甘肃酒泉市天仓地区早白垩世介形类的发现及其地质意义  

The discovery of ostracods assemblages from Early Cretaceous Chijinpu Formation in Tiancang area, Jiuquan, Gansu Province, and its geological significance

作　　者：杨兵 李树才[1] 魏乃颐[2] 杨欣杰 韦一 YANG Bing;LI Shucai;WEI Naiyi;YAGN Xinjie;WEI Yi(Cores&Samples Center of Land&Resources,Langfang 065201,Hebei,China;Nanjing Institute of Geology and Mineral Resources,Nanjing 210016,Jiangsu,China;School of Safety Engineering,North China Institute of Science and Technology,Langfang 065201,Hebei,China)

机构地区：[1]中国地质调查局自然资源实物地质资料中心,河北廊坊065201 [2]中国地质调查局南京地质矿产研究所,江苏南京210016 [3]华北科技学院安全工程学院,河北廊坊065201

出　　处：《地质通报》2020年第4期433-441,共9页Geological Bulletin of China

基　　金：中国地质调查局项目《天山-北山成矿带那拉提-营毛沱地区地质矿产调查》(编号:DD20160010);国家自然科学基金项目《青藏高原始新世-渐新世古海拔演化的介形类和同位素证据》(批准号:41702366);中央高校基本科研业务费《古近纪华北-华南非海相介形类动物化石差异演化及其地质意义》(编号:3142018004)。

摘　　要：甘肃酒泉市天仓地区地层剖面发现丰富的介形类,计7属18余种,前人将该套地层划为上新统疏勒图组,本次结合化石时代和岩石组合,将其修订为早白垩世赤金堡组,并建立了2个介形类化石组合:下部Cypridea concina-Candona prona-Cypridea zhaobishanensis组合和上部Cypridea concina-Cypridea justa-Darwinulla leguminella组合,根据区域对比,将下部组合的时代厘定为早白垩世Hauterivian期,上部组合的时代厘定为早白垩世Barremian期。根据2个介形类组合的属种分布及化石形态特征的演化特征,对赤金堡组三段沉积期古生态、古气候进行讨论,认为湖盆在Barremian期较Hauterivian期更深广,气候具有变温暖湿润的趋势,这与全球早白垩世气候波动事件有良好的响应。Diverse and abundant ostracods fossils were found from the Tiancang area of Jiuquan, Gansu Province.This research was based on 18 species of ostracods that belong to 7 genera.Based on the age of the fossils and the rock assemblage, we revise the strata to Chijinpu Formation of Early Cretaceous instead of Shuletu Formation of Pliocene in previous research.two assemblages were observed: Cypridea concina-Candona prona-Cypridea zhaobishanensis assemblage in the lower part and Cypridea concina-Cypridea justa-Darwinulla leguminella assemblage in the upper part.The correlation of the ostracods assemblages from the study section with the ostracods fauna in the same strata in other parts of the world indicates that the lower assemblage is of Hauterivian epoch, and the upper assemblage is of Barremian epoch.Based on an analysis of the evolution of fossil morphology and species distribution, the authors hold that the basin was deeper and wider in the Barremian epoch than in the Hauterivian epoch, while the climate showed a tendency of warming and wetting, which had a good response to the global climatic fluctuation events during Early Cretaceous.

关 键 词：介形类 早白垩世 古环境 赤金堡组 甘肃 

分 类 号：P534.53[天文地球—古生物学与地层学] Q915[天文地球—地质学]