塔里木中央隆起区上奥陶统的牙形刺  

UPPER ORDOVICIAN CONODONTS FROM THE CENTRAL HIGH,TARIM BLOCK,NW CHINA

作　　者：王志浩[1] 李越[1] 王建坡[2] 马俊业[1] 姚小刚[1] 黄智斌[3] 张园园[1] 

机构地区：[1]中国科学院南京地质古生物研究所,南京210008 [2]中国科学院广州南海海洋研究所,广州510301 [3]中国石油天然气股份有限公司塔里木油田分公司勘探开发研究院,新疆库尔勒 841000

出　　处：《微体古生物学报》2009年第2期97-116,共20页Acta Micropalaeontologica Sinica

基　　金：中国科学院创新工程方向性项目(KZCX2-YW-Q05-01,KZCX2-YW-122);国家自然科学基金项目(40572069,40532009)的资助

摘　　要：塔里木板块中央隆起区的上奥陶统,即巴楚露头剖面吐木休克组和良里塔格组以及塔克拉玛干沙漠腹地塔中油田井下良里塔格组皆为灰岩相。作者对前人报道的牙形刺带作了修改,首次系统描述牙形刺动物群全貌,共计14属21种。在曾归入Pygodus serra带和P. anserinus带的吐木休克组底部和下部发现Yangtzeplacognathus jianyeensis,故应改为Yangtzeplacognathus jianyeensis带;吐木休克组中部因发现Baltoniodus alobatus和B.variabilis共生,应属B. alobatus带。在Yangtzeplacognathus jianyeensis带和Baltoniodus alobatus带之间尚未发现可靠的B. variabilis,因此是否存在B. variabilis带尚存疑问。巴楚露头区上奥陶统的牙形刺序列由下而上应为Yangtzeplacognathus jianyeensis带, Baltoniodus variabilis带?,B. alobatus带和Belodina confluens带。塔中的良里塔格组则可识别出B. confluens带和Yaoxianognathus yaoxianensis带。将中央隆起区牙形刺动物群组合与其相邻的柯坪地块进行对比,说明晚奥陶世因两个地理区水深的差异导致牙形刺带完整性的差异。Upper Ordovician in the Central High, Tarim Block are composed of ramp facies limestone. The Tumuxiuke and Lianglitag formations are outcropped from Bachu, western part of the Central High, meanwhile, only Lianglitag Formation is occurred from drillings of the Tazhong Oil Field, central Taklamakan Desert. It is the first time to systematically describe the Upper Ordovician conodonts from these units. There are 21 species referred to 14 genera. The conodont biozonations are also revised. The basal part of the Tumuxiuke Formation formerly referred to the Py- godus serra and P. anserinus zones is referred to the Yangtzeplacognathus jianyeensis Zone at present because of the occurrence of Yangtzeplacognathus jianyeensis. The middle and upper parts of the Tumuxiuke Formation is referred to the Baltoniodus alobatus Zone because of the occurrence of 13altoniodus alobatus. Baltoniodus variabilis has not been found below the B. alobatus Zone, although it occurs associated with B. alobatus. Therefore, the presence of the Baltoniodus variabilis Zone is in doubt. In this case, the Upper Ordovician conodont sequence consists of Yao- xianognathus yaoxianensis, Belodina confluens, Baltoniodus alobatus, B. variabilis（？）, and Yangtzeplacognathus jianyeensis zones in descending order. Comparing with the adjacent Kalpin area which is assigned to a deeper slope facies and yields a more complete biozonation, we suggest that the depth differentiation of the sea water is significant in controlling the fanal variety.

关 键 词：牙形刺 生物带 系统古生物学 上奥陶统 中央隆起区 塔里木板块 

分 类 号：Q915[天文地球—古生物学与地层学]