T O Pryce

Simon Carrignon

Mélissa Cadet

Kay Thwe Oo

Naing Saw

Thu Thu Oo

Arkar Win

Baptiste Aye

Bérénice Pradier

Peter Bellina

Petchey

Naing Oo

Arkar Aye

Baptiste ; Pradier

Bérénice Pradier

Clémence Bellina

Peter Le Meur

Miljana Petchey

T O Radivojević

Pryce

S B10 Pxrf

A Partial Prehistory of the Southwest Silk Road: Archaeometallurgical Networks along the Sub-Himalayan Corridor

Keywords: Southwest Silk Roads, Archaeometallurgy, Lead isotope analysis, Myanmar, Yunnan, Southeast Asia, Prehistory, Complex Networks Analysis, Leiden Algorithm Community Analysis Southwest Silk Roads, Archaeometallurgy, Lead isotope analysis, complex networks, community detection, Myanmar, Yunnan, Southeast Asia, Prehistory

de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

The 'Silk Road' (SR) has been a source of perennial academic and public interest since the term was introduced in the late 19 th century (von Richthofen 1877), but the historiography of the concept can be traced to the medieval [START_REF] Polo | The Travels of Marco Polo[END_REF]) and antique [START_REF] Claudius | Geographia[END_REF] periods. The diachronic, predominantly, east-west interactions represented by the SR are widely acknowledged to have massively stimulated the civilizations of participating populations, with long-distance movements of goods, far more varied than those implied eponymously, modes of thought, technologies and people. It is a truism to state the SR's pertinence to the modern world, encapsulated since 2013 by China's 'Belt and Road Initiative', but the SR's origin has been a longstanding topic of discussion, and one complicated by the fact there are numerous 'roads'. Of course, the SR of popular imagination involves camels and caravanserai spanning the desertic steppe, and these routes (there are many) are indeed of massive importance historically; and of particular relevance to the history of metallurgy in eastern Asia (e.g. [START_REF] Linduff | Metallurgy in Ancient Eastern Asia: Retrospect and Prospects[END_REF]. However, this paper concerns the origins of the Southwest Silk Road (SSR), which remains less well known than their supra-Himalayan counterparts, or even their nautical variants, the Maritime Silk Roads (MSR) (e.g. [START_REF] Bellina | Maritime Silk Roads' Ornament Industries: Socio-political Practices and Cultural Transfers in the South China Sea[END_REF][START_REF] Bellina | Southeast Asian early Maritime Silk Road trading polities' hinterland and the sea-nomads of the Isthmus of Kra[END_REF].

In Mandarin, the SSR is known as the 茶馬道, or 'Tea Horse Road', these being the chief goods known to have moved to the Chinese imperial capital of Chang'an in Shaanxi province. The SSR routes varied over time, with four main variations attested historically for the mid-1 st to early 2 nd millennia AD (Figure 1), connecting Chang'an to Chengdu in Sichuan province, Dian/Dali in Yunnan province, before continuing west to northern Myanmar (Mian), Bangladesh, India (Yandu); while alternate branches went south to northern Vietnam (Jiaozhi), Laos, Thailand and Cambodia [START_REF] Yang | Horses, Silver, and Cowries: Yunnan in Global Perspective[END_REF][START_REF] Yang | Between Winds and Clouds. The Making of Yunnan. Second Century BCE to Twentieth Century CE[END_REF]. Knowledge of earlier, pre-3 rd c. AD, SSR routes is limited to Yunnan, Sichuan and Shaanxi provinces (plus Jiaozhi, northern Vietnam, Figure 2) as the other Mainland Southeast Asian (MSEA) territories were, at that juncture, 'prehistoric'. With this paper, we wish to question whether these trans-regional montane and riverine social interaction networks linking MSEA and southern China may be older, possibly considerably older, than the textual sources allow for. Archaeological evidence for horses and tea in early China is quite abundant (e.g. [START_REF] Jiang | The analysis and identification of charred suspected tea remains unearthed from Warring State Period Tomb[END_REF][START_REF] Li | Early evidence for mounted horseback riding in northwest China[END_REF][START_REF] Lu | Earliest tea as evidence for one branch of the Silk Road across the Tibetan Plateau[END_REF][START_REF] Wan | The Horse in Pre-Imperial China[END_REF]) but practically absent from prehistoric Southeast Asia. Therefore, alternative means of identifying proto-SSR interaction networks must comprise materials that a) might have been exchanged, and b) might be detected archaeologically. Within the Maritime Silk Road system, Southeast Asian forest products, including exotic woods, resins and spices, were famously in demand by more westerly consumers, located as far as the Mediterranean basin [START_REF] Bellina | Southeast Asian early Maritime Silk Road trading polities' hinterland and the sea-nomads of the Isthmus of Kra[END_REF][START_REF] Bellina | The archaeology of early contacts with India and the Mediterranean World from the fourth century BC to the fourth century AD[END_REF]. It is certainly conceivable that some of these materials were not available in southern China, despite some overlap in ecological conditions, and that detailed and fortuitous future MSEA sampling programmes could recover evidence for their being supplied north; as per the recent association of sappanwood and lead and copper ingot exchange in a 17 th c. AD wreck in the Gulf of Siam [START_REF] Venunan | A royal wreck? Morpho-technological, elemental and lead isotope analysis of ingots from the Bang Kachai II shipwreck, Thailand[END_REF]. More readily identifiable would be the exchange of semi-precious stones, for which there are precedents in the form of Taiwanese nephrite [START_REF] Hung | Ancient jades map 3,000 years of prehistoric exchange in Southeast Asia[END_REF], agate and carnelian beads produced by highly skilled artisans [START_REF] Bellina | Beads, social change and interaction between India and Southeast Asia[END_REF][START_REF] Bellina | Southeast Asian early Maritime Silk Road trading polities' hinterland and the sea-nomads of the Isthmus of Kra[END_REF], as well as recent evidence The bulk of archaeological sites concerned for our new data: HL30-1, HL29, HL29-1, HL28 and HL-TP1, are located in the southwestern environs of the UNESCO-listed Pyu citystate of Halin, (museum, 95.818957°E, 22.453651°N), ca. 15 km west of the Irrawaddy River in Sagaing Division (Figure 3). The monumental ruins of the Pyu city account for Halin's fame but the presence of prehistoric deposits spanning back to a mid-3 rd millennium Neolithic, as well subsequent Bagan remains, allows the possibility of investigating over 4000 years of Myanmar's history; from first farmers to the formation, and decline, of the first states (Pryce et al. in press). Understanding the impact of external cultural influence is essential to this endeavour, and the SSR in its developed and nascent forms could conceivably have played a significant role. Reconstructing social interaction networks is a task well-suited, for post-Neolithic societies, to archaeometallurgy and, in particular, lead isotope-based provenance research (Pryce et al. 2022a;2022b). HL29-1, HL30-1 and HL-TP1 were excavated by the Mission Archéologique Française au Myanmar between 2017 and 2020, while HL28 and HL29 were excavated by Myanma archaeologists in 2009-2010. HL29-1 was a multiphase deposit with a Bronze Age cemetery, Pyu cremation burials and Bagan occupation deposit. HL30-1 contained a Neolithic cemetery, a Bronze Age occupation deposit and an Iron Age cemetery. HL-TP1 was a mid-Bronze Age, Iron Age, Pyu and Bagan period occupation and salt production locale. HL28 and HL29 were Iron and Bronze Age cemeteries, respectively, whose assemblages were sampled by the lead author in 2019. For a summary of Halin archaeology see Pryce et al. (in press). A total of 38 Halin copper-base artefacts spanning over 2000 years of metal consumption were analysed, including: four axes, four bangles, six rings, seven bells, five spearheads, ten wires, one casting spillage and one plate-like fragment (Figure 5, Table 1). Their typological, technological, elemental and lead isotopic data add to the 32 published Myanmar samples [START_REF] Dussubieux | Myanmar's role in Iron Age interaction networks linking Southeast Asia and India: Recent glass and copper-base metal exchange research from the Mission Archéologique Française au Myanmar[END_REF]Pryce et al. 2018a;2014). In the absence of early copper mining and smelting evidence in Myanmar, as well as geological data generally, we also collected 25 geological samples from nine copper mineralisations in Sagaing Division, Mandalay Division, Kachin State and Shan State, to gain some handle on regional geological variation (Figure 3, Table 1). The three southern Myanmar samples come from the littoral settlement of Maliwan (98.623468°E, 10.324234°N), recently excavated by the French Archaeological Project in Peninsular Myanmar and Thailand [START_REF] Bellina | Myanmar's earliest Maritime Silk Road port-settlements revealed[END_REF]

Methodology

Optical Microscopy (OM)

The metal samples were mounted in epoxy resin, ground with silicon carbide paper (from 800 to 4000 grits) and then polished using diamond suspensions (1 and 0.25 µm). After etching with alcoholic ferric chloride, microstructural evidence for thermo-mechanical treatments was investigated using an optical microscope (Leica DLLM). Mineral samples were not studied by OM.

X-ray Fluorescence (XRF)

XRF was used for the OM samples' bulk elemental composition of major, minor and (some) trace elements, conducted at the Laboratoire Archéomatériaux et Prévision de l'Altération (LAPA-IRAMAT/CEA) in Saclay, France. XRF data were acquired using a NITON XL 3t GOLDD+ portable XRF analyser in 'laboratory mode' (fixed stand), with a max 40 kV accelerating voltage in the 'alloys' mode. Accuracy and precision were assessed with eleven Certified Reference Materials (Table 2). Good results for majors and minor components were confirmed but note that light elements at low concentrations like phosphorous, silicon, aluminium, magnesium and sulphur were not reliably detected due to non-vacuum conditions. The analyses were performed on the OM mounted and polished sections using a 3 mm beam diameter, which allowed for reliable results as long as the sample was larger than this. Three such spot analyses were made for each sample to account for corrosion and inclusions. Small and/or corroded OM/XRF samples were carbon coated for analysis in a JEOL 7001F instrument, in order to establish the bulk composition of samples less 3 mm in diameter, those with intergranular corrosion, and to study any inclusions. Both secondary electron (SE) and backscattered electron (BSE) modes were used, using a 20 kV accelerating voltage, a 10 mm working distance with an Oxford Silicon Drift Detector, and processed using Oxford Instruments Aztec software.

The detection limit was fixed at 0.5 wt.% with a count rate of 4000/s (detection time of 40 s), which gave good spectral resolution with respect to background noise. We consider the relative quantification error (2 σ) is circa 10% of the measured value. SEM-EDS accuracy was evaluated using the same CRMs as used for the pXRF analysis, and we obtained good results for the major elements ( [START_REF] Manhes | Lead isotope study of basic-ultrabasic layered complexes: Speculations about the age of the earth and primitive mantle characteristics[END_REF]. Thallium NIST SRM 997 was used to correct for instrumental mass bias and all parameters were adjusted to obtain the closest values relative to NIST SRM 981, as determined by DSTIMS [START_REF] Thirlwall | Multicollector ICP-MS analysis of Pb isotopes using a 207Pb -204Pb double spike demonstrates up to 400 ppm/amu systematic errors in Tl-normalization[END_REF]. More details about SARM-CRPG lead isotope analysis are available in [START_REF] Aebischer | Disruption of the geochemical metal cycle during mining: Multiple isotope studies of lake sediments from Schefferville, subarctic Québec[END_REF][START_REF] Cloquet | Atmospheric pollutant dispersion around an urban area using trace metal concentrations and Pb isotopic compositions in epiphytic lichens[END_REF].

As per the SEALIP/BROGLASEA programmes, LIA was used to look for 'consistency' with known and characterised production systems, in recognition that there could be other, as yet uncharacterised, primary and/or secondary production systems, as well as mixing, alloying and recycling impacting interpretation (e.g. Budd et al., 1993;[START_REF] Pryce | More questions than answers: the Southeast Asian Lead Isotope Project 2009-2012[END_REF]Pryce et al., , 2011b;;Wilson and Pollard, 2001). These consistencies were judged by proximity of data points on

Complex networks analysis

As this paper will evoke with examples from the internally-manageable Myanma LI datasets, manual LI interpretation is unsuited to detecting pertinent anthropological patterning in very large datasets. Therefore, the available LI data for all Bronze Age metal objects, ores and slags from MSEA and southern China were processed using a complex networks analysis approach termed 'community detection' (or modularity analysis). Previous applications in southeastern Europe used the 'Louvain' algorithm [START_REF] Radivojević | Community structure of copper supply networks in the prehistoric Balkans: An independent evaluation of the archaeological record from the 7th to the 4th millennium BC[END_REF] as applied to elemental data but here we opted for an improved 'Leiden' algorithm [START_REF] Traag | From Louvain to Leiden: guaranteeing wellconnected communities[END_REF] for our LI data, although both Louvain and Leiden algorithms present similar robustness on archaeological data (Grujić & Radivojević forthcoming). Our application of complex networks analysis in this paper is novel and required substantial method development, which will be detailed in the discussion (and available at https://github.com/simoncarrignon/bronze-age-ssr). We do not consider our method definitive but do contest that it is offering reliable and archaeologically/geochemically-justified preliminary rationalisations of large datasets that merits dissemination at this juncture.

Our current protocol requires a definition of 'consistency' for lead isotope ratios that takes into account Southeast Asia's and southern China's high geological diversity as well as the variability of known prehistoric copper production LI signatures. For each of the three 204 Pb-denominated ratios (those most geologically sensitive), the difference between any pair of artefacts' LI ratios must be as small or smaller than our production-defined thresholds in ordered to be considered potentially consistent -i.e. subject to human evaluation of the algorithmic proposition. Applying this measure to the whole dataset allows us firstly to identify groups/modules of artefacts that exhibit the strongest connections within the group and weaker connections outside of it, as outlined by [START_REF] Radivojević | Community structure of copper supply networks in the prehistoric Balkans: An independent evaluation of the archaeological record from the 7th to the 4th millennium BC[END_REF]. Secondly we calculate the same strength/weakness of connectivity but now between sites/assemblages, using the principle that if a high density of artefacts from sites belong to the same module, those sites potentially share a meaningful link. Halin HLTP1 ring fragment bdl bdl 0,4 bdl bdl bdl bdl bdl bdl bdl 0,0 0,1 1,4 bdl bdl bdl bdl 0,1 97,1 bdl bdl 0,1 bdl 0,1 0,0 bdl bdl bdl bdl bdl bdl bdl 99,3 pXRF Low leaded copper Hammered/annealed 38 SEALIP/MY/MLW/1 Maliwan fragment bdl bdl 0,1 7,6 bdl bdl bdl bdl bdl bdl 0,0 0,1 13,4 bdl 0,5 bdl bdl bdl 78,1 0,1 bdl bdl bdl bdl bdl 0,1 bdl bdl bdl bdl bdl bdl 100,0 pXRF Low leaded bronze As cast 39 SEALIP/MY/MLW/2 Maliwan fragment bdl bdl 0,7 19,4 bdl bdl bdl bdl bdl bdl bdl 0,1 3,5 bdl 0,6 0,0 bdl bdl 75,0 0,1 0,1 0,4 bdl bdl bdl 0,1 bdl bdl bdl bdl bdl bdl 100,1 pXRF Medium leaded bronze As cast 40 SEALIP/MY/MLW/3 Maliwan fragment bdl bdl bdl 0,1 bdl bdl bdl bdl bdl bdl 0,0 0,7 0,0 bdl 0,0 bdl bdl bdl 98,4 bdl bdl 0,1 bdl bdl bdl bdl bdl 0,8 bdl bdl bdl bdl 100,0 pXRF Medium copper As cast 41 SEALIP/MY/BAW/1 Baw Mountain, Kyaukse Cu mineral 72,4 4,6 0,2 bdl bdl bdl bdl bdl bdl bdl bdl bdl 0,1 bdl 0,1 bdl bdl bdl 3,3 bdl bdl 0,3 0,1 bdl bdl bdl bdl 6,4 bdl bdl 12,3 bdl 99,7 pXRF Mineral 42 SEALIP/MY/BAW/2 Baw Mountain, Kyaukse Cu mineral 60,8 2,4 0,5 bdl bdl bdl bdl bdl bdl bdl bdl bdl 0,9 bdl 0,6 bdl bdl bdl 5,4 bdl bdl 0,7 bdl bdl bdl bdl 0,3 3,0 bdl bdl 24,9 bdl 99,7 pXRF Mineral 43 SEALIP/MY/BAW/3 Baw Mountain, Kyaukse Cu mineral 55,5 0,1 0,3 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 0,2 bdl bdl 0,5 1,4 bdl bdl 1,5 bdl bdl bdl bdl 0,3 5,8 bdl bdl 33,5 bdl 99,1 pXRF Mineral 44 SEALIP/MY/BWD/1 Bawdwin Cu mineral bdl bdl bdl 0,1 bdl bdl bdl bdl bdl bdl bdl bdl 42,9 bdl 3,6 bdl bdl 0,2 37,0 0,5 0,3 0,1 0,1 bdl bdl bdl bdl 13,2 bdl bdl Elemental & OM:

Results

F

The Halin samples exhibit only three alloy classes (Table 3), using the conventional alloying cutoff of 1 wt. %, with bronze predominating (21), followed by copper ( 14) and lastly leaded copper (2).

Notwithstanding the majority of medium-high corrosion levels (9+13 vs 15 'low') likely obscuring original tin and lead contents, and thus reducing the potential to identify modality in the elemental data, our samples are clearly regionally atypical in that the Iron Age samples are almost all unleaded. This is mainly visible in the HL28 assemblage, which consists in part of wire bundles of a near-pure copper (97-99 wt. % Cu, Sn & Pb not detected), likely representing raw, at most part-refined, product from the smelter, which could have served as highly frangible commodity money [START_REF] Dussubieux | Myanmar's role in Iron Age interaction networks linking Southeast Asia and India: Recent glass and copper-base metal exchange research from the Mission Archéologique Française au Myanmar[END_REF], but also of small bronze and copper bells and rattles that would usually be leaded alloys in the MSEA Iron Age, so as to improve castability in a decorative object. The only definitely leaded Halin artefacts are a leaded copper ring from an Iron Age HL29-1 context, and a leaded copper ring fragment from Bagan period HLTP1. Of the Maliwan artefacts, two are leaded bronze and one is copper but the lack of typology does not allow us to assess the suitability of alloy to usage. In terms of working techniques, the study artefacts are predominantly as cast (29), followed by hammered/annealed (5), hammered (1) and annealed (1), with the remainder (4) too corroded for microstructures to be visible (Figures 678). As our majority metal artefact class is that of Iron Age raw copper wires, it is striking that they are all cast, as opposed to drawn or hammered. The Iron Age raw copper pseudo-spearheads were also left as cast, which is commensurate with our interpretation of them as ingots or commodity money, and not weapons or tools. We note that the Bronze Age axes from HL29 and HL29-1 were also as cast or too corroded to tell, whether they were produced in copper or bronze, which suggests they were never thermomechanically-treated for use as tools or weapons, nor work-hardened through use, and were thus possibly produced explicitly for funerary rites (as per Bronze Age Ban Non Wat axes, Pryce 2011). Surprisingly, the only artefacts to present evidence of thermal and/or mechanical treatments are an Iron Age copper bell or rattle from HL28 and a selection of Bronze Age bronze bangles and rings from HL29-1, as well as two Bagan period leaded copper rings from HL29-1 and HLTP-1. The three Maliwan artefacts were as cast but as they are fragmentary we cannot evaluate their original use. The Halin elemental results exhibit a low variability when compared with other Myanmar copperbase metal datasets, which reveal six alloy types: two Bronze Age fragments from the Oakaie area approach the threshold of 'arsenical bronze'; one Iron Age bangle from Kokkokhahla composed of arsenical copper; 18 Bronze and Iron Age ornament and tool fragments made from bronze, 17 Iron Age wires and pseudo-spearheads made from copper; one Iron Age high-tin bronze bowl fragment from Supan; one Bronze Age socketed small spearhead or large arrowhead from Nyaung'gan in leaded copper (Pryce et al. 2018a: Table 2). As per Halin, there is a clear tendency for Iron Age copper and Bronze Age bronze but again, this is likely to be by virtue of the older artefacts being definite finished products whereas the later wire bundles and pseudo-spearheads appear to constitute a specific aspect of regional funerary tradition, potentially deposits of commodity money [START_REF] Dussubieux | Myanmar's role in Iron Age interaction networks linking Southeast Asia and India: Recent glass and copper-base metal exchange research from the Mission Archéologique Française au Myanmar[END_REF].

The lower number of alloy classes at Halin is due to the absence of high-tin bronzes, which are an exotic class in MSEA, likely representing mid-late 1 st millennium BC exchange systems with South Asia [START_REF] Bennett | The high-tin bronzes of Thailand[END_REF]Pryce & Bellina 2018). There is only one other high-tin bronze ) and, given the extensive monumental and textual evidence for Indian influence at Halin, it is probable that such alloys exist there but haven't been excavated and/or identified yet. The other minor alloying constituent apparently absent from Halin is that of arsenic, which we will come back to in light of lead isotope data.

Lead Isotope Analysis: Our presentation and interpretation of these data proceeds in stages, from new Myanmar artefact data, all Myanmar artefact data, the addition of Myanmar mineral data, comparison with regional (MSEA and Yunnan) production, and finally Bronze Age consumption data to assess potential evidence for proto-SSR interactions. This layering is intended to make our interpretative process more transparent, as is our use of simple double biplots that capture all possible isotope variation, and the provision of full tabulated raw data (Table 4). To remind the reader, for artefacts to have lead isotope consistency, they must plot together on both graphs.

All our new data plot within known ranges for Southeast Asian artefacts. Within the data cloud, only two clusters appear at this stage, C1 and C2 (Figure 9). C1 comprises SEALIP/MY/HL28/3-9+11 and SEALIP/MY/HL29/1-3 but not SEALIP/MY/HLTP1/1, which does not have a compatible 207 Pb/ 204 Pb ratio. C2 comprises SEALIP/MY/HL29-1/1-4+7, SEALIP/MY/HL30-1/1, SEALIP/MY/HL28/10 and SEALIP/MY/HLTP1/2 but not SEALIP/MY/HL29-1/8 or SEALIP/MY/MLW/3, which do not have compatible 207 Pb/ 204 Pb ratios. Thus, from the new data we can distinguish two possible shared sources of raw copper or recycled bronze, C1 composed of Iron Age copper wires and copper pseudo spearheads, and C2 composed of Bronze Age bronze bangles, Iron Age bronze casting spillage and a Bagan period bronze ring. The remaining data are somewhat dispersed but can be compared to previous Myanmar artefact data (Figure 10).

The clustering of these data indicates that C1 also includes SEALIP/MY/MT/1 and SEALIP/MY/NGO1-3 & 5-10, Iron Age raw copper pseudo-spearhead and wires, respectively. As per our previous study (Pryce et al. 2018a), the proliferation of unalloyed copper suggests C1 represents an as yet unlocated primary (smelting) production centre. Similarly, C2 is expanded with the addition of SEALIP/MY/OAI/2, SEALIP/MY/OAI3/2-4, SEALIP/MY/MHT/3 and SEALIP/MY/SP/1; in order, a Bronze Age leaded1 bronze platy fragment, Bronze Age bronze bracelet and ring fragments, a Bronze Age bronze ring fragment, and an Iron Age high-tin bronze bowl, respectively, which suggests C2 could represent a secondary (foundry) production signature. We now also distinguish C3, comprised of SEALIP/MY/OAI1/1 and SEALIP/MY/HL28/15 & 18; a Bronze Age bronze axe and Iron Age bronze bells/rattles. C3 could potentially include SEALIP/MY/MHT/1, a Bronze Age bronze fragment, but there is ca. 5% divergence in 208 Pb/ 204 Pb ratios. Given that all the C3 samples are alloyed, we tentatively, given low sample numbers, suggest the signature represents a secondary production centre.

Regarding the few Myanmar artefacts with significant arsenic contents, the Kokkokhahla samples were never submitted for lead isotope analysis, as their weak context did not justify the expense. However, the two Oakaie samples (SEALIP/MY/OAI/1 & SEALIP/MY/OAI3/3) plot relatively close together for 206 Pb/ 204 Pb and 207 Pb/ 204 Pb but differ by ca. 2.5% on 208 Pb/ 204 Pb ratios. Given these samples are more 'urogenic', having a higher proportion of lead decayed from 238 U, this could increase the variability of their constituent lead derived from 232 Th decay, 'thorogenic'. The other samples plotting in this area, SEALIP/MY/MOH/1 & SEALIP/MY/HL29/4, do not contain measurable quantities of arsenic. Among the remaining data there are hints of further consistency but insufficient sample numbers to propose tentative groups, certainly without reference to potential copper production signatures. As stated in the introduction, our mineral samples do not necessarily come from regions known or even suspected of having ancient metal production. They were analysed in order to gain an appreciation of lead isotope variation in north-central Myanmar copper mineralisations, in the absence of published geological data. As per the rest of MSEA, Figure 11 shows there is a significant dispersion in these mineral signatures; so much so that we have excluded some far outliers from the graphs as the other results would be hard to read. In light of the new Myanmar artefact data, our (Pryce et al. 2018a) interpretation of Letpadaung mine being unrelated to ancient copper production holds (cf. [START_REF] Moore | Nyaung-gan: A preliminary note on a Bronze Age cemetery near Mandalay, Myanmar (Burma)[END_REF]. The Yang Tse Copper sample2 differs considerably from that of Letpadaung despite their physical separation of just over 5 km, suggesting the two mineralisations are of different geological formations, as seen at Phu Lon in northern Thailand (Pryce et al. 2011b). Nevertheless, neither of the modern Monywa mines are consistent with ancient metal samples, with the vaguely possible exception of SEALIP/MY/HL28/13, an Iron Age bronze bell.

Of the other mineralisations, sampled from copper minerals rather than modern ingots, it can be seen that both Kawlin and Baw Mountain have very tight and distinct signatures, which do not correspond to any metal artefacts (Figures 3 & 13). Pala Dauk Hter Taung's signature is more dispersed in its 206 Pb/ 204 Pb ratios but two of the samples appear compatible with SEALIP/MY/HL29/6, a Bronze Age bronze axe. However, we strongly discount the reliability of this link due to the absence of archaeological evidence for early exploitation (or even habitation) in that locality. The Mingan samples have substantial urogenic and thorogenic variation and are inconsistent with any metal samples. Thabeik Kyinn has more dispersion than the aforementioned Kawlin and Baw Mountain mineralisations, but considerably less than the Mingan and Pala Dauk Hter Taung samples. Of note, two of its samples fall within the C2 cluster defined above, which is interesting as this mineralisation is located only ca. 50 km from Halin, some of whose metal samples are also C2 compatible. Ancient production is not known at Thabeik Kyinn but these results suggest it should be checked.

Finally, there are two clusters, C4 and C5, that are extremely intriguing in terms of primary copper production centre potential. The native leaded copper and malachite samples from Bawdwin, a lead/silver mine known to be operated up to 500 years ago (LaTouche & Brown 1909), plot closely together (C4) and are highly consistent with a leaded copper ring from HL29-1 (SEALIP/MY/HL29-1/8). HL29-1 is primarily a Bronze Age cemetery but this ring was found in context #1018, which is a jar burial dating to the Bagan period (Pryce et al. in press). This association suggests, albeit on the evidence of one archaeological find, that Bawdwin metal production could be twice as ancient as previously thought, up to 1000 years old. This proposition is supported by C5, which although having a more urogenic lead isotope signature, represents copper minerals from Nant Twin in association with artefact signatures from OAI3 (SEALIP/MY/OAI3/7, a possible bronze cutting tool) and HL29 (SEALIP/MY/HL29/4, a bronze axe). The difference is that these artefacts are both dated to the Bronze Age, which could thus push Shan State copper production back another two [START_REF] Zou | Investigation of early Bronze Age civilizations in Yunnan: a scientific analysis of metallurgical relics found at the Guangfentou ruins in Jiangchuan[END_REF]. C6 is a cluster we consider identifiable once regional copper production data are included. Error bars are smaller than symbols.

Nevertheless, it is clear that the majority of the Myanmar metal samples are not consistent with the studied minerals, and we can thus look towards other, proven, prehistoric copper production systems in MSEA and southwest China (Figures 3 & 12). Within the former these are limited to the Khao Wong Prachan Valley (KWPV) in central Thailand [START_REF] Pigott | Archaeology of copper production: Excavations in the Khao Wong Prachan Valley, central Thailand, in South-East Asian Archaeology[END_REF], Phi Lon (PL) in northern Thailand [START_REF] Pigott | Mining archaeology in geological context. The prehistoric copper mining complex at Phu Lon, Nong Khai Province, northeast Thailand[END_REF] and the Vilabouly Complex (VC) in central Laos [START_REF] Pigott | Prehistoric Copper Production and Exchange in Southeast Asia[END_REF][START_REF] Tucci | Ancient Copper Mining in Laos: Heterarchies, Incipient States or Post-State Anarchists?[END_REF]), all of which have been geochemically characterised within SEALIP/BROGLASEA [START_REF] Cadet | Laos' central role in Southeast Asian copper exchange networks: A multi-method study of bronzes from the Vilabouly Complex[END_REF]Pryce et al. 2011c;2011b;2014). Within the latter, there is no doubt that there are likely to be a great many metal production loci in this strongly metallogenic region but we can only go by what has been identified and published: Guangfentou in Yunnan [START_REF] Zou | Investigation of early Bronze Age civilizations in Yunnan: a scientific analysis of metallurgical relics found at the Guangfentou ruins in Jiangchuan[END_REF] and Raojiadi in Sichuan [START_REF] Chen | Alloy ratio and raw material sourcing of Warring States Period bronze bracelets in Huili County, Southwest China by pXRF and MC-ICP-MS[END_REF].

Guangfentou, Phu Lon and Raojiadi all have rather dispersed isotopic signatures, doubtless representing multiple mineralisations at the same mine (as at Phu Lon, [START_REF] Kamvong | The origin and evolution of skarn-forming fluids from the Phu Lon deposit, northern Loei Fold Belt, Thailand: Evidence from fluid inclusion and sulfur isotope studies[END_REF], or the processing of ores from multiple mines (as proposed for Guangfentou by [START_REF] Zou | Investigation of early Bronze Age civilizations in Yunnan: a scientific analysis of metallurgical relics found at the Guangfentou ruins in Jiangchuan[END_REF] but Figure 12 clearly indicates that C1, which has a very tight signature, is not compatible with the known copper production sites, and thus remains an unknown. However, C2 is highly consistent with the Vilabouly Complex in central Laos, a primary rather than secondary copper signature as suggested above. A potential 1300+ geodesic kilometre Bronze Age exchange system was identified previously with Oakaie/Nyaung'gan artefacts (Pryce et al. 2018a) but with the Halin material it now extends through the Iron Age and as far as the Bagan Period. Of course, old artefacts could have been recycled over time but, in our opinion, it is unlikely the original isotopic signature would hold after perhaps centuries of reuse: mixing, alloying and recycling (see e.g., [START_REF] Bray | Form and flow: the 'karmic cycle' of copper[END_REF][START_REF] Liu | Social hierarchy and the choice of metal recycling at Anyang, the last capital of Bronze Age Shang China[END_REF].

C3, as tight as C1 but not as dense, and representing Bronze and Iron Age consumption remains without consistency. Neither are C4 and C5 compatible with the other known production signatures, suggesting our linking them to Bawdwin and Nant Twin Lashio mineralisations holds for the time being. At this stage we believe we can add C6 to our list of possible groups, with consistency seen between the Khao Wong Prachan Valley copper production signature (Figure 8). This ca. 1000 geodesic kilometre exchange route was already detected with a Bronze Age bronze bracelet from Oakaie 3 (Pryce et al. 2018a), which we can now reinforce with SEALIP/MY/HL29/8, a bronze spearhead. It is pertinent that C6 does not seem to extend into the Iron Age as, after many years of uncertainty, the latest radiometric dating from the Khao Wong Prachan Valley suggests that metal production there did not persist beyond the Bronze Age [START_REF] Higham | A prehistoric copper-production centre in central Thailand: its dating and wider implications[END_REF]. SEALIP/MY/HL28/13 & 14 are not C6 members as they are incompatible in their 207 Pb/ 204 Pb ratios. We do not consider SEALIP/MY/NYG/1 a C6 member, despite its high isotopic consistency, as it is a leaded alloy and C6 is a copper signature.

Having now assessed the Halin (and Maliwan) data with respect to: 1. themselves, 2. all Myanmar artefacts, 3. Myanmar minerals, and 4. MSEA and southwestern Chinese production systems, the next logical step would be 5. MSEA and southern Chinese consumption data. Our recent investigations of northern MSEA/southern Chinese exchange systems have attempted this stage manually, with reasonable results for the existence of late 2 nd through 1 st millennium BC networks running from Yunnan to Vietnam, Thailand and Myanmar (Pryce et al. 2022a;2022b). Our substantial new Myanmar dataset, which covers over two millennia, offers the possibility to [START_REF] Yang | Horses, Silver, and Cowries: Yunnan in Global Perspective[END_REF]). Manual processing of Myanmar data with regards to the 'late 2 nd /early 1 st millennium BC interaction arc between Mainland Southeast Asia and Southwest China' identified in Pryce et al. (2022b) indicates:

 The present study's group C1 is compatible with SEALIP/CH/HBS/4, a 800-600 BC (Mid Bronze Age) flat copper fragment from Hebosuo on Lake Dian in Yunnan. This does not necessarily mean the C1 source is in the Dian area but that its product was accessible to communities in north-central Myanmar and Yunnan. As C1 samples are mostly mid-late 1 st millennium BC, we can thus draw our proto-SSR network closer to the above-depicted historical SSR.  C2, which is highly consistent with the Vilabouly Complex copper production signature, is also compatible with SEALIP/TH/BC/1 & 4, a bronze socketed spearhead and O-section bangle from Bronze Age Ban Chiang in northeast Thailand. A great many MSEA artefacts are consistent with this production signature and its output spans the Bronze and Iron Ages, thus linking to the historical SSR.  C3 is not consistent with previously identified groups outside of Myanmar.  Neither is C4 but as our only dated artefact in this group is dated to the Bagan period, early 2 nd millennium AD, we have very few comparative regional data.  The urogenic C5 could include potentially include SEALIP/TH/BNW/6, a 1000-900 BC copper axe from Ban Non Wat in northeast Thailand.  As mentioned above, C6 is compatible with copper production from the Khao Wong Prachan Valley in central Thailand, a volume of isospace far less densely occupied than that of the Vilabouly Complex. C6 is consistent with SEALIP/TH/BNW/5, 7 & 8, a bronze axe and copper-base chisel and axe, respectively, from 1000-900 BC Ban Non Wat. There are no Iron Age or later data consistent with this group.

Not previously identified potential groupings include:

 SEALIP/MY/HL28/14, an Iron Age bronze bell, is compatible with SEALIP/TH/NPW/11, a late 2 nd millennium BC Early Bronze Age bronze axe from Non Pa Wai in central Thailand, thus spanning the Bronze and Iron Ages and potentially abutting SSR networks.  SEALIP/MY/HL29-1/5, a Bronze Age bronze axe, is consistent with SEALIP/TH/BC/2 & 3, bronze O-section bangles from Bronze Age Ban Chiang, thus not adjoining the historical SSR period.

Therefore, of the eight potential groups, three offer chronological contiguity with the SSR. Manual processing of the above datasets is not too problematic but their presentation already becomes difficult due to the density of data points: hence the lack of a figure provided here. These issues are massively compounded if we attempt to add the full regional datasets for Bronze and Iron Age and Historical samples. The resulting mass of overlapping multi-coloured symbols over three ratios makes the identification of individual samples and groups very difficult. 'Zooming in' only obscures potential clusters and disguises the overall diversity of the dataset. Likewise, one can process one site versus another one at a time, but this discounts the possibility of clusters only being detectable across multiple sites. Furthermore, sites are not always the appropriate scale of analysis, if we are interested in a particular period, alloy or typology for example. While the lead author has long prided himself in using simple biplots of raw data (e.g. Pryce et al. 2011b: ), easily intelligible to the non-specialist reader, we have reached a point when a data processing evolution is required to more objectively evaluate the combined datasets for proto-SSR evidence.

Discussion on the potential for a Bronze Age SSR

Thus far, and in all but one previous SEALIP-BROGLASEA publication, attributions of 'consistency' between LI signatures for copper/lead-base metal consumption or between those of consumption and production, were decided by Mk1 Eyeballing of the data cloud. Subjectivity does not necessarily imply these interpretations were liberal. Indeed, our previous application of an 'objective' measure, Kernel Density Estimates (Pryce et al. 2011b), gave such broad compatibility, at 10% confidence increments, that the lead author was deeply dissatisfied by their historical likelihood. Wary of the LI archaeology interpretative pitfalls of yesteryear in the Mediterranean arena (summarised in Pollard 2009), Pryce resorted to excessive conservatism in Southeast Asia: requiring that a metal artefact plot within the data cloud of a well-defined production signature before suggesting consistency, or giving only effusive estimates of potential proximity between consumption signatures.

To address this, we assumed that any two samples should be considered provisionally consistent and potentially sharing the same supply route: using the same raw material source, a market place or a mediator, if the difference between their lead isotope (LI) ratios is within the interval of total variance between the LI ratios of an assemblage of artefacts, archaeologically-reasoned to represent a single primary copper production signature. To define our LI ratio thresholds, we choose the slag and ingot assemblages from four sites in two areas: Non Pa Wai and Nil Kham Haeng in the Khao Wong Prachan Valley (KWPV) of central Thailand, and Puen Baolo and Thong Na Nguak in the Vilabouly Complex (VC) of central Laos. All four sites are well-documented primary copper production loci with both technological and geochemical characterisations [START_REF] Cadet | Laos' central role in Southeast Asian copper exchange networks: A multi-method study of bronzes from the Vilabouly Complex[END_REF]2022;[START_REF] Natapintu | Current Research on ancient copper-base metallurgy in Thailand, in Prehistoric Studies: The Stone and Metal Ages in Thailand[END_REF][START_REF] Pigott | Archaeology of copper production: Excavations in the Khao Wong Prachan Valley, central Thailand, in South-East Asian Archaeology[END_REF][START_REF] Pryce | Prehistoric Copper Production and Technological Reproduction in the Khao Wong Prachan Valley of Central Thailand[END_REF]2011c;2011b). Assemblages of slag, which represents an anthropogenic and pooled LI signature of minerals (ore, gangue and flux), ceramic (crucible, tuyère and furnace) and fuel ash, from these sites produced coherent and easily distinguishable LI production fields. To these fields may be added the LI signatures of raw copper artefacts, identified as ingots, excavated at the respective loci, which corresponded very closely to the associated slag fields. Given the congruence of time, location and technology, it is reasonable to assume these ingots were smelted on site from local minerals. These combined, slag and ingot, LI signatures plot closely3 but not exactly in the same isospace, and these margins can be calculated easily. We generated a distribution of difference in the three LI ratios: 208 Pb/ 204 Pb, 207 Pb/ 204 Pb and 206 Pb/ 204 Pb, between every pair of samples from the KWPV and, separately, VC groups (Figure 13). In mathematical terms, for two samples A and B and with LI ratios if then

𝑅 𝐴 𝑖 < 𝑅 𝐵 𝑖 𝑅 𝐴 𝑖 < 𝑅 𝐵 𝑖 𝐷 𝑖
. Thus. if ratio I for sample A is 80 and ratio I for sample B is 100, B is 20% larger (𝐴,𝐵) = 1 -𝑅 𝐴 𝑖 𝑅 𝐵 𝑖 than A. Using the relation between these ratios allows us to account for the fact that LI ratios do not vary linearly, and samples with higher LI ratios can have larger differences in their ratio compositions while still exhibiting consistency. In Figure 14, we see the maximum difference for our regional production-defined ratios are: 0.7% for 208 Pb/ 204 Pb, 0.4% for 207 Pb/ 204 Pb, and 2.6% for 206 Pb/ 204 Pb. Thus any two random samples with all three ratio differences below these thresholds would be considered provisionally consistent. However, during testing we found that using 100% thresholds was giving excess attributed 14, with large areas under the curve for low variation, and disproportionately smaller areas under the curve with higher variation. We therefore experimented with variations from 75% to 95%. The 75% threshold was too strict, eliminating potential consistency attribution from samples that would on an archaeological basis be highly expected to be consistent; ergo typologically, technologically and chronologically compatible artefacts from nearby sites. We settled on applying a 95% threshold, which eliminated the unworkable levels of connectivity but retained previous inter-assemblage consistency attributions made by traditional subjective interpretation and highlighted several new consistencies to be evaluated from an archaeological perspective. A 95% threshold gives the following absolute inter-sample differences for the three ratios: 206 Pb/ 204 Pb of 1.603%; 207 Pb/ 204 Pb of 0.213%; and 208 Pb/ 204 Pb of 0.365%.

We then computed the same measure between all pairs of Myanmar archaeological copper-base consumption samples and all regional Bronze Age copper-base consumption samples; including the southern Chinese assemblages for which suitable LI data are available4 : Yunnan -Haimenkou (HMK), Chenggong (CGG), Dabona (DAB), Dali (DL), Lijiang (LG), Lijiashan (LJ), Shizhaishan (SZH), Wanjiaba (WJB), Yangfutou (YGT) [START_REF] Cui | The archaeological research of lead isotopes: examples of bronzes from Yunnan, China, and Vietnam[END_REF]; Guangxi -Andengyang (ADY) and Yuanlongpo (YLG) [START_REF] Anon | Wuming Matou Xianqinmu [The Pre-Qin Tombs in Matou, Wuming[END_REF].

Following the complex networks community detection approach from [START_REF] Radivojević | Community structure of copper supply networks in the prehistoric Balkans: An independent evaluation of the archaeological record from the 7th to the 4th millennium BC[END_REF], but focusing on lead isotope rather than elemental data, as Southeast Asia's geological diversity is more amenable to such an approach than Southeast Europe [START_REF] Killick | Geological constraints on the use of lead isotopes for provenance in archaeometallurgy[END_REF], we conducted complex network analysis in two steps (as outlined in methods). First we used the LI data to estimate the number of groups with high densities of consistency. These groups represent artefacts sharing consistent isotopic signatures and thus potentially sharing same supply routes/networks: sources of raw materials, market places, producers, merchants, mediators etc; theoretically copper for unleaded copper or unleaded bronze, or lead for leaded copper or leaded bronze. In the second step, we linked sites / geographic areas where these artefacts were found, with the number of shared consistent artefacts as a measure of potential relatedness between two sites/areas, creating a network between them and, still following the approach from Radivojević & Grujić (2018), extracting communities using the Leiden Algorithm [START_REF] Traag | From Louvain to Leiden: guaranteeing wellconnected communities[END_REF]. Since Radivojević & Grujić (2018) used the Louvain algorithm, which exhibited satisfactory computing prowess and robustness, a novel and improved method appeared, Leiden algorithm, which guaranteed faster computing and enhanced precision. While both algorithms present excellent results when applied to the same dataset (Grujić & Radivojević forthcoming), we opted for the most recent one (Leiden). The Leiden algorithm operates by partitioning the network into clusters of spatial areas that maximize the number of links between areas within the same cluster (or modules), while minimizing the number of links between areas not in the same cluster. In other words, it extracts communities of areas that share consistent artefacts and splits into different communities of areas sharing fewer elements. 5 This community detection or modularity F o r P e e r R e v i e w 31 approach allowed us to model communities of places that may have had interacting populations; whether by means of direct or indirect material culture exchanges, complete or incomplete technological transmissions, or the actual movement of people -as individuals, groups or en masse. While evaluation of these options requires detailed assessment of chronology, typology, alloy type, production methods and socioeconomic ascribed values, our approach does give us a means of rationalising a large and unwieldy database that is otherwise underexploited.

Figure 15: Biplots of LI data from regional Bronze Age assemblages, as processed by our defined consistency thresholds to identify groups of artefacts. From a regional dataset of 281 Bronze Age (or southern Chinese equivalent) samples, a total of 29 'groups' (GPE, sample level patterning) were computed using the Leiden algorithm (Figure 15). Nineteen of those consisted of only one sample (no consistency), and of the multi-member groups, GPE20 consists of only two members, CH/CGG/2 & CH/WJB/2, but presents no anomalies as the sites represented are ca. 115 km distant and contact might be expected. GPE14 has three members, SEALIP/TH/BPT/4, SEALIP/TH/NNT/9 & CH/HMK/7, of which the latter is ca. 1100 km distant but would not surprise regional archaeologists given the Mekong River covers much of the route. GPE21 comprises three members, CH/CGG/4, CH/YGT/1 & CH/YLG/7, of which the first two sites are ca. 60 km apart but the latter ca. 600 km -we do not feel qualified to comment on the probability of this group but note that the Pearl River and its tributaries make up much of the route. GPE8 consists of three highly radiogenic samples (SEALIP/TH/PL/1, SEALIP/TH/PL/6 & SEALIP/TH/NNT/8) from northern Thailand, for which consistency is not surprising from an archaeological perspective. done using igraph package [START_REF] Csárdi | The igraph software package for complex network research[END_REF]. The communities have been detected using the Leiden algorithm [START_REF] Traag | From Louvain to Leiden: guaranteeing wellconnected communities[END_REF]. Following from groups (samples), we moved on to detecting communities (or modules), which allowed us to assess the presence and degree of connectivity between groups (and hence the sites and areas they originated from). Our schematic representation is non-geographic but shows the three main communities of sites with metal assemblages comprised of artefacts with algorithmically-consistent LI signatures (Figure 16). The lines drawn between the sites shows that two sites share at least one sample from the same group. The thickness of those lines is a function of the number of artefacts from similar groups shared by two sites, normalised by the total number of samples a site has. In order to understand the implications of these computations, it is necessary to add the geographical component (Figure 17). The dark grey lines equate to a geolocalised projection of Figure 1, the historically reconstructed 7 th -13 th c. AD SSR, and the other colours represent our communities. What is immediately apparent is the extent of the connectedness of communities, which showcase the Bronze Age metal exchange network. It covers parts of all Mainland Southeast Asia and well into Yunnan and Guangxi, with the exception of Cambodia and central/southern Vietnam, for which there are no late 2 nd /early 1 st millennium BC metals data. However, we acknowledge that we do not have metal networks extending into northeastern India or beyond Yunnan/Guangxi further north into China, which is critical as the historic SSR served to supply the imperial capital at Xi'an. The lack of an Indian connection at this juncture may be real, as current archaeological data indicate such interactions effloresced from the mid-1 st millennium BC [START_REF] Bellina | Maritime Silk Roads' Ornament Industries: Socio-political Practices and Cultural Transfers in the South China Sea[END_REF][START_REF] Bellina | Southeast Asian early Maritime Silk Road trading polities' hinterland and the sea-nomads of the Isthmus of Kra[END_REF][START_REF] Dussubieux | Myanmar's role in Iron Age interaction networks linking Southeast Asia and India: Recent glass and copper-base metal exchange research from the Mission Archéologique Française au Myanmar[END_REF]) but these cultural exchanges could well have precedents. As concerns China, there is a dearth of archaeometallurgical data from Guangxi, Guangdong and Sichuan, the other provinces close to MSEA, though prehistoric metal assemblages there are plentiful. We acknowledge our lack of familiarity with Chinese archaeology and geology -though we hope interested Chinese colleagues pursue the idea (as they now are for general Neolithic and Bronze Age research, see [START_REF] Ma | Understanding the transport networks complex between South Asia, Southeast Asia and China during the late Neolithic and Bronze Age, The Holocene 09596836221131698[END_REF][START_REF] Yao | Bridging the time gap in the Bronze Age of Southeast Asia and Southwest China[END_REF]. In summary, we postulate that the geographical extent of our Bronze Age metal exchange network is equivalent to the historical SSR routes from Yunnan and possibly Guangxi, south into Vietnam, Laos, Thailand and Myanmar. This does not imply, however, that the nature of those networks is equivalent. Firstly, we note that the reconstructed historical SSR in Figure 1 shows both places (sites and/or regions) and routes; often seen as following riverine lines of communication. Our reconstructed Bronze Age metal network shows only places, with geodesic lines representing isotopic consistency rather than transport. The routes via which Bronze Age metal (and potentially metal technologies) were moved by people is unclear but could be montane, riverine, marine, or a combination of those (see [START_REF] Pryce | Initiating discourse on the (multi?) directionality of the Mainland Southeast Asian Bronze Age transition[END_REF]. Indeed, when we break down the networks by community (Figure 18), we see quite distinct patterning that may represent overlapping networks, either contemporary or sequential within our available chronological resolution.

The orange network equates to an unknown primary or secondary copper production signature; thus we cannot be certain in which direction the metal was moving. That said, the major community concentration is in western and central Yunnan, from which it extends 600-800 km Rivers probably account for these putative exchange networks, the Daying or Nanting and Irrawaddy/Chindwin into Myanmar, with portions of montane portage likely. These are historic SSR routes. The occurrence of the Yunnan-centred distribution community 850-1100 km south at Non Nok Tha, Phu Lon and Ban Tong in northern northeast Thailand is harder to explain as these data are not fully published and scrutinised, but a pathway including the Lancang/Mekong River via southern Yunnan is not implausible and also lies on a historic SSR route. As we have previously stated, community detection is but a guide and we discount the likelihood of Tham Than Nam Lot Yai in southern Thailand participating in this network but it is not impossible.

The green network also equates to an unknown primary or secondary copper production signature. However, Hebuoso and Shangxihe, near Kunming, sit at what appears to be the apex of this distribution, which extends ca. 350 km northwest to Lijiang, ca. 600 km east to Andengyang in Guangxi, ca. 500 km southeast to Dai Trach, Gò Mun and Thành Dên in northern Vietnam, ca. 750 km southwest to Halin in north-central Myanmar and ca. 800 km south to Ban Phak Top in northern northeast Thailand. Again, rivers probably account for much of these passages, the Pearl River to Guangxi, the Red River to Vietnam and the aforementioned to Myanmar and possibly Thailand, including montane portage. These are also historic SSR routes.

The blue community equates to the central Lao Vilabouly Complex primary copper production signature, suggesting that metal (raw, semi-finished or finished product) were transported north, south and west over scales ranging from 300 km geodesic (Ban Non Wat) to 450 km geodesic (Tham Pà Ping) to 1100 km geodesic (Tham Than Nam Lot Yai) and 1300 km geodesic (Oakaie), also by the 10 th or possibly 11 th c. BC. We consider it unlikely that VC copper was exchanged ca. 770 km north to Yuanlongpo but the community identification does not interpret for us and can be used to check future typo-technological associations between these areas [START_REF] Ciarla | Rethinking Yuanlongpo: the case for technological links between the Lingnan (PRC) and central Thailand in the Bronze Age[END_REF]. For the northeast Thai sites (and Ban Non Wat has VC signature metal by the Iron Age, [START_REF] Pryce | More questions than answers: the Southeast Asian Lead Isotope Project 2009-2012[END_REF], river routes do seem most likely, using the Mekong and its tributaries. However, for the southern Thai and north-central Myanma assemblages it is again unknown; though marine transport is likely for the south, and even a cross-peninsular transportation and mounting the Irrawaddy River could explain the western distribution. There is no indication that VC metal was exchanged into northern Vietnam or Yunnan but Tham Pà Ping does approach the current Lao:Viet border.

The yellow community equates to the central Thai Khao Wong Prachan Valley primary copper production signature, suggesting that raw metal, semi-finished or finished goods were transported east to the relatively nearby site of Ban Non Wat at ca. 180 km distance, but also to Halin and Oakaie, ca. 1000 km to the NNE by the 10 th c. BC. Despite being the largest known sites for prehistoric copper production in MSEA [START_REF] Pigott | Prehistoric Copper Production and Exchange in Southeast Asia[END_REF][START_REF] Pigott | Archaeology of copper production: Excavations in the Khao Wong Prachan Valley, central Thailand, in South-East Asian Archaeology[END_REF][START_REF] Pryce | Prehistoric Copper Production and Technological Reproduction in the Khao Wong Prachan Valley of Central Thailand[END_REF], it has long been noted that the distribution for this copper, as reconstructed by lead isotope-based provenance studies, seems to have been limited (see Pryce et al. 2011b; 2014 for possible explanations) and has never been detected in Iron Age consumption assemblages. Given the lack of intermediary sites with KWPV-compatible metal assemblages, the route between central Thailand and north-central Myanmar is unknown, but is probably considerably longer than the geodesic track and may have involved multiple actors. There is no indication that KWPV metal moved north to be consumed in northern northeast Thailand, Laos, Vietnam, Guangxi and Yunnan. While neither the yellow nor blue communities map onto historic SSR routes they are certainly coeval with the orange and green communities, which do so map. Indeed, one might have to look at historic Maritime Silk Road pathways to explain part of the yellow and blue community distributions; the MSR also being suspected of greater antiquity than historical data allow for [START_REF] Bellina | Maritime Silk Roads' Ornament Industries: Socio-political Practices and Cultural Transfers in the South China Sea[END_REF]Dussubieux & Bellina 2018). It is notable that while varying our threshold from 75-95% did impact the number of groups of artefacts detected, the communities of sites remained stable, which hints our reconstructions may have some resilience.

Finally, we wish to give consideration to the respective social exchange mechanisms represented by the Bronze Age metal network and the historical SSR. The SSR represented in Figure 1, for the Nanzhao-Dali period, 7th-13th c. AD, was ultimately a means of supplying required commodities, horses, tea, precious metals, from frontier regions to the imperial state capital at Xi'an. It was a tribute and/or profit-driven phenomenon of a powerful and hierarchical central state [START_REF] Yang | Between Winds and Clouds. The Making of Yunnan. Second Century BCE to Twentieth Century CE[END_REF]. As Yang (2008) also notes, this was not the origin of the historical period SSR in the 3 rd -2 nd c. BC, which was a process motivated by Han military ambitions to seek a direct path to central Asia. From what can be reconstructed of Early Bronze Age MSEA metallurgy, copper/bronze production and consumption behaviours were not solely motivated by market forces for commodities [START_REF] Pryce | Prehistoric Copper Production and Technological Reproduction in the Khao Wong Prachan Valley of Central Thailand[END_REF][START_REF] Pryce | Prehistoric Copper Production and Technological Reproduction in the Khao Wong Prachan Valley of Central Thailand[END_REF]White & Hamilton 2019;[START_REF] White | From Community Craft to Regional Specialisation: Intensification of Copper Production in Pre-State Thailand, in Craft Specialization and Social Evolution: In Memory of[END_REF]. In late 2 nd -early/mid-1 st millennium BC MSEA, and in particular the most studied MSEA regions of north-central Myanmar and northeast and central Thailand, copper-base metal has a weak but not invisible correlation with hierarchical behaviours. Instead metal was made and used by and within small, probably independent, communities, both at the few (KWPV, VC and PL) primary production sites [START_REF] Cadet | Technological reconstruction of the late prehistoric primary copper production of the Vilabouly Complex (central Laos)[END_REF][START_REF] Pigott | Prehistoric copper mining and smelting in Southeast Asia: evidence from Thailand and Laos, in Ban Chiang, Northeast Thailand, Volume 2C: The Metal Remains in Regional Context[END_REF][START_REF] Pryce | Prehistoric Copper Production and Technological Reproduction in the Khao Wong Prachan Valley of Central Thailand[END_REF]2011c;2011a), and also at the more widespread secondary production and consumptions sites (Hamilton & White 2019;[START_REF] White | Providing a Regional Socioeconomic Context for Prehistoric Metallurgy in Thailand, in Ban Chiang, Northeast Thailand[END_REF]. There is even solid lead isotope evidence for the movement of copper-base metals and production materials (slag and/or ore) between primary productions centres, strongly suggesting an at least partial basis of gifting in metal exchange (as per SEALIP/TH/NPW/1, excluded from our threshold calculation Pryce et al. 2011b;2014). With the probable exception of Ban Non Wat in southern northeast Thailand [START_REF] Higham | The Bronze Age of Southeast Asia: New Insight on Social Change from Ban Non Wat[END_REF]2022), and possibly those of Khok Charoen in central Thailand and Oakaie/Halin in north-central Thailand (Pradier 2022), the appearance and adoption of copper-base metal does not seem to be coeval with noticeable shifts away from pre-existing Neolithic modes of life [START_REF] Higham | The later prehistory of Southeast Asia and southern China: the impact of exchange, farming and metallurgy[END_REF][START_REF] Higham | Bronze Metallurgy in Southeast Asia with Particular Reference to Northeast Thailand[END_REF]Pradier 2022;[START_REF] Pradier | Pratiques funéraires et dynamique spatiale à Oakaie 1, une nécropole à la transition du Néolithique à l'Âge du Bronze au Myanmar (Birmanie) / Funerary practices and spatial dynamic at Oakaie 1, a burial ground at the transition of the Neolithic and Bronze Age in Myanmar (Burma)[END_REF]Pryce et al. 2018b;in press;[START_REF] White | Providing a Regional Socioeconomic Context for Prehistoric Metallurgy in Thailand, in Ban Chiang, Northeast Thailand[END_REF].

Notwithstanding our unwillingness to push our argument into unfamiliar archaeometallurgical territory, namely the provinces of Sichuan, Guangxi, Guangdong and Guizhou, perhaps the termination of our reconstructed networks (Figures 17 & 18) in Yunnan is indicative of the sociopolitical reality of late 2 nd -early-mid 1 st millennium BC southern China. If the Han conquest of the Dian kingdom in the 2 nd c. BC was intended to subdue a 'frontier' territory and population, then perhaps the relatively integrated southern metal networks simply did not exist into central China 800-900 years prior. That is not to say no contact or interaction, but not of the intensity that saw KWPV and VC metals move over 1000 km geodesic from the very outset of the Myanmar Bronze Age (Pryce et al. 2018a), as well as the Yunnan-centred distributions evidenced in this paper. That the Vietnamese Bronze Age does not fit the general MSEA pattern, recalls the 3 rd c. BC SSR network as reconstructed in Figure 2. In conclusion, we do not argue for a literal prehistoric incarnation of the historic SSR with all its associated economic and political associations. Rather we posit that the long-dated pre-existence of widespread connectivity of reasonable intensity, via .5 bdl bdl 0.9 84.9 3.1 bdl bdl bdl bdl bdl B12 certified value 0.1 9.6 0.0 0.2 0.6 85.7 2.6 0.0 0.2 0.2 0.1 0.0 51.13-4 pXRF bdl 0.3 bdl 0.1 0.4 91.0 bdl bdl 1.9 0.9 4.9 bdl 51.13-4 SEM-EDS bdl bdl bdl bdl 0.7 87.7 bdl bdl 1.9 1.1 7.8 bdl 51.13-4 certified value 0.0 0.3 0.0 0.0 0.3 88.8 0.1 0.0 1.8 0.9 7.3 0.0 71.32-4 pXRF 0.3 6.4 bdl 4.

Figure 1 :

 1 Figure 1: The SSR during the Nanzhao-Dali period, 7th-13th c. AD, reproduced with permission from (Yang 2004: Map 2).

Figure 2 :

 2 Figure 2: The SSR before the 3rd c. BC, reproduced with permission from (Yang 2004: Map 1), with the exclusion of Mainland Southeast Asia due to lack of textual sources.

Figure 3 :

 3 Figure 3: Excavations yielding copper-base artefacts for the present study, with respect to Halin village, the National Museum, and the southern part of the Pyu city wall (white line approximation).

Figure 4 :

 4 Figure 4: Map showing the present study sites/locations, terrain, major rivers and national boundaries. Black squares represent sampled mineralisations, pink circles represent Myanmar Iron Age consumption sites (excavated by the MAFM under the direction of J.-P. Pautreau), orange circles represent Myanmar Bronze Age -Bagan period consumption sites excavated by the MAFM (under the direction of the lead author), and red circles other consumption sites cited in the paper. Green circles represent the documented prehistoric copper producing centres with lead isotope characterisations.

Figure 5 :

 5 Figure 5: The study's archaeological artefacts. Please note missing image for SEALIP/MY/HLTP1/2.

Figure 6 :Figure 7 :

 67 Figure 6: Optical micrographs. Top-left, as cast wire bundle (HL28/2) with round copper sulphide inclusions, top-right, wire bundle (HL28/5), bottom-left bronze cast bell/rattle (HL28/12) and bottom-right bronze as cast bangle (HL29-1/1). Bottom, a bronze ring with an as cast microstructure (HL29-1/7).

Figure 8 :

 8 Figure 8: HL28/18 almost entirely composed of corrosion products but with an identifiably as-cast structure.

  (SEALIP/MY/SP/1 inPryce et al. 2018a

Figure 10 :

 10 Figure 10: Lead isotope ratios for all Myanmar metal artefacts. C3 represents a cluster we consider identifiable once previously published Myanma data are included. Error bars are smaller than symbols. Published data from[START_REF] Dussubieux | Myanmar's role in Iron Age interaction networks linking Southeast Asia and India: Recent glass and copper-base metal exchange research from the Mission Archéologique Française au Myanmar[END_REF] Pryce et al. 2018a; 2014).

Figure 11 :

 11 Figure 11: All Myanmar artefact and mineral LI data, representing all four stable isotope ratios. Letpadaung and Sabad Taung samples plot far to the left and right, respectively, and two Mingan samples plot off scale for 208 Pb/ 204 Pb ratios,

Figure 12 :

 12 Figure 12: All Myanmar artefact plus mineral LI data deemed potentially relevant in the previous section, representing all four stable isotope ratios, plotted against published copper production systems in Thailand (Khao Wong Prachan Valley and Phu Lon), Laos (Vilabouly Complex), Yunnan (Guangfentou) and Sichuan (Raojiadi) (Chen et al. 2020; Pryce

  contiguity with the historically attested SSR ca. 3 rd c. BC (Figure2,

Figure

Figure 13 :

 13 Figure 13: Biplots showing the relatively high, at a regional scale, consistency in LI ratios of slag and copper-base metal artefacts from the Khao Wong Prachan Valley (Non Pa Wai and Nil Kham Haeng) and the Vilabouly Complex (Puen Baolo and Thong Na Nguak). The two NPW outliers, a bronze axe and a slag fragment, are represented by a red cross.

Figure 14 :

 14 Figure 14: Distribution of distances between KWPV and VC samples for each lead isotope ratio. Vertical dashed blue lines represent the values for the 75,85 and 95 percentiles.

  large multi-member groups:  GPE1 consists of 39 samples from Myanmar, Thailand, Vietnam and Yunnan;  GPE2 consists of 52 samples from Laos, Myanmar, Thailand, Vietnam, Yunnan and Guangxi;  GPE3 consists of 40 samples from Myanmar, Thailand, Vietnam, Yunnan and Guangxi;  GPE4 consists of 8 samples from Myanmar, Thailand, Vietnam and Yunnan;  GPE5 consists of 79 samples from Laos, Myanmar, Thailand, Vietnam, Yunnan and Guangxi;  GPE6 consists of 34 samples from Myanmar, Thailand and Yunnan.

Figure 16 :

 16 Figure 16: Network of sites based on shared artefacts from the same family, each node colour represent a different community detected by the Leuven community detection algorithm. The edges between nodes from within the same community are coloured using the colour of the community. The edges that link nodes from different communities are black.



  The yellow community is comprised of central and southern northeast Thai and northcentral Myanma sites;  The blue community is comprised of northern northeast Thai, central and northern Lao, north-central Myanma and central Guangxi sites;  The orange community is comprised of northern northeast and southern Thai, northern Vietnamese, north-central Myanma and central and western Yunnan sites.  The green community is comprised of north-central Myanmar, northern northeast Thai, northern Vietnamese, central Guangxi, central and western Yunnan

Figure 17 :Figure 18 :

 1718 Figure 17: Map showing the reconstructed Nanzhao-Dali period SSR (from Figure1), overlain with our calculated Myanmar multi-period and regional Bronze Age assemblage communities, using the same colour codes as for Figure16.

  in north-central Myanmar.

Figure 1 :Figure 2 :Figure 3 :Figure 4 :Figure 5 :Figure 6 :Figure 7 :Figure 8 :Figure 9 :Figure 10 :Figure 11 :Figure 12 :Figure 13 :Figure 14 :Figure 15 :Figure 16 :Figure 17 :Figure 18 :

 123456789101112131415161718 Figure 1: The SSR during the Nanzhao-Dali period, 7th-13th c. AD, reproduced with permission from (Yang 2004: Map 2). 274x314mm (120 x 120 DPI)

  3 7.1 80.5 0.8 bdl 0.4 bdl bdl bdl 71.32-4 SEM-EDS bdl 6.4 bdl 3.1 7.3 81.8 0.8 bdl 0.4 bdl bdl bdl 71bdl bdl bdl bdl 0.1 99.7 0.1 bdl bdl bdl bdl bdl SRM-500 SEM-EDS bdl bdl bdl bdl 0.4 99.4 bdl bdl bdl bdl bdl bdl SRM-500 certified value 0.0 0.0 0.0 0.0 0.0 99.7 0.1 0.0 0.0 0.0 0.0 0.0 C1123 pXRF bdl bdl bdl bdl bdl 97.4 bdl 2.5 bdl bdl bdl bdl C1123 SEM-EDS bdl bdl bdl bdl bdl 96.5 bdl 3.4 bdl bdl bdl bdl C1123 certified value 0.0 0.0 0.0 0.0 0.0 97.4 0.0 2.3 0.0 0.0 0.0 0.0 SRM1275 pXRF bdl bdl bdl bdl bdl 86.9 10.7 bdl 1.6 0.4 bdl bdl SRM1275 SEM-EDS bdl bdl bdl bdl bdl 87.9 10.1 bdl 1.5 0.5 bdl bdl SRM1275 certified value 0.0 0.0 0.0 0.0 0.1 88.2 9.8 0.0 1.5 0.4 0.0 0.0 L-20-1 pXRF bdl 0.5 bdl 0.3 14.4 84.2 0.2 bdl bdl 0.1 bdl bdl L-20-1 SEM-EDS bdl 0.5 bdl bdl 14.6 84.0 bdl bdl bdl bdl bdl bdl L0 bdl 0.1 18.0 80.3 0.1 bdl 0.3 bdl bdl bdl UZ-52-3 SEM-EDS bdl 1.0 bdl bdl 18.2 80.2 bdl bdl bdl bdl bdl bdl UZ-52-3 certified value 0.1 1.1 0.0 0.1 17.0 81.1 0.1 0.0 0.3 0.0 0.0 0.0 F o r P e e r R e v i e w

Table 1 :

 1 . Current study samples, names and context information.

					Sample type					Mass
	1	SEALIP/MY/BAW/1 Baw Mountain, Kyaukse	Mineral	Cu mineral	surface collection			geological	-	-
	2	SEALIP/MY/BAW/2 Baw Mountain, Kyaukse	Mineral	Cu mineral	surface collection			geological	-	-
	3	SEALIP/MY/BAW/3 Baw Mountain, Kyaukse	Mineral	Cu mineral	surface collection			geological	-	-
	4	SEALIP/MY/BWD/1	Bawdwin		Mineral	Cu mineral	surface collection			geological	-	-
	5	SEALIP/MY/BWD/2	Bawdwin		Mineral	Cu mineral	surface collection			geological	-	-
	6	SEALIP/MY/KAW/1	Kawlin		Mineral	Cu mineral	surface collection			geological	-	-
	7	SEALIP/MY/KAW/2	Kawlin		Mineral	Cu mineral	surface collection			geological	-	-
	8	SEALIP/MY/KAW/3	Kawlin		Mineral	Cu mineral	surface collection			geological	-	-
	9	SEALIP/MY/MIN/1	Mingan		Mineral	Cu mineral	surface collection			geological	-	-
		SEALIP/MY/MIN/2	Mingan		Mineral	Cu mineral	surface collection			geological	-	-
		SEALIP/MY/MIN/3	Mingan		Mineral	Cu mineral	surface collection			geological	-	-
		SEALIP/MY/NTL/1	Nant Twin village		Mineral	Cu mineral	surface collection			geological	-	-
		SEALIP/MY/NTL/2	Nant Twin village		Mineral	Cu mineral	surface collection			geological	-	-
		SEALIP/MY/NTL/3	Nant Twin village		Mineral	Cu mineral	surface collection			geological	-	-
		SEALIP/MY/PDHT/1 Pala Dauk Hter Taung	Mineral	Cu mineral	surface collection			geological	-	-
		SEALIP/MY/PDHT/2 Pala Dauk Hter Taung	Mineral	Cu mineral	surface collection			geological	-	-
		SEALIP/MY/PDHT/3 Pala Dauk Hter Taung	Mineral	Cu mineral	surface collection			geological	-	-
		SEALIP/MY/ST/1	Sabad Taung		Mineral	Cu mineral	surface collection			geological	-	-
		SEALIP/MY/ST/2	Sabad Taung		Mineral	Cu mineral	surface collection			geological	-	-
		SEALIP/MY/ST/3	Sabad Taung		Mineral	Cu mineral	surface collection			geological	-	-
		SEALIP/MY/TKN/1	Thabeik Kyinn		Mineral	Cu mineral	surface collection			geological	-	-
		SEALIP/MY/TKN/2	Thabeik Kyinn		Mineral	Cu mineral	surface collection			geological	-	-
		SEALIP/MY/TKN/3	Thabeik Kyinn		Mineral	Cu mineral	surface collection			geological	-	-
		SEALIP/MY/YTCM/1	Yang Tse Copper		Mineral equivalent	Cu ingot	personal collection			modern	-	low
		SEALIP/MY/HL28/1	Halin HL28		Consumption artefact	wire bundle	MoC excavation	2013/2/3-A		IA	8,05	low
		SEALIP/MY/HL28/2	Halin HL28		Consumption artefact	wire bundle	MoC excavation	2013/2/3-B		IA	9,75	low
		SEALIP/MY/HL28/3	Halin HL28		Consumption artefact	wire bundle	MoC excavation	2013/2/3-C		IA	7,85	low
		SEALIP/MY/HL28/4	Halin HL28		Consumption artefact	wire bundle multi	MoC excavation	2013/2/3-D		IA	7,95	low
		SEALIP/MY/HL28/5	Halin HL28		Consumption artefact	wire bundle multi	MoC excavation	2013/2/3-D		IA	-	low
		SEALIP/MY/HL28/6 SEALIP/MY/HL28/7 SEALIP/MY/HL28/8 SEALIP/MY/HL28/9 SEALIP/MY/HL28/10 SEALIP/MY/HL28/11 SEALIP/MY/HL28/12 SEALIP/MY/HL28/13 SEALIP/MY/HL28/14 SEALIP/MY/HL28/15	Halin HL28 Halin HL28 Halin HL28 Halin HL28 Halin HL28 Halin HL28 Halin HL28 Halin HL28 Halin HL28 Halin HL28	Consumption artefact Consumption artefact Consumption artefact F Consumption artefact Production artefact Consumption artefact Consumption artefact o Consumption artefact Consumption artefact r wire bundle multi wire bundle wire bundle wire bundle possible casting spillage wire bundle large bell/rattle small bell/rattle small bell/rattle Consumption artefact small bell/rattle	MoC excavation MoC excavation MoC excavation MoC excavation MoC excavation MoC excavation MoC excavation MoC excavation MoC excavation MoC excavation	2013/2/3-D 2013/2/3-E 2013/2/3-F 2013/2/3-G 2013/2/3-H 2013/2/3-I 04/02/2014 2013/2/5-A 2013/2/5-B 2013/2/5-C		IA IA IA IA IA IA IA IA IA IA	-10,1 3,9 6,55 9,5 7,9 189,65 39,6 25,15 15	low low low low medium low low low medium medium
		SEALIP/MY/HL28/16	Halin HL28		Consumption artefact	small bell/rattle	MoC excavation	2013/2/5-D		IA	19,4	low
		SEALIP/MY/HL28/17 SEALIP/MY/HL28/18 SEALIP/MY/HL29/1 SEALIP/MY/HL29/2 SEALIP/MY/HL29/3 SEALIP/MY/HL29/4 SEALIP/MY/HL29/5	Halin HL28 Halin HL28 Halin HL29 Halin HL29 Halin HL29 Halin HL29 Halin HL29		Consumption artefact Consumption artefact Consumption artefact Consumption artefact Consumption artefact Consumption artefact Consumption artefact	small bell/rattle small bell/rattle pseudo spear head P pseudo spear head pseudo spear head axe e axe	MoC excavation MoC excavation MoC excavation MoC excavation MoC excavation MoC excavation MoC excavation	2013/2/5-E 2013/2/5-F 2013/2/1 2013/2/2 2013/2/8 2013/2/6 2013/2/7		IA IA ? ? ? ? ?	18,15 16,95 18,6 20,25 13,45 243,8 243,15	low medium low low low medium high
		SEALIP/MY/HL29/6 SEALIP/MY/HL29/7 SEALIP/MY/HL29/8 SEALIP/MY/HL29-1/1 SEALIP/MY/HL29-1/2 SEALIP/MY/HL29-1/3	Halin HL29 Halin HL29 Halin HL29 Halin HL29-1 Halin HL29-1 Halin HL29-1		Consumption artefact Consumption artefact Consumption artefact Consumption artefact Consumption artefact Consumption artefact	asymmetric curved axe spearhead spearhead e bangle bangle r HL29 Burial 14 HL29 Burial 8 Skeleton 11 HL29 Burial 6 Skeleton 14 B12, Context 1043 B12, Context 1043, A bangle B12, Context 1043, B	2006 2001 2005 1540 1541a 1541b	2016/2/38 2016/2/34 2016/2/39	? ? ? BA BA BA	243 216 230 2,45 4,9 4,5	high high high
		SEALIP/MY/HL29-1/4	Halin HL29-1		Consumption artefact	bangle (double line)	B12, Context 1043, C	1541c		BA	4,05	high
		SEALIP/MY/HL29-1/5 SEALIP/MY/HL29-1/6 SEALIP/MY/HL29-1/7 SEALIP/MY/HL29-1/8 SEALIP/MY/HL30-1/1 SEALIP/MY/HLTP1/1 SEALIP/MY/HLTP1/2	Halin HL29-1 Halin HL29-1 Halin HL29-1 Halin HL29-1 Halin HL30-1 Halin HLTP1 Halin HLTP1		Consumption artefact Consumption artefact Consumption artefact Consumption artefact Consumption artefact Consumption artefact Consumption artefact	axe flat ring ring spiral square section ring ring platy fragment ring fragment	B30, Context 1076 B28, Context 1080 B1, Context 1021 R Jar burial, Context 1018 HL30-1/7027 HL-TP1/4001 e HL-TP1/6519	1659 1648 1506 -7539		BA BA Bagan Bagan IA Bagan Bagan	214,85 29,5 47 1,262 2,6	low low low high high
		SEALIP/MY/MLW/1 SEALIP/MY/MLW/2 SEALIP/MY/MLW/3	Maliwan Maliwan Maliwan		Consumption artefact Consumption artefact Consumption artefact	fragment fragment fragment	TP6/6003 TP6/6003 v TP6/6003			IA IA IA	low low low
							i e
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										9

  Table2). Bulk compositions for each sample were obtained by a mean of 3-4 areas scan (0.4 mm 2 ) per sample. The analyses were performed in areas without corrosion products, when possible.

	F o r
	P e
	e r
	R e
	v
	i e
	w
	12

Table 2 :

 2 CRMs for the present study, as analysed with pXRF, SEM-EDS and with certified values given. Data given to 1d.p. Lead isotope analysis (LIA) was conducted at the Service d'Analyse des Roches et des Minéraux of the Centre for Petrographic and Geochemical Research (SARM-CRPG) in Nancy, France, using MC-ICP-MS after lead extraction

	Multi Collector -Inductively Coupled Plasma -Mass Spectrometer (MC-ICP-MS)
	F o r
	P e
	e r
	R e
	v
	i e
	w
	13

  208 Pb/ 204 Pb vs 206 Pb/ 204 Pb and 207 Pb/ 204 Pb vs 206 Pb/ 204 Pb biplots for traditional manual interpretation.

Table 3 :

 3 Elemental compositions for metal and mineral samples, and working techniques for metal samples. SEM-EDS and pXRF data are given to 1d.p..

	#	Sample	Site	Object	O	Ba Sb	Sn

Cd Pd Ag Ru Mo Nb Zr Bi Pb Se As Au W Zn Cu Ni Co Fe Mn Cr V Ti Al S Cl P Si Mg Analytical total Analytical technique Corrosion products Probable alloy Working techniques

	1 SEALIP/MY/HL28/1	Halin HL28	wire bundle	4,7 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 93,4 bdl bdl 0,2 bdl bdl bdl bdl bdl 1,4 0,3 bdl 0,1 bdl	100,0	SEM-EDS	Medium	copper	As cast
	2 SEALIP/MY/HL28/2	Halin HL28	wire bundle	bdl bdl bdl bdl bdl bdl bdl bdl 0,0 0,0 bdl bdl bdl bdl 0,0 bdl bdl bdl 99,1 bdl bdl 0,8 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl	100,0	pXRF	Low	copper	As cast
	3 SEALIP/MY/HL28/3	Halin HL28	wire bundle	1,2 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 97,5 bdl bdl 0,4 bdl bdl bdl bdl bdl 0,9 bdl bdl 0,0 bdl	100,0	SEM-EDS	Low	copper	As cast
	4 SEALIP/MY/HL28/4	Halin HL28	wire bundle multi	bdl bdl bdl bdl bdl bdl bdl bdl 0,0 bdl bdl bdl bdl bdl 0,0 bdl bdl bdl 99,5 bdl bdl 0,4 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl	100,0	pXRF	Low	copper	As cast
	5 SEALIP/MY/HL28/5	Halin HL28	wire bundle multi	bdl bdl bdl bdl bdl bdl bdl bdl 0,0 bdl bdl bdl bdl bdl 0,0 bdl bdl bdl 98,8 bdl bdl 0,4 bdl bdl bdl bdl bdl 0,8 bdl bdl bdl bdl	99,9	pXRF	Low	copper	As cast
	6 SEALIP/MY/HL28/6	Halin HL28	wire bundle multi	bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 0,0 bdl bdl bdl 97,5 bdl bdl 0,5 bdl bdl bdl bdl bdl 1,2 bdl bdl 0,8 bdl	100,0	pXRF	Low	copper	As cast
	7 SEALIP/MY/HL28/7	Halin HL28	wire bundle	bdl bdl bdl bdl bdl bdl bdl bdl 0,0 0,0 bdl bdl bdl bdl 0,0 bdl bdl bdl 99,5 bdl bdl 0,4 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl	100,0	pXRF	Low	copper	As cast
	8 SEALIP/MY/HL28/8	Halin HL28	wire bundle	1,2 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 97,2 bdl bdl 0,5 bdl bdl bdl bdl bdl 1,1 bdl bdl 0,1 bdl	100,0	SEM-EDS	Low	copper	As cast
	9 SEALIP/MY/HL28/9	Halin HL28	wire bundle	1,8 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 96,1 bdl bdl 0,3 bdl bdl bdl bdl bdl 1,1 0,4 bdl 0,3 bdl	100,0	SEM-EDS	Low	copper	As cast
	10 SEALIP/MY/HL28/10	Halin HL28	possible casting spillage 17,5 bdl bdl 15,7 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 66,3 bdl bdl bdl bdl bdl bdl bdl bdl bdl 0,4 0,1 0,2 bdl	100,2	SEM-EDS	High	bronze	As cast
	11 SEALIP/MY/HL28/11	Halin HL28	wire bundle	bdl bdl bdl bdl bdl bdl bdl bdl 0,0 0,0 bdl bdl bdl bdl 0,0 bdl bdl bdl 99,2 bdl bdl 0,8 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl	100,0	pXRF	Low	copper	As cast
	12 SEALIP/MY/HL28/12	Halin HL28	large bell/rattle	bdl bdl bdl 4,5 bdl bdl bdl bdl 0,0 0,0 bdl bdl bdl bdl 0,0 bdl bdl bdl 92,7 bdl bdl 0,1 bdl bdl bdl bdl bdl bdl bdl bdl 2,6 bdl	100,0	pXRF	Medium	bronze	As cast
	13 SEALIP/MY/HL28/13	Halin HL28	small bell/rattle	bdl bdl bdl bdl bdl bdl bdl bdl 0,1 0,1 bdl bdl bdl bdl bdl bdl bdl bdl 99,4 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl	99,6	pXRF	Low	copper	Hammered/annealed
	14 SEALIP/MY/HL28/14	Halin HL28	small bell/rattle	bdl bdl bdl 4,2 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 80,3 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl	84,5	SEM-EDS	High	bronze	As cast
	15 SEALIP/MY/HL28/15	Halin HL28	small bell/rattle	bdl bdl bdl 4,2 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 83,4 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl	87,6	SEM-EDS	High	bronze	As cast
	16 SEALIP/MY/HL28/16	Halin HL28	small bell/rattle	bdl bdl bdl 1,2 bdl bdl bdl bdl 0,0 0,0 bdl bdl bdl bdl 0,0 bdl bdl bdl 98,0 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 0,7 bdl	100,0	pXRF	Medium	bronze	As cast
	17 SEALIP/MY/HL28/17	Halin HL28	small bell/rattle	bdl bdl bdl 11,0 bdl bdl bdl bdl 0,0 0,0 0,0 bdl bdl bdl 0,0 bdl bdl bdl 88,2 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 0,6 bdl	100,0	pXRF	Medium	bronze	As cast
	18 SEALIP/MY/HL28/18	Halin HL28	small bell/rattle	bdl bdl bdl 6,2 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 80,1 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 0,6 bdl	86,9	SEM-EDS	High	bronze	As cast
	19 SEALIP/MY/HL29/1	Halin HL29	pseudo spear head	bdl bdl bdl 1,5 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 97,8 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl	99,3	SEM-EDS	High	bronze	As cast
	20 SEALIP/MY/HL29/2	Halin HL29	pseudo spear head	bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 0,1 bdl 0,0 bdl bdl bdl 96,7 bdl bdl 1,7 bdl bdl bdl bdl bdl 0,2 bdl bdl 1,3 bdl	100,0	pXRF	Low	copper	As cast
	21 SEALIP/MY/HL29/3	Halin HL29	pseudo spear head	bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 0,1 bdl 0,0 bdl bdl bdl 99,5 bdl bdl 0,5 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl	100,1	pXRF	Low	copper	As cast
	22 SEALIP/MY/HL29/4	Halin HL29	axe	20,2 bdl bdl 5,4 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 63,6 bdl bdl bdl bdl bdl bdl bdl bdl bdl 10,6 bdl 0,1 bdl	100,0	SEM-EDS	High	bronze	As cast
	23 SEALIP/MY/HL29/5	Halin HL29	axe	50,2 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 7,3 bdl bdl 5,3 bdl bdl bdl bdl 8,1 bdl 0,5 bdl 22,6 2,2	96,2	SEM-EDS	High	copper	Corroded
	24 SEALIP/MY/HL29/6	Halin HL29	asymmetric curved axe bdl bdl bdl 11,4 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 88,1 0,0 bdl 0,0 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl	99,6	pXRF	High	bronze	As cast
	25 SEALIP/MY/HL29/7	Halin HL29	spearhead	bdl bdl bdl 15,9 bdl bdl bdl bdl bdl bdl bdl bdl 0,6 bdl bdl bdl bdl bdl 82,9 bdl bdl bdl bdl 0,1 0,0 0,1 bdl bdl bdl bdl bdl bdl	99,6	pXRF	High	bronze	As cast
	26 SEALIP/MY/HL29/8	Halin HL29	spearhead	bdl bdl bdl 5,2 bdl bdl bdl bdl bdl bdl 0,1 bdl 0,4 bdl bdl bdl bdl bdl 91,5 bdl bdl 1,6 bdl 0,1 0,1 0,3 bdl bdl bdl bdl bdl bdl	99,3	pXRF	High	bronze	Corroded
	27 SEALIP/MY/HL29-1/1	Halin HL29-1	bangle	bdl bdl bdl 10,8 0,1 bdl bdl bdl bdl bdl bdl bdl 0,4 bdl 0,1 bdl bdl 0,3 87,1 bdl bdl 1,0 bdl bdl bdl bdl bdl bdl bdl bdl 0,3 bdl	100,0	pXRF	Medium	bronze	As cast
	28 SEALIP/MY/HL29-1/2	Halin HL29-1	bangle	bdl bdl bdl 9,8 bdl bdl bdl bdl bdl bdl bdl 0,0 0,2 bdl 0,1 bdl bdl 0,1 87,1 bdl bdl 2,3 bdl bdl bdl bdl bdl 0,1 bdl bdl 0,2 bdl	100,0	pXRF	Medium	bronze	Annealed
	29 SEALIP/MY/HL29-1/3	Halin HL29-1	bangle	bdl bdl bdl 8,6 bdl bdl bdl bdl bdl bdl bdl 0,0 0,1 bdl 0,1 bdl bdl 0,1 90,9 bdl bdl 0,1 bdl bdl bdl bdl bdl bdl bdl bdl 0,1 bdl	100,0	pXRF	Medium	bronze	Hammered
	30 SEALIP/MY/HL29-1/4	Halin HL29-1	bangle (double line)	bdl bdl bdl 6,9 bdl bdl bdl bdl 0,0 bdl bdl bdl 0,3 bdl 0,1 bdl bdl 0,4 86,4 bdl 0,0 4,3 bdl bdl bdl bdl bdl bdl bdl bdl 1,7 bdl	100,0	pXRF	Medium	bronze	Hammered/annealed
	31 SEALIP/MY/HL29-1/5	Halin HL29-1	axe	16,4 bdl bdl 6,5 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl 73,3 bdl bdl bdl bdl bdl bdl bdl 0,1 1,2 0,9 1,1 1,0 bdl	100,4	SEM-EDS	High	bronze	Corroded
	32 SEALIP/MY/HL29-1/6	Halin HL29-1	flat ring	bdl bdl bdl 2,0 bdl bdl bdl bdl 0,0 bdl bdl bdl 0,1 bdl bdl bdl bdl 0,1 97,9 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl	100,0	pXRF	Low	bronze	Hammered/annealed
	33 SEALIP/MY/HL29-1/7	Halin HL29-1	spiral square section ring bdl bdl bdl 5,8 bdl bdl bdl bdl bdl bdl bdl 0,0 0,1 bdl 0,1 bdl bdl 0,1 93,9 bdl bdl 0,1 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl	100,0	pXRF	Medium	bronze	As cast
	34 SEALIP/MY/HL29-1/8	Halin HL29-1	ring	bdl bdl 0,1 bdl bdl bdl bdl bdl bdl bdl bdl bdl 1,5 bdl bdl bdl bdl bdl 96,4 bdl bdl 0,1 bdl 0,1 0,0 0,0 bdl bdl bdl bdl bdl bdl	98,4	pXRF	Low	leaded copper Hammered/annealed
	35 SEALIP/MY/HL30-1/1	Halin HL30-1	ring	bdl bdl bdl 9,5 bdl bdl bdl bdl bdl bdl bdl bdl 0,2 bdl bdl bdl bdl bdl 89,3 bdl bdl 0,6 bdl bdl bdl bdl bdl bdl bdl bdl bdl bdl	99,7	pXRF	High	bronze	As cast
	36 SEALIP/MY/HLTP1/1	Halin HLTP1	platy fragment	bdl bdl 1,5 29,3 bdl bdl bdl bdl bdl bdl bdl bdl 0,1 bdl bdl bdl bdl bdl 67,6 bdl bdl 0,8 bdl bdl bdl 0,2 bdl bdl bdl bdl bdl bdl	99,5	pXRF	High	bronze	Corroded
	37 SEALIP/MY/HLTP1/2

Table 4 :

 4 Full raw lead isotope data for the present study samples.

	SEALIP ID	Lab ID	Material type	206Pb/204Pb err (2σ) 207Pb/204Pb err (2σ) 208Pb/204Pb err (2σ) 207Pb/206Pb err (2σ) 206Pb/207Pb err (2σ) 208Pb/206Pb err (2σ)
	1 SEALIP/MY/BAW/1 1907566	Mineral	18,428	0,002	15,764	0,002	38,805	0,006	0,856	0,00003	1,1683	0,00003	2,106	0,0001
	2 SEALIP/MY/BAW/2 1907567	Mineral	18,425	0,002	15,768	0,001	38,814	0,004	0,856	0,00003	1,1679	0,00003	2,107	0,0006
	3 SEALIP/MY/BAW/3 1907568	Mineral	18,433	0,002	15,757	0,001	38,796	0,004	0,855	0,00002	1,1690	0,00002	2,105	0,0010
	4 SEALIP/MY/BWD/1 1907569	Mineral	18,385	0,002	15,793	0,002	38,767	0,004	0,859	0,00002	1,1635	0,00002	2,109	0,0001
	5 SEALIP/MY/BWD/2 1907570	Mineral	18,391	0,002	15,797	0,002	38,787	0,005	0,859	0,00002	1,1636	0,00002	2,109	0,0001
	6 SEALIP/MY/KAW/1 1907571	Mineral	18,306	0,002	15,646	0,002	38,904	0,006	0,855	0,00004	1,1700	0,00004	2,125	0,0002
	7 SEALIP/MY/KAW/2 1907572	Mineral	18,305	0,002	15,646	0,002	38,900	0,006	0,855	0,00003	1,1700	0,00003	2,125	0,0001
	8 SEALIP/MY/KAW/3 1907573	Mineral	18,322	0,001	15,652	0,001	38,921	0,004	0,854	0,00003	1,1706	0,00003	2,124	0,0001
	9 SEALIP/MY/MIN/1 1907560	Mineral	18,833	0,003	15,704	0,003	39,445	0,008	0,834	0,00003	1,1986	0,00003	2,094	0,0001
	SEALIP/MY/MIN/2 1907561	Mineral	19,099	0,002	15,719	0,002	41,699	0,005	0,823	0,00003	1,2144	0,00003	2,183	0,0001
	SEALIP/MY/MIN/3 1907562	Mineral	19,260	0,002	15,725	0,002	42,711	0,005	0,817	0,00003	1,2241	0,00003	2,218	0,0001
	SEALIP/MY/NTL/1 1907563	Mineral	19,189	0,002	15,763	0,002	39,175	0,005	0,822	0,00003	1,2167	0,00003	2,042	0,0001
	SEALIP/MY/NTL/2 1907564	Mineral	19,186	0,002	15,764	0,002	39,133	0,006	0,822	0,00004	1,2153	0,00004	2,040	0,0001
	SEALIP/MY/NTL/3 1907565	Mineral	19,226	0,012	15,763	0,011	39,172	0,030	0,820	0,00013	1,2190	0,00013	2,037	0,0005
	SEALIP/MY/PDHT/1 1804225	Mineral	18,414	0,001	15,605	0,001	38,522	0,003	0,848	0,00002	1,1799	0,00002	2,092	0,0001
	SEALIP/MY/PDHT/2 1804226	Mineral	18,356	0,003	15,615	0,002	38,326	0,006	0,851	0,00003	1,1757	0,00003	2,088	0,0001
	SEALIP/MY/PDHT/3 1804227	Mineral	18,795	0,001	15,592	0,001	38,160	0,004	0,829	0,00002	1,2061	0,00002	2,030	0,0001
	SEALIP/MY/ST/1 1804222	Mineral	28,219	0,002	16,258	0,002	40,422	0,005	0,576	0,00002	1,7360	0,00002	1,433	0,0001
	SEALIP/MY/ST/2 1804223	Mineral	21,635	0,001	15,885	0,001	42,281	0,004	0,734	0,00002	1,3618	0,00002	1,955	0,0001
	SEALIP/MY/ST/3 1804224	Mineral	21,204	0,001	15,889	0,001	41,796	0,004	0,749	0,00001	1,3344	0,00001	1,971	0,0001
	SEALIP/MY/TKN/1 1907574	Mineral	18,552	0,003	15,746	0,003	38,999	0,007	0,849	0,00003	1,1775	0,00003	2,102	0,0001
	SEALIP/MY/TKN/2 1907575	Mineral	18,356	0,003	15,725	0,002	38,759	0,007	0,857	0,00004	1,1667	0,00004	2,112	0,0001
	SEALIP/MY/TKN/3 1907576	Mineral	18,350	0,002	15,757	0,002	38,673	0,005	0,859	0,00003	1,1646	0,00003	2,108	0,0001
	SEALIP/MY/YTCM/1 1907577 Mineral equivalent	17,885	0,004	15,596	0,005	37,853	0,012	0,873	0,00008	1,1461	0,00008	2,117	0,0002
	SEALIP/MY/HL28/1 1804228 Consumption artefact	18,501	0,009	15,569	0,009	38,643	0,021	0,841	0,00007	1,1884	0,00007	2,089	0,0001
	SEALIP/MY/HL28/2 1804229 Consumption artefact	18,430	0,002	15,616	0,002	38,634	0,009	0,847	0,00010	1,1803	0,00012	2,096	0,0002
	SEALIP/MY/HL28/3 1804230 Consumption artefact	18,589	0,002	15,614	0,002	38,811	0,009	0,840	0,00010	1,1906	0,00012	2,088	0,0002
	SEALIP/MY/HL28/4 1804231 Consumption artefact	18,596	0,002	15,618	0,001	38,826	0,004	0,840	0,00002	1,1906	0,00002	2,088	0,0001
	SEALIP/MY/HL28/5 1804232 Consumption artefact	18,589	0,001	15,616	0,001	38,809	0,004	0,840	0,00001	1,1904	0,00001	2,088	0,0001
	SEALIP/MY/HL28/6 1804233 Consumption artefact	18,580	0,001	15,618	0,001	38,799	0,003	0,840	0,00001	1,1898	0,00001	2,088	0,0001
	SEALIP/MY/HL28/7 1804234 Consumption artefact	18,608	0,001	15,616	0,002	38,829	0,005	0,839	0,00002	1,1918	0,00002	2,087	0,0001
	SEALIP/MY/HL28/8 1804235 Consumption artefact	18,597	0,002	15,618	0,002	38,825	0,009	0,840	0,00010	1,1908	0,00012	2,088	0,0002
	SEALIP/MY/HL28/9 1804236 Consumption artefact	18,611	0,002	15,617	0,001	38,839	0,005	0,839	0,00001	1,1920	0,00001	2,087	0,0001
	SEALIP/MY/HL28/10 1804237 Production artefact	18,292	0,001	15,703	0,001	38,542	0,003	0,859	0,00001	1,1647	0,00001	2,107	0,0001
	SEALIP/MY/HL28/11 1804238 Consumption artefact	18,593	0,002	15,618	0,002	38,814	0,005	0,840	0,00002	1,1904	0,00002	2,088	0,0001
	SEALIP/MY/HL28/12 1804239 Consumption artefact	18,687	0,002	15,627	0,002	38,532	0,006	0,836	0,00002	1,1958	0,00002	2,062	0,0001
	SEALIP/MY/HL28/13 1901264 Consumption artefact	17,984	0,001	15,598	0,001	37,925	0,004	0,868	0,00002	1,1523	0,00002	2,109	0,0001
	SEALIP/MY/HL28/14 1901265 Consumption artefact	18,120	0,001	15,605	0,001	38,103	0,004	0,862	0,00002	1,1605	0,00002	2,103	0,0001
	SEALIP/MY/HL28/15 1901266 Consumption artefact	18,542	0,008	15,700	0,006	38,691	0,017	0,847	0,00002	1,1805	0,00002	2,087	0,0001
	SEALIP/MY/HL28/16 1901267 Consumption artefact	18,531	0,002	15,669	0,002	38,664	0,005	0,846	0,00002	1,1820	0,00002	2,086	0,0001
	SEALIP/MY/HL28/17 1901268 Consumption artefact	19,080	0,002	15,697	0,002	39,201	0,005	0,823	0,00002	1,2148	0,00002	2,055	0,0001
	SEALIP/MY/HL28/18 1901269 Consumption artefact	18,565	0,005	15,700	0,003	38,636	0,009	0,846	0,00005	1,1819	0,00005	2,081	0,0001
	SEALIP/MY/HL29/1 1901270 Consumption artefact	18,583	0,002	15,607	0,002	38,787	0,004	0,840	0,00003	1,1900	0,00003	2,087	0,0001
	SEALIP/MY/HL29/2 1804240 Consumption artefact	18,573	0,002	15,616	0,001	38,776	0,005	0,841	0,00002	1,1896	0,00002	2,088	0,0001
	SEALIP/MY/HL29/3 1804241 Consumption artefact	18,573	0,002	15,616	0,001	38,776	0,005	0,841	0,00002	1,1896	0,00002	2,088	0,0001
	SEALIP/MY/HL29/4 1804242 Consumption artefact	19,192	0,001	15,771	0,001	39,196	0,002	0,822	0,00001	1,2171	0,00001	2,042	0,0001
	SEALIP/MY/HL29/5 1804243 Consumption artefact	18,718	0,001	15,704	0,001	39,010	0,003	0,839	0,00001	1,1921	0,00001	2,084	0,0001
	SEALIP/MY/HL29/6 1907640 Consumption artefact	18,399	0,004	15,620	0,004	38,460	0,009	0,849	0,00004	1,1772	0,00004	2,090	0,0002
	SEALIP/MY/HL29/7 1907641 Consumption artefact	18,842	0,002	15,689	0,002	38,786	0,006	0,833	0,00004	1,2003	0,00004	2,059	0,0001
	SEALIP/MY/HL29/8 1907642 Consumption artefact	18,060	0,002	15,541	0,002	38,037	0,005	0,861	0,00003	1,1615	0,00003	2,106	0,0001
	SEALIP/MY/HL29-1/1 1804244 Consumption artefact	18,331	0,001	15,718	0,001	38,645	0,004	0,857	0,00001	1,1663	0,00001	2,108	0,0001
	SEALIP/MY/HL29-1/2 1804245 Consumption artefact	18,332	0,001	15,725	0,001	38,659	0,004	0,858	0,00001	1,1659	0,00001	2,109	0,0001
	SEALIP/MY/HL29-1/3 1804246 Consumption artefact	18,343	0,001	15,727	0,002	38,671	0,005	0,857	0,00001	1,1663	0,00001	2,108	0,0001
	SEALIP/MY/HL29-1/4 1804247 Consumption artefact	18,326	0,001	15,720	0,001	38,644	0,005	0,858	0,00001	1,1657	0,00001	2,109	0,0001
	SEALIP/MY/HL29-1/5 1804248 Consumption artefact	18,469	0,003	15,660	0,003	38,645	0,008	0,848	0,00003	1,1794	0,00003	2,092	0,0001
	SEALIP/MY/HL29-1/6 1804249 Consumption artefact	19,024	0,001	15,748	0,001	39,085	0,004	0,828	0,00002	1,2081	0,00002	2,054	0,0001
	SEALIP/MY/HL29-1/7 1804250 Consumption artefact	18,376	0,002	15,712	0,002	38,670	0,006	0,855	0,00002	1,1696	0,00002	2,104	0,0001
	SEALIP/MY/HL29-1/8 1907638 Consumption artefact	18,393	0,002	15,794	0,002	38,771	0,005	0,859	0,00002	1,1639	0,00002	2,108	0,0001
	SEALIP/MY/HL30-1/1 1907639 Consumption artefact	18,324	0,002	15,719	0,002	38,665	0,005	0,858	0,00003	1,1650	0,00003	2,110	0,0001
	SEALIP/MY/HLTP1/1 1907643 Consumption artefact	18,596	0,002	15,748	0,002	38,840	0,005	0,847	0,00002	1,1802	0,00002	2,089	0,0001
	SEALIP/MY/HLTP1/2 1907644 Consumption artefact	18,357	0,002	15,738	0,002	38,602	0,006	0,858	0,00005	1,1658	0,00005	2,103	0,0002
	SEALIP/MY/MLW/1 1804394 Consumption artefact	18,425	0,001	15,705	0,001	38,981	0,004	0,852	0,00001	1,1731	0,00001	2,116	0,0001
	SEALIP/MY/MLW/2 1804395 Consumption artefact	17,784	0,001	15,576	0,001	38,472	0,004	0,876	0,00000	1,1417	0,00000	2,164	0,0001
	SEALIP/MY/MLW/3 1804396 Consumption artefact	18,357	0,002	15,770	0,003	38,653	0,008	0,859	0,00001	1,1640	0,00001	2,106	0,0002

19

Figure 9: Lead isotope ratios for all Halin and Maliwan metal artefacts. C1 and C2 represent two clusters we consider identifiable within the new copper-base artefact data. Error bars are smaller than symbols.

  The reason can be seen in the non-parametric distributions in Figure

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	connectivity in the wider dataset.
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A borderline case, with 1.3 wt. % Pb in a highly corroded matrix.Page

of 78 Cambridge University Press Cambridge Archaeological Journal

Which like the Letpadaung sample is a modern ingot and thus represents a pooled signature of that mine's minerals.

The two outliers consist of a low-tin bronze axe, one of the earliest copper-base artefacts known in Southeast Asia, and interpreted as an import(Pryce et al. 2011c), and a slag fragment that is more consistent with minerals from Phu Lon in northern Thailand. This latter sample is one of two regional examples of slag and/or minerals apparently being transported between primary copper production loci, and not a labelling error as the batches were processed months apart(Pryce et al. 2011b;[START_REF] Pryce | Metallurgy in Southeast Asia[END_REF][START_REF] Pryce | More questions than answers: the Southeast Asian Lead Isotope Project 2009-2012[END_REF]. The data from these two outliers were thus eliminated from our calculations but for sound archaeological/archaeometric reasons, rather than them not fitting our preconceptions.

Erring on the side of inclusivity for Chinese sites where the dating broadly equates to the Bronze Age in MSEA terms.

All the computation was done using R Programming language (R Core Team 2021) and are available online as a git repository: https://github.com/simoncarrignon/bronze-age-ssr. All network operations have been Page 31 of 78 Cambridge University Press Cambridge Archaeological Journal

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Acknowledgments

We offer our particular thanks to Daw Kalayar Myat Myat Htwe, who has longstanding interests in Myanmar archaeometallurgy and who helped us obtain the geological samples for this study, and also Daw Cherry Thin, who allowed us access to previously excavated material in the Halin National Musem. The freshly excavated samples came from the fieldwork of the Mission Archéologique Française au Myanmar, which was funded by the Commission Consultative de Fouilles of the Ministère de l'Europe et des Affaires Etrangères during the period 2013-2020. The analytical data in this paper derive from the Agence National de Recherche-funded project 'BROGLASEA' (https://anr.fr/Project-ANR-16-CE27-0011). The statistical processing of BROGLASEA data was conducted under the auspices of the Fondation Fyssen-funded project, 'Network Analysis for Archaeometallurgy, and Beyond' (NAAMB). We also thank the National Institute for Mathematical and Biological Synthesis (NIMBioS) for the IT support. We wish to thank the two anonymous reviewers for their constructive criticism.

is a Senior Researcher for the French Centre for Scientific Research since 2013Pryce has been Director of the French Archaeological Mission in Myanmar since 2012, until its suspension in 2021. He is Director of the BROGLASEA/SEALIP since 2008 and has conducted archaeometallurgical research in Southeast Asia since 2004. Pryce was previously postdoctoral researcher at the French Institute of Research for Development in 2013, and the University of Oxford from 2009 to 2012.