二叠系-三叠系(P/T)界线一直是国内外地质学家研究的热点。二叠纪末发生了一系列重大的地质事件,如地球历史上最大的生物大灭绝、广泛的火山喷发、海平面变化、联合古大陆解体等。该地质时期的生物地层学、事件地层学研究者从生物地层学、磁性地层学、化学地层学,特别是同位素地层学和环境地球化学等多个方面对灭绝的原因进行了研究。与整个碳循环密不可分的碳同位素在地史时期的变化特点引起了多方面的重视和关注,一些学者认为在解释生物灭绝、地层对比方面,其有重要的作用;然而,综合不同学者的研究结果,碳同位素变化在最大最小值、碳同位素发生剧烈变化与生物界线的位置先 Permian - Triassic (P / T) line has been the hot spot of geologists at home and abroad. A series of major geological events took place at the end of Permian, such as the largest extinction of life in the history of the earth, extensive volcanic eruptions, sea level changes and the unification of the ancient continent. During the geological period of bio-stratigraphy and event stratigraphy, researchers studied the causes of extinction from the aspects of bio-stratigraphy, magnetic stratigraphy, chemical stratigraphy, especially isotopic stratigraphy and environmental geochemistry. Some scholars think that it has an important role in explaining the biological extinction and stratigraphic contrast. However, based on the research of different scholars As a result, the carbon isotope changes at the maximum and minimum values, the carbon isotope changes drastically and the biological boundary first