吉林省四平南部下二台群小壳化石的发现及其地质意义     

佟文选  王福泰  任锡钢 《吉林大学学报(地球科学版)》1992,(1)

吉林省四平南部1:5万半拉山门、石岭街、下二台子、叶赫站幅的吉林省境内区调,首次在经过修订的下二台群黄顶子组下部条带状硅质大理岩中,采获丰富的小壳化石,初步确定为3属6种,其中4新种。属于辽北地区新确立的清河镇动物群辐射演化而来的新的动物群。从而,为这套地层的划分对片、时代确定,提供了重要的古生物佐证。  相似文献   

减压微色谱柱在矿石分析中的应用研究——P350萃淋树脂分离光度法测定痕量金     

龚治湘  宋金如  罗静 《岩矿测试》1993,(3)

研究了甲基膦酸二甲庚酯(P350)减压微色谱柱对Au的萃取性能。减压条件下,2mol/LHCI或浓度<25％的王水介质中的Au被萃取在P350(Φ3mm)微色谱柱上,再用小体积的1％Na_2SO_3定量洗脱。与常规柱相比,减压微色谱柱分离具有柱效高、洗脱体积小、速度快、节省大量试剂等优点。经标准样品验证,方法可用于含Au 0.025～200g/t地质样品的分析。  相似文献   

丹东地区中生代地层-古生物     

李杰儒  李超英  孙常玲 《国土资源》1993,(3)

丹东地区小岭组植物化石共9属12种。动物化石腹足类4属6种,叶肢介1属2种。均为首次发现。这些化石的发现为小岭组应属早白垩世而不属侏罗纪,提出了令人信服的证据。同时,阐述了古地理环境和地层特征,并与邻区进行了对比。  相似文献   

Implications of trace fossil assemblages from Late Paleozoic Glaciomarine Talchir Formation, Raniganj Basin, India     

Biplab Bhattacharya  H.N. Bhattacharya   《Gondwana Research》2007,12(4):509-524

The trace fossil assemblages of the ice-marginal shallow marine sediments of the Talchir Formation (Permo-Carboniferous), Raniganj Basin, India, record the adverse effect of extreme climatic conditions on biota. The glaciomarine Talchir succession starts with glacial sediments near the base and gradually passes to storm-laid shallow marine sediments up-section. The fine-grained storm sediments host abundant trace fossils. Although the studied ichnites characteristically show marginal marine affinity, the ichnodiversity and bioturbation intensity suggest a lower than normal shallow marine trace fossil population. Further, endobenthic annelids, worms and crustaceans are identified as dominant trace-makers.

Sediment reworking near the ice-grounding line, extremely cold climate, high-energy storm sedimentation and anomalous water chemistry hindered organic colonization during the early phases of Talchir sedimentation. Later, climatic amelioration ushered in a favourable ambience for the benthic community to colonize within or beyond the storm weather wave-base in the outer shoreface–shelf environment. Fluctuating storm energy dominantly controlled the availability and influence of other environmental stimuli in the environment, and thus, governed the distribution, abundance and association of the studied ichnites. However, impoverished ichnodiversity, sporadic distribution of the traces, overall smaller burrow dimensions, absence of body fossils, dominance of worms and annelids as trace-makers all indicate a stressed environmental condition, induced by cold climate and lowered marine salinity due to influx of glacier melt-out freshwater during climatic amelioration, in the Permo-Carboniferous ice-marginal sea.  相似文献   

柴达木盆地西缘阿尔金山南坡上干柴沟组大古植物化石的发现及其地质意义          下载免费PDF全文

仲新 《甘肃地质》2007,16(4):26-30

阿尔金南坡干柴沟地区上干柴沟组新发现Podagonium-Quercus大古植物化石组合,该组合指示上干柴沟组中下部地层的时代为新近纪中新世,与我国华北板块、华南板块和青海乌兰、泽库等地区比较,显示出低分异度和低丰度的特点。从该植物组合相伴产出的Austrocypris分析,表明该地区纬向气候带属高温少雨、干湿交替的疏林草原环境,有利于柴西陆相成油盆地主力油源层的发育。  相似文献   

渤海湾盆地早第三纪水平面升降和全球海平面升降的不一致性   总被引：4，自引：0，他引：4  

李守军 《地质论评》1998,44(1):31-34

本文通过对渤海湾盆地下第三系中半咸水化石纵向分布特点研究,并根据新的地层划分方案,利用古生物－岩相综合分析方法绘制了该地区早第三纪水平面升降曲线,发现半咸水生物出现在水进初期,在最大水进期消失,水平面升降曲线一全球海平面升降曲线无直接关系,即水平面的上升示受海平面上升的影响,从而证明此阶段无海侵发生,非海侵观点对于总结我国陆相地层的油气勘探理论及实践具有重要意义。  相似文献   

遗迹化石与潮控滨线海泛面的识别及准层序相组合──以塔里木盆地下志留统塔塔埃尔塔格组为例   总被引：1，自引：0，他引：1  

齐永安 《矿物岩石》1998,(4)

塔里木盆地下志留统塔塔埃尔塔格组主要由潮坪沉积组成。根据遗迹化石与沉积特征,固底控制的遗迹化石Ｇｙｒｏｌｉｔｈｅｓ常常与沉积性不连续面（海泛面）有关,潮控滨线中的准层序由三类岩相组成,其中含砾砂岩相（相Ａ）为潮道沉积,未见遗迹化石;含交错层理细砂岩相（相Ｂ）为砂坪沉积,仅见少量的遗迹化石Ｓｋｏｌｉｔｈｏｓ;强生物扰动粉砂岩、泥岩相（相Ｃ）为砂、泥混合坪沉积,发育有丰富的遗迹化石,代表Ｓｋｏｌｉｔｈｏｓ－Ｃｒｕｚｉａｎａ混合遗迹相。  相似文献   

The journal Communications in Numerical Methods in Engineering with Biomedical Applications becomes the International Journal for Numerical Methods in Biomedical Engineering (IJNMBE) from 1st January 2010     

Perumal Nithiarasu  Rainald Löhner 《国际地质力学数值与分析法杂志》2009,33(16):1769-1770

Communications in Numerical Methods in Engineering, founded by Roland W. Lewis in 1985, will change its title to the ‘International Journal for Numerical Methods in Biomedical Engineering’ and has a revised Aims and Scope. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

Shell‐shape and morphometric variability in Mytilus galloprovincialis from micro‐tidal environments: responses to different hydrodynamic drivers          下载免费PDF全文

Vanessa Moschino  Monica Bressan  Luigi Cavaleri  Luisa Da Ros 《Marine Ecology》2015,36(4):1440-1453

Tidal conditions differently influence inter‐tidal organisms in terms of general physiological and metabolic responses. In this study we investigated the morphological response in shells of Mytilus galloprovincialis native to different micro‐tidal coastal environments in the Northern Adriatic Sea. Our purpose was to highlight the ecophenotypic variability across tidal levels and to elucidate how tidal currents and waves produced by anthropogenic activities may play a part in modulating shell morphology. Three sampling sites were selected: an open‐sea area 15 km off‐shore and two sites within the lagoon of Venice, the first near one of its three inlets, and the other one in the proximity of Venice city centre. At each sampling site, organisms were seasonally collected at different depths within their vertical zonation, either in the inter‐tidal zone – i.e. at both the highest and lowest tide zonation limits, and subtidally. The mussel shells were analysed by investigation of their morphometric relationships (height/length and width/length ratios) and by elliptic Fourier analysis of the shell contours. Shell thickness and condition index were also evaluated for a better comprehension of energy allocation/partitioning. Estimates based on long‐term measurements, visual observation, wind statistics and wave growth laws allowed an evaluation of the forces acting on shells. At the open‐sea site, the observed phenotypic variability of both shell shape and thickness was clearly related to the tidal vertical zonation. At the two lagoon sites, the currents generated by tidal flow through the inlet and the waves caused by the frequent passage of boats influenced both shell shape and thickness. A trade‐off between protection and growth was apparent along the tide gradient, as emphasized by the differences in the partitioning and allocation of energy between shell and flesh production.  相似文献   

深海原位取芯钻机作业机理分析及实验研究     

杨磊  丁忠军  李德威  李宝钢  杨雷  任玉刚  刘庆亮  刘敬喜 《海洋技术学报》2015,34(1):32-37

针对深海运载器海底岩芯原位取样作业需求,对基于水下运载器的深海原位取芯钻机在深海低温、高压、底层流速多变等特点条件下的作业机理及受力进行分析,并选取硬质合金钻头和PDC钻头进行了取芯钻头的轴向力、切向力和切削功率的数学力学对比计算,确定了单环四齿周向均布的金刚石复合片(PDC)钻头设计方案。在理论分析基础上,针对深海钴结壳设计了台架试验,开展钻进试验研究。通过理论计算和实验研究,探寻了一种基于深海运载器的钴结壳小型钻机设计方法,确定了钻机功率、转速、钻进正向压力和取芯率等基本参数选取范围,对开展海底岩芯原位取样作业具有重要的指导意义。  相似文献