华南伊迪卡拉纪"庙河生物群"的属性分析   总被引：4，自引：0，他引：4  

TANG Feng  唐烽  尹崇玉  刘鹏举  段德麟  高林志 《地质学报》2008,82(5):601-614

我国南方伊迪卡拉(震旦)系陡山沱组页岩中,保存了以"庙河生物群"为代表的宏体碳质压膜化石群,以大量底栖固着的多细胞藻类为主,还包含推测的后生动物和海绵动物、可疑的遗迹化石等多门类生物化石,化石类型多样、分异显著,代表着新元古代"雪球"冰期之后和寒武纪早期后生动物大爆发前夕地球早期多细胞生物的一次大规模的进化辐射事件。本文通过比较湖北秭归庙河和贵州江口翁会两个典型产地的宏体化石优势属种的形态特征,以及两地所处的沉积古环境,分析探讨了这些优势类别与现生多细胞生物(包括红藻、褐藻和绿藻三大高级藻类)的亲缘关系。研究表明,寒武纪之前大约35~10Ma间,各门类多细胞藻类广泛发育,与后生动物的先驱分子构成独特的古生态群落。  相似文献   

微堆中子活化技术测定多金属结核和海洋沉积物中多元素     

张卫华 《岩矿测试》1992,11(3):246-248

介绍了微堆中子活化法对多金属结核及其伴生海洋沉积物样品中痕量元素的测定条件,讨论了误差来源。实验结果给出了某些元素的地球化学特征,为研究多金属结核的形成提供了依据。  相似文献   

华南伊迪卡拉纪类水母化石新发现     

唐烽  钟玲  金幸生  郭东辉  尹崇玉 《地质通报》2016,35(1):1-9

An abundant and diversified assemblage of benthic fossils from the Ediacaran Doushantuo black shales in the Wenghui section of Guizhou Province contains two discoidal carbonaceous forms, Kullingia rotadiscopsis sp. nov. and Eoaequorea xingi gen. & sp. nov. The fossils have well-preserved concentric rings and radiating lines, and resemble many circular casts and moulds in Ediacaran clastic and carbonate rocks in the world, such as Aspidella, Ediacaria, Cyclomedusa, Eoporpita, Ovatoscutum, Spriggia and Kullingia. The Doushantuo carbonaceous macrofossils help us to inquire into the current functional identifications of circular disks as the holdfasts of unknown organism or scratch circles. Although there is not sufficient correspondence in morphology to warrant reinterpreting all previously described Kullingia and Aspidella form-genus-type structures, these carbonaceous compressions are prone to be the ancestor of pelagic jellyfish-like organisms with medusoid hydrozoan affinity.  相似文献   

深海沉积物中龙须菜降解菌群的筛选与鉴定及多样性分析          下载免费PDF全文

丁志新  陈兴麟  周治东  金敏  曾润颖 《应用海洋学学报》2016,35(2):151-156

以龙须菜为唯一的营养源对深海沉积物进行富集和筛选,获得一个可降解龙须菜(Gracilaria lemaneiformis)、紫菜(Porphyra umbilicalis)和海带(Laminaria japonica)产生还原性寡糖的菌群.通过16S rRNA序列及16S rRNA-RFLP分析对该菌群中的细菌多样性进行了研究.结果表明,降解菌群中的细菌组成主要为弧菌属(Vibrio,8株)、火色杆菌属(Flammeovirga,7株)和希瓦氏菌属(Shewanella,5株),其中希瓦氏菌属和火色杆菌属的细菌在菌群中的丰度较高.采用龙须菜为唯一营养源的筛选培养基对菌群中的细菌进行分离,获得4株具有琼胶酶活力的细菌,包括2株火色杆菌属和2株希瓦氏菌属细菌.培养和未培养的结果均表明火色杆菌和希瓦氏菌这2个属为所研究的深海沉积物主要的龙须菜降解菌.对原始降解菌群和所分离的关键菌株进行了龙须菜酶解产糖能力的比较,结果发现菌群中的弧菌属菌株虽然自身没有酶解龙须菜的能力,但可能可以协助关键菌株,提高菌群对龙须菜的降解效率.因此本研究中所获得的菌群和菌株有望在琼胶寡糖的绿色生产中得到广泛应用.  相似文献   

大鹏湾盐田水域反曲原甲藻数量的时空变化特点     

林永水  周近明  林秋艳 《热带海洋学报》1995,(4)

对１９９０年３月３０日－５月５日广东大鹏湾盐田水域反曲原甲藻Ｐｒｏｒｏｃｅｎｔｒｕｉｎｓｉｇ－ｍｏｉｄｅｓＢｏｈｍ进行研究。详细分析了反曲原甲藻数量的时空变化及分布特点。多元回归分析表明：影响反曲原甲藻数量变化的环境因子，表层主要是亚硝酸氮，而底层仅与盐度相关。４月２０日盐田水域发生赤潮，经水样分析，发现表层水体中反由原甲藻数量很高（大于３００个·ｍｌ（－１）），占浮游植物数量的８６％以上。由此说明，反曲原甲藻是此次赤潮的原因种之一。本种通过扫描电子显微镜观察和分析所确认，并作了形态特征描述。  相似文献   

厦门筼筜湖水产生物体内重金属含量及评价   总被引：1，自引：0，他引：1  

阮金山 《海洋通报》2006,25(5):84-89,96

根据2001年7月厦门筼筜湖的水生生态环境调查资料,着重分析了筼筜湖鱼类、虾类、蟹类体内重金属的含量分布。结果表明:筼筜湖内的蟹类体内Cu,Pb,Cd和Zn的含量明显高于虾类和鱼类。文中还根据我国《食品中铜、铅、镉、锌限量卫生标准》,对15种水产生物体内的重金属污染程度进行评价,结果筼筜湖的鱼类和虾类体内的重金属含量基本未超标,但蟹类体内的Pb,Cd含量已超标。  相似文献   

基于长基线系统深海采矿ROV精确定位   总被引：1，自引：0，他引：1  

杨放琼  谭青  彭高明 《海洋工程》2006,24(3):95-99

对于深海采矿集矿机ROV的定位,采用传统的长基线水声定位系统通常存在较大误差。对此提出了一种新的算法模型,首先通过比较集矿机测量位置与前一次修正位置的几何关系,对当前集矿机的位置进行修正,然后利用新的集矿机位置修正声速的数值,并得出重新修正后的集矿机测量位置。这样反复的多重迭代使得在某一时刻集矿机ROV的测量位置逐步趋近其理想位置,实现长基线系统的水声精确的三维立体定位。通过数值仿真分析,结果显示与传统的长基线水声定位方法相比,通过该方法获得的集矿机行驶轨迹能更好地趋近其理想行驶曲线,表明该算法的有效性。  相似文献   

Impact of small-scale biogenic sediment structures on bacterial distribution and activity in Arctic deep-sea sediments   总被引：1，自引：0，他引：1  

Nadia V. Quéric  & Thomas Soltwedel 《Marine Ecology》2007,28(S1):66-74

  相似文献   

Experiments on the resuspension of estuarine sediments containing benthic diatoms     

V. N. de Jonge  J. van den Bergs 《Estuarine, Coastal and Shelf Science》1987,24(6)

A laboratory system was used to test the effect of water flow on the resuspension of mud and sand sediments and, specifically, benthic diatoms from the Ems estuary, The Netherlands. Current velocities generated by two rotating cylinders in a cylindrical tank were determined by a small float and a laser Doppler velocimeter. At low angular velocities, the amount of suspended matter increased linearly with angular velocity and the float current velocity. However, at higher angular velocities, the increase in current velocity was less because of the strong turbulence: concomitantly, the current velocity boundary layer (δ) became thinner and the suspended matter concentration increased rapidly. The dominant diatom species from the sandy sediment were suspended in two distinct groups, one of which consisted of the species Navicula aequorea, Navicula salinicola, Ophephora martyi and Opephora pacifica, and was more exclusively bound to sand grains than the other. The benthic diatom species inhabiting the silty sediment did not show this difference. The most important shortcoming in the experiments was the inability to determine the radial and vertical velocity components. This precluded reliable calculations of the shear stress. The data presented emphasize the importance of finding a method to determine the shear stress under experiments and field conditions so that direct comparisons can be made. Despite this it is assumed that, just as under the experimental conditions discussed, under natural conditions in shallow waters resuspension starts at current velocities as low as ca. 10 cm s⁻¹.  相似文献   

Polychlorobiphenyl and pesticide residues in monkfish Lophius piscatorius and black scabbard Aphanopus carbo from the Rockall Trough     

Mormede  Sophie; Davies  Ian M. 《ICES Journal of Marine Science》2001,58(3):725-736

  相似文献