Preface
Bronze research, including inscriptions, shapes and styles, production processes, circulation and consumption, is one of the five ways to understand Shang civilization. Mr. Zhang Guangzhi proposed that merchants maintained their rule by controlling bronze resources and the production and circulation of bronzes, and Liu Li and Chen Xingcan further pointed out that the expansion of the Shang Dynasty was for the control and acquisition of resources, but some scholars believe that the Shang king's control over the surrounding areas was not very strong. It is difficult to give a clear answer from the perspective of traditional archaeology, and through the scientific and technological testing of bronzes, it is possible to determine its production technology and mineral source, thus providing more data support for the discussion of these theories, and can also test existing theories.
Lead isotope analysis is an important method for studying the origin of minerals in ancient bronzes. Mr. Jin Zhengyao was the first to detect that a considerable part of the bronzes of the Tomb of The Lady of Yin Xu contained highly radioactive lead isotopes and deduced that some of the metal resources of the Shang Dynasty may have originated in southwest China. His conclusions caused a lot of discussion, and archaeologists learned about the analysis methods of lead isotopes, and gradually applied them widely to chinese bronze research. Although metallurgical archaeologists have accumulated lead isotope data on bronzes and smelting and casting relics from the pre-Qin period, more data on bronzes in different regions and at different times are needed to solve important problems such as the source and circulation of metal resources in the Shang Dynasty.
A considerable number of Shang Dynasty bronzes have been excavated in the Haidai area, but there has been little systematic scientific detection and analysis at present. This paper mainly introduces the lead isotope ratio data and research results of some bronzes excavated from the Liujiazhuang site in Jinan in the late Shang Dynasty. The scientific research of the Liujiazhuang site is not only conducive to deepening the understanding of the Shang Dynasty bronzes at this site, but also provides a new perspective for understanding the relationship between the Shang period culture in the Haidai area and the Yin Ruins in Anyang. The lead in the bronze ware of the Liujiazhuang site is mainly based on lead of highly radioactive genesis, and its data is relatively concentrated, which provides a reference standard for the analysis of highly radioactive lead in the Shang Dynasty. By comparing the lead isotope data of the bronzes excavated from the Liujiazhuang site with other published Shang Dynasty data, this paper believes that the data of highly radioactive lead isotopes in the Shang Dynasty had subtle changes in the Middle Shang Period and the late yin Xu Phase II. Although it is not yet possible to explain exactly why this change occurred, this finding offers a possibility for exploring the political and economic activity of different stages of the Shang Dynasty.
1. Overview of the site
Located about 3 kilometers northwest of the ancient city district of Jinan, Shandong Province, the Liujiazhuang ruins are a site from the Shang and Zhou Dynasties and the Tang to the Ming and Qing dynasties. Nearly 20 Shang Dynasty bronzes were excavated from the Liujiazhuang site in the 1970s. From July 2010 to February 2011, the Jinan Archaeological Research Institute conducted archaeological excavations on the site and achieved important results, a total of 77 Shang Dynasty tombs were found, and 8 tombs unearthed bronzes, of which 3 (M109, M121 and M122) excavated bronzes with a relatively large number of bronzes and many artifacts with inscriptions. The excavation of the Liujiazhuang site has provided important information for the further study of Shang Dynasty archaeology in the Haidai area. According to the typological analysis of the pottery and bronze artifacts excavated from the Liujiazhuang site in the excavation report, it can be seen that the remains of the site mainly correspond to the second to fourth phases of the Yin Ruins, and the main remains are the third phase of the Yin Ruins. The tombs that belong to the second phase of yin ruins have M38 and M81, and only 1 piece of copper has been excavated. The tombs that belong to the third phase of Yin Ruins have M109, M112, M121, M122, and M122, of which the three larger tombs M109, M121, and M122 have more bronze artifacts, the bronze containers are in the same style and most of them have more exquisite ornaments, and M112 unearthed 1 piece of copper, knight, and ge. Only M56 belongs to the fourth phase of Yin Ruins, and 1 piece of copper, go and bow ware has been unearthed. In order to further deepen the understanding of the bronzes excavated from the Liujiazhuang site and study the sources of their ore materials and the type of alloy, we sampled and analyzed some of the bronze containers, weapons and tools excavated from the Liujiazhuang site.
Second, sample and analysis methods
This time, 39 pieces of bronze artifacts excavated from the Liujiazhuang site were selected for detection and analysis, and the composition analysis of the surface of the copper was first analyzed by portable X-ray fluorescence spectrometer to roughly determine the alloy type; then the rust on the surface of the copper was sampled and the lead isotope ratio was determined. Previous studies have shown that lead isotope data of rust on the surface of copper can represent data on the copper body. During the sampling process, we also selected an artifact (LJZ Unsigned-1) and sampled both the patina and the copper matrix to compare the patina and the copper body. Therefore, there are 40 samples available for analysis. Since the portable X-ray fluorescence spectrometer detects the surface of the artifact, the chemical composition of the corrosion on the surface of the copper is actually analyzed, and it is not possible to determine whether the matrix composition of the measured copper can be accurately reflected. However, this method can be better qualitatively analyzed to determine the presence or absence of alloying elements such as lead and tin, and the amount of alloying elements reflected in them represents the level of the alloying element content to some extent. In cases where destructive sampling is not possible, qualitative analysis by a portable X-ray fluorescence spectrometer can help us gain an overall understanding of the type of alloy in the artifact. The 39 bronze artifacts selected were mainly from 6 tombs, and several samples were collected (Table 1; Schedule 1).
Lead isotope analysis used the Multi-Receiver Inductively Coupled Plasma Mass Spectrometer (MC-ICP-MS) of the Academy of Earth and Space Sciences of Peking University to test the lead isotope ratio of samples. The instrument analysis accuracy is less than 0.01%, 0.01% and 0.1% respectively for the analytical accuracy of 207Pb/206Pb, 208Pb/206Pb and 206Pb/204Pb, respectively. The test uses the international lead isotope standard solution SRM981 calibration instrument, and every 6 to 8 samples tested is a standard solution. After the test was completed, we used the calculation method of Wei Guofeng et al. to compare the numerical changes of the substrate of the sampled LJZ no number-1 and the lead isotope of its surface rust corrosion to test the reliability of the measured data. Its calculation formula is: △ rust - base (%) = (R rust / R base -1) × 100%, the calculation results are shown in Table 2. The error with the instrument analysis accuracy (207Pb/206Pb208Pb/206Pb206Pb/204Pb207Pb/206Pb and 208Pb/206Pb is slightly higher than the instrument measurement error, while 206Pb/204Pb is within the instrument measurement error range. We believe that such errors are within the acceptable range relative to the Shang Dynasty lead isotope data range and will not affect the final analysis results.
When analyzing with a portable X-ray fluorescence spectrometer, the measurement is mainly made where there is less surface rust. Each artifact is measured by 2 to 3 points and the average is calculated. We used the Bruker Tracer III. SD type instrument of Shandong University for analysis, measuring at a temperature of 40 kV, 11.8 microamps, using a yellow filter (Yellow Filter), the measurement time is 60 seconds. After the measurement, the data processing was carried out using Bruker S1Cal software, and the standard samples used were purchased for Shandong University to purchase a group of 17 Jam series samples produced by MBH.
3. Analyze the results
Lead isotopes are of great significance in the study of ancient copper, lead resources and the circulation of products. Its important advantage is that the ratio of lead isotopes changes very little during the smelting process of ore, so the lead isotope ratio of copper can reflect the source of its ore to a certain extent. Of course, lead isotope analysis also has its limitations, that is, it is necessary to determine what kind of metal the lead isotope ratio represents the source of the metal, and also to consider the remelting and mixing of ancient metals. But in any case, lead isotope ratio studies can provide very important information.
The lead isotope analysis results of 39 bronzes at the Liujiazhuang site show that the ratio of 208Pb/204Pb to 204Pb of 29 bronzes is concentrated between 41 and 43, and the ratio of 206Pb/204Pb is concentrated between 20.5 and 22 (Appendix II), which belongs to the so-called highly radioactive genesis lead (208Pb/204Pb>40, 206Pb/204Pb> The ratio of 20,207Pb/206Pb208Pb/204Pb is between 38 and 40, and the ratio of 206Pb/204Pb is concentrated between 17.6 and 19.5; the ratio of lead isotope in 1 piece of bronze is much lower than that of other artifacts, with a ratio of 36.1831 for 208Pb/204Pb and 16.3168 for 206Pb/204Pb. Since the lead isotope of copper is related to the source of the lead it contains (red copper and copper-tin alloy artifacts, the lead contained in them is mainly from the original trace amount of lead in the copper mine, so its lead isotope can represent the source of copper ore; copper with high lead content is mainly consciously added lead as an alloy component, and its lead isotope represents the source of lead ore), so it is necessary to combine the alloy type with lead isotopes to investigate. According to portable X-ray fluorescence spectrometer data, there are 3 pieces of red copper (group A), 31 pieces of tin-containing copper and 4 pieces of copper-lead alloy (group E). We divided the 31 tin-containing bronzes into trace lead groups (group B, 5 pieces, Pb) according to the amount of lead content
From the perspective of alloy type, highly radioactive lead is present in various alloy types of copper, but it seems that the ratio of radioactive lead isotopes in copper with high lead content is higher (208Pb/204Pb> 42, 206Pb/204Pb>21.5, 207Pb/206Pb
From the perspective of instruments, highly radioactive lead is also present in various types of instruments (Figure III; see Table III). A total of 21 pieces were analyzed in the container, including 16 pieces containing highly radioactive lead isotopes and 5 pieces of ordinary lead isotopes. There are 13 weapons, including 9 highly radioactive lead and 4 ordinary lead. Among the 2 pieces of carriage and horse ware, 1 piece of lead of high radioactive origin and 1 piece of ordinary lead. All 3 tools contain highly radioactive lead isotopes.
Chronologically, highly radioactive lead is mainly concentrated in the artifacts of the second and third phases of the Yin Ruins (Figure IV; see Table III). Of the 39 bronze artifacts measured, only 1 was in the second phase of Yin Ruins, which was a lead bronze artifact of highly radioactive origin. Of the 33 bronze artifacts in the third phase of Yin Ruins, 7 were ordinary lead bronzes (about 21.2%), and 26 were lead bronze artifacts of highly radioactive origin (about 78.8%). The 2 pieces of bronze in the fourth phase of Yin Ruins are ordinary lead bronze ware. This is slightly different from the use and growth process of the late Shang high radioactive lead resources summarized by Mr. Kim Jong-yew, who proposed that the proportion of highly radioactive lead isotope coppers in the first and second phases of Yin Hui was 78% and 81% respectively, but in the third phase of Yin Hui, it plummeted to 38%, and only 6% in the fourth phase of Yin Hui. The proportion of highly radioactive lead isotope bronzes in the third phase of Yin Ruins at the Liujiazhuang site is 78.8%, which is basically equivalent to the proportion of the second phase of Yin Ruins in Jin Zhengyao's text, and is much higher than the proportion of the third phase of Yin Ruins in his text. There are three possible differences. First, many of the bronzes excavated from the third phase of the Yin Ruins tomb at the Liujiazhuang site are characteristic of the second phase of the Yin Ruins, and the dates they were cast may be in the second phase of the Yin Ruins. Second, the third phase of Yin Ruins did have new metal sources imported, and the use of new resources by higher-ranking nobles was more exclusive. A total of 61 bronze artifacts were excavated from the third phase of the Yin Ruins tomb analyzed by Jin Zhengyao, of which 39 were from the Guojiazhuang M160, and only 9 were highly radioactive lead bronzes, accounting for 23% of all the bronzes detected in the M160. M160 unearthed 10 sets of copper yao and knighthood, which belong to higher-level tombs. Another 22 came from 7 units (6 tombs and 1 formation), and 14 belonged to lead bronzes of highly radioactive origin, accounting for 63% of all copper detectors. The 6 tombs have unearthed fewer bronze artifacts and belong to the middle and low-grade tombs. Third, this difference may be regional. Liujiazhuang is far away from the capital Yin Ruins, about 250 kilometers, and the change of its bronze style may have a certain lag. Regardless of which judgment is supported by future analysis, we will have a better understanding of the dissipation of highly radioactive lead isotope coppers in the Shang Dynasty, the development and change of Shang Dynasty bronzes, and the circulation.
4. Relevant discussions
(i) Diachronic changes in lead bronze vessels of high radioactive genesis in the Shang Dynasty
Most of the highly radioactive lead isotope ratios of the bronzes excavated from the Liujiazhuang site are relatively concentrated, and the ratio of 208Pb/204Pb is concentrated between 41 and 43, the ratio of 206Pb/204Pb is concentrated between 20.5 and 22, and the ratio of 208Pb/206Pb is concentrated between 0.72 and 0.78, which provides new information for understanding the highly radioactive cause of lead. Scholars' previous research on lead of highly radioactive genesis has two main aspects: one is that the large number of copper artifacts containing highly radioactive lead isotopes in the Shang Dynasty are one source or multiple sources, and the other is the source of mineral origin. The one-source theory of highly radioactive lead isotope sources is supported by most scholars, but some scholars believe that the possibility of polysentific theory cannot be completely ruled out. Scholars also have different opinions on the origin of lead of high radioactivity, including the southwest region of Yunnan, the middle reaches of the Yangtze River, the Qinling region, and even African sources, but the latter's views have been criticized by the vast majority of scholars.
While it is difficult for the available data to provide definitive answers to both of these questions, the data from the Liujiazhuang site offer a new idea that there were diachronic changes in the Shang Dynasty high radioactive lead isotopes that could provide more information about the social economy of the Shang Dynasty. Mr. Peng Zicheng and Kim Jong-yew have all found that the isotope of high radial lead in different regions is different, but this discovery has not been discussed in depth. The relative concentration of lead isotope data at the Liujiazhuang site provides a reference standard for comparison with lead isotope data excavated at different sites. By comparing the lead isotope data at the Liujiazhuang site with other published Shang Dynasty data, we found that at least all the data on lead of highly radioactive genesis could be divided into two groups (since the lead isotopes of copper with different lead content were not significantly different, the different lead content copper artifacts were discussed together in groups) (Figure 5; Figure 6; Table 4). Group A is represented by the data of Liujiazhuang site, the general data is relatively concentrated, and the vast majority of the 208Pb/204Pb ratio is less than 42.5, and the slope of 207Pb/204Pb is about 0.13 compared to 206Pb/204Pb. The data subjects belonging to Group A are Panlong City, Zhengzhou Mall, Zhengyang Leap Tower, Luoshan Tianhu and other sites. It should be noted that although Panlong City and Zhengzhou Mall can be classified into Group A in terms of slope, the data of these two sites seem to be different from other group A data, and their ages are obviously earlier than the ages of other excavated A group bronzes, and the rationality of their classification into Group A remains to be verified in the future. The slope of 207Pb/204Pb in Group B is about 0.16 compared to 206Pb/204Pb, and a considerable part of the data has a ratio of 208Pb/204Pb greater than 42.5, a ratio of 207Pb/204Pb is greater than 16.1, and a ratio of 206Pb/204Pb is greater than 22.5. The data subjects belonging to Group B mainly include Hanzhong (this article analyzes the sites of bronze artifacts excavated in Hanzhong as a whole, as well as in the western Jin dynasty below), Xingan, Sanxingdui and other sites. In addition, Anyang Yinxu, Jinxi, Tanheli, Jinsha, etc. contain data on both A and B groups of lead isotopes. Among them, the difference between the lead isotope of Anyang YinXu and Jinxi bronze is related to the age. The bronze main body belonging to the first and second phases of Yin Ruins can be classified as Group B, while the bronzes belonging to the late stages and the third phase of Yin Ruins are mainly in Group A. Tanheli and Jinsha are relatively late, both belonging to the end of the Shang Dynasty and the beginning of the Zhou Dynasty. The two sets of data A and B appeared simultaneously in YinXu and Jinxi, and the difference was related to age, indicating that the difference between the two sets of highly radioactive lead isotopes should not be caused by the measurement errors of different instruments. Of course, the grouping of data for individual sites is not absolute, but these exceptions do not affect the feasibility of grouping (see Table IV). In addition, there are a small amount of data on the slope of Group A, but the 208Pb/204Pb ratio is greater than 42.5, the 207Pb/204Pb ratio is greater than 16.1, and the 206Pb/204Pb ratio is greater than 22.5, which may represent a mixture of metals containing two lead isotope data signals.
Groups A and B have alternating eras of highly radioactive lead isotopes. Group A first appeared in Zhengzhou Shangcheng and Panlong City, both of which are relatively early in age, both from the early Shang to the Middle Shang period. However, in addition to the ruins of Zhengzhou Shangcheng and Panlong City in Group A, the main chronology of bronzes excavated from other sites such as Luoshan Tianhu and Zhengyang Leap Tower is between the second and third phases of Yin Ruins, and some of them can be late to the fourth phase of Yin Ruins; some of the bronzes in the Leap Building can be classified into Group B as early as the first phase of Yin Ruins (some of the data of the Leap Tower can be classified into Group B, and the bronze age represented by these data may be earlier, but because many cannot be staged, we have not subdivided it). Lead isotopes containing Group B appear to be mainly concentrated in the middle and late Middle Shang to the early stage of the second stage of Yin Hui. The main body of bronze in The Hanzhong region belongs to the second period of the Middle Shang to the Yin Ruins, but there are also individual artifacts that can be brought to the early Shang, or as late as the third and fourth phases of the Yin Ruins. The age of the Xingan Tomb is still controversial, but scholars generally tend to believe that its age is no later than the second period of Yin Ruins, nor before the Middle Shang Period. Although scholars have different views on the burial age of the artifact pit, they all believe that the age of the first pit is slightly earlier than the second pit, and from the relics excavated from the two artifact pits, the age of the two pits is generally not later than the second phase of the Yin Ruins. In general, it seems that in the Middle Commercial Stage, the ratio of lead of highly radioactive genesis of bronzes changed from Group A to Group B, and in the later stage of the second period of Yin Ruins, it changed from Group B to Group A. It is worth noting that by the end of the Shang Dynasty and the beginning of the Zhou Dynasty, both the Tanheli and Jinsha sites contained data on highly radioactive lead isotopes belonging to both Groups A and B, but it is unclear whether this phenomenon is universal. According to the carbon 14 dating data of the recently excavated Sanxingdui site No. 4 pit (95% probability of falling from 3148 to 2966), the burial age of Sanxingdui No. 4 pit should be within the third and fourth phases of Yin Ruins. Therefore, it is not excluded that there may be artifacts from the third and fourth phases of the Yin Ruins in the newly excavated artifact pits of Sanxingdui. We look forward to the disclosure of information on the excavation of the new artifact pit of Sanxingdui and the scientific and technological testing information of the newly excavated bronze artifacts. This information will complement the missing rings between the third and fourth phases of the Yin Ruins in the upper and middle reaches of the Yangtze River, and thus potentially help us understand why the TanheLi and Jinsha sites in the late Shang And early Zhou Dynasties contained both group A and group B high radioactive lead isotope data.
From the geographical distribution point of view, the distribution range of group B lead isotopes is wider, and almost all the sites of the bronze vessels that have been tested from the early Shang to the early stage of the Yin Ruins have B artifacts. Group A, on the other hand, was mainly concentrated in the influence of the late Shang culture in the late Yin Hui Phase II to the third period. The reasons for this diachronic change in the isotopes of highly radioactive lead are unclear, either within the same source or as a result of a mixture of lead metals containing highly radioactive origin with metals containing ordinary lead, and it cannot be completely excluded that Groups A and B represent two different sources. It is worth noting that the lower age limit of the Zhengzhou Shangcheng and Panlong City ruins in Group A may be in the Middle Shang Period, and there may be some overlap with the upper limit of group B sites, but there seems to be no obvious mixture of copper high radioactive lead isotopes between the two. China merchants are a turbulent period, Zhengzhou mall decline and Xiaoshuangqiao, Huanbei mall has risen one after another, the change of high radioactive lead isotope and political and social changes occur at about the same time, it seems to suggest that the rise of the new center may have mastered a new source of ore (lead ore) in the process of rising. In any case, the identification of differences in lead of highly radioactive genesis is meaningful, it provides the possibility of a phased investigation of the circulation of lead of highly radioactive origin, and it also provides a new perspective on the socio-economic development of the Shang Dynasty.
(ii) Common lead isotope discussion
Highly radioactive lead isotopes can serve as an identifier to make it possible to trace the circulation of Shang dynasty metal resources or products. The highly radioactive lead isotope can basically be divided into two groups A and B according to the relationship of the times, allowing us to discuss the diachronic changes in the circulation of metal resources or products in the Shang Dynasty. In fact, scholars have noticed that there are also diachronic changes in the metal resources indicated by ordinary lead isotopes, and this diachronic change has lasted almost throughout the Entire Chinese Bronze Age. Mr. Jin Zhengyao comprehensively analyzed the lead isotope data of the Shang Zhou period and believed that at least three sources of ordinary lead isotope ratios in the Shang Dynasty (a.206Pb/204Pb≈16.5, b.206Pb/204Pb≈17.5, c.206Pb/204Pb≈18.25) were developed and utilized in different time periods.
The ordinary lead data of the Liujiazhuang site can be divided into four groups, and the a, b and c groups correspond to the three groups of ordinary lead isotopes divided by Mr. Jin Zhengyao (Figure 7; Figure 8). There is only 1 bronze artifact in the Liujiazhuang site group A, and this lead isotope was basically only found in the late Erlitou culture and the Zhengzhou Shangcheng period. This 1 piece of the Liujiazhuang site may have been recast using early bronzes. There is also only 1 bronze artifact in Group B of the Liujiazhuang ruins, which belongs to the fourth phase of Yin Ruins. Group b bronzes do seem to have only begun to be used in the fourth period of Yin Ruins. There are 4 bronze artifacts in Group C of the Liujiazhuang Site, of which 3 belong to the third phase of Yin Ruins and 1 belongs to the fourth phase of Yin Ruins. Group C lead isotopes were found in The Second to Fourth Stages of Yin Hui, but were mainly concentrated in the Second to Third Stages. In addition to the three sets of ordinary lead isotopes divided by Kim Jong-yew, there is another set of lead isotope data (group d), 208Pb/204Pb≈39-40, 206Pb/204Pb≈19-19.5, 208Pb/206Pb≈2.06-2.09 (see Figure 7; Figure 8). Numerically they should be classified as highly radioactive lead isotopes, but they are difficult to separate from ordinary lead in group c in terms of data distribution. They all belong to the third phase of Yin Hui, and 2 pieces are red copper, and the other 2 pieces are not high in lead, indicating that this set of data is likely to represent copper ore information. They may be homologous to copper ores containing highly radioactive lead isotopes, nor can they exclude that copper is contaminated with minerals containing highly radioactive lead isotopes during the casting process.
(iii) The circulation of lead isotopes and late-shang metal resources
The possibility of grouping highly radioactive lead isotopes and further breakdowns of common lead isotope data increase our understanding of diachronic trends in metal resources indicated by lead isotope ratios. Due to space limitations, this article will mainly focus on late Shang bronzes containing high radioactive lead isotopes of group A to explore the circulation of metal resources and bronzes in the late Shang Dynasty and their political and economic significance. Late Shang bronzes containing group A type of highly radioactive lead isotopes were mainly excavated from Yin Ruins, Liujiazhuang, Leap Tower, Tianhu, Jinxi and so on. The above-mentioned areas are traditionally within the influence and radiation range of the late Shang culture, and the lead isotope reflects that its copper raw materials also have homology, which is of great enlightenment significance for us to understand the political and economic structure of the late Shang.
First, the data on lead isotopes gives us a deeper understanding of the circulation of late merchant resources. In the past, scholars tended to pay more attention to the circulation of bronze products, but according to the existing evidence, it can be speculated that bronze raw materials are likely to be within the scope of circulation. Group A type of highly radioactive lead isotopes account for a significant proportion of local and Yinxu style bronzes, and lead isotope data are not related to copper styles, indicating that the resources used everywhere are homologous. On the other hand, there is growing evidence that many bronzes with a local style may have been locally cast. Pottery fans, molds, cores, etc. related to casting copper containers found at sites such as Qingjian Xinzhuang prove that the Western Jin region has the ability to cast bronze containers independently. Since there are also certain differences in alloy composition between bronzes in the Yinxu style and the local style in the Western Jin Dynasty, it is speculated that many bronzes with local styles may have been cast locally. From this, we speculate that the nobles in the Western Jin Dynasty may have had access to circulating metal raw materials– obtained from Anyang through trade. Of course, it cannot be ruled out that the locals will remelt the obtained Shang-style bronzes and cast their own bronzes, but the difference in alloy composition between the aforementioned local style bronzes and the Yinxu style bronzes makes this possibility relatively small.
Secondly, the data on lead isotopes also further support the position of Anyang YinXu in the production and circulation of copperware. The homology of highly radioactive lead isotopes in various places in the late Shang Dynasty further supports the fact that bronzes with Yinxu style excavated in Liujiazhuang, Yanlou, Tianhu, Jinxi and other places are likely to have been produced in Anyang. This is consistent with the conclusion reached by previous scholars based on the research done on the bronze style, that is, the vast majority of YinXu style bronzes were produced in Anyang. After more than 80 years of archaeological excavations, a number of relatively large-scale copper casting workshops of the late Shang Dynasty have been found in Anyang Yin Ruins, including the northeast of Xiaotun, the north of the nursery, Xiaomintun and the newly discovered Renjiazhuang South. Although no scholar has yet calculated the production capacity of bronzes at these sites, it is conceivable that the number of bronzes produced should be very large, and according to the excavations, the area of bronze workshops in the southern and western handicraft areas of Yin Ruins has been expanding. On the one hand, the expanding production scale shows that the demand for bronze is increasing, on the other hand, it also shows that Yin Ruins should have a very stable supply channel for metal raw materials. Mineral resources represented by group A type lead isotopes can be regarded as one of the signs of stable supply of mineral materials.
Of course, we also need to explore how merchants obtained such stable metal resources, what was the mechanism of circulation of bronze resources and products implied by their artifact styles and lead isotope data, and whether their circulation was directly controlled by the merchant royal family or upper nobility or whether it might also include some commercial exchange activities.
Conclusion
The bronze artifacts excavated at the Liujiazhuang site mainly contain highly radioactive lead isotopes, but also a small amount contain ordinary lead isotopes. There is no direct correlation between the lead isotope ratio and the type of artifact and the type of alloy. The Liujiazhuang site has a comparative set of high radioactive lead isotope ratio data, providing a standard for comparison with other sites. By comparison, we believe that the highly radioactive lead isotopes of the Shang Dynasty can be divided into two groups, and that there may be some alternation between the two groups. In the early Shang period, Zhengzhou and Panlongcheng were Group A, and in the early days of the Shang Dynasty to Yin Ruins, they were mainly Group B, and Group A re-became the mainstream from about the late second period of Yin Hui. However, it is not yet possible to determine whether the two sets of data represent two different sets of sources of highly radioactive lead isotopes or whether they are the result of the same source but mixed with other different resources. The consistency of lead isotopes in the late Shang Dynasty suggests that their copper resources may be homologous, but it is still necessary to analyze the different sites in combination with archaeological typology, bronze casting techniques, bronze inscriptions and other information to understand the socio-economic significance behind them.
P.S. Thanks to Anne Underhill, Professor Chen Xuexiang, Fan Rong, Shen Dewei, Wu Xiaotong and other students for their opinions and suggestions in the process of writing and revising this article, to Hao Ying of Jinan Archaeological Research Institute for their help in the sampling process, and to Professor Cui Jianfeng and Zhang Ji, Zou Guisen and other students for their guidance and help in the sample analysis process. This research has been awarded by the National Science Foundation (NSF, project number: 1744615), the Mac Millan International Dissertation Research Fellowship, the Council on East Asian Studies, and the Council on East Asian Studies. Support from the Albers-Coe-Hazard Fund in Yale's Department of Anthropology.