Gold and Bronze. Metals, Technologies and Networks in the Eastern Balkans during the Bronze Age. National Archaeological Institute, Bulgarian Academy of Sciences., 2018
Increased interest in the fractionation of Sn isotopes has led to the development of several tech... more Increased interest in the fractionation of Sn isotopes has led to the development of several techniques for preparing cassiterite (SnO 2 , the primary ore of Sn) for isotopic analysis. Two distinct methods have been applied in recent isotopic studies of cassiterite: (a) reduction to tin metal with potassium cyanide (KCN) at high temperature (800 °C), with subsequent dissolution in HCl, and (b) reduction to a Sn solution with hydriodic acid (HI) at low temperature (100 °C). This study compares the effectiveness and accuracy of these two methods and contributes additional methodological details. The KCN method consistently yielded more Sn (> 70% in comparison with < 5%), does not appear to fractionate Sn isotopes at high temperatures over a 2-hour period and produced consistent Sn isotope values at flux mass ratios of ≥ 4:1 (flux to mineral) with a minimum reduction time of 40 min. By means of a distillation experiment, it was demonstrated that HI could volatilise Sn, explaining the consistently low yields by this method. Furthermore, the distillation generated Sn vapour, which is up to 0.38‰ per mass unit different from the starting material, the largest induced Sn fractionation reported to date. Accordingly, the HI method is not recommended for cassiterite preparation for Sn isotopic analysis.
Isotopic analysis has proved to be an effective approach to determine the provenance of copper or... more Isotopic analysis has proved to be an effective approach to determine the provenance of copper ore sources for the production of bronze artifacts. More recently, methods for Sn isotopic analysis of bronze have been developed. However, the viability of tin isotopes as a means to define groupings that may be attributed to varying ore sources, production methods, or recycling is still in question. In part, this is due to the numerically and/or geographically limited nature of published datasets. This study reports on the Sn isotopic composition of 52 artifacts from the later Bronze Age (1500-1100 BCE) from Serbia and western Romania. The majority of samples cluster between 0.4 and 0.8 per mil for d 124 Sn, and 0.2 and 0.4 per mil for d 120 Sn (relative to NIST SRM 3161A), and this isotopic grouping of bronze artifacts occurs across Serbia. However, groupings of isotopically heavier and lighter artifacts are evident, and each corresponds to a more limited geographic range. Artifacts associated with higher dSn values are limited to the Vojvodina region of northern Serbia, whereas a cluster of bronzes with lower Sn-isotopic signatures are constrained to the Banat along the Serbia-Romania border, and Transylvania. One low-value outlier corresponds to an uncontextualized find near Kru sevac at the southern extent of the study area. Geographic correlation of the low-value cluster with known tin mineralization in Transylvania, and the moderate-value cluster with placer tin deposits of western Serbia, suggests that these distinct bronze Sn-isotopic signatures might reflect exploitation of different tin ores. The small cluster of high Sn-isotopic values from bronzes from the Vojvodina region might reflect bronze recycling in this area that lies furthest from both known tin ore sources.
Tin is a rare metal that is essential for making bronze, the defining technology of the Bronze Ag... more Tin is a rare metal that is essential for making bronze, the defining technology of the Bronze Age. The source(s) of tin for Aegean bronze is undetermined but several small Bronze Age tin mines have been documented in the circum-Aegean region. The discovery of Bronze Age archaeological sites in West Serbia near a tin placer deposit on the flanks of Mt. Cer led to an investigation of this site as a potential additional Bronze Age tin mine in the region. Geochemical prospecting of stream sediments flowing from Mt. Cer allowed for categorization of streams based on relative tin grade. Tin grade is highest in the Milinska River, a likely combination of a broad catchment area with multiple ore-bearing tributaries, and a topographic profile that favors the accumulation of placer deposits. A survey of cornfields along the southern pluton margin discovered archaeological sites spanning the Neolithic to the Iron Age. Unlike older and younger sites, those of the Bronze Age were found only along the Milinska and Cernica Rivers where placer tin grades are highest, but appear to be absent where tin is scarce or absent. This suggests that these sites were associated with the exploitation of the tin ore. C
Tin is a rare metal that is essential for making bronze, the defining technology of the Bronze Ag... more Tin is a rare metal that is essential for making bronze, the defining technology of the Bronze Age. The source(s) of tin for Aegean bronze is undetermined but several small Bronze Age tin mines have been documented in the circum-Aegean region. The discovery of Bronze Age archaeological sites in West Serbia near a tin placer deposit on the flanks of Mt. Cer led to an investigation of this site as a potential additional Bronze Age tin mine in the region. Geochemical prospecting of stream sediments flowing from Mt. Cer allowed for categorization of streams based on relative tin grade. Tin grade is highest in the Milinska River, a likely combination of a broad catchment area with multiple ore-bearing tributaries, and a topographic profile that favors the accumulation of placer deposits. A survey of cornfields along the southern pluton margin discovered archaeological sites spanning the Neolithic to the Iron Age. Unlike older and younger sites, those of the Bronze Age were found only along the Milinska and Cernica Rivers where placer tin grades are highest, but appear to be absent where tin is scarce or absent. This suggests that these sites were associated with the exploitation of the tin ore. C
Gold and Bronze. Metals, Technologies and Networks in the Eastern Balkans during the Bronze Age. National Archaeological Institute, Bulgarian Academy of Sciences., 2018
Increased interest in the fractionation of Sn isotopes has led to the development of several tech... more Increased interest in the fractionation of Sn isotopes has led to the development of several techniques for preparing cassiterite (SnO 2 , the primary ore of Sn) for isotopic analysis. Two distinct methods have been applied in recent isotopic studies of cassiterite: (a) reduction to tin metal with potassium cyanide (KCN) at high temperature (800 °C), with subsequent dissolution in HCl, and (b) reduction to a Sn solution with hydriodic acid (HI) at low temperature (100 °C). This study compares the effectiveness and accuracy of these two methods and contributes additional methodological details. The KCN method consistently yielded more Sn (> 70% in comparison with < 5%), does not appear to fractionate Sn isotopes at high temperatures over a 2-hour period and produced consistent Sn isotope values at flux mass ratios of ≥ 4:1 (flux to mineral) with a minimum reduction time of 40 min. By means of a distillation experiment, it was demonstrated that HI could volatilise Sn, explaining the consistently low yields by this method. Furthermore, the distillation generated Sn vapour, which is up to 0.38‰ per mass unit different from the starting material, the largest induced Sn fractionation reported to date. Accordingly, the HI method is not recommended for cassiterite preparation for Sn isotopic analysis.
Isotopic analysis has proved to be an effective approach to determine the provenance of copper or... more Isotopic analysis has proved to be an effective approach to determine the provenance of copper ore sources for the production of bronze artifacts. More recently, methods for Sn isotopic analysis of bronze have been developed. However, the viability of tin isotopes as a means to define groupings that may be attributed to varying ore sources, production methods, or recycling is still in question. In part, this is due to the numerically and/or geographically limited nature of published datasets. This study reports on the Sn isotopic composition of 52 artifacts from the later Bronze Age (1500-1100 BCE) from Serbia and western Romania. The majority of samples cluster between 0.4 and 0.8 per mil for d 124 Sn, and 0.2 and 0.4 per mil for d 120 Sn (relative to NIST SRM 3161A), and this isotopic grouping of bronze artifacts occurs across Serbia. However, groupings of isotopically heavier and lighter artifacts are evident, and each corresponds to a more limited geographic range. Artifacts associated with higher dSn values are limited to the Vojvodina region of northern Serbia, whereas a cluster of bronzes with lower Sn-isotopic signatures are constrained to the Banat along the Serbia-Romania border, and Transylvania. One low-value outlier corresponds to an uncontextualized find near Kru sevac at the southern extent of the study area. Geographic correlation of the low-value cluster with known tin mineralization in Transylvania, and the moderate-value cluster with placer tin deposits of western Serbia, suggests that these distinct bronze Sn-isotopic signatures might reflect exploitation of different tin ores. The small cluster of high Sn-isotopic values from bronzes from the Vojvodina region might reflect bronze recycling in this area that lies furthest from both known tin ore sources.
Tin is a rare metal that is essential for making bronze, the defining technology of the Bronze Ag... more Tin is a rare metal that is essential for making bronze, the defining technology of the Bronze Age. The source(s) of tin for Aegean bronze is undetermined but several small Bronze Age tin mines have been documented in the circum-Aegean region. The discovery of Bronze Age archaeological sites in West Serbia near a tin placer deposit on the flanks of Mt. Cer led to an investigation of this site as a potential additional Bronze Age tin mine in the region. Geochemical prospecting of stream sediments flowing from Mt. Cer allowed for categorization of streams based on relative tin grade. Tin grade is highest in the Milinska River, a likely combination of a broad catchment area with multiple ore-bearing tributaries, and a topographic profile that favors the accumulation of placer deposits. A survey of cornfields along the southern pluton margin discovered archaeological sites spanning the Neolithic to the Iron Age. Unlike older and younger sites, those of the Bronze Age were found only along the Milinska and Cernica Rivers where placer tin grades are highest, but appear to be absent where tin is scarce or absent. This suggests that these sites were associated with the exploitation of the tin ore. C
Tin is a rare metal that is essential for making bronze, the defining technology of the Bronze Ag... more Tin is a rare metal that is essential for making bronze, the defining technology of the Bronze Age. The source(s) of tin for Aegean bronze is undetermined but several small Bronze Age tin mines have been documented in the circum-Aegean region. The discovery of Bronze Age archaeological sites in West Serbia near a tin placer deposit on the flanks of Mt. Cer led to an investigation of this site as a potential additional Bronze Age tin mine in the region. Geochemical prospecting of stream sediments flowing from Mt. Cer allowed for categorization of streams based on relative tin grade. Tin grade is highest in the Milinska River, a likely combination of a broad catchment area with multiple ore-bearing tributaries, and a topographic profile that favors the accumulation of placer deposits. A survey of cornfields along the southern pluton margin discovered archaeological sites spanning the Neolithic to the Iron Age. Unlike older and younger sites, those of the Bronze Age were found only along the Milinska and Cernica Rivers where placer tin grades are highest, but appear to be absent where tin is scarce or absent. This suggests that these sites were associated with the exploitation of the tin ore. C
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