third of the volume (32 m3 with 85 t of rock/ore results in roughly 28 t of pure ores); we were also able to measure the gold content in some parts of

9 All the investigations of the samples were carried out in the field by Th. Stllner and A. Courcier, while M. Jansen investigated all the samples at the laboratory by a time-consuming separation of gold tinsels and analyzing them by quantitative methods in the frame of his PhD-study; part of these results will be published in the extensive version of this paper.

the deposit that ranges between 10 ppm and 180 ppm at various parts of this part of the deposit (in the mean-rate: 130 g/t Au; 70 g/t Ag). Such an estimate would end in a yield of 3,46 kg of gold and roughly 1,96 kg of silver (the noble metals certainly were not parted during the Kura-Araxes period which would result in around 5 kg of a gold-silver alloy).

This result provides but only a general idea of the noble metals yield; therefore the general calculation of the ore-deposits yield only can be generalized roughly; according to the entire gold grade measured by Tsho-chonelidze and Hauptmann (Tshochonelidze 1975; Hauptmann et al. 2010) and those meas-ured in lodes prehistorically mined we have to calculate with something between 4,6 g/t and 150 g/t; if we take the mean of 77,3 g and cal-culate all the ore with 6000 t in the prehistoric mining period we would end up with a yield of roughly 460 kg of gold. According to the com-paratively small cut-backs that had been found

in the beneficiation debris and in the ores we only have to account for some kilograms which have been lost during this production.

Considering the fact that the mine was operated around 300 to 400 years a yearly amount of nearly 1 kg of pure gold can be argued. When comparing a yearly yield of 7 to 20 g that a gold panner had in the Upper-Rhine in Europe in the 18th century this seems a lot (Hofmann 1991, 38).

At the end the question raises if such a production yield had a reasonable societal impact? What kind of societal importance can be assumed? Can we regard the gold-production as a whole year activity with considerable socio-economic impact or as a special-ized societal activity only on occasions? Answering such questions needs several parameters such as further information about the societies and also the settlement organization as well as percep-tion about the societal value of the gold. Gold is quiet rare in the Transcaucasian cultures of the 4th and the beginning 3rd millen-nium (Sioni group; Kura-Araxes-culture): From Late Chalcolithic and Early Bronze Ages only a few objects can be listed from archae-ological contexts such as graves. According to these rare examples (such as the Soyuq Bulaq tumulus [Lyonnet et al. 2010] or Para-vani-Khulgumo Kurgan N 1 [Kvavadze et al. 2007; Gambashidze et al. 2010a, 413 Mtsignobari-Kat Nr. 580, fig XXXIV-580; pl. G-II-8]) gold was either rare or rarely deposited as a grave good. This stands in contrast to the Martkopi-Bedeni-stage and the Trialeti culture when gold became a regular item of lavishly equipped elite-graves. Such golden objects reflect only the exclusiveness of gold in a consumers value-system; but what kind of societal

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Fig. 25: The Paravani-calculation shows the time-consumption for producing 1 g of gold in the ore-deposit of Sakdrissi in regard of the technical processes reconstructed by excavations and experiments, the Paravani earring after Gambshidze et al. 2010a.


consequences one can reconstruct from the production? Is there a possibility to calculate the societal effort to produce one of these items?

In respect of all the data that we collected from excavation, the ore-deposit and the experiments such an attempt seems prom-ising. If we take the earring of Paravani (Fig. 25) with a weight of 9.4 g of Au/Ag as an example, we could calculate its production efforts (further called the Paravani-calculation). According to our experiments we could estimate 3.46 min for the production of 1 kg of ore/rock; for the separation and beneficiation work the value is much higher and can be estimated with 224 min for 1 kg; the loss of ore- and rock cut-offs is considerable during that work; at the end only roughly a third to a quarter (measured 27%) go to a fur-ther wet panning and gold washing. All these working steps take the same time whatever gold enrichment is in the ore-concentrate. But none the less the gold grade influences directly the amount of time to produce 1 g of gold: if one calculates the amount of time according to the enrichment of Ag/Au found in mine 1/2-N-exten-sion (see above) one could end up with 42 h to produce 1 g of gold (Fig. 25)10. Regarding this amount of time it becomes clear that a low grade deposit would raise the efforts in a considerable way: wood consumption, the amount of rock extraction as well as the particular time-consuming beneficiation work is enormously increased if a lode does not contain 100 g/t but only 5 to 10 g/t in the mean. By using the Paravani-calculation it seems possible to also understand limitations that decided whether a lode was workable or not. By considering these data we also get an impres-sion how many people might have been involved to the produc-tion. If we take the Paravani-earring as an example: the heavy ring (9.4g) would have needed to be produced at least 3 days for a group of 16 persons (Fig. 25). Without integrating other data one could argue that expeditions could have sporadically reached the mining site to produce such items on special occasions (e.g. funer-als, festivals, gifts and social processes of negotiation). But if one look to the general estimate of an annual yield of 1 kg of gold one would estimate the need of 16 workers to produce this amount within 330 working days with eight hours of permanent work.

10 Other parameters such as the time-span for wood working, for preparing the tool-set (four to six hammers and one antler had been consumed to perform one fire-set with a yield of 50 kg [how many hammers break depends particularly on the skills of the miner]; therefore we generally estimate according to B. Craddocks experiences 1h for preparing the tool set for the production of 1 g Ag/Au. Also the wood working and the crucible melting can only roughly estimated according to general experiences: as all these presumptions range rather on a higher estimation-level they would not negatively influence the general calculation.

The Hinterland in MashaweraValley

If such a social-economic model can be proposed, depends also on the involvement of local populations. So it is necessary to draw attention to the regional settlement pattern. According to the recent settlement research in the Mashavera-valley there is no doubt about permanent settlements of the 4th and the beginning of the 3rd millennium; there is the large Dzedzvebi-settlement pla-teau in the centre which has a strategic position within the valley (Fig. 1; Fig. 26); it has a largeness of nearly 60 ha and can be con-sidered one of the largest in the Transcaucasus (Stllner et al. 2008; 2010; 2011); besides this area there is further evidence from one of the western side valleys (the Abanoshevi-valley) where recent res-cue excavations have brought to light occupation from the early 4th millennium (Leila-Tepe-culture/Sioni) but also Kura-Araxes-evidence11. It is interesting also to look on the intense settlement-pattern of the late 2nd mill. and the beginning of the 1st mill. BC. as a contrast. While the late Bronze Age to Early Iron Age settle-ment occupation seems more spread in various settlement cores (at the Dzezvebi-plateau but also in the village of Kazreti: Sinau-ridze 1985) the evidence of the Kura-Araxes-culture seems more concentrated to the Dzedzvebi plateau (recent reports: Stllner et al. 2008; Stllner et al. 2010; Stllner/Gambashidze 2011)12.

The Balitshi-Dzedzvebi settlement is most interesting by its chronology and its habitation structure: after six campaigns (2007-2011, 2013) our project produced a general insight into the settlement: In general the settlement-plateau can be divided into four parts, of which the first consists of a small terraced hill-ock in the north of the plateau (Dzedzvebi I). All the evidence of sherds scatter and other occasional findings allow a dating to the Late Bronze to Early Iron Age phase. The area Dzedzvebi II fol-lows in southern direction: it can be described as a slightly inclin-ing terraced area that nowadays is densely vegetated by the so-called Dzedzvi-bushes (white-thorn); a track-road that favourably cut through the whole settlement plateau enabled insight to pre-historic features on its surfaces: all the find-scatter as well the trenches opened so far produced nearly exclusively Kura-Araxes pottery, obsidian flakes and stone-implements. There once existed obviously a Kura-Araxes settlement at this area especially at the inclining slopes; north of this area some graves were discovered: it was by mere chance that the first of these graves was detected by a grave-digger while this part currently is used as the villages graveyard. Besides three graves (grave-finds 2007, grave 2/2008, 6/2011) which roughly date to the Kura-Araxes II and III-stage

11 Unpublished reports of 2012-2013 rescue-excavations: I. Gambashidze, G. Gogotshuri, G. Mindiashvili and V. Litcheli.

12 The whole settlement pattern certainly needs further detailed field work; at the moment it seems that in Late Bronze/Early Iron Age there existed some denser settled cores while such an evidence for the Kura-Araxes period is documented only for the Dzedzvebi-settlement.


a workshop-area was excavated. All of the houses date to Kura-Araxes II and can certainly be linked with metallurgical activities: while in house 1 and 2 (Dzedzvebi II.2) a multi-periodical smelting and ore/slag-crushing site was detected the evidence of house 3 (Dzedzvebi II.3) was different: house 3 consisted of a large central room of nearly 110 m2 where hundreds of grinding stones were discovered (Fig. 27.a-b); the flour-sediments have been tested and contained some smaller amounts of gold (Fig. 27.c): this gold can clearly be linked with the workshop-activities as the basaltic back-ground of the base rocks certainly provide no gold enrichments at all. Crucible fragments found at the site complete the impression that both house-complexes once formed a part of workshop-area where ores were processed (Fig. 22); this is especially true for the

time-consuming gold-ore milling. It is fatherly striking that these activities can be considered contemporary to the mining at the Sakdrisi-Kachagiani mine. The production-activities certainly had also effects on the ideology of the community: Beside some the

regular graves found in various areas of the settlement two skull burials have been brought to light, presumably containing skulls of juvenile individuals (Fig. 28). These burials obviously were bur-ied along with a special ritual: one was detected in a stone slab cist within one of the side-rooms of house 3, the other within a pit beneath the grinding work-place of the workshop in house 1/2.

Area III that is enclosed to the south has provided no proof for settlement-activities so far: it is a rather flattened areal that also forms the smallest part of the Dzedzvebi-plateau between the two

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Fig. 26: The Dzedzvebi-settlement-plateau, Mapping of survey-features and areas of excavations; graphics: DBM/RUB/GNM, A. Hornschuch.


a b

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Fig. 27: a.-b. Mapping of stone-tools, obsidian flakes, crucibles and ore pieces in house 3, Dzedzwebi II.3; c. soil samples in Balitshi-Dzedzvebi clearly mark the working of gold containing sands, as there is no gold in soils and in volcanic rocks (basalts) in the surrounding.

Fig. 28: Balitshi-Dzedzvebi, II.2-3, workshop settlement, a. cist grave with juvenile skull burial in house 3/2009; b. metallurgical workshop house 2/2013, skull burial in beneath grinding- and milling installation, Photo: DBM/RUB/GNM, Th. Rabsilber, F. Schapals

a b


river valleys of the Mashavera and the Dampudka-water-courses. The area has been investigated by small soundings in 2010: No clear set-tlement-evidence has been detected especially in its northern part. Perhaps this area was reserved for ritual activities of various kind: In area III.1 a burial ground has been excavated: the area contained two chamber burials, further small pits with cremation-remnants and three larger pits with depositions of grinding tools. The ritual vari-ety is extremely interesting as it again resembles the mental sphere of the Kura-Araxes population. Some of the tools deposited cer-tainly belonged to the gold manufacturing processes (anvil-stones, grinders, crushing plates). They were positioned to three flat stor-age-pits that may once have served as containers13 (Fig. 29). But also

13 The sediments of these pits had been completely sieved but produced not a single charred grain remnant.

the chamber burials provide some insight: both contained several individuals who got re-deposited to the north-eastern edge of the chamber; in both chambers the latest individual was buried in a seated way in the south-western part (Fig. 30). This bears a spe-cial succession of burial and re-deposition when another individ-ual was laid down to the chamber. But this seems only one part of the complex burial rites: After studying all the osteology remains a presumption won safety: parts of the vertebrae and also pelvis bones had been removed once probably during the re-deposi-tion process14. The burial-ground of area III.1 is the by-far most sig-nificant feature that allows some access to the complex mental sphere of the Kura-Araxes populations at the Mashavera-Valley;

14 All the osteology and aDNA-investigations are in responsibility of Dr. Lars Fehren-Schmitz (Gttingen, now Santa Cruz, University of California).

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Fig. 28: Balitshi-Dzedzvebi, II.2-3, workshop settlement, a. cist grave with juvenile skull burial in house 3/2009; b. metallurgical workshop house 2/2013, skull burial in beneath grinding- and milling installation, Photo: DBM/RUB/GNM, Th. Rabsilber, F. Schapals


according to the grave-gifts there is so far no indication for any dif-ferentiation in respect of richness and social status: only some calcareous beads and one or two vessels (bowl-jug combinations) have been deposited to the graves, but nearly no metal at all. There is only one exception, a burial (Nr. 2) in area II.4 that significantly also dates to the younger Kura-Araxes stage III (Martkopi-stage) (beginning and first half of the 3rd mill.), in which the tumulus-burials appeared again in the Trans-Caucasian area. The double grave interestingly was disturbed (ritually robbed?) and contained the only prestigious goods found so far: a bead chain with axe- and pick-shaped pendants of a copper alloy. Certainly the lack of pres-tigious goods in the older steps does not mean that such once did not exist in the Kura-Araxes society. Especially the lack of gold is of interest as there is inevitable proof of the gold production (see also below).

Possible settlement structures exist in the south where stone-slab plateaus forms something like a borderlines towards the settlement plateau of Dzedzvebi IV; these structures run across the Dzedzvebi-plateau but have not been extensively investigated so far; one of these plateaus got cut through by bulldozing work alongside the track-way and allowed therefore some insight in 2008: The profile that we were able to document proofed them basically as Late Bronze Age stone-settings.

Finally there is area IV (southern plateau) where the pla-teau consists of a large flat settlement ground (Fig. 31). The area

is bordered by steep flanks in the east and the west while the southern part is fortified by a section wall that hinders access from the slightly inclining terrains towards east. This situation certainly resembles the appearance of the Late Bronze Age to Early Iron Age settlement: According to excavations in 2010 and 2013 there is no doubt that the flanks were fortified: In area IV.2 a four phased fortification of the Late-Bronze Age to the Early Iron Age has been excavated: A parallel gate that obviously was blocked during its latest stage displayed the ancient access situ-ation from the south (excavation 2013). Different from our first results (Stllner et al. 2011 p 196), it also became clear that parts of older structures had been destroyed during these construction activities; nearly none of the original Early Bronze Age stratigra-phy survived; but the chronology of the pottery especially indi-cate that the older Kura-Araxes settlement spans to the first half of the 3rd millennium (Kura Araxes 3rd stage). This seems charac-teristic also for other parts at the southern plateau: Late Bronze-Age to Early Iron Age occupation is superposing the older lay-ers: a significant stratigraphy was discovered at area IV.3 (trench 4 and 5) where excavations were continued after a first sound-ing in 2010. In 2013 the older observations could be assured: the stratigraphy includes a succession of late chalcolithic lay-ers (Sioni-group) followed by a house flour of Kura-Araxes date (Fig. 32); this layers were again overlain by Late Bronze-Age to Early Iron Age layers which brought to light remains of at least

Fig. 30: Balitshi-Dzedzvebi, III.1, grave 3, photo: DBM/RUB/GNM, Th. Rabsilber.


two houses with various baking ovens of Trans-Caucasian type. The question if there was continuity between the 3rd to the late 2nd millennium cannot be answered so far: this must be said although one of the pits also provided pottery of Middle Bronze Age (Trialeti-culture) origin.

An important finding was the discovery of a crucible in one of the oldest pits of Sioni-origin: the pit was dug into the origi-nal ground and therefore must be considered as one of the oldest occupation at this area. The metallurgical crust of the crucible got analysed in the Bochum laboratory: a slight enrichment of silver was ascertained while copper-traces are not at an utilizable level at the inside of the vessel. However we interpret the crucible it is clear that it once served for metallurgical purposes most likely to smelt noble metals. Especially the silver-level stands in accordance to the silver contents of the ore-deposit (Fig 22.a).

The Chalcolithic and Early Bronze Age layers of the south-ern plateau provide valuable insight: first of all there is evidence for a longer occupation in surrounding of the noble-metal-bear-ing deposits of the Mashavera valley that lasted over a longer time span as the mining activities so far evidenced in Sakdrisi. Were there other deposits being exploited? If the southern plateau set-tlement once was of different function than the workshop-area in area II.2-3 cannot be answered yet with security. Further fieldwork is thus required to understand both the settlement parts according to their settlement pattern and economic structure.

Gold-trade: Provenance studies and a socio-economic model

To establish a reasonable model about the gold exploitation in the Mashavera-valley, we have to consider further aspects: despite the detailed results about the production of gold, the technical and social circumstances we have only little informa-tion about the consumption of gold. There are biases such as the lack of gold in regional burials especially during the older phases of mining in Sakdrisi in the 2nd half of the 4th millennium. This lack of grave-goods made of noble metals coincides with nearly all regions in the Transcaucasus; besides some seldom exceptions such as the late chalcolithic graves of Soyuq-Bulaq (Kura valley, Azerbaijan: Akhundov 2004; Lyonnet et al. 2010), noble metals are extremely rare in graves. This is somewhat surprising at the first hand. To understand this lack of evidence we have to real-ize two principal possibilities: first of all a possible reluctance to divest status objects to graves; in such a case the lack of prestig-ious noble metals would be the result of a special burial custom. Such a custom would stand in contrast to younger monumen-tal graves of the Martkopi/Bedeni and Trialeti tumulus-culture where gold items obviously got higher valued in the grave fur-nishings (in general Kushnareva 1997; Dschaparidze 2001; Kohl 2007). A second reason could be still the high exclusiveness of such items that would have been only buried on seldom occasions

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Fig. 31: Aerial photo of the southern plateau (Baltishi-Dzedzvebi IV) in 2013, DBM/RUB/GNM, M. Schaich, ArcTron, Altenthann.


at all. In such a case it would not wonder that graves with gold items were even more seldom than the generally rare Kura Araxes burials. It would be simply more difficult to discovery such burials. The case example of the Soyuq-Bulaq burial though older pro-vides a reason for such an argument. The prestigious gold, silver and semi-precious stone beads display perfectly what could be expected in these early stages. These grave-goods certainly can be listed in one line with the golden beads from the Arslantepe princely burial which resembles doubtlessly some sort of Cau-casian tradition (Frangipane et al. 2002). What kind of noble metal items might have been in use in contemporary communi-ties can be depicted easily by the objects that had been found in the Northern Caucasian Cuban area (socalled Maikop phenomen: summarizing Trifonov 1994; Govedarica 2002; Kohl 2007). We are far from a deeper understanding of the object-landscape-com-munity-entanglement that once may have existed between the various Caucasian populations. But what is fairly clear that there already was an interregional ideological sphere which for instance could be displayed in a special iconography (e.g. Mai-kop prestigious metal objects). But the positive evidence that is given by the Maikop monumental tombs also raises the question if such objects could also be expected from other communities where such items were not buried. Golden and silver vessels with depictions of animals and landscapes presumably had an impor-tant memorial value for the communities that have used them on special occasions (e.g. Kohl 2007, ppfig.??). It therefore is justi-fied to ask if such objects have been deposited in graves or in reg-ular places of commemoration or if they are simply hidden in our record by different social practices?

Considering such preconditions it was almost impossible to find a simple answer about the consumption of Sakdrisi gold:

There are only very few contemporary examples of regional gold15. According to recent archaeometallurgical work there is a fairly good knowledge about the isotopic variation of the Transcauca-sian ore-deposits and about copper and gold objects from the 4th to the 2nd millennium B.C (e.g. Courcier 2012; 2014; Hauptmann/Klein 2009; Hauptmann et al. 2010; Wolf et al. 2011). And accord-ing to the ongoing PhD-study of M. Jansen (Bochum) we are well informed about the geochemical characterization of the Sakdri-si-gold (Jansen in prep.). So we are able to understand the prov-enance of copper-objects in the surrounding and contemporary to the Sakdrisi-deposit (Courcier 2012) and we are able to compare the Sakdrisi-deposit to the generally younger gold artifacts from kurgans of the 3rd and the beginning of the 2nd mill. (Jansen in prep).

If looking first to the next gold objects found in the region one might start with the famous items from rich graves of the 3rd and early 2nd mill. The gold that has been analysed according to its chemical composition shows Ag-contents which do not fit with the natural variation of silver in the Sakdrisi-deposit. Most of these gold artefacts are generally higher in silver contents (Hauptmann 2011, 181-182). If this can be reasoned in a different primary source or is reasoned by co-smelting of different gold on occa-sions to furnish those lavishly equipped graves is matter of ongo-ing investigations (e.g. by help of isotope-data: Jansen in prep.).

If we take the copper-alloys as a possible comparison for the provenance of metals between the late 5th and the 4th mill BC the recent provenance data from the Azerbaijan Kura-valley (e.g. Mentesh Tepe, Soyuq Bulaq) enable to establish a possible

15 In addition it should be stressed how difficult it is to get permission for any geochemical analysing

Fig. 32, Balitshi-Dzedzvebi IV.3, N-profile in trench 4/2013, drawing: DBM/RUB/GNM, H.-J.Lauffer; graphics: DBM/RUB/GNM, F. Klein.


hypothesis. Most of the chalcolithic copper alloys seem to origi-nate from different deposits (the Armenian, Georgian and Azer-baijan ore-deposits of the TEMB) (Courcier 2012; 2014; Courcier/Jallilov in prep.); also EBA-metals seem to originate from further distances and not necessarily from the surroundings. So it seems that the communities of the Azerbaijan Kura-valley had access to deposits in the ore-rich mountains south of it. If this provenance-relation is correct one would expect exchange relations either with those regions and their deposits or with communities using these areas for their living (such as pastoral activities). So it certainly also would not wonder if the Madneuli-deposits (such as Sakdrisi) have been used by the late chalcolithic and EBA-Kura-basin communi-ties at the beginning. This coincides with the first evidence of noble-metal smelting at the Dzedzvebi-settlement (see above). Follow-ing the river-streams up to the southern side valleys (such as the Mashavera-valley) one certainly could reach the Madneuli-Sakdrisi region within a reasonable short time (the foot walking distance is approximately 100 km to 200 km to the sites in the Kura-Valley). Did such a demand establish a permanency in using the Mashav-era-valley deposit? What we can reconstruct from our production data is some kind of continuous production especially at the end of the 4th mill. But as argued above, the production of single pres-tigious gold items or even of a larger number would not necessar-ily imply a permanent production for instance at the beginning of the deposit use. Production of that kind could have been done also by the local communities on special occasions: if we just calculate a yearly gold yield of 1 kg (according to roughly 400-500 years of production in Sakdrisi) and if we fatherly consider the Paravani-calculation we result in a full-time professional work of around 15 persons16. If we take in account that even a larger portion of the Mashavera sedentary community was involved, the production of noble metals could have been a specialized but still a part time activity. Considering such conditions the production of gold also can be understood as a regular social practice that was carried out on special occasions (e.g. intertribal exchange gifts, funeral occa-sions, religious feasts).

According to the river-stream system it would not wonder if the late chalcolithic and EBA-communities of the lower Mashav-era and Kura-valley stood in regular relation with those communi-ties up the stream; noble and other metals may have been one of the exchange items that established relations between those com-munities and allowed intertribal exchange of all kind. This might have favoured the establishment of a more permanent exploita-tion of gold in the Mashavera valley. This should not wander as the late 4th millenium seems a time in which societal endeavours and

16 By considering a basic value of 42h for 1 g gold produced from a fairly rich deposit and 50h of working a week we end with 840 working weeks or 15 persons full-time occupation a year.

mental departures determined many societies in and around the Caucasus (see in general Hansen 2011).

But to understand these complex endeavours to spe-cial sources as a special social practice it needs further intensive research of these exchange patterns especially on the basis of fur-ther archaeological and archaeometrical research.

Postscriptum: In 2012 the Mining Licence of the Sak-drisi-Kachagiani hillock has been sold to RMG Gold Ltd. Sakdrisi=Kachagiani hillock is therefore in great danger to be destroyed in near future. The site shall be exploited to gain its gold reserves which are estimated 3.5 t of gold. All the efforts made by researchers and the Georgian public in 2013 and the beginning of 2014 still have not led to re-establish the Heritage status of Kacha-giani hillock. If this will not be happened, an extraordinary mon-ument of great scientific value will then be sacrificed to economic interests.

Appendix: Recent results from laboratory work on the gold of Sakdrisi

by Moritz Jansen, Th. Stllner and A. Courcier

1. Au, Ag and Cu contents from the prehistorically and historically mined ore lodes of Sakdrisi

In summer 2013 extensive sampling took place at the ore-lodes of the Sakdrissi mines that have been worked and exploited in ancient times; all mines (mine 1 and 2) that have been extracted down to a level of nearly 30 m below ground have been sampled in the areas of the 2004 to 2011 excavations of the Georgian-Ger-man expedition. This was important while those ore-lodes have been proven to be extracted in the late 4th millennium BC; other samples came from ancient worked areas that have been re-mined in the 5th and 6th century AD. This later re-opening reached depths down to 8m; in mine B3 it became clear that the late-antique min-ers particularly did use the un-mined lode-residues that remained at the walls of the older forerunning mine; this had been tested to have still considerable gold contents. In the field we were test-ing many of these areas positively by a portable PXRF; the tool is advantageous as it can be used even in small rifts and provides a quick result; but its limitations are the small measuring spot and the detection level that lies with gold by appr. 0,002 to 0,005 wt%, In the Bochum laboratory all the samples were re-measured by XRF and by Laser ICP-MS that allows a much better and homogenized result. These investigations have been carried out after the return of the 2013 field-season and will be presented here for the first time.

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Fig. 33 Contents of gold, silver and copper in ancient mined parts of the Sakdrisi mine; not that depart from sample 1 all the samples represent left overs being not mined in old time (either during the late 4th and early 3rd mill. BC), graphics: DBM, M. Jansen, Th. Stllner

Fig. 34: Mine 1 underground (intersected by modern explora-tion gallery): sample points and their gold content according to the analysis in the Bochum laboratory.


2. Ore fragments in Dzedzwebi

Nut-sized fragments of ore were found during the exca-vations of Areal II in Dzedzwebi. These fragments are quartzite, sometimes with small amounts of green oxide copper ores. Obvi-ously, all of them were brought to Dzedzvebi from the nearby located deposit of Madneuli and Sakdrisi (Dzedzvebi itself has basaltic base-rocks with no mineralization). We would not exclude that some of these pieces were collected to produce beads or pig-ments. Sample 8617a contains small inclusions of native copper in hematite. Other pieces are made up of hematite and quartz. Sil-ver-containing gold was observed in sample 8663 (Fig. 35) along with barite and copper sulfides, which is identical with the associ-ation of the lodes from Sakdrissi. It proves the delivery of Sakdrisi ores to the workshop-site in Dzedzvebi II.2 and II.3 (Kura-Araxes period, end of 4th mill. BC).

3. Gold earrings of Hasansu

Two golden locken-rings from Hasansu/Azerbaijan dating to the later Kura Araxes period (mid of 3rd millennium) were tested for their chemical composition (Fig. 36-37). The samples were pro-vided by Dr. Netjaf Museibli who excavated the Hasansu kurgans in West Azerbaidjan (Kura-river valley of which the Mashavera river is a tribute). The main and minor elements were analyzed by Electron probe Micro Analysis (EPMA); the trace elements were analyzed by Laser Ablation ICP Mass Spectrometry (LA-ICP-MS). The objects were compared to primary gold from Sakdrisi analyzed in the same way.

In contrast to analyzed gold objects of the third millennium from Georgia the gold of Hasansu is characterized by very low trace element concentrations (Fig. 38). Other Georgian gold objects are

Fig. 35: Dzedzvebi, Area II/2, sample 8663 Gangue of quartz (dark grey) and hema-tite (light grey) surrounded by porous vol-ume. It is caused by the oxidation pro-cesses during the natural origin of the ore deposit. Note the brilliant white inclu-sions of silver bearing gold. The associa-tion and texture in this picture is identical with ores from Sakdrisi and the one shown by Gialli (2013, 62f) from gold mineraliza-tions at Madneuli. SEM-picture, back scat-ter detection mode. Photo: M. Jansen, Deutsches Bergbau-Museum Bochum.

Fig. 36 Golden earrings of Hasansu, each weight about 3,9 and 4 g of gold, Photo: DBM/CNRS, A. Courcier by courtesy of N. Museibli, Azer-baidjan Academy of Science, Archaeological Institute.

Fig. 37 Shaft-hole axe, daggers/spearheads and flat axe and chisel from Hasansu-kurgan, Photo: DBM/CNRS, A. Courcier by courtesy of N. Museibli, Azerbaidjan Academy of Science, Archaeological Institute

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Gold in the Caucasus

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