AIA Presentation 2015

David Peterson, Ph.D.The MoDa Group and Director, Samara Ancient Metals Project

Eurasia Before the Golden Age Metal Technology and Metal Networks, ca. 3000-1500 BC

AIA, Minnesota Society and Macalester CollegeSeptember 24, 2015

structure+composi-on

Source: http://thehistoryofeuropepodcast.blogspot.com/2012/06/incredible-khvalynsk-culture-of-lower.html

Khvalynsk

KhvalynskCemeteryEneolithic,5000-4500BCE

circumpon-cmetallurgicalprovince

P r o v i n c e

Metallurgical Focus

Metalworking Focus

Metalworking Focus

Metallurgical Focus

Metallurgical Focus

Eurasian Steppe Zone Caucasus Zone

Metallurgical Focus

Metalworking Focus

Metalworking Focus

Metallurgical Focus

Metallurgical Focus

Province

ca.3500-2000BC(E.N.Chernykh1992)

CaspianSea

.Samara

arcOESstudiesofcopperandbronzefromtheEurasiansteppes

E.N.Chernykh(1970,1992);ChernykhandKuzminykh(1987)



cri-queofmethodM.Pollard,C.BaS,B.Stearn,andS.Young,Analy/calChemistryinArchaeology




leadisotopesT.Stöllner,etal.AnatolianMetalV(2011)




leadisotopesT.Stöllner,etal.AnatolianMetalV(2011)

usedinrecentmajorsyntheses2publishedbyCUP(bothin2007),1byUofCA(2008)

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

KamyshlasitesSamara,Russia,15thcenturyBCE

SamaraValleyProjectTheSamaraValleyProject:ABronzeAgeLandscapeintheRussianSteppes,editedbyD.Anthony,D.Brown,A.Khokhlov,P.Kuznetsov,andO.Mochalov.LosAngeles:CotsenIns-tuteofArchaeology,UCLA.

‘Moonscape’ofancientminepitsExcavatedcoppermineshad

KargalycomplexOrenburg,Russia

Dri&mineinKargalyca.1800-1400BCE

DridmineatKargalyca.1800-1400BC

samplesremovedbyhandwithjeweler’ssaw,mountedinbakelite,groundandpolished

•  samplesarepreserved•  analysisisrepeatable•  thesamesamplesareusedfor

electronmicroprobe,metallography,SEM-EDS,andnanoSIMS

16elementswereanalyzedbyelectronmicroprobewavelength-dispersivespectrometry(WDS),200ppmresolu-on:

•  iron•  cobalt•  nickel•  copper

•  zinc•  arsenic•  an-mony•  -n

•  sulfur•  aluminum•  silicon•  manganese

•  silver•  bismuth•  lead•  gold

metalworking casting annealing forging

ingot

object

process product / by-product

slag

mining

ore processing sorting crushing roasting

smelting

ore

ore

alloying

recycling

splash

scrap

co-smelting

metallurgicalcycle:processesandproducts

metalworking casting annealing forging

ingot

object

process product / by-product

slag

mining

ore processing sorting crushing roasting

smelting

ore

ore

alloying

recycling

splash

scrap

co-smelting

metallurgicalcycle:processesandproducts

recycling

UtevkaVIkurgancemeteryca.2000BCkurgan6,grave6

Kurgan6

arsenicvalueselectronmicroproberesultsmetalworkfromburialassemblages(Samara,Russia,3rdand2ndmillenniumBCE)

ironandan-monyelectronmicroproberesultsmetalworkfromburialsintheUtevkaVIandPotapovkaIkurgancemeteries(Samara,Russia)

PotapovkaI

UtevkaVI

SamaraR.

VolgaR.

workpaSern2worked+annealed+light-moderatecoldwork(hammering)

workpaSern3worked+annealed+heavycoldwork

chisel,UtevkaVI,kurgan6,grave6 knife,UtevkaVI,kurgan6,grave6chisel

0

5

10

15

20

25

Potapovka I Utevka VI

WP 2WP 3

21

12

16

9

comparisonofworkpaSernscopperandbronzemetalworkfromPotapovkaIandUtevkaVI

NizhnyayaOrlyanka

SpiridonovkaII SamaraR.

VolgaR.

PotapovkaI

UtevkaVI

electrumfoil-coveredpendantsfromEarlySrubnaya-PokrovkakurganburialsMiddleVolga,ca.1850-1700BCE

SpiridonovkaII

NizhnyayaOrlyanka

electronmicroproberesults*foil-coveredpendants,NizhnyayaOrlyankaandSpiridonovkaII

goldcontentisover20xgreaternearthesurface

*Dr.PeterNorthoverandDr.ChrisSalterDepartmentofMaterials,OxfordUniversity

theSEMimageshowsthatthegold-silvercrystalstructuregoestosurface

goldenrichmentwasnotcausedbyaddinganewlayerofgoldtooutsideofthefoil

goldenrichmentwascausedbyremovingsilverfromthesurfaceofthefoiltoadepthof5μm

SpiridonovkaIIpendantDP94backscaSerSEMimage

nanoSIMSmapoffoil*SpiridonovkaIIpendant

gold

silver

copper

*Dr.ZihuaZhu,EMSL(DoE),Richland,WA

ca.7μm

thereisnodiffusion

bond

thereisoverlapbetweengold-

andsilver-enrichedzones

thissupportsthehypothesisof

deple-ongilding

Gold-coveredornamentsfromotherLBAkurgangravesintheMiddleVolga(untested)

ancientdeple-ongildingAndesH.Lechtman(1973)TheGildingofMetalsinPre-ColumbianPeru.Applica/onofScienceinExamina/onofWorksofArt(W.Young,ed.),pp.38-52MesopotamiaS.LaNiece(1995)Deple-onGildingfromThirdMillenniumBCUr.Iraq57:41-47A.Hauptmannetal.(2010)GoldfromtheRoyalTombsofUr,2600BC:GildingTechniques,TumbagaAlloys,Deple-onGilding–ontheUseofaHand-HeldXRFSpectrometer.MetallaSonderheH3:57-59

Badakhshan

Royal Cemetery of Ur ca. 2600 BC

Samara Samara, ca. 1800 BC

wasthedeple-ongildingtechniquetransferredalongthesameroutesaslapis?

‘pea

rls’

DP8

8 D

P89

‘pearls’

DP88 DP89

KutulukIEBA(Yamnaya),ca.1950BCE

Inventory from Sintashta grave 30 Reconstruction of the Arkaim Settlement

SintashtapaSernMBAII,ca.2100-1800BCE

Funding² Wenner-GrenFounda-on² Na-onalScienceFounda-on² OfficeofResearch,FacultyResearchCommiSee,Humani-esandSocialSciencesResearchCommiSee,andCollegeofArt&LeSers,IdahoStateUniversity

ResearchCentersandIns2tutes² EnvironmentalMolecularSciencesLaboratory(Richland,Washington)² Ins-tutefortheHistoryandArchaeologyoftheVolga(Samara,Russia)² CenterforArchaeology,MaterialsandAppliedSpectroscopy,IdahoStateUniversity

StudentsandColleaguesfrom² UniversityofChicago² HartwickCollege

Gilded Lilies to Filthy Lucre

Technical and Behavioral Changes in Early Gold Technology in Eurasia DAVID PETERSON1, ZIHUA ZHU2, BRAD PAIGE1, PAVEL KUZNETZOV3, MONICA TROMP4, OLEG MOCHALOV3 and JOHN DUDGEON1

BACKGROUND

Gold was sought in vast quan es for elite burials by Scythians and other Eurasian steppe peoples from the 9th century BC onward [4]. Gold most o en appears in thin sheet ornaments, or as a foil covering wooden ornaments carved in the Scythian animal style. Despite this, li le is known of the gilding tech-‐niques that were u lized by steppe metalworkers before the Iron Age of the 1st millennium BC.

The neglected pre-Iron Age development of gilding in the steppes was addressed through the analysis of three ornaments recovered from burials in the Nizhnyaya Orlyanka and Spiridonovka II kurgan cemeteries in Samara, Russia (Fig. 1, 2). These cemeteries are part of the Early Srubnaya culture, and date to the be-‐ginning of the Late Bronze Age, ca. 1850-1700 BC [5, 6]. The Nizhnyaya Orlyanka pendants were recovered from kurgan 3, grave 8 at the cemetery (Fig. 3). The Spiridonovka II pendant is from kurgan 2, grave 29, which is the burial of a juvenile (11-12 years old), and probably female [7]. Spiridonovka II is reputed to be the richest Srubnaya cemetery in the Volga-Ural region [8].

PREVIOUS ANALYSIS Each ornament has an unalloyed copper core covered with electrum foil (gold+silver). In sec on, each sample’s dimensions measure about 3.75 x 3.75 mm. Analysis of the ornaments by electron probe microanalysis with wavelength dispersive spectrometry (EPMA-WDS) was performed at Oxford Materials with the assistance of Dr. Peter Northover and Dr. Chris Salter [9]. EPMA analysis of sec ons through these foils detected higher content of sil-‐ver than gold in the bulk, and more gold at the surface. This is most drama c in the Spiridonovka II girl’s pendant. This has over 95% Ag and 3.5% Au in the bulk of the foil, plus less than 2% Cu (Table 1, DP94 in-‐ner), while at the surface, there is over 73% Au and only about 24% Ag (Table 1, DP94 outer). This seemed remarkable since the foil is only 50 micrometers (μm) thick (Fig. 4), and led to the hypothesis that the foil had been gilded.

We examined the pendants further using scanning electron microscopy at Idaho State University’s Center for Archaeology, Materials and Applied Spectroscopy (CAMAS). Spectral data for each pixel in the scanned areas were collected for hypermapping (Fig. 4), in order to visualize the enrichment pa ern. Sig-‐nificant enrichment of gold on the outer surface of the Spiridonovka II pendant can be seen in Fig. 4. The gold-rich outer surface is about 5 μm thick. The EDS hypermap clearly shows the deple on of silver in the gold-rich surface (Fig. 4). The black-and-white backsca er SEM image of the same area (Fig. 4, right) also shows the forma on of regular silver-gold crystals from the interior of the foil to the surface. Gold enrich-‐ment therefore occurs within the same structure as the rest of the foil, and was not added on to it as is normally the case with gilding.

Fig. 3. Burials in the Nizhnyaya Orlyanka kur-‐gan cemetery [11].

NanoSIMS ANALYSIS The gold enrichment on the surface of the Spiridonovka II pendant was probably the result of deple on gilding, which involves the re-‐moval of silver from electrum, and not the addi on of a gold cover-‐ing to the outside of it. Deple on gilding has been iden fied this early only once before, at Ur in Early Dynas c (ED) Mesopotamia [2]. Higher resolu on analysis was needed to determine with great-‐er certainty whether the division between the gold-enriched zone and bulk of the foil shows a fusion weld from bonding separate sheets of material together, or there is a more diffuse division be-‐tween gold- and silver-rich zones from the removal of silver ions. This is a significant difference, since deple on gilding is linked to gold refinement, which was not regularly prac ced for at least an-‐other 1100 years.

To resolve this we applied nanoscale secondary ion mass spectrometry (NanoSIMS), made available through a grant of instrument me by the Environmental Molecular Sciences Laboratory (EMSL) in Rich-‐land, Washington, the first user facility in the world to provide NanoSIMS. SIMS analyzes composi on by spu ering the surface of a specimen with a focused primary ion beam, ejec ng secondary ions that are measured with a mass spectrometer. EMSL’s new genera on NanoSIMS measures the distribu on of ions of selected analytes down to 50 nanometers for element imaging, with parts per million resolu on. The map of ions of the gold and silver in the foil (Fig. 5) shows a diffuse division between gold- and silver-rich zones characteris c of deple on gilding. The pendant’s surface appears smooth and coherent due to burnishing (Fig. 2), but the SEM image from EMSL’s NanoSIMS (Fig. 5) shows that just below the surface the structure is spongy due to the deple on of silver.

FROM GILDED LILIES TO FILTHY LUCRE The heavy gold enrichment at the surface of the Spiridonovka II pendant (73% Au at the surface, compared to only 3.5% in the bulk of the electrum foil) is best explained as the product of deple on gilding by the ap-‐plica on of a solu on of minerals and salt to the surface [10]. This is corrosive to silver but not gold, and re-‐sults in a black scale that may be washed away, followed by burnishing to create a micrometers-thick “but coherent, smooth gold enriched surface” [2]. Another method of deple on gilding is by a cementa on pro-‐cess like that used at the gold refinery of King Croesus in Lydia [1] and in the Precolumbian Andes [10]. This requires prolonged hea ng of the electrum foil in a sealed pot, in contact with salt or alum as well as clay or brick dust to absorb the silver ions diffused from the bulk to the surface. This leaves a “gradual gradient in composi on from the surface down into the alloy,” and when carried out long enough will result in refine-‐ment [2]. The clear break between gold– and silver-rich zones and spongy structure of the area of gold en-‐richment fit the pa ern for the corrosion process described above. A pa ern similar to the cementa on process was found in the pendants from Nizhnyaya Orlyanka, but gold enrichment was not sufficient to con-‐clude that it was done on purpose.

In ED Ur, deple on gilding was performed by a similar corrosion process [2]. Its appearance there and the par cipa on Ur and the Bronze Age steppes in networks for the distribu on of lapis lazuli [3] suggest that knowledge of this technique may have traveled the prehistoric Silk Road with early luxuries. Deple on gilding implies the associa on of gold with beauty and greater value than the other metals that were re-‐moved and hidden below the surface of the object. It was 2000 years before technology for "gilding the lily"—giving the surface of a rare and valuable material, electrum, a more golden color—was used to refine gold. If gold was so valuable, why did it take so long for this shi to occur? The uses of gold went beyond the desire to acquire more of the precious material. Gold refinement produces a color change and a loss of mass from the removal of silver. The manipula on of electrum for bodily adornment in the Spiridonovka II pendant would have been made more difficult by purifica on; removal of all of the silver would have result-‐ed in loss of 95% of a scarce material that was already worked into a very thin foil. The mo va on for re-‐finement was not adornment, but control of the composi on of the material itself. Analysis of the earliest Lydian coins shows that slightly before refinement was introduced, electrum was struck into coins of regular weight and form as assurance of redeemability by the Lydian state [12]. Faith in this new medium for mar-‐ket interac ons, tax, and tribute was tested in its early years, crea ng a greater need to control the make-up of official currency and to sustain permanent shops [13]. Size and weight were not enough. The ideal be-‐came a pure material that remained as a commodity itself when faith in coin and state was challenged.

ONGOING RESEARCH Iden fica on of deple on gilding during the Bronze Age in the Volga-Ural steppes has led to the ques on of how widespread these techniques were in the prehistory of the surrounding region. Peterson will travel to Kazakhstan to collect samples from Bronze and Iron Age contexts in May 2013 for new analyses.

Fig. 2. Pendants from Nizh-‐nyaya Orlyanka (le and middle) and Spiridonovka II (top right). Arrows show sample loca ons. Right: The original pendant form.

Fig. 4. SEM-EDS hypermap and black and white BSED image (inset) of the Spiridonovka II pendant (values in normalized weight %).

Fig. 1. Loca on of Nizhnyaya Orlyanka and Spiridonovka II in the Middle Volga Region of Samara, Russia.

Frieze from a gold pectoral from Tolstaya mogila, Ordzhonikidze, Ukraine (Scythian, 4th century BC).

silver-rich foil (3.55% Au, 94.72% Ag) gold-rich surface (73.29% Au, 24.40% Ag)

Early gold work was not made of pure gold, but instead with a natural gold-silver alloy, electrum. Gold refining was introduced ca. 600 BC with the min ng of the first coins in Lydia, in present day Turkey [1]. 2000 years earlier, similar techniques were used in Early Dynas c Mesopotamia to enrich gold on the surface of ornaments from the Royal Tombs of Ur [2]. How widespread were these techniques, and what drove the shi in their use from the surface enrichment of gold, known as deple on gilding, to full-fledged gold refining?

We recently discovered the oldest known example of deple on gilding from the prehistoric Eurasian steppes. The steppes facilitated the movement of people, objects, and ideas as part of the pre-‐historic Silk Road [3]. Through The Silk Road Metallurgy Project, we are con nuing the inves ga on of the origins and spread of these techniques and their applica on in gilding and refining by some of the ancient world’s most avid gold consumers--Eurasian steppe pastoralists. Here we present the early stages of this research.

Table 1. EPMA results for copper, silver, and gold in electrum foil covering Late Bronze Age ornaments from the Middle Volga (in weight %).

Sample Site Cu Ag Au DP92 Nizhnyaya Orlyanka 1.75 76.09 21.86

DP93 inner Nizhnyaya Orlyanka 1.33 78.33 20.12 DP93 outer Nizhnyaya Orlyanka 1.97 67.18 30.79 DP94 inner Spiridonovka II 1.62 94.72 3.55 DP94 outer Spiridonovka II 2.27 24.40 73.29

ACKNOWLEDGMENTS A por on of the research was performed using EMSL, a na onal scien fic user facility sponsored by the Department of Energy’s office of Biological and Environmental Research and locat-‐ed at Pacific Northwest Na onal Laboratory. Acquisi on of the samples was facilitated by Peterson’s par cipa on in the Samara Valley Project (Dr. David Anthony, PI), and collec on of new samples in Kazakhstan will be done in coordina on with the Tuzusai project directed by Dr. Claudia Chang (Sweet Briar College. EPMA was performed at Oxford Materials by Dr. Pe-‐ter Northover and Dr. Chris Salter, with assistance from Dr. Blanca Maldonado. Funding was provided by the Wenner-Gren Founda on for Anthropological Research through Individual Re-‐search Grant 6760. This material is based upon work supported by the Na onal Science Founda on under Grant No. 0431940. Any opinions, findings, and conclusions or recommenda-‐ons expressed in this material are those of the authors and do not necessarily reflect the views of the Na onal Science Founda on. This work was also partly supported by the Na onal

Science Founda on under Grant No. BSC 0821783, PHY 0852060, and the Office of Research and College of Arts and Le ers, Idaho State University.

REFERENCES 1. Craddock, P.T., M. R. Cowell and M.-F. Guerra, 2000. Controlling the Composi on of Gold and the Inven on of Gold Refining in Lydian Anatolia. Anatolian Metal III: 67-77. 2. La Niece, S. 1995. Deple on Gilding from Third Millennium BC Ur. Iraq 57: 41-47. 3. Kuzmina, E. E. , 2008. Prehistory of the Silk Road. University of Pennsylvania Press, Philadelphia. 4. Parzinger, H., 2008. The Scythians: Nomadic Horsemen of the Eurasian Steppe. In UNESCO 2008, pp. 19-24.UNESCO, 2008. Preserva on of the Frozen Tombs of the Altai Moun-‐

tains. Ateliers Industria, Paris. 5. Kuznetsov, P. and O.Mochalov, 1999. Nestandartnyi rannesrubnyi kurgannyi kompleks yuga lesostepnogo Povolzh’ya. In Okhrana i Izuchenie Pamyatnikov Istorii i Kul’tury v Samar-‐

skoi Oblas 1: 59-92. 6. Kuznetsov, P., 1996. Nov’ye radiouglerodnyie daty dlya khronologii kul’tur eneolita-bronzovogo veka lesostepnogo Povolzh’ya. Arkheologiya i radiouglerod 1: 56-60. 7. Kokhlov, A. 1999. Kraniologicheskie materialy Spiridonovskogo II mongilnika (kurgan 1). Okhrana i Izuchenie Pamyatnikov Istorii i Kul’tury v Samarskoi Oblas 1: 93-97. 8. Anthony, D., and D. Brown, n.d. Srubnaya Cemetery in Kurgan 3. Samara Valley Project. Web. 16 April 2012. 9. Peterson, D., 2007. Changing Technologies and Transforma ons of Value in the Middle Volga and Northeastern Caucasus, ca. 3000-1500 BCE . Unpublished Ph.D. disserta on, Uni-‐

versity of Chicago. 10. Lechtman, H. 1973. The Gilding of Metals in Pre-Columbian Peru. Applica on of Science in Examina on of Works of Art, W. Young, ed., Museum of Fine Arts, Boston, pp. 38-52. 11. Mammonov, A.E., ed., 1997. Sergievskii raion: Drevnost’ i Srednevekov’e. Samara Pedagogical University, Samara. 12. Wallace, R.W. 1987. The Origin of Electrum Coinage. American Journal of Archaeology 91: 385-397. 13. Herodotus. Histories I: 94.

Gold coin a ributed to Croesus, ruler of the Anatolian kingdom of Lydia, ca. 550 BC (Bri sh Museum).

Fig. 5. NanoSIMS map of gold and silver distribu on in the Spiridonovka II elec-‐trum foil (red is gold, silver is green). Width of gold-rich zone is ca. 5 μm wide.

1. Idaho State University; 2. Environmental Molecular Sciences Laboratory; 3. Ins tute for the History and Archaeology of the Volga; 4. University of Otago

² SamaraStatePedagogicalUniversity

² OxfordMaterials² IdahoStateUniversity

AIA Presentation 2015

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