西藏岗巴察且拉剖面阿普特阶-阿尔布阶界线附近的菊石生物地层  

AMMONITE BIOSTRATIGRAPHY NEAR THE APTIAN-ALBIAN BOUNDARY IN CHAQIELA SECTION,GAMBA,TIBET

作　　者：彭博[1,2] 沙金庚[2] 蔡华伟[2] 李建国[2] 张晓林[2] 王亚琼[2] 饶馨[2] 

机构地区：[1]国土资源部南京地质矿产研究所,江苏南京210016 [2]中国科学院南京地质古生物研究所,江苏南京210008

出　　处：《地层学杂志》2014年第3期268-276,共9页Journal of Stratigraphy

基　　金：中国科学院战略性先导科技专项(B类)(XDB03010101);国家自然科学基金(No.40872013);青年基金(No.41302011)资助

摘　　要：全球性的下白垩统阿普特阶-阿尔布阶界线或阿尔布阶的底界迄今尚未得到统一。我国藏南岗巴盆地发育有包括阿普特阶和阿尔布阶在内的良好的海相白垩纪地层,并产有菊石和双壳类等宏体化石。因此,此区是研究阿普特阶-阿尔布阶界线的重要地区。经鉴定,岗巴察且拉剖面阿普特阶-阿尔布阶界线附近的菊石包括了2科5属4种和4未定种:Hypacanthoplites xizangensis Chao,Acanthohoplites aschiltaensis(Anthula),Douvilleiceras mammillatum(Schlotheim),Cheloniceras seminodosum,Cheloniceras sp.,Acanthohoplites sp.,Hypacanthoplites sp.和?Pseudosonneratiasp.。此菊石动物群自下而上可以划分出3个组合/层:阿普特期晚期Hypacanthoplites组合,阿普特期末期Hypacanthoplites-Acanthohoplites组合和阿尔布期早期Douvilleiceras-?Pseudosonneratia组合。菊石的组合及其层序表明岗巴察且拉剖面中Hypacanthoplites-Acanthohoplites与Douvilleiceras-?Pseudosonneratia之间可能存有潜在的阿普特阶-阿尔布阶的生物地层界线。The Global Aptian/Albian Boundary Stratotype Section and Point of Lower Cretaceous has not been confirmed.Well-exposed marine Cretaceous deposits in the Gamba basin of southern Tibet yield macrofossils such as ammonites and bivalves,which are important for Aptian-Albian biostratigraphy.A total of five genera,including four species and four indeterminated species,have been recognized near the Aptian-Albian boundary in Chaqiela section：Hypacanthoplites xizangensis Chao,Acanthohoplites aschiltaensis（Anthula）,Douvilleiceras mammillatum（Schlotheim）,Cheloniceras seminodosum,Cheloniceras sp.,Acanthohoplites sp.,Hypacanthoplites sp.,and ？Pseudosonneratia sp.The stratigraphic occurrences of ammonites can be grouped into three assemblages/beds.In ascending order,they are the early late Aptian Hypacanthoplites bed,late Aptian Hypacanthoplites-Acanthohoplites lineage assemblage,and late early Albian Douvilleiceras-？Pseudosonneratia assemblage.These ammonite assemblages/beds indicate that there exist a potential Aptian/Albian biostratigraphy boundary between the Hypacanthoplites-Acanthohoplites lineage assemblage and Douvilleiceras-？Pseudosonneratiaassemblage in Chaqiela section,Gamba.

关 键 词：生物地层 菊石 双壳类 阿普特阶-阿尔布阶界线 岗巴东山组 岗巴 西藏 

分 类 号：P534.53[天文地球—古生物学与地层学]