中国西南地区中三叠统安尼阶界线层型研究

由于中三叠统安尼阶界线的首选标志一直存在争议，导致该阶的全球标准界线层型剖面和点位长期未能确定。为解决安尼阶界线研究停滞不前的问题，本项目计划利用中国早-中三叠世地层发育、研究基础相对较好的有利条件，在已有较好菊石研究基础的贵州紫云新苑和广西金牙、外里剖面加强下-中三叠统牙形石生物地层研究，在牙形石研究基础较好的贵州望谟甘河桥和紫云石头寨剖面进一步加强下-中三叠统菊石生物地层研究，完善牙形石和菊石生物序列和对比关系，为安尼阶界线首选标志的确定提供依据；同时开展磁性地层、化学地层、同位素年代学等研究，确定磁性地层和碳同位素化学地层在界线附近的变化规律及其与生物地层的对应关系；在有条件的剖面进一步验证下-中三叠统界线的年龄值，力争能提出奥伦尼克阶-安尼阶界线层型候选剖面的建议。研究成果在推动中三叠统安尼阶界线层型研究的开展以及力争将三叠系安尼阶全球界线层型确立在中国方面有重要科学意义。

The Global Boundary Stratotype Section and Point of the Anisian (Middle Triassic) has not been determined for a long time, because the preferred boundary mark of this stage has been differently recognized. In order to solve the problem of the stagnant situation of the research work on the Olenekian-Anisian boundary, based on the favorable conditions of the well-developed Early-Middle Triassic strata as well as the good research foundation in China, this project plans to strengthen the study in the Lower Triassic-Middle Triassic conodont biostratigraphy of the Xinyuan section in Ziyun County, Guizhou and the Jinya-Waili sections in Guangxi, in these sections the ammonites are well studied; strengthen the research on the Lower-Middle Triassic ammonite biostratigraphy of the Ganheqiao section in Wangmo County and Shitouzhai section in Ziyun County, Guizhou, in these sections the conodonts are well studied; improve and perfect the conodont biological sequences and the ammonite biological sequences and their contrast relationship during the Olenekian-Anisian period, to provide scientific basis for the ascertaining the preferred boundary mark of the Anisian; meanwhile, carry out research on the magnetiostratigraphy, chemo-stratigraphy and isotopic geochronology, to determine the changing rules of the carbon isotope and the magnetiostratigraphy near the Lower-Middle Triassic boundary and their corresponding relationship with the biostratigraphy; further verify the age of the Lower-Middle Triassic boundary by the research on the isotopic geochronology in conditional sections; strive to propose the suggestion of the candidate section for the Olenekian-Anisian boundary stratotype. The research results have important scientific significance for further promoting the research on the Olenekian-Anisian boundary stratotype, and striving to establish the Global Boundary Stratotype Section and Point of the Anisian in China.