吐鲁番大、小桃儿沟及雅尔湖石窟壁画成分分析

Composition Analysis of the Murals in Turpan Dataorgou Caves,Xiaotaorgou Caves and Yarkhoto Lake Caves

本文利用光学显微镜、扫描电镜及能谱、X射线衍射和激光拉曼光谱分析法,对吐鲁番大、小桃儿沟及雅尔湖石窟壁画残存试样进行研究,介绍了三个石窟壁画的剖面结构、所含植物种类、不同色彩的颜料成分等分析结果。研究结果表明:壁画表面分布有大量微裂纹,颜料颗粒不均匀;壁画的草泥层含有大量麦茎秆及少量的麦子,且在部分石窟粉底层下部还发现了棉纤维和苎麻纤维;白色颜料主要为石膏,黑色颜料为炭黑,红色颜料有铁红和铅丹,青蓝色颜料为石绿和绿盐的混合矿物,土黄色颜料则是由石英、钠长石与石膏、白垩混合调制而成。此外,在小桃儿沟第5窟发现大量的含铅颜料变色现象。

In this research, optical microscopy profiling method, scanning electron microscopy with EDS, X - ray diffraction and Raman spectrometry were used to characterize the maral sam- ples from Dataorgou Caves,Xiaotaorgou Caves and Yarkhoto Lake Caves in Turpan. The cross section structures of the murals were described, the plant fibers were identified, and the com- position of the different colored pigments were analyzed in this article. It is showed that the sur- face of the murals were full of microcracks, and the particles of the pigments were nonuniform ; Lots of straws and a small amount of wheat were found in the mud layer, even some cotton and flax were found in some grottoes; the white pigments were mainly contain gypsum, the black pigments were mainly carbon both malachite and atacamite ments were mixed by quartz, black, the res pigments were were found in the blue pigmen albite, gypsum and calcite. In either iron oxide red or red lead, ts, and the yellowish -brown pig- addition, discoloring phenomenon of the lead - based pigments was found in the fifth cave of the Xiaotaorgou Caves.