The Studies On The Geographical Origin Characteristics Of Turquoise From The Laziya Mine Sites In Luonan,Shannxi Province And The Surrounding Mine Areas

Turquoise as a precious stone has a long history. It has a strong sense of cultural identity and heritage. As early as in the Neolithic period, it was used by our ancestors.As a kind of scarce resource, it always poses a question about its place of origin for scholars. They believed that from the source of turquoise to the site that turquoise artifacts were found, there must be a resource corridor, which was called the "Turquoise road" by scholars. But where is the road ? The academic circles have different opinions on it.At present, idea on study is to connect with the accurate historical relics and the known Turquoise mine, but such logic is flawed in that the existing mines may not be found or mined in a certain period of ancient times.Some American scholars study on turquoise traces that combined the ancient Turquoise mining sites, cultural relics and existing turquoise mine samples, and get the comprehensive result. And then by making the judgment of producing area, this can not only expand the coverage of the data, but also is much more consistent with the ideas of archaeology.In China, the research of turquoise origin has not been systematic. Moreover, we did not find the ancient Turquoise mining site within a definite time, which increases the difficulty of tracing studies on turquoise cultural relics. In 2010, we found that the ancient Turquoise mining site in Luonan County, Shaanxi province. During 2012-2015, we carried out five times of surveys and excavations at this site. We found the site had a large amount of archaeological remains-pottery shards, stone artifacts.Based on the laziya ancient turquoise mine as the main research object, the nature of the site, the age of the site, the ancient mining tools and gemological feature of Laziya turquoise are researched. Combined with other Turquoise mines in eastern Qinling Mountains, using the Raman spectroscopy, portable X fluorescence spectrometer, LA-ICP-AES, the ratio of lead and strontium isotopes. Try to establish a distinction model of the turquoise ore that from different areas in China. The results of this study can provide services for archaeological research.The main research contents and results were as follows:(1)A group of caves were found nearby a tributary of the Luo river at Luonan County, Shaanxi Province. A large amount of archaeological remains - pottery shards, stone artifacts were found in these sites, Which stone artifacts include stone hammers, stone balls, grindstones, stone lamp,etc. Preliminary research findings:Stone hammers were considered as the tools of mining.Qualitative analysis of ore,blue green blocks are turquoises.From the pottery shards and the 14C dating results, it was believed that the turquoise were mined during the late Neolithic Age and the Spring and Autumn period. The discovery of the Laziya ancient turquoise mine ruins in Shaanxi has undoubtedly provided significant information about the origin of turquoise in China.(2)During the exploration of Laziya site’s nature, functional localization of hammer stones is the key factor of estimating the nature of the site. Laziya stone hammers are the main research objects in this paper and are categorized in Type A and Type B, five sub-categories in total. During research process of coexistent implements like stone balls and millstones, we find out the two objects are actually a set of tools that can manufacture stone hammers. According to statistical materials of mining stone hammers at home and abroad, such hammers spread widely. They were used mainly in Bronze Age, and their excavated areas locate mainly around the ancient mining sites. These stone mining hammers can be direct proof of estimating the age of mining sites. Therefore, Laziya stone hammers belong to Bronze Age, while not the remains of the Old Stone Age. Compared with mining stone hammers in other ancient mining sites at china and abroad, it can be noticed that the general feature of Laziya stone hammers is small, narrow, long and exquisite. These hammers are obviously different from the big and round stone hammers that mine ancient bronze ores. The reason that they have such features should be relevant to the features of turquoise ores they mine.(3)Research shows that Portable X-ray fluorescence spectrometer (PXRF) has some feasibility in the research of the origin of cultural relics in the field of archaeology.Given that,Experiment with PXRF to detect five turquoise mines in the East Qinling area, To analyze all the experimental data, we found that there are differences in the aspect of certain Element content in different mines. Get three principal components through principal component analysis, its cumulative variance contribution rate to get up to 86.374%.And the former two is 70.09%. Therefore, determining Sn、Sb、Te、Sr、Ni、 Ba、V、Mo、U regard as the Characteristic elements,Which can be partly achieved turquoise identifying different mines.This study shows that PXRF binds PCA can distinguish different producing area in general.By applying the model to test the turquoise from the Erlitou site, and the result shows that some of the Erlitou turquoise should be from the Laziya ancient turquoise mine.(4)To distinguish the Laziya ancient Turquoise mine from four other turquoise mines in the East Qinling area using the LA-ICP-AES. Crunching all the experimental data, we found that there are differences in the content of certain compounds in different mines. Get three principal components through principal component analysis, its cumulative variance contribution rate to get up to 84.96%.And the former two is 72.289%. Therefore, determining V2O5 NiO、B2O3、 SrO、BaO、CaO、ZrO、MnO2 regard as the eigen compound, then combined with comparative analysis of related compounds,Which can be partly achieved turquoise identify different mines.This study shows that LA-ICP-AES binds PCA and analysis of compound content,can distinguish different producing area in general.(5)Turquoise from the ancient mines of Laziya in Luonan and modern Turquoise samples from four regions at the east of Qinling Mountains are collected as objects of study, and TI-MS is applied to test the ratio of the lead isotope of Turquoise in different places of origin. It is discovered that the Turquoise samples from the same place of origin has a lead isotope ratio with comparatively good consistency. The lead isotope ratio(207Pb/208Pb) of Turquoise from five mining areas can be divided into two groups by the ratio 0.410. The lead isotope ratio of Turquoise samples from Luonan and Baihe mining area in Shaanxi Province is mostly under 0.410, while the ratio of Turquoise samples from Yunxian and Zhushan in Hubei Province and Xichuan in Henan Province is mostly above 0.410. The strontium isotope ratio(87Sr/86Sr) of Turquoise from these areas can be divided into two groups by the ratio 0.7105.The strontium isotope ratio of Turquoise samples from Zhushan and Xichuan mining is mostly under 0.7105, others is mostly above 0.410. If we combine the lead(207Pb/206Pb、207Pb/204Pb)& strontium(87Sr/86Sr) isotope ratio can be used to appropriately distinguish the places of origin of Turquoise in these mines.In conclusion, it is feasible to track Turquoise’s place of origin with the lead & strontium isotope ratio.