CAJ | 학술논문

由于地处低纬度下扬子碳酸盐缓坡台地较深水区,安徽巢湖地区的下三叠统由一系列泥、灰岩旋回层组成,并含有丰富的菊石化石.通过对巢北平顶山和马家山一带上二叠统顶部和下三叠统多条剖面的系统研究,建立了在华南乃至低纬度特提斯地区具有代表性的、以属级分类单位为基础的下三叠统菊石生物地层序列(从下而上):Ophiceras-Lytophiceras带、Gyronites-Prionolobus带、Flemingites-Euflemingites带、Anasibirites带、Columbites-Tirolites带和Subcolumbites带.在提议的全球印度阶-奥伦尼克阶界线层型候选剖面--巢湖平顶山西坡剖面上,Flemingites-Euflemingites带之底与牙形石Neospathodus waageni首现点比较接近,可以作为本界线主要辅助标志之一.记述采自该区上二叠统顶部及下三叠统,尤其是印度阶-奥伦尼克阶界线附近的一些具有年代地层意义的菊石化石资料,以供该界线层型确定和选择参考.
유우지처저위도하양자탄산염완파태지교심수구,안휘소호지구적하삼첩통유일계렬니、회암선회층조성,병함유봉부적국석화석.통과대소북평정산화마가산일대상이첩통정부화하삼첩통다조부면적계통연구,건립료재화남내지저위도특제사지구구유대표성적、이속급분류단위위기출적하삼첩통국석생물지층서렬(종하이상):Ophiceras-Lytophiceras대、Gyronites-Prionolobus대、Flemingites-Euflemingites대、Anasibirites대、Columbites-Tirolites대화Subcolumbites대.재제의적전구인도계-오륜니극계계선층형후선부면--소호평정산서파부면상,Flemingites-Euflemingites대지저여아형석Neospathodus waageni수현점비교접근,가이작위본계선주요보조표지지일.기술채자해구상이첩통정부급하삼첩통,우기시인도계-오륜니극계계선부근적일사구유년대지층의의적국석화석자료,이공해계선층형학정화선택삼고.
The uppermost Permian and Lower Triassic are completely exposed in Mt. Pingdingshan and Mt. Majiashan, Northwest Chaohu City, Anhui Province, East China, where the Lower Triassic is well developed and composed of the alternations of mudrock and limestone deposited on a deep part of the Lower Yangtze carbonate ramp, containing rich ammonoid fossils. 37 genera and 60 species are recognized from the uppermost Permian and Lower Triassic at the North Pingdingshan Section, West Pingdingshan Section and South Majiashan Section. In addition, many specimens were also collected from the North Majiashan Section and the Guimengguan Section in South Chaohu. A complete Lower Triassic ammonoid zonation can be retrieved in ascending order: Ophiceras Lytophiceras Zone, Gyronites Prionolobus Zone, Flemingites Euflemingites Zone, Anasibirites Zone, Columbites Tirolites Zone and Subcolumbites Zone. The base of the Flemingites Euflemingites Zone is very close to the FAD of conodont Neospathodus waageni at the West Pingdingshan Section, which was proposed as the GSSP of the Induan Olenekian boundary. This paper describes some better preserved ammonoid fossils of biostratigraphic importance with emphasis on those around the Induan Olenekian boundary, plus a few specimens from the uppermost Permian Tapashanites Pleuronodoceras Zone.