Stratification Of Permian Fusulinid-beaning Stratum And Chronostratigraphy In Baliu Region，Mojiang Cunty Of Yunnan Province

In2009,the author participated in the drawing of four map of the Yunnan1：50000regional geological survey-included Mani street, Guangfeng, Niukong andZuobo area.Two Permian sections were measured in Baliu Distirct, Mojiang County,Yunnan Province. A lot of the fusulinid fossils were collected, and the research on thechronostratigraphy of fossils were done through the age assignment and regionalcomparison.This text according to the principle of modern stratigraphy,based on regionalstratum clear scheme of “Lithostratigraphy of Yunnan Province”,and combinatewith the situation of this regional geological survey,determined the stratigraphicsequence of the research area.Permian are widespread in the research area, and thefusulinid-beaning stratum include three formations: Xiamidi Formation, XianrendongFormation and Baliu Formation.Baliu Formation and the underling XianrendongFormation are comfortable contact by continuous carbonate rocks. Both Xianrendongand Xiamidi Formation are composed of continuous carbonate rocks and they are alsocomfortable contact with each other. Xiamidi Formation contains two parts: the upperpart are carbonate rocks with fusulinids, the lower part are terrigenous clasticsediments.Abundant fossil specimens are collected,containing fusulinids, foraminifera,brachiopods, coral, bryozoon and plant fossils. Fusulinids are the most significant inall above because their roles in Carboniferous and Permian chronostratigraphy arevery important. Fifteen genus and thirty nine species fusulinids are identified. No onenew species are found, but most of them are the first discovery in the research area. It supports new materials to bistratigraphy of this area.6fusulinids fossil zones are established by comprehensive research: Turn frombottom to top:Triticites-Eoparafusulina pusilla assemblage zoneDarvasites sinensis-Rugosofusulina ex gr. Paramoderata intervallum zoneRugosofusulina ex gr. paramoderata-Pseudofusulina krotowi intervallum zoneSchwagerina ex gr.cushmani-Pseudofusulina radioflucta assemblage zonePseudofusulina radioflucta-Neoschwagerina kwangsiana intervallum zoneNeoschwagerina kwangsiana range zoneThrough the fossils and Fusulinid zone, chronostratigraphic division was carriedout， which was the Zisongian、 Longlinian、 Luodianian-Xianboan、Kuhfengian-Lengwuan.The Carboniferous-Permian boundary and Middle-LatePermian boundary were studied, which improved the study accuracy of Permianfusulinid-beaning stratum.10genus and16species typical fusulinids are described.