塔里木盆地西北缘上奥陶统印干组的层孔虫及其生物古地理意义  

LATE ORDOVICIAN STROMATOPOROIDS FROM THE YINGAN FORMATION IN NORTHWESTERN TARIM BASIN AND THEIR PALAEOBIOGEOGRAPHIC IMPLICATIONS

作　　者：梁昆 张园园[1,2] 张雨晨 魏鑫[1,2] 唐鹏 LIANG Kun;ZHANG Yuan Yuan;ZHANG Yu Chen;WEI Xin;TANG Peng(Nanjing Institute of Geology and Paleontology,Chinese Academy of Sciences,Nanjing 210008;State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing 210008)

机构地区：[1]中国科学院南京地质古生物研究所,江苏南京210008 [2]现代古生物学和地层学国家重点实验室,江苏南京210008

出　　处：《地层学杂志》2023年第4期472-477,共6页Journal of Stratigraphy

基　　金：第二次青藏高原综合科考项目(2019QZKK0706);国家自然科学基金(42202021)共同资助。

摘　　要：新疆柯坪县阿日苏西剖面位于塔里木板块西北缘,该剖面的上奥陶统凯迪阶印干组顶部的生物礁灰岩产出丰富的层孔虫化石,与珊瑚共同构建层状生物礁。本文首次报道该层孔虫动物群计3属3种,分别为恩扎斯曲折层孔虫Camptodictyon amzassensis(Khalfina,1960)、雅沃尔斯基简单网层孔虫Simplexodictyon yavorskyi(Nestor,1966)、罗森层孔虫(未定种)Rosenella sp.。其中,C.amzassensis是晚奥陶世全球广布分子,在印干组中呈现高丰度并占据礁格架之重要成分,表明塔里木板块与泛冈瓦纳海区存在生物古地理亲缘关系。该层位的Simplexodictyon是小层孔虫目(Stromatoporellida)的最老地层记录,表明当时的塔里木板块可能是其起源地,之后才扩散到华北板块等地。Abundant stromatoporoids have been found in the biostromal reef at the topmost Yingan Formation at the Arisu West Section in the Kalpin area,Xinjiang.Three species of stromatoporoids belonging to 3 genera are identified for the first time from the Yingan Formation,including Camptodictyon amzassensis(Khalfina,1960),Simplexodictyon yavorskyi(Nestor,1966)and Rosenella sp.These stromatoporoids serve as one of the main reef-building elements,and interact with associated corals to form the biostrome in the top part of the Yingan Formation.Among the occurred species,Camptodictyon amzassensis is widely distributed in the peri-Gondwanan regions during the Late Ordovician,and therefore its abundant occurrences in the Yingan Formation suggests a likely close paleobiogeographic relationship between Tarim and other peri-Gondwanan regions.The finding of Simplexodictyon in the Yingan Formation of Early Katian age represents the earliest occurrence of Stromatoporellida,suggesting a possible origination of the Simplexodictyon species in the Tarim and then spread into other regions like North China during the Katian.

关 键 词：层孔虫 晚奥陶世 塔里木板块 印干组 新疆柯坪 

分 类 号：P534.42[天文地球—古生物学与地层学]