AMMONOIDS ASSEMBLAGES OF THE MIDDLE AND LATE JURASSIC FROM NIELAMU COUNTY, TIBET
-
摘要: 藏南聂拉木地区有关侏罗纪的地层及古生物的研究,前人己有报导。本文对该区的中、上侏罗统菊石的组合特征,并结合邻区及国外有关地区的菊石组合及其时代,将本区的菊石进一步划分为五个组合及一个菊石层。同时,对其上下层位关系与时代分布也作相应的讨论。Abstract: The ammonoids described in the paper were collected from the middle and upper Jurassic in Nielamu County of southern Tibet in 1980 and 1981, Stratigraphically, these fossils can be divided into four assemblages and an ammonoids-bearing stratum as follows: 1. Macrocephalous-Indocephalous assemblage located at the basement of Menbu Formation, mainly consists of Macrocephalitidae, 2.Aulacosphinctoibes-Ptychophylloceras lalonglaensis assemblage derives from the middle and upper parts of Menbu Formation with few Katroliceras and Metagravesia genera etc, 3.Virgatosphinctes-Haplophylloceras pinque assemblage from the upper section of Xiumo Formation is characterized by plenty of Virgatosphinctes (sPP.). 4.Berriasella-Blanfordiceras assemblages at the lower part of Gucuo Formation are principally composed of Berriasellidae. Mayaitids-bearing stratum lies at the lower part of Menbu Formation, Based on the correlation analysis among the ammonid faunas and the other faunas from some parts of the world, it is considered the faunas in Tibet present a completed series from Callovian to Tithonian, It is interested that the Tithonian may be divided into three parts with three ammonoids-bearing strata of different features.
-
[1] 王义刚、张明亮, 珠穆朗玛峰地区的地层-侏罗系, 珠穆朗玛峰地区科学考察报告-地质, 科学出版社, 1957年. [2] 张启华、黄亚平, 西藏聂拉木地区侏罗系及下白垩统的菊石, 青藏高原地质论文集第11集, 第179-198页. [3] 余光明, 徐钮林等, 1983年, 西藏聂拉木地区侏罗纪地层的划分和对比, 青藏高原地质论文集第11集, 1983, 第165-178页. [4] 赵金科等, 珠穆朗玛峰地区侏罗、白垩纪菊石, 珠穆朗玛峰地区科学考察报告, 古生物(第三分册), 1976第503-545页, 图版1-18科学出版社. [5] Arkell, W.J.et al., 1957, Mesozoic Ammonoidea Treatise on invertebrate Paleontology, pt,L, Mollusca 4, P.80-437. [6] Carious, E., 1973, Ammonites of the Callovian and Oxfordian.in Hallam,A,1973 Atlas of Paleobiogeography, P.289-295. [7] Enay, R., 1962, Ietage Tithonique,Colloque du Jurassique, Luxembourg, P.355-379. [8] Enay., R, 1973, Upper Jurassic(Tithonian)Ammonites.in Hallam, A.1973,Atlas of Paleobiogeography, P.297-307. [9] Hegrat, G., 1971, Le Berriasien du Sud-Est de la France,These Lyon, 2vol., 676pP.Documents de lab,de Geol,Sci.Lyon n. 43(fasc.1). [10] Mazenot, G., 1939, Les palaehoplitidae Tithonique et Berriasiens du sud-Est de la France,Mem,Soc.Geol.Fran,paris, N,S,tomel8, No.41, face 1-4. 303PP., 40pls. [11] Spath, L.F., 1927-1933, Revision of the Jurassic cephalopod faunas of Kuchh(Cutch).India Geol,sur,Mem., Palaeont,Indica, new,ser., v,9, mem,2,pts.1-6, 45pp., 130pls. -
计量
- 文章访问数: 476
- HTML全文浏览量: 52
- PDF下载量: 232
- 被引次数: 0