荆门龙王山墓葬出土玉器的材质及矿源特征研究

龙王山墓葬位于湖北省荆门市，属于大溪文化向屈家岭文化过渡的关键时期，距今约5 000年。该墓葬共出土玉器73件，玉器品质普遍较好。长江中游地区历来鲜少出土玉器，而时代更迭之期更是社会变革之际，无论是从地理位置还是从时期上来看，研究龙王山墓葬出土的玉器都具重大意义。采用相对密度检测，红外光谱仪（FTIR）及激光剥蚀电感耦合等离子体质谱仪（LA-ICP-MS）研究出土玉器的谱学及化学成分特征，鉴定其材质，并对用料水平及矿源进行了探究。红外光谱结果显示龙王山墓葬出土玉器的红外吸收谱图可分为两类：软玉类和玛瑙类。软玉类玉器的红外吸收峰表现为1 207，1 123，1 028，928，775，700，602，488和425 cm-1处。玛瑙类玉器的红外吸收峰表现为1 158，814，790，702，572，521及405 cm-1。软玉类玉器有71件，且品质都非常好，说明龙王山墓葬先民对玉料的分选能力很强。将龙王山墓葬的用料水平与同时期其他地区的考古学文化的用料水平进行对比，龙王山墓葬的用料水平远超同期；将龙王山墓葬的用料水平与湖北地区新石器时代的用料水平进行对比，龙王山墓葬的用料水平远超湖北地区平均水平。LA-ICP-MS的结果显示软玉质玉器的微量元素主要包含K和P等，微量元素赋存情况以W，U，P及Sb元素富集，Th和Ti元素亏损为主。玉器的稀土配分型式图多样，水平海鸥状、左倾式、右倾式皆有。Ce异常普遍不明显，Eu以正异常及负异常为主。采用多元统计方法中的逐步判别法，辅助SPASS软件，对龙王山墓葬出土玉器的稀土元素及微量元素含量进行投点，推断大部分玉料来自某个与新疆成矿环境类似的矿床，但因其地球化学特征的多样性，不排除玉料多来源的可能性。

Study on the Material and Mineral Source Characteristics of Jade Excavated From Longwangshan Tomb in Jingmen

Longwangshan Tomb, located in Jingmen city, Hubei Province, belongs to a key transitional period between the Daxi Culture and the Qujialing Culture, dating back about 5, 000 years. The tomb unearths 73 pieces of jade, whose quality is generally good. In the past a few years, few jade articles have been unearthed in the middle reaches of the Yangtze River. At the same time, the changing period of time is also a period of social change. The study of jade articles unearthed from the Longwangshan Tomb is of great significance in terms of geographical location and period. Relative density detection, infrared spectrometer and laser ablation inductively coupled plasma mass spectrometer are used to study the spectral and chemical composition characteristics of unearthed jade articles, identify their material, and explore the level of selecting jade material and mineral source. The infrared spectrometer results show that the infrared absorption spectrum of jade excavated from Longwangshan Tomb can be divided into two categories: tremolite and agate. The infrared absorption peaks of tremolite jades are at 1 207, 1 123, 1 028, 928, 775, 700, 602, 488 and 425 cm-1. The infrared absorption peaks of agate jades are at 1 158，814，790，702，572，521 and 405 cm-1. There are 71 pieces of tremolite jade, and the quality is very good, indicating that the level of jade selected by the ancestors of the Longwangshan Tomb is very high. Comparing the level of selecting jade in the tombs of Longwangshan with that of other archaeological cultures of the same period, the level of selecting jade in the tombs of Longwangshan is far superior to that of the same period. Comparing the level of selecting jade in the tombs of Longwangshan with that in the Neolithic age of Hubei province, the level of selecting jade in the tombs of Longwangshan is far higher than the average level of Hubei province. The laser ablation inductively coupled plasma mass spectrometer showed that trace elements of jades made of tremolite mainly consist of Al, Na, Mn, K, P, etc. and are enriched in W, U, P and Sb elements, while Th and Tielements are depleted. The rare earth distribution patterns of jades are diverse, including horizontal seagull shape, left inclined type and right inclined type. Ce anomalies are generally not obvious, while Eu anomalies are mainly positive and negative. With the help of SPASS software, the rare earth elements and trace elements content of the jade excavated from Longwangshan Tomb were analyzed, and the jade was inferred to be from a deposit with the similar metallogenic environment to Xinjiang. However, the possibility of multiple sources of jade was not ruled out because of the diversity of its geochemical characteristics.