Plume Tectonics and Earth's greatest biocrisis

为了弄清地球上跨越古生界-中生界的地球最大灭绝的原因，在4年的时间里，在中国南部(四川、陕西、云南、关西、紫河间)进行了6次野外调查。除了项目负责人外，还有1名中国同行(姚教授)和5名来自日本的研究生和中国参加，重点研究了四川的朝天段、峨眉山段和陕西的吴家坪段。现场进行了详细的描述，并结合钻井采集了岩样。岩石样品在实验室进行了XRF、质谱仪、Moessbauer谱等分析，并对九州和日本本州的等值岩石进行了野外研究和室内分析对比。结果表明：1.跨越G-L界线和P-T界线的酸性凝灰岩层的扩张发育；2.日本大洋中部古环礁灰岩中酸性凝灰岩层的进一步扩展；3.全球范围内双相生物灭绝与酸性火山作用的同步性。上述研究成果部分归纳为17篇科学论文和5部著作。其余结果的公布正在按适当的时间表进行。

Field research was conducted along well-exposed sections in South China (Sichuan, Shaanxi, Yunnan, Guanxi, Zihejian) for 6 times in 4 years, in order to clarify the cause of the Earth's greatest mass extinction across the Paleozoic-Mesozoic boundary. In addition to the leader of the project, a Chinese counterpart (Prof. Yao) and 5 graduate students from Japan and China participated.Intensely studied were the Chaotian and Emeishan sections in Sichuan plus the Wujiapin section in Shaanxi. Detailed description in the field and collection of rock samples were combined with drilling. Rock samples were processed in the laboratory for XRF, Mass spectrometer, Moessbauer spectroscopy etc. Additional field study and indoor analysis were done for the equivalent rocks in Kyushu and Honshu (Japan) for comparison. Analysis focused on the double-phased mass extinction, i.e., both across the G-L, boundary and P-T boundary, and the following results were obtained.1.Extensive development of acidic tuff beds across the G-L and P-T boundaries of double-phased mass extinction.2.Further extension of these tuff beds in mid-oceanic paleo-atoll limestone in Japan.3.Synchronicity between double-phased mass extinction and acidic volcanism in a global scale.Above results were partly summarized into 17 scientific articles and 5 books. Publication of the rest results is going on in a proper schedule.