Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Archaeometric evidence for the earliest exploitation of lignite from the bronze age Eastern Mediterranean


This paper presents the earliest evidence for the exploitation of lignite (brown coal) in Europe and sheds new light on the use of combustion fuel sources in the 2nd millennium BCE Eastern Mediterranean. We applied Thermal Desorption/Pyrolysis–Gas Chromatography-Mass Spectrometry and Polarizing Microscopy to the dental calculus of 67 individuals and we identified clear evidence for combustion markers embedded within this calculus. In contrast to the scant evidence for combustion markers within the calculus samples from Egypt, all other individuals show the inhalation of smoke from fires burning wood identified as Pinaceae, in addition to hardwood, such as oak and olive, and/or dung. Importantly, individuals from the Palatial Period at the Mycenaean citadel of Tiryns and the Cretan harbour site of Chania also show the inhalation of fire-smoke from lignite, consistent with the chemical signature of sources in the northwestern Peloponnese and Western Crete respectively. This first evidence for lignite exploitation was likely connected to and at the same time enabled Late Bronze Age Aegean metal and pottery production, significantly by both male and female individuals.


Making fire was a crucial stage in the development of humankind1,2 and inhaling its smoke was an inevitable result of this process. The increasing ability to manage fires and their temperatures also allowed for more sophisticated methods of cooking, and enhanced the development of craft technologies such as pottery production and the melting and casting of metals. To date, ancient fire-making has mostly been studied through the residual ash and other remains taken from fireplaces, and from the thermal alteration and soot marks visible on artifacts, in addition to the information provided by experimental archaeology and ethnoarchaeology (e.g.3,4,5). Only recently has it become possible to understand the inhalation of smoke by past individuals by studying its chemical and microscopic traces in human dental calculus6,7,8,9. Our study of combustion markers in human dental calculus is part of a larger project which aims to understand culinary practices of the 2nd millennium BCE Eastern Mediterranean, i.e. the Middle Bronze Age (ca. 2000–1600 BCE), the Late Bronze Age (ca. 1600–1200/1050 BCE) and the Early Iron Age (after 1200/1050 BCE) (Fig. 1; Table S1; SM Text 2). During this time, the Eastern Mediterranean transformed into an early globalized region, characterized by complex stratified societies employing writing systems and sophisticated craftsmanship as well as large-scale production centres producing goods often aimed at trans-regional exchange. The written and archaeological evidence also reveals a high degree of individual mobility between the Mycenaean Aegean, Hittite Anatolia, Cyprus, the Levant’s trade centres and city kingdoms, Mesopotamia and Middle and New Kingdom Egypt10,11,12. Therefore, we have selected human dental calculus from key sites of the 2nd millennium in the Aegean (Tiryns, Chania), the Levant from the north (Alalakh) via present-day Lebanon (Kamid el-Loz) to the south (Megiddo, Tel Erani) and Egypt (Abusir el-Meleq, Thebes). Tiryns and Chania were major harbour and palatial sites in the Aegean. Tiryns was a focus of large-scale craft production of the Northeastern Peloponnese and closely linked to Mycenae, the nearby major Late Bronze Age political centre in that region of Southern Greece13. As part of the increasing control of Crete by the Mainland palaces, Chania became one of the key centres for the Mainland’s exploitation of the island14. The Levantine cities (Alalakh, Kamid el-Loz, Megiddo, Tel Erani) were situated in between and usually influenced by or under the control of the great empires of Anatolia, Syro-Mesopotamia and Egypt, the latter represented by samples in our study. The 2nd millennium was also marked by the large-scale production of goods and their subsequent trade, especially pottery and metal objects, throughout the Eastern Mediterranean10. Most noteworthy is the mass production of pottery in the Late Bronze Aegean, a large part of which was exclusively produced for export to Cyprus and the Levant. So far, there has been little discussion of the resources that were used to fuel the kilns and ovens for this proto-industrial production in densely settled and probably largely de-forested areas, whereas the fuels used for cooking have been increasingly studied in the Eastern Mediterranean Bronze Age4,15,16,17. Our study of chemical combustion markers aims at a better understanding how this unprecedented level of interconnection transformed both local cooking practices and the procurement of fuel.

Figure 1
figure 1

Map of the Eastern Mediterranean featuring the sites included in this study and the currently-known key lignite sources in Greece (created by R.C.P. with QGIS3, using Natural Earth raster data:, 2021. QGIS Geographic Information System. QGIS Association.


Chemical analyses

Thermal Desorption-Gas Chromatography-Mass Spectrometry (TD-GC–MS) and Pyrolysis–Gas Chromatography-Mass Spectrometry (Py-GC–MS) of the human dental calculus revealed a significant abundance of combustion markers in 74 of the 77 samples retrieved from the 67 individuals studied (SM Appendix, Text 1.2; Tables S1, S2a and S2b).

Wood and dung combustion

The dominant biomarkers identified were polynuclear aromatic hydrocarbons (PAHs), i.e. organic compounds with two to six membered aromatic rings typical of chars or soot associated with smoke resulting from the long-term and/or repeated exposure to fires in more or less close vicinity. The ratios of these PAHs are typical of combustion, rather than petrogenic sources deriving from modern environmental contamination18,19,20, as would be expected for ancient exposure to smoke/fires. All samples with significant abundances of PAHs also revealed biomarkers indicative of conifer wood combustion. These included the diterpenoid acid esters methyl dehydroabietate and methyl abietate, their free acids being significant components found in Pinaceae wood (which includes genera such as Pinus, Picea, Larix, Abies and Cedrus) and resin. These thermally-derived methyl esters were accompanied by defunctionalized diterpenoids which included 19-norabieta-4,8,11,13-tetraene, 19-norabieta-4(18),8,11,13-tetraene, 19-norabieta-3,8,11,13-tetraene, tetrahydroretene, dihydroretene, retene and dehydroretene. These methyl esters and defunctionalized diterpenoids reflect the strong heating process which the conifer wood would have undergone during its burning, and its production of the subsequently inhaled smoke. Additional chemical evidence for conifer wood combustion is revealed by the relative abundance of the dimethylphenanthrenes (DMPs). These have been shown to be diagnostic, with 1,7-dimethylphenanthrene, deriving chemically from the diterpenoids characteristic of conifers, dominating the m/z 206 profile and producing distinctively high 1,7/1,7 + 2,6-DMP ratios of ~ 0.921,22. The presence of these biomarkers and the characteristic ratios confirms the inhalation of smoke from the burning of conifer (e.g. Pinaceae) woods23,24,25. More generally, the ratios of the PAHs fluoranthene to pyrene have allowed us to further identify and discriminate between dung, wood, and fossil fuel sources, with ratios of ~ 0.8 for dung, ~ 1 for wood and 1.40 for lignite/coal26,27. A 1,7/1,7 + 2,6-DMP ratio of ~ 0.5 is typical of animal dung burning, whereas values for oakwood (hardwood) and pinewood (softwood) are ~ 0.7 and ~ 0.9 respectively18. The use of dung as fuel was attested in 29 of the individuals studied here, based on the combined 1,7/1,7 + 2,6-DMP ratio consistent with the burning of dung (see SI 1), and a fluoranthene/pyrene ratio of ~ 0.8 indicative of the combustion of dung26,27 (Table S1). Hardwoods and softwoods were also used as fuels, the chemical data identifying their use in 58 and 64 individuals respectively (Table S1), and indicating exposure to smoke from multiple fuel sources in the case of the majority of individuals, presumably reflecting local availability of potential fuel resources at these sites.

Lignite (brown coal) combustion

An unusual biomarker distribution (Fig. 2) was observed in six Late Bronze Age and two Early Iron Age individuals from Tiryns and three Late Bronze Age individuals from Chania (Table S1). The most diagnostic components included succinimide (m/z 56, 99), benzoic acid (m/z 77, 105, 122), benzamide (m/z 77, 105, 121), phthalic anhydride (m/z 76, 104, 148) and phthalimide (m/z 76, 104, 147) (Fig. 2 and Table S2b). The finding of the succinimide and aromatic biomarkers in samples from Tiryns and Chania and, thus, only in samples from the Aegean, is significant. These specific biomarkers are usually observed together in self-ignited brown and black coal heaps28,29 where the potential for self-combustion is high. The absence of these characteristic aromatic biomarkers from the vast majority of the calculus samples, and their co-occurrence specifically in the PAH-rich calculus samples, excludes exogenous, pre- or post-excavation, contamination as a possible source. The presence of these biomarkers is particularly significant since Greece has important lignite deposits, all of which are surface deposits mined as opencast resources30,31,32,33,34, which would also have made them visible to ancient populations. The main lignite deposits were formed in intermountain basins such as Ptolemais in Macedonia and Megalopolis in the central Peloponnese, while smaller lignite deposits were created in the western Peloponnese at sites such as Olympia and Pyrgos30,31 as well as in Kandanos and Vrysses Apokoronou in western Crete33,34. Lignite chemistry reflects the plant input of their formation, which can thereby provide clues to potential sources. The chemical profiles in the calculus samples containing the lignite biomarkers from both Tiryns and Chania do not reveal chemical evidence for sulfur or its derivatives, suggesting the lignite had a low sulfur source. Megalopolis is the closest lignite deposit to Tiryns, although lignite from this site is known to be relatively high in sulfur31,32 which is inconsistent with the evidence from Tiryns. Further investigation of the full-scan TD–GC–MS data from the Tiryns calculus samples containing the lignite-related biomarkers also revealed an unresolved complex mixture (UCM), observed as a notable hump in the chromatograms and typical of lignites35. Furthermore the biomarkers present are characteristic of higher plants from both gymnosperms and angiosperms consistent with the palaeoecology of southeastern Europe36. The gymnosperm-derived diterpenoid compounds dominate the higher plant input, and include not only the fossil biomarkers dehydroabietane, simonellite and 2-methylretene, which can derive from a wide range of conifers, and the more specific 6-dehydroferruginol and diaromatic totarane indicative of a Cupressaceae (e.g. Taxodium sp., subfamily Taxodioideae)37,38,39,40. Importantly, there were no pimarane- or isopimarane-type diterpenoids, nor abietane-type diterpenoid acids detected, which suggests that a significant pine (Pinus spp.) input for the lignite can be excluded37,40,41. Notably, the diterpenoids identified are also accompanied by a number of monoterpenoids: p-cymene, thujone and carvenone, and the sesquiterpenoids: calamenene, α-calacorene, calamene, cadalene and isocadalene. These terpenoid counterparts to the particular diterpenoids identified have been observed in several Cupressaceae, in particular Taxodium spp.39,42,43. Lignite from Megalopolis has been noted for its lack of gymnosperms32 and an angiosperm predominance32,36, which again argues against this as the likely lignite source. The relative abundance of these mono-, sesqui- and diterpenoids is interesting, given the prevalence of conifers growing in a swamp environment, typical of Taxodium species and other closely related Cupressaceae (and subfamily Taxodioideae) known to have grown in the western Peloponnese during the late Miocene Epoch36. Present-day Taxodium and other Taxodioideae are not found in Europe and only in North America. The biomarker evidence for angiosperms includes the presence of 18α(H)-oleanane and it is notable that sample TIR002B shows an n-alkane Cmax at C29 for n-nonacosane, which is consistent with and indicative of Quercus (oak) species, C29 known to be the dominant n-alkane in Quercus38. Additionally, the more diagnostic angiosperm biomarkers3,3,7,12a-tetramethyl-1,2,3,4,4a,11,12,12a-octahydrochrysene and 2,2,4ab,9-tetramethyl-1,2,3,4,4a,5,6,14b-octahydropicene44, were identified and have been found in angiosperm-containing lignite/coals45. Notably, hopanes, most clearly seen in TIR002.B which also has a pronounced UCM indicative of the lignite component, are significant constituents (Fig. 2 and Table S2b); the presence of only trace amounts of hopanes in other lignite-containing Tiryns samples (Table S2b) may reflect the known antibacterial properties of the higher plant terpenoids that dominate these samples46. These hopanes are characterized by a base peak at m/z 191 and molecular ions (M+.) m/z 368, 370, 384, 398, 412, 426, 440, 454, 468 and 482 corresponding to the C27, C28, C29, C30, C31(S,R), C32(S,R), C33(S,R), C34(S,R) and C35(S,R) 17α(H),21β(H) hopane biomarkers observed (see Table S2a, b for details). The C29/C30 (norhopane/hopane) ratio of > 1 suggests an anoxic, organic-rich source47. Gammarcerane, indicative of a notably saline depositional environment, is absent. The steranes identified in TIR002B (using mass chromatogram m/z 217) provide additional detail on the source of the lignite input (see Table S2b). The relative abundances of the ααα-20R C27, C28 and C29 regular steranes was 31%, 38% and 31% respectively. The relative dominance of C28 steranes is indicative of a significant algal (e.g. lacustrine) input48 and the relative abundance of the regular steranes, combined with the absence of marine-derived C30 steranes47, suggest a wet environment with terrestrial and planktonic inputs48. This is consistent with a paralic-freshwater swamp source for the lignite48, as observed for the Taxodium-dominated conifer swamps constituting the telmato-deltaic lignite deposits of the western Peloponnese around Pyrgos and Olympia31,49. The lignites identified in the three calculus samples from Chania are chemically distinct from the Tiryns lignite source and derive from two different sources (see Table S2b). Chania samples XAN003.B and XAN004.B also revealed biomarkers characteristic of higher plants from both gymnosperms and angiosperms. However, unlike the Tiryns lignite samples these had a far more significant angiosperm input. The common fossil conifer biomarkers dehydroabietane, simonellite and 2-methylretene, and the more specific 6-dehydroferruginol and diaromatic totarane indicative of a Cupressaceae, were not detected in these samples, with retene, dehydroretene and abietic acid (as its thermally-derived methyl ester) being the dominant diterpenoids in these samples and consistent with a Pinaceae input. Although both lignite and wood from extant conifers could be contributing to this, the 1,7/1,7 + 2,6-DMP ratios of 0.5 for both samples would be more consistent with lignite and/or a dung-burning component (13). These were accompanied by the monoterpenoid p-cymene, and the sesquiterpenoids α-cedrene calamenene and α-calacorene, which were also notably different in their relative abundance to those observed in the Tiryns lignite source. Significantly, the samples are dominated by angiosperm biomarkers and are notably high in 18α(H)-oleanane, reflecting this. With an oleanane index (oleanane/hopane) of 1.3 indicative of a very significant angiosperm component in the lignite50, an oleanane index above 0.2 also points to a lignite formed in the Tertiary Period50,51 and in a marine deltaic environment51. Further evidence for a marine input into the lignite, in addition to the gymnosperm and angiosperm terrestrial input, comes from a number of different classes of biomarkers. The pristane/phytane ratio (Pr/Ph) informs on the redox conditions of the depositional environment; low values (< 1) reflect anoxic, deep water and marine inputs51, which is consistent with the 0.56 value for these two Chania samples. Hopanes, most clearly seen in XAN004.B which also has a very pronounced UCM indicative of the lignite component, are significant constituents, characterized by a base peak at m/z 191 and molecular ions (M+.) m/z 368, 370, 398, 412, 426, 440, 454 and 468 respectively, with the C27, C29, C30, C31(S,R), C32(S,R), C33(S,R) and C34(S,R) 17α(H),21β(H) hopanes predominating (see Table S2b for details). The C29/C30 (norhopane/hopane) ratio of > 1 suggests an anoxic, organic-rich source47, with the presence of gammarcerane indicative of a saline depositional environment. The steranes identified (using mass chromatogram m/z 217) provide additional detail on the source of the lignite input for these two samples (see Table S2b). The short-chain pregnanes, diginane and homodiginane, characterized by a base peak at m/z 218 and molecular ions (M+.) m/z 288 and 302 respectively, were identified as the major steranes present; these C21 and C22 biomarkers are notably high in marine, carbonate-rich environments52,53 and dominate the C27-C29 steranes in these samples. Moreover, the relative abundances of the ααα-20R C27, C28 and C29 regular steranes (63%, 22% and 15% respectively) indicate a predominantly marine input, corroborated by the additional presence of the more unusual C30 steranes, which are indicative of a marine source47. Interestingly, secosteranes, specifically the C27, C28 and C29 8,14-secosteranes, were identified; these are believed to derive from sponge lipid membranes and their symbiotic bacteria, as previously reported in marine-derived fossil fuels49. The decreasing C31-C35 homohopanes and the diasteranes, being in similar abundance to the regular steranes, also suggests a clastic input for the lignite54. In considering the possibility of surface lignite sources local to Chania, Vrysses and Kandanos are in relatively close proximity. Kandanos is an intermontane source and therefore a marine input into the lignite would not be expected. In contrast, Vrysses lignite is within the sedimentary history of the Cretan Neogene as one of frequently changing land-sea distribution33. These Neogene sediments have a wide extension in the low coastal plains in the northern part of Chania province. At Vrysses the deposits of Pantanassa Formation show fluvial clastic sediments with paralic and marine sedimentary environments and silty clays, which contributed to the Miocene lignitic beds33. There have also been palaeoenvironmental studies of Miocene leaf assemblages from sediments at Vrysses, which have revealed moderate amounts of gymnosperms, including Pinus sp., yet angiosperm taxa made up 95% of the total flora55. The complex suite of lignitic, marine and terrestrial biomarkers, with Pinus-derived diterpenoids and yet a dominance of angiosperm biomarkers, as observed in XAN003.B and XAN004.B, is consistent with the paralic and palaeobotanical context of the lignite source at Vrysses, located only 20 miles away from Chania. In contrast, the lignite source from Chania individual XAN001.B does not contain abietane-type acids, although diterpenoids confirming a gymnosperm conifer input are present. These were accompanied by the monoterpenoid: p-cymene, and the sesquiterpenoids: α-cedrene calamenene, and α-calacorene, although in different relative abundances to XAN003.B and XAN004.B, and included an unidentified methanoazulene, β-cedrene and the tentatively identified sesquiterpene, δ-cadinene, not seen in the samples from these two Chania individuals. Overall, it was again quite different to those terpenoid biomarkers observed in the Tiryns lignite source. There was an absence of both angiosperm and marine biomarkers and was again quite different to those terpenoid biomarkers observed in the Tiryns lignite source. Given the intermontane, inland location, combined with the low sulfur content of the lignite56, Kandanos, located only 25 miles from Chania, may have provided this second local lignite source in the case of the XAN001.B individual.

Figure 2
figure 2

(A) Reconstructed total ion chromatogram of the thermal desorption profile (310 °C for 5 min, 610 °C for 10 s (see Materials and Methods)) of human dental calculus from TIR002.B. Peak identities: the lignite/coal markers numbered 1–5 were identified as: 1 = succinimide, 2 = benzoic acid, 3 = benzamide, 4 = phthalic anhydride, 5 = phthalimide. Also shown are the structures of eight polynuclear aromatic hydrocarbons (combustion markers): naphthalene, 1-methylnaphthalene, biphenyl, fluorene, 9,10-dihydrophenanthrene, phenanthrene, anthracene, 1-methyl anthracene, fluoranthene and pyrene. In addition, the structures of the terpenoids characteristic of Cupressaceae deriving from the lignite are shown, i.e. the main monoterpenoid compound identified: p-cymene, the main sesquiterpenoid compounds identified: calamenene and cadalene, and the main diterpenoid compounds identified: diaromatic totarane, retene and 6-dehydroferruginol. The main lignite-derived hopanes, 17α(H),21β(H)-norhopane and 17α(H),21β(H)-hopane are also shown. (B) Charcoal particle from TIR002.B (unknown taxon).


Dental calculus microremains were obtained from 54 individuals, allowing further analysis of combustion-related microremains, including charcoal, non-diagnostic burnt material, unburnt wood remains and melted phytoliths (SM Appendix, Text 1.3; Tables S1 & S3; Fig. S2). Although studies of airborne contributions to the composition of dental calculus are still in their infancy and not all populations exposed to smoky environments exhibit combustion products in their calculus57, such particles, when present, can reveal local fire use. Variation in abundance and size distribution of these microremains indicates multiple depositional pathways, including food (melted phytoliths, combustion products), airborne transport (combustion products)—mostly within 20 km—and unknown pathways (unburnt wood)8,58. For example, while smaller charred particles may reflect inhaled airborne particles transported over long distances, larger combustion particles probably derive from more direct contact with smoky environments, as well as charcoal-covered, charred foods and soil char adhering to food59. Charred remains in individuals across samples, together with individuals showing chemical evidence for lignite, tend to contain slightly larger particles (Figs. S2S7), although given the minimal difference in size it is unclear if this indicates less transport of charred remains or closer contact with fire. Although size-based thresholds for reconstructing transport distances for airborne charred remains in dental calculus have not yet been determined, we note that particles in the 2–10 μm size fraction, PM10, as found at all sites except at Abusir el-Meleq (Table S3), can enter through the throat. nose and subsequently the lungs, and so might be injurious to human health60.

Combustion products

Microparticle analysis revealed black-brown opaque to translucent particles with a size range of 3 to > 100 μm in all samples61. Particles smaller than this may be black carbon (amorphous carbon) or black mineral particles and were not quantifiable. Amongst the larger fractions, some were indicative of charcoal, particularly particles ranging from 20 to 60 μm. These can originate from partially combusted wood, straw, leaves, bark and other materials. In most cases, the origin of these combustion particles cannot be identified due to their small size. Identifiable charcoals typically appear as sub-rectangular sheets (Fig. S2), but cannot be attributed to specific taxa when they occur below a size of 100 × 50 μm. The length–width ratios of the particles indicate that they tend to derive from the combustion of timber rather than grass (Table S3). Generally however, the particles present here cannot be identified and for this reason we focus on combustion particles as a whole. These microparticles occur across the samples and they do not appear to be more frequent in certain groups (site, sex etc.) when measured in counts or as per milligram of sample. Neither are they more common in samples that were shown to contain traces of inhalation of lignite smoke. They occur in a highly variable pattern, from several particles to hundreds in each sample. They are rare in several samples, including ABU003, XAN008 and MGD008.

Lignite combustion

Lignite reference samples from Ptolemais (Greece) and Staniantsi (Bulgaria) were analyzed to identify morphology diagnostic of lignite. Lignite particles were found to be opaque and exhibited little plant cell morphology. Microscopic analysis showed that although lignite morphology largely overlaps with charcoal, it is distinctively uniformly fractured. However, the identification of lignite fragments under the polarizing microscope requires large particle sizes for identification, which are usually not embedded in dental calculus. Possible fragments in the calculus are too small to distinguish confidently.

Discussion and conclusion

The chemical data obtained in this study show the first and earliest evidence obtained to date for the exploitation and use of lignite in Europe and the Mediterranean during the 2nd millennium BCE. The GC–MS and microscopy have also further demonstrated the diversity of fuels being used at this time in the Eastern Mediterranean, and we were able to link the usage of fuel with particular individuals via their inhalation of combustion markers.

With regard to the selection of fuel for fire-making, it seems evident that burning conifer (Pinaceae and Cupressaceae spp.) wood, or charcoal made from this wood, played a crucial role in fire management. The distribution maps of wood species in the area suggest that Pinus nigra, Pinus pinea and Abies cephalonica found widely across the Eastern Mediterranean would have been the most likely conifer sources62,63. Moreover, our data shows that hardwood like oak and probably olive was also used, albeit on a seemingly slightly less frequent basis. The virtual absence of wood combustion markers in samples from Egypt is likely due to the fact that the individuals studied were not exposed to open fires for long periods of time, perhaps due to a consistently warmer climate. Although recent research has pointed to the importance of dung for fire-making in the prehistoric past64,65,66,67, its use has rarely been considered for the 2nd millennium BCE Eastern Mediterranean, but our results suggests it seems to have been an important additional fuel in almost all contexts. This evidence points to an opportunistic use of locally available wood and dung for daily fire making in the context of cooking, heating, torches, incense burners etc. The occurrence of wildfires might also have had an impact, albeit on a much smaller level compared with the regular and daily exposure to domestic fires. An integrative analysis of contextual, archaeobotanical, phytolith and anthracological studies of ovens in pyrotechnological workshops at Tiryns has indicated the relevance of Pinus nigra, Abies sp. and Quercus sp. for fire-making, including Olea europaea, consistent with the data presented here and indicating the use of softwoods and hardwoods as fuel sources. Inhalation of combustion particles from the burning of Olea europaea could not be differentiated beyond the burning of hardwoods.

Most notably and unexpected is the evidence for the combustion of lignite. So far, lignite was thought to have been used for the first time in Classical Greece, as discussed by Theophrastus (374/369–288/285 BCE) when describing different kinds of coals with regard to fire and temperature management (Theophrastus, On Stones, 16; Translation:68). He also mentions the possibility that lignite could have been collected from the surface of the land close to Olympia (i.e. in the western Peloponnese; ca. 150 km overland distance from Tiryns), and that lignite was particularly useful for metallurgy. Clearly this literary source demonstrates ample experience with lignite as a resource for fire management by the fourth century BCE, but it had not been previously possible to date the beginning of its exploitation or confirm its technological use scientifically. Although recently published evidence suggests lignite was being used in China by ca. 1600 BCE69, it seems that its exploitation in Greece had started in the thirteenth century BCE at the very latest, given that the Tiryns individuals with chemical evidence for lignite in their dental calculus lived and worked during the decades between the mid-thirteenth century and the early twelfth century BCE, i.e. the heyday of the Mycenaean palatial workshops at Tiryns and its immediate aftermath. The individuals from Chania are slightly earlier and belong to the fourteenth-thirteenth centuries BCE, when Chania was under Mycenaean control after Crete had been conquered by forces from the Greek mainland during the fifteenth century BCE and Crete was subsequently increasingly exploited70,71.

There is no clear link between the inhalation of lignite particles and sex, and both sexes seem to have been involved in lignite pyrotechnologies. All individuals showing lignite particles from the Lower Citadel of Tiryns were buried with no additional goods, which has been interpreted as an indication of their lower status, whereas their placement under or between the high-status architecture in this area contradicts this interpretation72. All three individuals with chemical evidence for lignite inhalation from Chania and two from Tiryns (TIR002, TIR006) also show anthropological evidence for hard physical labor, with a pronounced physical development of the muscles of the right arm. One female individual from Chania (XAN001) even shows evidence of degenerative/rheumatic changes, whereas the other two individuals with lignite inhalation probably died too young to display these changes73. Although it is challenging to link this anthropological evidence to specific kinds of labor, these individuals might nevertheless be interpreted as male and female craftspeople of probably different social statuses, who at least in part, conducted heavy work close to the kilns and ovens that produced pottery, metal and/or vitreous materials.

Tiryns, Chania and their surroundings were important centres for the large-scale production of pottery during the Late Bronze Age. The landscape of the Argolid around Tiryns was known for its large-scale pottery production. This is evident from specialized potters’ centres like Berbati74, the pottery kiln from the early twelfth century BCE found on the Lower Citadel of Tiryns in the immediate vicinity of the slightly older burials we studied75,76, and the tens of thousands of vessels which seem to have been produced every year to meet the demands of the palaces and beyond, given that they were exported all over the Mediterranean77,78. Moreover, there is evidence for metal working in Tiryns in the thirteenth and twelfth centuries BCE79,80 as well as for glass working81. For Chania, there is ample evidence for the large-scale production of fine ware pottery and large transport vessels in the region82. The limitation of locally available wood resources must have posed significant challenges, since it is highly likely that densely settled areas like the Late Bronze Age Argolid or the bay of Chania were largely deforested at that time. Such heat-intensive craft production must have raised the need to acquire sufficient additional fuel, with lignite being particularly useful due to the higher energy density and easier temperature control83. Moreover, at Chania, it seems natural for lignite to have been sourced from deposits in close proximity, at both Vrysses and Kandanos, but in the case of Tiryns, it took a particular effort to transport lignite from deposits at Olympia over ca. 150 km by land, and even further by sea. This underlines the scale and capability of Mycenaean palatial administration which is well known from textual sources of that time84,85. It is also interesting to note the lack of evidence for the exploitation of the sulfur-rich lignite deposits around Megalopolis in the central Peloponnese (ca. 80 km overland distance from Tiryns), despite their greater distance from Tiryns. This may point to knowledge of the adverse effects of sulfur in metallurgy. The systematic exploitation of lignite, possibly to supply the high fuel demands of the workshops, would have contributed to the establishment of permanent, large-scale specialized craft production at palaces, which were usually associated with workshops86,87, or as specialized craftspeople villages like the aforementioned village of Berbati, irrespective and detached from local wood resources. The possibility of establishing permanent fuel-intensive manufacturing places with the help of coal would later become most prominent and evident with modern industrialization88.

Future research will reveal if similar specialized pyrotechnologies can also be traced at other sites, and what proportion of the overall populations at both Tiryns and Chania were exposed to the inhalation of smoke from lignite fires, a fuel type that would later become both central and integral to the modern industrial revolution some 3000 years later.


Archaeological background

Intensive archaeological fieldwork in the Eastern Mediterranean has brought to light a rich corpus of human skeletal evidence from the 2nd millennium BCE (Fig. 1; SI Appendix, Text 2; Table S1). All individuals selected by us for analysis were excavated and documented in their archaeological context, most of them found in different kinds of intramural burials. All burials were studied anthropologically, palaeopathologically using medical techniques in the case of Tiryns, and archaeologically; dating is based on radiocarbon dates and/or associated grave goods.

Chemical analyses

Eighty samples of dental calculus taken from 67 human individuals from eight sites across the Eastern Mediterranean were analyzed by Thermal Desorption-Gas Chromatography-Mass Spectrometry (TD–GC–MS) and Pyrolysis–Gas Chromatography-Mass Spectrometry (Py–GC–MS). Two sediment samples from one of the sites (Alalakh: ALA119.C), were additionally analyzed. This technique facilitates the identification of both free/unbound and bound/polymeric organic components. It also involves minimal sample manipulation which reduces the problems of contamination and sample loss, and requires small sample sizes89,90, which is often an important consideration with archaeological material. All 77 calculus samples produced moderate to significant amounts of free organic material. They also revealed similarly moderate to significant amounts of a bound/polymeric organic constituent.

Polycyclic aromatic hydrocarbons (PAHs) were of key interest in this study, hence the need to enhance their detection as part of the methodology applied. Characterization of PAHs provides some concerns in terms of the instrumental parameters used during analysis, namely the need to release ancient PAHs from the matrix they are adsorbed onto without creating them as artefacts of thermal cracking91,92. In this case, the impact of the substrate is minimal, given that the calcium in the hydroxyapatite matrix of the dental calculus does not promote the formation of PAHs93 Furthermore, to produce PAHs from thermal cracking a minimum temperature of c. 700 °C is required93,94, which is significantly higher than the temperatures reached here, preserving the signatures introduced in antiquity. The instrument parameters used for this study were selected on the basis of previous work carried out on optimizing PAH detection and analyses92,93,95,96.

TD/Py-GC–MS was performed on a Gerstel TDU Cryogenically-controlled Pyrolysis unit interfaced (320 °C), to an Agilent Technologies 7890B GC split/splitless injector (280 °C) linked to an Agilent Technologies 5977A MSD (electron voltage 70 eV, filament current 220 μA, source temperature 230 °C, quadrupole temperature 150 °C, multiplier voltage 2200 V, interface temperature 300 °C). The acquisition was controlled by a MassHunter ChemStation computer, in full scan mode (10-550amu). Approximately 2–5 mg of calculus sample was weighed into a quartz tube with glass wool end plugs. The tube was placed into a pyroprobe platinum heating coil via a Gerstel Multi-Purpose-Sampler and Gerstel Cold-Injection-System 4. The sample was thermally desorbed at 310 °C for 5 min in open split mode at 60 mL/min. After 4.5 min, the sample was pyrolyzed at 610 °C for 10 s, to provide sufficient energy for higher molecular weight PAHs to become volatilized and detected, but for a short enough time to prevent complete pyrolysis or the formation of PAHs in situ from macromolecular material93,94. At the same time the GC temperature program and data acquisition commenced. Separation was performed on a fused silica capillary column (30 m × 0.25 mm i.d) coated with 0.25 μm 5% phenyl methyl silicone (DB-5). Initially the GC was held at 45 °C for 5 min and then temperature programmed from 45 °C-320°C at 6 °C/min and held at final temperature for 15 min, total 65.83 min, with helium as the carrier gas (constant flow 1 mL/min, initial pressure of 7.3614 psi, split at 60 mL/min). The run was repeated with the same sample being pyrolysed at 610 °C for 20 s. Peaks were identified on the basis of both their mass spectra (NIST Mass Spectral Database and additional data referenced below), and relative retention times (relative retention indices (RRIs)).

The findings of the chemical analysis are shown in Tables S1, S2a and S2b.

Analysis of microremains (SI Appendix, Text 1.2)

Extraction used an EDTA-based approach as it poses fewer vapor risks compared with HCI methods97. We added ~ 1 ml of 0.5 M EDTA to decalcify weighed dental calculus chunks in 1.5 ml eppendorf tubes under a Bio Air Aura Mini laminar flow in the Department of Primatology at the Max Planck Institute for Evolutionary Anthropology, Leipzig. Samples were left in EDTA until decalcification was complete, which varied from a few hours to a few days. The samples were then centrifuged at 2000 × g for 10 min (Roth Mini-centrifuge), and the EDTA was removed from the samples by pipetting the supernatant. This process was repeated three times. During the final wash, 25% glycerine was added. In some cases, decalcification was already complete from prior protein extraction. In these cases, 100 μl of 25% glycerine solution was directly but slowly added to the tubes to avoid spillage due to foaming of residual sodium dodecyl sulfate from protein extraction. When samples were ready, 20 µl of each sample were mounted on glass slides with 18 × 18–22 × 22 mm coverslips. Mounting was done in the laminar flow and examined under brightfield and cross-polarized light on a Zeiss Axioscope microscope at 400 × magnification (Num. Aperture = 0.95). Samples were analyzed by examining the whole slide and any encountered microremains were photographed, described, and documented using the International Code for Starch Nomenclature (ICSN, 2011) and International code of Phytolith Nomenclature98,99. For combustion products, length and width measurements were taken to further identify the source and this was done using micrographs (Measurement data presented in Table S1 and S3).


  1. 1.

    Aiello, L. C. & Wheeler, P. The expensive-tissue hypothesis. The brain and the digestive system in human and primate evolution. Curr. Anthropol. 36, 199–221 (1995).

    Google Scholar 

  2. 2.

    Wrangham, R. W. Catching Fire. How Cooking Made Us Human (Basic Books, 2009).

  3. 3.

    Gur-Arieh, S., Maeir, A. M. & Shahack-Gross, R. In On Cooking Pots, Drinking Cups, Loomweights and Ethnicity in Bronze Age Cyprus and Neighbouring Regions, (eds. Karageorghis, V. & Kouka, U.) 349–355 (A.G. Leventis Foundation, 2011).

  4. 4.

    Gur-Arieh, S. et al. The taphonomy and preservation of wood and dung ashes found in archaeological cooking installations. Case studies from iron age Israel. JASc 46, 50–67 (2014).

    Google Scholar 

  5. 5.

    Mentzer, S. M. Microarchaeological approaches to the identification and interpretation of combustion features in prehistoric archaeological sites. J. Archaeol. Method Theory 21, 616–668 (2014).

    Google Scholar 

  6. 6.

    Hardy, K. et al. Neanderthal medics? Evidence for food, cooking, and medicinal plants entrapped in dental calculus. Naturwissenschaften 99, 617–626 (2012).

    ADS  CAS  PubMed  Google Scholar 

  7. 7.

    Hardy, K. et al. Dental calculus reveals potential respiratory irritants and ingestion of essential plant-based nutrients at lower palaeolithic Qesem cave Israel. Quatern. Int. 398, 129–135 (2016).

    Google Scholar 

  8. 8.

    Radini, A., Nikita, E., Buckley, S. A., Copeland, L. & Hardy, K. Beyond food. The multiple pathways for inclusion of materials into ancient dental calculus. Am. J. Phys. Anthropol. 162, 71–83 (2017).

    PubMed  Google Scholar 

  9. 9.

    Radini, A. et al. Neanderthals, trees and dental calculus. New Evidence from El Sidrón. Antiquity 90, 290–301 (2016).

    Google Scholar 

  10. 10.

    Aruz, J. (ed.). Beyond Babylon. Art, Trade, and Diplomacy in the Second Millennium B.C. Catalog of an Exhibition at the Metropolitan Museum of Art, New York, Nov., 2008–Mar. 15, 2009 (Yale University Press; Metropolitan Museum of Art, 2008).

  11. 11.

    Feldman, M. H. Diplomacy by Design. Luxury Arts and an “International Style” in the Ancient Near East, 1400–1200 BCE (University of Chicago Press, 2006).

  12. 12.

    Hodos, T. (ed.). The Routledge Handbook of Archaeology and Globalization (Routledge, 2017).

  13. 13.

    Maran, J. in Mycenaeans Up to Date, (ed. Schallin, A.-L. & Turnabitu, I.) 277–293 (Svenska Institutet i Athen, 2015).

  14. 14.

    Maran, J. in Ariadne’s Threads, edited by A. L. D’Agata (Scuola Archeologica Italiana di Atene, 2005), pp. 415–431.

  15. 15.

    Vetters, M., Brysbaert, A., Ntinou, M., Tsartsidou, G. & Margaritis, E. People and plants piecing. Together archaeological and archaeobotanical data to reconstruct plant use and craft activities in mycenaean tiryns. Opuscula 9, 93–132 (2016).

    Google Scholar 

  16. 16.

    Dunseth, Z. C., Junge, A., Fuchs, M., Finkelstein, I. & Shahack-Gross, R. Geoarchaeological investigation at the intermediate bronze age negev highlands site of mashabe sade. Tel Aviv J. Inst. Archaeol. Tel Aviv Univ. 43, 43–75 (2016).

    Google Scholar 

  17. 17.

    Fall, P. L., Falconer, S. E. & Klinge, J. Bronze age fuel use and its implications for agrarian landscapes in the eastern Mediterranean. J. Archaeol. Sci. Rep. 4, 182–191 (2015).

    Google Scholar 

  18. 18.

    Yunker, M. B. et al. PAHs in the fraser river basin. A Critical appraisal of PAH ratios as indikators of PAH source and composition. Org. Geochem. 33, 489–515 (2002).

    CAS  Google Scholar 

  19. 19.

    Tobiszewski, M. & Namiesnik, J. PAH diagnostic ratios for the identification of pollution emission sources. Environ. Pollut. 162, 110–119 (2012).

    CAS  PubMed  Google Scholar 

  20. 20.

    Tobiszewski, M. Application of diagnostic ratios of PHAs to characterize the pollution emission sources. IPCBEE 69, 41–44 (2014).

    CAS  Google Scholar 

  21. 21.

    Benner, B. A. et al. Distinguishing the Contributions of residential wood combustion and mobile source emissions using relative concentrations of dimethylphenanthrene isomers. Environ. Sci. Technol. 29, 2382–2389 (1995).

    ADS  CAS  PubMed  Google Scholar 

  22. 22.

    Elmquist, M., Zencak, Z. & Gustafsson, Ö. A 700 year sediment record of black carbon and polycyclic aromatic hydrocarbons near the EMEP air monitoring station in aspvreten Sweden. Environ. Sci. Technol. 41, 6926–6932 (2007).

    ADS  CAS  PubMed  Google Scholar 

  23. 23.

    Rogge, W. F., Hildemann, L. M., Mazurek, M. A., Cass, G. R. & Simoneit, B. R. T. Sources of fine organic aerosol. 9. Pine, oak, and synthetic log combustion in residental fireplaces. Environ. Sci. Technol. 32, 13–22 (1998).

    ADS  CAS  Google Scholar 

  24. 24.

    Simoneit, B. R. T., Rogge, W. F., Lang, Q. & Jaffé, R. Molecular characterization of smoke from campfire burning of pine wood (Pinus elliottii). Chemosphere Glob. Change Sci. 2, 107–122 (2000).

    ADS  CAS  Google Scholar 

  25. 25.

    Simoneit, B. R. T. Biomass burning. A review of organic tracers for smoke from incomplete combustion. Appl. Geochem. 17, 129–162 (2002).

    CAS  Google Scholar 

  26. 26.

    Lee, M. L., Prado, G. P., Howard, J. B. & Hites, R. A. Source identification of urban airborne polycyclic aromatic hydrocarbons by gas chromatographic mass spectrometry and high resolution mass spectrometry. Biomed. Mass Spectrom. 4, 182–186 (1977).

    CAS  PubMed  Google Scholar 

  27. 27.

    Verma, R., Patel, K. S. & Verma, S. K. Indoor polycyclic aromatic hydrocarbon concentration in central India. Polycyclic Aromat. Compd. 36, 152–168 (2016).

    CAS  Google Scholar 

  28. 28.

    Jehlicka, J., Zacek, V., Edwards, H. G. M., Shcherbakova, E. & Moroz, T. Raman spectra of organic compounds kladnoite (C6H4(CO)2NH) and Hoelite (C14H8O2). Rare sublimation products crystalling on self-ignited coal heaps. Spectrochim. Acta Part A 68, 1053–1057 (2007).

    ADS  CAS  Google Scholar 

  29. 29.

    Fabiańska, M. J. et al. Gaseous compounds and efflorescences generated in self-heating coal-waste dumps. A case study from the upper and lower silesian coal basins (Poland). Int. J. Coal Geol. 116–117, 247–261 (2013).

    Google Scholar 

  30. 30.

    Christanis, K. Coal facies studies in Greece. Int. J. Coal Geol. 58, 99–106 (2004).

    CAS  Google Scholar 

  31. 31.

    Kavouridis, K. Lignite industry in Greece within a world context. Mining, energy supply and environment. Energy Policy 36, 1257–1272 (2008).

    Google Scholar 

  32. 32.

    Siavalas, G. et al. Palaeoenvironment of seam I in the marathousa lignite mine, megalopolis basin (Southern Greece). Int. J. Coal Geol. 78, 233–248 (2009).

    CAS  Google Scholar 

  33. 33.

    Gentzis, T., Goodarzi, F., Koukouzas, C. N. & Foscolos, A. E. Petrology, mineralogy, and geochemistry of lignites from crete Greece. Int. J. Coal Geol. 30, 131–150 (1996).

    CAS  Google Scholar 

  34. 34.

    Karageorgiou, D. E. et al. Development of lignite in crete. Comparison of basins, possibilities of exploitation. Bull. Geol. Soc. Greece 43, 2236–2245 (2017).

    Google Scholar 

  35. 35.

    Oros, D. R. & Simoneit, B. R. T. Identification and emission rates of molecular tracers in coal smoke particulate matter. Fuel 79, 515–536 (2000).

    CAS  Google Scholar 

  36. 36.

    Velitzelos, D., Bouchal, J. M. & Denk, T. Review of the cenozoic floras and vegetation of Greece. Rev. Palaeobot. Palynol. 204, 56–117 (2014).

    Google Scholar 

  37. 37.

    Otto, A., Walther, H. & Püttmann, W. Sesqui- and diterpenoid biomarkers preserved in taxodium-rich oligocene oxbow lake clays, weisselster Basin, Germany. Org. Geochem. 26, 105–115 (1997).

    CAS  Google Scholar 

  38. 38.

    Otto, A., Simoneit, B. R. T. & Rember, W. C. Conifer and angiosperm biomarkers in clay sediments and fossil plants from the miocene clarkia formation, Idaho, USA. Org. Geochem. 36, 907–922 (2005).

    CAS  Google Scholar 

  39. 39.

    Simoneit, B. R. T., Otto, A., Kusumoto, N. & Basinger, J. F. Biomarker compositions of glyptostrobus and metasequoia (cupressaceae) fossils from the eocene buchanan lake formation, Axel Heiberg Island, Nunavut, Canada reflect diagenesis from terpenoids of their related extant species. Rev. Palaeobot. Palynol. 235, 81–93 (2016).

    Google Scholar 

  40. 40.

    Diefendorf, A. F., Leslie, A. B. & Wing, S. L. A phylogenetic analysis of conifer diterpenoids and their carbon isotopes for chemotaxonomic applications. Org. Geochem. 127, 50–58 (2019).

    CAS  Google Scholar 

  41. 41.

    Otto, A., Simoneit, B. R. T. & Wilde, V. Terpenoids as chemosystematic markers in selected fossil and extant species of pine (Pinus, Pinaceae). Bot. J. Linn. Soc. 154, 129–140 (2007).

    Google Scholar 

  42. 42.

    Su, Z., Yuan, W., Wang, P. & Li, S. Ethnobotany, phytochemistry, and biological activities of taxodium rich. Pharm. Crops 4, 1–14 (2013).

    CAS  Google Scholar 

  43. 43.

    Jain, N. & Sharam, M. Ethanobotany, phytochemical and pharmacological aspects of Thuja orientalis. A review. Int. J. Pure Appl. Biosci. 5, 73–83 (2017).

    ADS  Google Scholar 

  44. 44.

    Haberer, R. M., Mangelsdorf, K., Wilkes, H. & Horsfield, B. Occurrence and palaeoenvironmental significance of aromatic hydrocarbon biomarkers in oligocene sediments from the mallik 5L–38 gas hydrate production research well (Canada). Org. Geochem. 37, 519–538 (2006).

    CAS  Google Scholar 

  45. 45.

    Liu, B., Zhao, C., Ma, J., Sun, Y. & Püttmann, W. The origin of pale and dark layers in Pliocene lignite deposits from Yunnan Province, Southwest China, based on coal petrological and organic geochemical analyses. Int. J. Coal Geol. 195, 172–188 (2018).

    CAS  Google Scholar 

  46. 46.

    Stefanova, M., Markova, K., Marinov, S. & Simoneit, B. R. T. Biomarkers in the fossils from miocene-aged chukurovo lignite, Bulgaria, Sesqui- and Diterpenoids. Bull. Geosci. 80, 93–97 (2005).

    CAS  Google Scholar 

  47. 47.

    El-Sabagh, S. M. et al. Distribution of triterpanes and steranes biomarkers as indication of organic matters input and depositional environments of crude oils of oilfields in Gulf of Suez, Egypt. Egypt. J. Pet. 27, 969–977 (2018).

    Google Scholar 

  48. 48.

    Fleck, S., Michels, R., Izart, A., Elie, M. & Landais, P. Palaeoenvironmental assessment of Westphalian fluvio-lacustrine deposits of Lorraine (France) using a combination of organic geochemistry and sedimentology. Int. J. Coal Geol. 48, 65–88 (2001).

    CAS  Google Scholar 

  49. 49.

    Sofikitis, E., Siavalas, G., Chatziapostolou, A., Kalaitzidis, S. & Christanis, K. Greek coastal mires. A preliminary study of the Agoulinitsa Peatland, Western Peloponnese. Bull. Geol. Soc. Greece 40, 191–200 (2018).

    Google Scholar 

  50. 50.

    Moldowan, J. M. et al. The molecular fossil record of oleanane and its relation to angiosperms. Science 265, 768–771 (1994).

    ADS  CAS  PubMed  Google Scholar 

  51. 51.

    Wang, G.-C., Sun, M.-Z., Gao, S.-F. & Tang, L. The origin, type and hydrocarbon generation potential of organic matter in a marine-continental transitional facies shale succession (Qaidam Basin, China). Sci. Rep. 8, 6568 (2018).

    ADS  PubMed  PubMed Central  Google Scholar 

  52. 52.

    Wang, G., Chang, X., Wang, T.-G. & Simoneit, B. R. Pregnanes as molecular indicators for depositional environments of sediments and petroleum source rocks. Org. Geochem. 78, 110–120 (2015).

    CAS  Google Scholar 

  53. 53.

    Requejo, A. G., Hieshima, G. B., Hsu, C. S., McDonald, T. J. & Sassen, R. Short-chain (C21 and C22) diasteranes in petroleum and source rocks as indicators of maturity and depositional environment. Geochim. Cosmochim. Acta 61, 2653–2667 (1997).

    ADS  CAS  Google Scholar 

  54. 54.

    Waples, D. W. & Machihara, T. Biomarkers for geologists. A practical guide to the application of steranes and triterpanes in petroleum geology (American Assoc. of Petroleum Geologists, 1991).

  55. 55.

    Zidianakis, G., Mohr, B. A. R. & Fassoulas, C. A late Miocene leaf assemblage from Vrysses, western Crete, Greece, and its paleoenvironmental and paleoclimatic interpretation. Geodiversitas 29, 351–377 (2007).

    Google Scholar 

  56. 56.

    Vamvuka, D., Tsamourgeli, V., Zaharaki, D. & Komnitsas, K. Potential of poor lignite and Biomass blends in energy production. Energy Sour. Part A Recov. Util. Environ. Eff. 38, 2079–2085 (2016).

    CAS  Google Scholar 

  57. 57.

    MacKenzie, L., Speller, C. F., Holst, M., Keefe, K. & Radini, A. Dental calculus in the industrial age: human dental calculus in the Post-Medieval period, a case study from industrial Manchester. Quat. Int. (2021).

    Article  Google Scholar 

  58. 58.

    Power, R. C., Salazar-García, D. C., Straus, L. G., González Morales, M. R. & Henry, A. G. Microremains from El Mirón Cave Human Dental calculus suggest a mixed plant-animal subsistence economy during the magdalenian in Northern Iberia. J. Archaeol. Sci. 60, 39–46 (2015).

    Google Scholar 

  59. 59.

    Peters, M. E. & Higuera, P. E. Quantifying the source area of macroscopic charcoal with a particle dispersal model. Quatern. Res. 67, 304–310 (2007).

    ADS  Google Scholar 

  60. 60.

    Valavanidis, A., Fiotakis, K. & Vlachogianni, T. Airborne particulate matter and human health. Toxicological assessment and importance of size and composition of particles for oxidative damage and carcinogenic mechanisms. J. Environ. Sci. Health Part C 26, 339–362 (2008).

    CAS  Google Scholar 

  61. 61.

    Blackford, J. J. Charcoal fragments in surface samples following a fire and the implications for interpretation of subfossil charcoal data. Palaeogeogr. Palaeoclimatol. Palaeoecol. 164, 33–42 (2000).

    Google Scholar 

  62. 62.

    Boratyński, A., Browicz, K. & Zieliński, J. Chorology of Trees and Shrubs in Greece. 2nd ed. (Sorus, 1992).

  63. 63.

    Browicz, K. Chorology of Trees and Shrubs in South-West Asia and Adjacent Regions (Polish Scientific Publications, 1994).

  64. 64.

    Koromila, G. et al. The Neolithic tell as a multi-species monument: Human, animal, and plant relationships through a micro-contextual study of animal dung remains at Koutroulou Magoula, central Greece. J. Archaeol. Sci. Rep. 19, 753–768 (2018).

    Google Scholar 

  65. 65.

    Karkanas, P. Late Neolithic household activities in marginal areas: the micromorphological evidence from the Kouveleiki caves, Peloponnese, Greece. JASc 33, 1628–1641 (2006).

    Google Scholar 

  66. 66.

    Portillo, M., Kadowaki, S., Nishiaki, Y. & Albert, R. M. Early Neolithic household behavior at Tell Seker al-Aheimar (Upper Khabur, Syria): a comparison to ethnoarchaeological study of phytoliths and dung spherulites. JASc 42, 107–118 (2014).

    Google Scholar 

  67. 67.

    Stiner, M. C. et al. A forager-herder trade-off, from broad-spectrum hunting to sheep management at Aşıklı Höyük, Turkey. PNAS 111, 8404–8409 (2014).

    ADS  CAS  PubMed  PubMed Central  Google Scholar 

  68. 68.

    Caley, E. R. & Richards, J. F. C. Theophrastus on Stones. Introduction, Greek Text, English Translation and Commentarx (1956).

  69. 69.

    Ruan, Q. & Wang, Y. Jartai pass site in Nilka county, Xinjiang. Archaeology 7, 57–70 (2017).

    Google Scholar 

  70. 70.

    Wiener, M. H. in The Great Islands, (eds. Macdonald, C. F., Hatzaki E. M. & Andreou, S.) 131–142 (Kapon Editions, 2015).

  71. 71.

    Niemeier, W.-D. Die Palaststilkeramik von Knossos. Stil, Chronologie und historischer Kontext (Mann, 1985).

  72. 72.

    Maran, J. Forschungen in der Unterburg von Tiryns 2000–2003. Mit einem Beitrag von Peter Marzolff. AA, 35–111 (2008).

  73. 73.

    Hallager, B. P. & McGeorge, P. J. P. Late Minoan III Burials at Khania. The Tombs, Finds and Deceased in Odos Palama (Åström, 1992).

  74. 74.

    Schallin, A.-L. in New Research on Old Material from Asine and Berbati, (ed. Wells, B.) 141–155 (Åström, 2002).

  75. 75.

    Damm‐Meinhardt, U. Die mykenische Palastzeit (SH III B2) und beginnende Nachpalastzeit (Beginn SH III C) (Reichert Verlag, 2015).

  76. 76.

    Prillwitz, S. & Hein, A. In The Transmission of Technical Knowledge in the Production of Ancient Mediterranean Pottery, (eds. Gauß, W., Klebinder-Gauss, G. & von Rüden, C.) 351–365 (Österreichisches Archäologisches Institut, 2015).

  77. 77.

    Stockhammer, P. W. Dissertation. Ruprecht-Karls-Universität, 2008.

  78. 78.

    Sherratt, E. S. in The Complex Past of Pottery, (eds. Crielaard, J. P., van Wijngaarden, G. J. & Stissi, V.) 163–211 (Gieben, 1999).

  79. 79.

    Rahmstorf, L. Kleinfunde aus Tiryns. Terrakotta, Stein, Bein und Glas/Fayence vornehmlich aus der Spätbronzezeit. Teilw. zugl.: Heidelberg, Univ., Diss., 2001 (Reichert Verlag, 2008).

  80. 80.

    Rahmstorf, L. in Mycenaeans Up to Date. Current Concepts and New Directions, (eds. Schallin, A.-L. & Turnabitu, I.) 143–149 (Svenska Instituten vid Rom och Athen, 2015). Current Concepts and New Directions.

  81. 81.

    Panagiotaki, M. et al. in Annales du 16e Congrès de l’Association Internationale pour l’Histoire du Verre, London, 7 - 13 September, 2003., (ed. Nenna, M.-D.) 14–18 (2005).

  82. 82.

    Hallager, E. (ed.). Late Minoan III Pottery. Chronology and Terminology. Acts of a Meeting held at the Danish Institute at Athens, August 12–14, 1994 (Univ. Press, 1997).

  83. 83.

    Karampinis, E. et al. Comparative study of combustion properties of five energy crops and greek lignite. Energy Fuels 26, 869–878 (2012).

    CAS  Google Scholar 

  84. 84.

    Killen, J. T. in A Companion to Linear B, (eds. Duhoux, Y. & Morpurgo Davies, A.) 159–200 (Peeters, 2011).

  85. 85.

    Shelmerdine, C. W. in Rethinking Mycenaean palaces, (eds. Galaty, M. L. & Parkinson, W. A.) 19–24 (Cotsen Institute of Archaeology University of California Los Angeles, 1999).

  86. 86.

    Killen, J. T. in Pylos Comes Alive, (eds. Shelmerdine, C. W. & Palaima, T. G.) 49–63 (Fordham University Press, 1984).

  87. 87.

    Shelmerdine, C. W. The Perfume Industry of Mycenaean Pylos (Åström, 1985).

  88. 88.

    Smil, V. Energy In World History (Routledge, 2020).

  89. 89.

    Buckley, S. A., Scott, A. W. & Evershed, R. P. Studies of organic residues from ancient egyptian mummies using high temperature-gas chromatography-mass spectronomy and sequential thermal desorption-gas chromatography-mass spectronomy and pyrolysis-gas chromatography-mass spectronomy. Analyst 124, 443–452 (1999).

    ADS  CAS  PubMed  Google Scholar 

  90. 90.

    González-Pérez, J. A., Almendros, G., de La Rosa, J. M. & González-Vila, F. J. Appraisal of polycyclic aromatic hydrocarbons (PAHs) in environmental matrices by analytical pyrolysis (Py–GC/MS). J. Anal. Appl. Pyrol. 109, 1–8 (2014).

    Google Scholar 

  91. 91.

    Terán, A., Gonzalez-Vila, F. J. & Gonzalez-Perez, J. A. Detection of organic contamination in sediments by double-shoot pyrolysis–GC/MS. Environ Chem Lett 7, 301–308 (2009).

    Google Scholar 

  92. 92.

    Biache, C., Lorgeoux, C., Saada, A., Colombano, S. & Faure, P. Fast method to quantify PAHs in contaminated soils by direct thermodesorption using analytical pyrolysis. Talanta 166, 241–248 (2017).

    CAS  PubMed  Google Scholar 

  93. 93.

    Sharma, R. K. & Hajaligol, M. R. Effect of pyrolysis conditions on the formation of polycyclic aromatic hydrocarbons (PAHs) from polyphenolic compounds. J. Anal. Appl. Pyrol. 66, 123–144 (2003).

    CAS  Google Scholar 

  94. 94.

    Medina-Vera, M. Pyrolysis-gas chromatography/mass spectrometry used for screening polycyclic aromatic hydrocarbons by desorption from sediment. J. Anal. Appl. Pyrol. 36, 27–35 (1996).

    CAS  Google Scholar 

  95. 95.

    Biache, C., Lorgeoux, C., Saada, A. & Faure, P. Behavior of PAH/mineral associations during thermodesorption: impact for the determination of mineral retention properties towards PAHs. Anal. Bioanal. Chem. 407, 3509–3516 (2015).

    CAS  PubMed  Google Scholar 

  96. 96.

    Nali, M., Corana, F., Montanari, L. & Pellegrini, L. A pyrolysis-gas chromatography/mass spectrometry study on coals. J. Anal. Appl. Pyrol. 29, 15–23 (1994).

    CAS  Google Scholar 

  97. 97.

    Tromp, M., Buckley, H., Geber, J. & Matisoo-Smith, E. EDTA decalcification of dental calculus as an alternate means of microparticle extraction from archaeological samples. J. Archaeol. Sci. Rep. 14, 461–466 (2017).

    Google Scholar 

  98. 98.

    International Committee for Phytolith Taxonomy. International Code for Phytolith Nomenclature (ICPN) 2.0. Ann. Bot. 124, 189–199 (2019).

    Google Scholar 

  99. 99.

    Madella, M., Alexandre, A. & Ball, T. International code for phytolith nomenclature 1.0. Ann. Bot. 96, 253–260 (2005).

    CAS  PubMed  PubMed Central  Google Scholar 

Download references


We thank Bristol Museums and Galleries for making the dental calculus from Horemkenesi available to us and Sue Giles who provided us with access to this material, and we also thank Shira Gur-Arieh, Stephanie Schnorr and Magdalene Ting for comments.


Open Access funding enabled and organized by Projekt DEAL. This research is part of Philipp W. Stockhammer’s European Research Council (ERC) Starting Grant project ‘FoodTransforms: transformations of food in the Eastern Mediterranean Late Bronze Age’ (ERC-2015-StG 678901-FoodTransforms) funded by the European Research Council. The anthropological research in Tiryns was funded within the project “Negotiating Change – Cultural and Social Transformations in the Late 2nd Millennium BCE East Mediterranean: Case Studies from Tiryns, Greece, and Tell es-Safi/Gath, Israel” (German-Israel Foundation for Science and Research; GIF; Grant No. 1080–132.4/2009; Aren Maeir and Joseph Maran) as well as the German Research Foundation (MA 1058/7–1 and 7–2; Joseph Maran). Katerina Harvati is supported by the German Research Foundation (DFG FOR 2237) and the European Research Council (ERC CoG 724703). Joann Fletcher is supported by Pharos Research.

Author information




P.W.S conceived the study. S.B., R.C.P., J.B., M.B., S.C. performed laboratory work. S.B., R.C.P., I.S. and C.S. analyzed data. P.M., K.H., M.F., T.S.S., M.S. and R.S. performed anthropological assessments. M.A.V., M.A., S.E., J.F., B.H., T.I., E.K., J.M., M.M., P.M., I.M., A.P., E.P., D.S.G., V.J.S., R.S., D.Y., K.A.Y. and P.W.S. assembled and interpreted archaeological material. S.B., R.C.P. and P.W.S. designed figures. C.S. and S.B. supervised laboratory work. All authors wrote the supplemental notes. S.B., R.C.P. and P.W.S. wrote the paper with input from all co-authors.

Corresponding authors

Correspondence to Stephen Buckley, Cynthianne Spiteri or Philipp W. Stockhammer.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher's note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Buckley, S., Power, R.C., Andreadaki-Vlazaki, M. et al. Archaeometric evidence for the earliest exploitation of lignite from the bronze age Eastern Mediterranean. Sci Rep 11, 24185 (2021).

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI:


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing