中国科学院南京地质古生物研究所机构知识库

根据岩石地层及生物地层研究，西藏申扎地区下二叠统昂杰组可分为下段的砂质灰岩、微晶灰岩、生物碎屑灰岩段和上 段的灰黑色薄层状泥岩、页岩夹钙质粉细砂岩段，时代为早二叠世亚丁斯克期—空谷期。系统采集了 24 件昂杰组灰岩段 C-O 同位素样品，测试结果表明，昂杰组样品δ13C 最大值为 6.312‰，最小值为 4.032‰，平均值为 5.794‰；δ18O 最大值 为-1.785‰，最小值为-7.476‰，平均值为-4.494‰。无机碳同

The Permian Angjie Formation is deposited in Xainza area, Tibet. The upper part is composed of sandstone and mudstone, whereas the lower part is sandstone intercalated with limestone. The age of the Angjie Formation is considered to be from Artinskian to Kungurian. 24 carbonate samples were collected in accordance with the carbon and oxygen isotope analysis, and the dating results yielded the maximum value of 6.312‰, the minimum value of 4.032‰, and the average carbon isotope value of 5.794‰. The maxi⁃ mum value of oxygen isotope is -1.785‰, the minimum value is -7.476‰, and the average value is -4.494‰. The δ13C has a posi⁃ tive shift, which is obvious and slow. It might have been influenced by the glaciation of the northern margin of Gondwana in the middle-late Early Permian period and the large-scale terrestrial plant reproduction.