X-ray powder diffraction (XRD) analysis, differential thermal analysis(DTA) and infrared absorption analysis have been done of the clays near the Permian/ Triassic boundary at Sangzhi County, Hunan Province.

• 本文对湖南桑植地区三叠系/二叠系界线粘土进行了X射线粉末衍射、差热,红外等分析。