关于滇西地质的一些新认识   总被引：1，自引：0，他引：1  

方润森  范健才 《现代地质》1993,7(4):394-401,T001

本文依据对云南西部保山、腾冲地区晚古生代丁家寨组、勐洪群含砾地层的研究,认为含砾地层属冰川成因,时限为中、晚石炭世的Baskirian期—Kasimovian期。其层位与西藏珠穆朗玛峰、阿里、拉萨地区及印度次大陆、泰国西部和马来西亚西部的冰成岩系均可对比。根据云南西部及邻区深部地质构造及澜沧江断裂的资料,论述了澜沧江断裂是一条超壳深的压性、压扭性深断裂,是冈瓦纳板块与扬子板块的结合带。结合带以西属于冈瓦纳大陆,以东均属扬子大陆。两大板块的最终敛合时间可能在古新世末期。  相似文献   

辽东复州湾中石炭世地层兼论华北地台中石炭统的划分   总被引：3，自引：0，他引：3  

汪曾荫  尚冠雄  张洪江  路素明  尚晶 《现代地质》1989,3(2):165

华北地台中石炭统本溪组一般仅代表中石炭世晚期沉积。从已知的几十个海陆交互相本溪组剖面来看,其中（虫筳）类生物群为Fusulina-Fusulinella带;牙形石生物群为Idtognathodus magnificus-Ⅰ.claviformis-Neognathodus ruondyi带,在整个华北地台均可依此进行对比。但在辽东半岛南缘的复州湾一带,中石炭世沉积特征却恰好与本溪剖面相反,下部层段以灰岩为主,上部层段以碎屑岩为主。下部含6层灰岩,（虫筳）类以Profusulinella的丰富种群为特征,可建立Profusulinella带,并可进而划分为3个亚带。牙形石则为Idiognathoides sinuatus-Ⅰ.corrugatus-Declinognathodus lateralis带。复州湾含灰岩为主的下部层段和本溪含碎屑岩为主的下部层段对比,依前者之生物组合建立本溪组下部复州湾段（c21）,代表华北地台中石炭世早期沉积;复州湾以碎屑岩为主的上部层段和本溪含5层灰岩的上部层段对比,依后者之生物组合限定为本溪组上部牛毛岭段（c22）,代表华北地台中石炭世晚期沉积。  相似文献   

Preliminary investigation of Late Pleistocene fauna from Ryonggok Cave No. 1, Sangwon County,North Hwanghae Province,Democratic People's Republic of Korea     

Rye Sun Choe  Kum Sik Han  Se Chan Kim  Myong Hyok Ri  Jae Nam Ri 《第四纪科学杂志》2021,36(6):1137-1142

The investigation of a limestone cave on the Ryonggok-ri of Sangwon County, North Hwanghae Province, DPRK, has yielded many faunal remains including Late Pleistocene deer, brown bears and horses. Uranium series dating of fossil teeth yielded dates of ~72ka at the base of Layer 2 – the bone-bearing unit – and ~44ka at the top. The rich and diverse mammal remains of Ryonggok Cave No. 1 are indicative of warm and humid temperate conditions during the Late Pleistocene, and reflect the presence of both dense forests and open grassland. In addition, pollen and spores from the site include two families and 24 genera of trees, six families and a genus of grasses and herbs, and two families and six genera of ferns, corroborating the environments inferred from the faunal remains.  相似文献   

Paleogene mammalian fauna exchanges and the paleogeographic pattern in Asia     

Ni  Xijun  Li  Qiang  Zhang  Chi  Samiullah  Khizar  Zhang  Limin  Yang  Yangheshan  Cao  Wenxin 《中国科学:地球科学(英文版)》2020,63(2):202-211

Mammals are the most important elements in Cenozoic terrestrial ecosystem. The composition and the character of a mammalian fauna are controlled by evolution time and evolutionary rate. Here we took 50 Asian Paleogene mammalian faunas as representatives and applied Bayesian Tip-dating method to infer the relationships and divergence times among these faunas.Based on the results of Bayesian Tip-dating analyses, we discussed the correlation between the paleogeographic changes and the mammalian fauna turn-overs. Compared with the traditional fauna correlation and sorting, Bayesian Tip-dating analyses revealed more detailed similarities reflected via the divergence times among the 50 faunas. We discovered that the early Eocene mammalian fauna, which firstly appeared in India subcontinent, is similar to the faunas of the same age in other parts of Asia. It is likely that a passage for the mammalian dispersal was formed before early Eocene. Bayesian inferring suggests that the first appearance of the dispersal passage is during 64.8–61.3 Ma. This time window is close to the time estimation for the initial time of India-Asia collision. During 57.1–47.2 Ma, India subcontinent probably had a habitat different from the main part of Asia, as it was reflected from the composition of the mammalian faunas. It is probably correlated with the uplifted Gangdese Mountain and shallow seas and lowlands on both sides of the collision region. The very remote divergence time(64.8 Ma) estimated by Bayesian inferring reflects the mammalian fauna turnover during the Eocene-Oligocene transition, obviously affected by the global cooling. Till the end of Oligocene, the Arabic Peninsula and Asian mainland remained separated and the mammalian faunas did not show clear connection.  相似文献   

燕辽生物群叶肢介动物群组成和演化^*          下载免费PDF全文

李罡 《古地理学报》2023,25(2):368-381

中国北方著名中、晚侏罗世的燕辽生物群含有丰富的叶肢介动物群。早期燕辽生物群也称为道虎沟生物群,主要产出层位为海房沟组,含有三饰叶肢介动物群,主要分子包括: 海房沟三饰叶肢介(Triglypta haifanggouensis)、滦平三饰叶肢介(T.luanpingensis)和平泉三饰叶肢介(T. pingquanensis)。晚期燕辽生物群又可称为玲珑塔生物群,主要产出层位为髫髻山组,含有丰富的叶肢介化石,主要分子包括: 建昌三饰叶肢介(Triglypta jiancangensis)、玲珑塔辽西叶肢介(Liaoxiestheria linglongtaensis)、大西山玲珑塔叶肢介(Linglongtaestheria daxishanensis)和青龙玲珑塔叶肢介(Linglongtaestheria qinglongensis)。文中总结了北方雕饰叶肢介(Aquilonoglypta)、柴达木叶肢介(Qaidamestheria)和针孔叶肢介(Punctatestheria)的最新研究成果,支持将柴达木叶肢介、辽西叶肢介和玲珑塔叶肢介划归北方雕饰叶肢介科。同时,三饰叶肢介是由针孔叶肢介演化而来,与柴达木叶肢介并无直接演化关系。  相似文献   

陕西洛南龙牙洞遗址的特征和环境   总被引：1，自引：0，他引：1       下载免费PDF全文

薛祥煦  邓涛  李传令  岳乐平  张宏彦  陈民权  张学锋 《第四纪研究》1999,19(2):170-175

要本文第一作者曾在陕西洛南龙牙南洞中获得洛南直立人的上臼齿及少量哺乳类化石。近年作者等又在龙牙北洞中采集到大量石制品及哺乳动物化石。龙牙洞是黄河流域最南的一个旧石器遗址。由30多种哺乳类化石组成的龙牙洞动物群是一个兼具古北界和东洋界动物的过渡型动物群,可与蓝田公王岭动物群对比,时代为早更新世晚期,是温暖、湿润的森林、草原、多水体环境条件下的动物组合。石制品非常丰富,属华北旧石器文化系统,但又可见南方文化的影响。龙牙北洞遗址很可能是洛南直立人制作石器的场地。  相似文献   

On the Yangtzeconus Priscus-Archaeospira Ornata Assemblage (Mollusca) of the Earliest Cambrian of China     

YU Wen 《《地质学报》英文版》2014,88(4):1262-1287

Yangtzeconus priscus-Archaeospira ornata, an important earliest Cambrian benthonic Assemblage of the Yangtze micromolluscan fauna, occurs mainly in the Lower Cambrian Zhongyicun and Dahai Members of the Yuhucun Formation in E Yunnan, the Tianzhushan Member （=Huangshandong Member） of the Dengying Formation in W Hubei and the Maidiping Member of the Hungchunping Formation in C Sichuan, China. About 90% of the genera of this Assemblage are unknown from the Nemakit-Daldynian and Tommotian molluscan Assemblages of the Siberian Platform, Russia. About 90% of the Siberian molluscan genera do not occur in the Zhongyicun and Dahai Members in the Meishucun section and in the corresponding beds of the Yangtze Platform, because the Tommotian molluscan Assemblage is characterizedly abundant archaeocyathids. It is clearly indicated that the Yangtze and Siberian molluscan Assemblages represent different bio- and lithofacies and ages. The age of the pre-trilobitic Yangtzeconus priscus-Archaeospira ornata Assemblage is older than that of the Nemakit-Daldynian and Tommotian molluscan Assemblages and referable to the Earliest Cambrian. Two new genera Mcnamaraconus and Zhangwentangoconus are herein proposed.  相似文献   

山东诸城晚白垩世恐龙动物群研究进展     

张艳霞 《山东地质》2014,(5):40-46

自从20世纪60年代初在山东诸城发现第一具恐龙骨架“巨型山东龙”以来,一系列具有代表性的恐龙骨骼化石在诸城白垩纪地层中被发现,特别是埋藏于诸城晚白垩世地层中恐龙骨骼化石群,最为引人注目。目前研究发现了包括鸭嘴龙类、角龙类、暴龙类等在内的多种恐龙类型,为丰富我国东部白垩纪恐龙动物群的研究提供了新的宝贵材料。该文系统总结和归纳了近些年来在诸城晚白垩世地层中发现的恐龙骨骼化石及其所代表的恐龙动物群类型的研究成果,同时又提出了目前依然存在的一些亟待解决的关键问题和研究意义,有助于下一步更好的深入研究诸城晚白垩世恐龙动物群。  相似文献   

基于WebGIS禽流感疫情耗费评估决策系统研究   总被引：1，自引：0，他引：1  

阎波杰  潘瑜春  赵春江  殷红梅  闫静杰 《测绘科学》2010,35(4):46-48,67

为在疫情应急反应中提供动态、准确的疫情信息及合理决策,提出了构建禽流感疫情耗费评估决策系统。本文介绍了系统的体系设计、多用途数据库设计及实现该系统的关键技术,主要实现了禽流感疫源空间位置确定、疫区和威胁区的快速划分及禽流感疫情动态耗费评估分析,最后以北京市大兴区为例,实现系统的初步应用。  相似文献   

鄱阳湖鱼类资源及渔业利用   总被引：10，自引：3，他引：10       下载免费PDF全文

张堂林  李钟杰 《湖泊科学》2007,19(4):434-444

1997年冬至2000年春,对我国最大淡水湖鄱阳湖的鱼类与渔业利用状况进行了调查.在1955年至2000年期间,鄱阳湖累计记录鱼类136种,隶属于25科78属;其中鲤科鱼类最多,有71种,占总种数的52.2%,其次是鲿科,12种,占8.8%本次调查期间共记录鱼类101种,新记录鱼类6种,即亮银鮈、洞庭小鳔鮈、光唇蛇鮈、短须鱊、方氏鳑鲏和粘皮鲻鰕虎鱼.还分析了该湖鱼类区系组成的变化、主要渔具的渔获物组成特征以及渔产量动态,提出了未来湖泊渔业可持续发展的建议.  相似文献