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51.
《中国显生宙腕足动物属志》对中国显生宙古生代(寒武纪、奥陶纪、志留纪、泥盆纪、石炭纪和二叠纪)和中生代(三叠纪、侏罗纪和白垩纪)9个纪的海相地层中、于1883至2015年、根据中国材料创建的757个属的腕足动物化石进行逐一查考和再研究,对属的取舍及其分类位置提出了新观点,并将相关的模式种展示于125个图版中。在最新各纪年代地层框架下,更新各属的地质历程,并确定各属的地理分布。在梳理相关的其他腕足动物属的基础上,论述各时期的化石组合或动物群;并对显生宙几个重大宏演化过程中腕足动物的作用和意义进行了探讨。中国的这些腕足动物化石,不仅在地层划分对比、盆地分析和矿产勘探上有重要意义,在古生态、古生物地理、古气候与古环境及全球古地理再造上,也具有独到的学术价值。 相似文献
52.
系统研究了新疆吐鲁番桃树园晚二叠世梧桐沟组双壳动物化石,讨论了化石组合特点及地质时代。根据化石组合内容、岩性和沉积特征,以及剖面结构,认为梧桐沟组的时代应为晚二叠世 相似文献
53.
孙柏年 《兰州大学学报(自然科学版)》1995,31(2):133-139
新疆塔里木盆地北缘二叠纪陆相地层中的植物化石丰富,共现28属48种,本文对其中的8属9种作了详细的描述了讨论,当前材料不仅大大丰富了塔北二叠纪植物群的内容,对塔北二叠纪地层的划分与对比具有重要作用,而且为塔北二叠纪植物地理区系和古板块位置的研究提供了新论证。 相似文献
54.
四川彭县小渔洞地区下三叠统飞仙关组,常伴随二叠系飞来峰灰岩出现。该文着重介绍了丙寅沟出露较好的飞仙关组地层剖面,分析岩石组合特征(基本层序的划分、顶底界线讨论等)、动物群面貌(着重介绍Claraiawangi和C.stachei化石带),并与同期地层对比。 相似文献
55.
Pyritization in the Gaojiashan Biota 总被引:2,自引:0,他引:2
CAI YaoPing HUA Hong 《科学通报(英文版)》2007,52(5):645-650
The Late Sinian (Ediacaran) Gaojiashan Biota was a soft-bodied fossil-Lagersttte dominated by sub-stantial pyritized, three-dimensionally preserved tubular and conotubular fossils. Soft-tissue pyritiza-tion is extremely scarce in the fossil records, especially in the Precambrian, therefore it has very im-portant and unique significance for the study of pyritization in the Gaojiashan Biota. Early pyritization played a pivotal role in the fossil preservation and two main factors ensured the successful pyritization of the fossils, namely rapid burial and permineralization. The former was controlled by secular storm deposition, and the latter was achieved by sufficient supply of available iron from sediments. SEM data of Conotubus demonstrate two types of preservation of the tubes (defined as type A and type B, re-spectively). In type A, pyritization took place relatively earlier and completely preserved both tube wall and coelom, but no detailed structure. While in type B, pyritization took place somewhat later and pre-served the integrated tube wall, but partially the coelom. The size frequency distribution of the pyrite framboids suggests that pyritization took place in two different environments with entire different oxygen content. 相似文献
56.
采用共混法与原位聚合法制备添加纳米二氧化硅恐龙化石保护材料.将制备恐龙化石保护材料与传统保护材料(硝基清漆)分别涂覆钢片,用3.5%氯化钠溶液浸泡腐蚀,测试腐蚀电位、腐蚀电流、交流阻抗和腐蚀速度;利用SPM和DSC测试保护材料分散性与热分解性.结果表明:共混法与原位聚合法制备保护材料腐蚀电流分别为3.481×10-7A/cm2、2.332×10-6A/cm2,硝基清漆腐蚀电流为4.181×10-6A/cm2,共混法制备保护材料腐蚀速度最小;三种保护材料失重腐蚀速率为1.18 g/(m2·h)、1.19 g/(m2·h)和1.29 g/(m2·h),共混法制备保护材料耐蚀性最好,交流阻抗谱测试结果与其一致;添加4%纳米SiO2制备水溶性保护材料时,共混法制备材料耐热性、分散性较原位聚合法好,两者涂膜附着力皆为1级. 相似文献
57.
据对贵阳乌当奶坡冲志留系下高寨田群上段地层、古生物、遗迹化石、岩石及沉积构造等方面资料的分析,认为其代表了从潮下带到潮间带到潮上带的一个潮坪沉积序到。文章还对遗迹化石进行了描述。 相似文献
58.
Geomicrobial functional groups: A window on the interaction between life and environments 总被引:1,自引:0,他引:1
ShuCheng Xie Huan Yang GenMing Luo XianYu Huang Deng Liu YongBiao Wang YiMing Gong Ran Xu 《科学通报(英文版)》2012,57(1):2-19
Microbes are well-known for their great diversity and abundance in modern natural environments.They also are believed to pro-vide critical links among higher organisms and their associated environments.However,the low diversity of morphological fea-tures and structures of ancient microbes preserved in sediments and rocks make them difficult to identify and classify.This diffi-culty greatly hinders the investigation of geomicrobes throughout Earth history.Thus,most previous paleontological studies have focused on faunal and floral fossils.Here,geomicrobial functional groups(GFGs),or a collection of microbes featured in specific ecological,physiological or biogeochemical functions,are suggested to provide a way to overcome the difficulties of ancient mi-crobe investigations.GFGs are known for their great diversity in ecological,physiological and biogeochemical functions.In addi-tion,GFGs may be preserved as the biogeochemical,mineralogical and sedimentological records in sediments and rocks.We reviewed the functions,origins and identification diagnostics of some important GFGs involved in the elemental cycles of carbon,sulfur,nitrogen and iron.GFGs were further discussed with respect to their significant impacts on paleoclimate,sulfur chemistry of ancient seawater,nutritional status of geological environments,and the deposition of Precambrian banded iron formations. 相似文献
59.
从古生物学本身的特征和多元统计分析方法中的聚类分析、因子分析和对应分析这3种方法的数学模型入手,讨论在古生物化石分类、鉴定中所遇到的两个基本的问题:变量的选择和分析方法的选择。 相似文献
60.
Yukio Isozaki 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2006,82(1):25-32
Unique new fossil assemblages containing the large bivalve family Alatoconchidae are recorded from the Guadalupian (Middle Permian) shallow marine limestone in Kamura, Kyushu. The large bivalves occur in the Neoschwagerina Zone and Lepidolina Zone. This discovery establishes that the biostratigraphic range of the family Alatoconchidae extends up to the top of the Lepidolina Zone (upper Capitanian of upper Guadalupian) i.e., to the end-Guadalupian extinction level. The largest Alatoconchidae in Kamura occurs in the Neoschwagerina Zone, the size of which is up to 50 cm long and 5 cm thick. Although details are still unknown, their morphology with a wing-like side projection of their valves appears very similar to that of Alatoconchidae that includes the well-known genus Shikamaia Ozaki. The bivalve-bearing Iwato Formation was derived from a mid-oceanic shallow marine carbonate build-up formed on a mid-oceanic paleo-seamount. The close association among the Alatoconchidae, typical Tethyan fusulines (Verbeekinidae) and rugose corals (Waagenophyllidae), plus their common extinction pattern suggests that the Alatoconchidae flourished in warm, shallow (photic) marine environments in low latitude areas in Panthalassa as well as Tethys. The extra-large size and double-layered shell with a translucent outer layer composed of prismatic calcite suggests that these bivalves may have hosted abundant photosynthetic algal symbionts to support their large-body metabolism. 相似文献