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在日本西南地区层状燧石层序中,用 Ishiga 图解研究了 P/T 界线之下的放射虫生产率变化。根据燧石层的厚度变化作图,两个露头上的图显示了地层变化的共性,表明该图是层状燧石层序对比的有效工具。生产率的共性变化还与浅海碳酸盐层序δ~(13)C 偏差变化能完全对比,P/T 界线之下的层状燧石记录了大洋浅层带曾明显发生过绝灭事件。根据 Ishiga 图、层状燧石层序的岩性变化和δ~(13)C 曲线,P/T 集群绝灭被划分为3个区间:Djulfian 阶晚期的前期绝灭区间,轻微绝灭,生物圈很快便恢复;Dorashamian 阶的主绝灭区间,其事件引起生物圈严重毁灭;早三叠世的余波区间,其事件延缓了主绝灭后生物的复苏。
In the stratiform chert sequence in southwestern Japan, Ishiga plots were used to study changes in radiolarian productivity below the P / T boundary. Based on the change in the thickness of the chert layer, the two outcrops show the commonness of the formation changes, indicating that the map is an effective tool for the stratigraphic correlation of the chert flint. The common change in productivity is also in complete contrast with the variation of δ 13 C in the shallow marine carbonate sequence. Stratigraphic flint beneath the P / T boundary records the apparent extinction event in the shallow oceanic zone. According to the Ishiga diagram, lithological changes of stratiform chert, and δ ~ (13) C curves, the P / T cluster extinction is divided into three intervals: the early extinction interval of the Late Djulfian stage is slightly extinct and the biosphere is very Rapid recovery; Dorashamian order of the main extinction interval, the event caused a serious destruction of the biosphere; early aftershocks interval, the event postponed the main extinction of biological recovery.