新化,湘潭等地跳马涧组的遗迹化石     

张欣平 《湖南地质》1991,10(2):97-104,T002

新化、湘潭等地跳马涧组的遗迹化石经笔者鉴定与描术者共15个遗迹属24个遗迹种(包括4个新遗迹种)。它们大部分属于跳马涧组上部,可分为Arenicolites-Palaeophycus组合,Skolithos-Planolites组合,Palaeophycus-Gordia组合,Rhizocorallium-Planolites组合,代表近滨环境,属Cruziana遗迹相。部分属于顶部Zoophycus-Cochlichnus组合和Zoophycus-Skolithos组合,属Zoophycus遗迹相上部。综合前人资料,湖南跳马涧组遗迹化石现已发现22属45种,可归并为居住迹、觅食迹、爬行迹、休息迹、啮食迹、钻孔、逃逸构造、生物扰动构造八种生态类型。由跳马涧组下部至顶部,由以居住迹为主的遗迹组合,转变为居住迹、觅食迹同等发育或以觅食迹为主,转变为啮食迹为主的组合。反映由前滨转变为近滨,再转变为远滨,代表海水加深、海侵扩大的过程。  相似文献   

东太平洋深海沉积物小于2μm组分的稀土元素地球化学特征   总被引：8，自引：0，他引：8  

刘季花  梁宏锋 《地球化学》1998,27(1):49-58

用等离子光谱测定了东太平洋９个深海沉积物样品的小于２μｍ组分及全岩的稀土元素,结果显示,小于２μｍ组分及全岩的稀土元素组成均受控于沉积物类型,而二者之间稀土元素组成的差异在钙质和硅质沉积物中出现相反的趋势。元素相分析和稀土元素赋存状态分析表明,这种差异主要由于沉积物物质组成的不同所致,表面在化学组成上,主要与ＭｎＯ,Ａｌ２Ｏ３Ｆｅ２Ｏ３,ＣａＯ含量的变化有关,大多数样品在小于２μｍ组分的稀土组成  相似文献   

太平洋多金属结核及沉积物标准物质研制   总被引：8，自引：0，他引：8  

王毅民  李家熙  高玉淑  宋浩威  罗代洪  王晓红  陈维岳  滕云业  周世光 《地球学报》1998,19(3):298-307

太平洋多金属结核及深海沉积物标准物质,ＧＳＰＮ－２,３和ＧＳＭＳ－２,３,４个样品已研制完成。ＧＳＰＮ－２,３和ＧＳＭＳ－２采自太平洋ＣＣ区,ＧＳＭＳ－３采自中太平洋海盆（ＣＰ区）。原样被加工成－２００目（７４μｍ）的均匀粉未,其均匀性采用高精度的Ｘ射线荧光光谱法检测。样品的特性值采用国内外多实验室协同分析的方式定值,有包括台湾大学在内的１４个国内实验室和１８个国外实验室参加了合作分析。测试组分分别达７９和８１个,定值组分６３个。全组分的百分总和分别为：９９．７％,９９．５％,９９．８％和９９．７％。这４个标准物质已于１９９７年被国家技术监督局批准为国家一级标准物质,序号分别为ＧＢＷ０７２９５,ＧＢＷ０７２９６,ＧＢＷ０７３１５和ＧＢＷ０７３１。  相似文献   

深海内波空间啁啾的演变研究     

孙美玲  王晶  郭凯  张旭东  孟俊敏 《中国海洋大学学报(自然科学版)》2015,45(1):114-120

根据基于两层流体推导的深海内波弱非线性薛定谔(Nonlinear Schrodinger,简称NLS)方程,引进空间啁啾的思想,研究深海区频散效应和非线性效应的作用。文中推导出了频散效应和非线性效应所致啁啾的表达式,采用数值计算方法计算了综合效应产生的总啁啾。分析了频散和非线性以及综合效应所致啁啾在深海内波传播中的演变规律。从空间啁啾的角度,解释中国南海东沙群岛附近深海区内波演变的机理。  相似文献   

Diet and food preference of intertidal Astrostole scabra (Asteroidea: Forcipulata)     

John C. Town 《新西兰海洋与淡水研究杂志》2013,47(4):427-435

Dietary composition in Astrostole scabra was ascertained by regular sampling at four geographically separated locations on the Kaikoura coast between January 1976 and January 1977. A. scabra is a food generalist and scavenger with a diet composed mainly of molluscs and crustaceans belonging to more than 60 genera. The diet was dominated numerically by chitons and trochid molluscs. Several site‐specific differences in dietary composition were apparent. Only Ischnochiton maorianus was a numerically important prey species at all study sites. Dietary diversity and evenness were more or less constant and comparable both seasonally and geographically. The proportion of intertidal seastars feeding fluctuated during the study from a peak of 42% in January to 23.7% in June 1976. Prey species were consumed in proportions independent of their abundance. In the laboratory, A. scabra, free of ingestive conditioning, discriminated between different prey species and preferentially consumed I. maorianus. There were strong prey preferences at the specific, but not at the familial, level.  相似文献   

Lobe construction and sand/mud segregation by turbidity currents and debris flows on the western Nile deep-sea fan (Eastern Mediterranean)     

S. Migeon  E. Ducassou  P. Rouillard  M. Revel-Rolland 《Sedimentary Geology》2010,229(3):124-143

Based on an unusual data set comprises bathymetric data, backscatter imagery, seismic-reflection and Chirp profiles, and sediment cores, the Late Quaternary lobe at the mouth of the youngest turbidite channel off the western Nile deep-sea fan was investigated. The large-scale construction of the lobe through time and space is mainly controlled by 1) a pre-existing topography inherited from the downslope movement of Messinian evaporites, and 2) the type and nature of gravity flows delivered to the basin floor. The margins of the lobe are defined by high-backscatter acoustic facies that contrasts strongly with the low-backscatter facies from the surrounding abyssal-plain deposits. Within the lobe, low-backscatter facies characterise the main channel-levee systems and lobate bodies immediately beyond the end of the channels. Cores reveal that the high-backscatter facies corresponds to a series of extensive but thin debris-flow deposits with a fingered margin. These debrites comprise a muddy-sand matrix and dispersed clasts with diameter of 5 to 10 cm. The lower backscatter facies at channel mouths corresponds to alternations of thin sandy turbidites and muddy hemipelagites. Extensive thin debris flows therefore traversed surprisingly low gradients to reach the distal fringes of the lobe complex but are never found in the lobate bodies just beyond the channel mouths. Although the Nile deep-sea fan is considered as a silt/mud-rich accumulation, sand-prone deposits exist within the lobe. This sand/mud segregation results either from the presence of channelized features in the lobe and/or from the hydrodynamic process of particle transport by debris flows and turbulent flows.  相似文献   

XX核电厂附近海域生态环境及潜在致灾生物研究     

张文斌  孙伟  许歆  王洪波  郑碧琪  鲁超  李靖  穆景利 《海洋科学》2022,46(7)

为了了解XX核电厂周边海域的生态环境状况,筛选潜在威胁核电厂冷源安全的致灾生物,分析影响致灾生物时空分布的主要环境因素,本研究于2018年进行了四个季节的生态调查。结果表明,研究海域浮游植物密度秋季最高,春季优势种为东海原甲藻,其他季节优势种为中肋骨条藻等硅藻。浮游动物密度夏季最高,以桡足类为主,春、夏季优势种还包括球型侧腕水母和薮枝螅水母。底栖动物的密度和生物量在秋季最高,优势种主要为豆形短眼蟹、长吻沙蚕和丝异须虫。浮游植物、浮游动物和底栖动物群落均在夏季最为稳定,群落多样性水平和物种丰度较高,且分布较为均匀。浮游植物群落的细胞丰度与悬浮物和磷酸盐的浓度正相关性最高。浮游动物的密度受温度和盐度的影响较大。底栖动物的群落分布主要受悬浮物和无机营养盐的浓度影响。本研究共筛选出17种威胁XX核电厂冷源安全的潜在致灾生物。海地瓜、棘刺锚参、海葵和球型侧腕水母的风险等级较高,其分布主要受温度和盐度的影响。后续工作中,XX核电厂应根据潜在致灾生物与环境因子的关系加强暴发机制研究、提升监测预警能力,并优化驱赶消杀技术和干扰体系,为核电厂冷源安全提供理论和技术保障。  相似文献   

履带式深海采矿车软底质行走性能分析     

苏强  吕海宁  杨建民  孙鹏飞 《海洋工程》2022,40(2):162-168

海底底质的物理力学参数不同于陆地土壤,其极低的抗剪强度和承压强度对深海采矿车的行走性能提出高要求。分析基于车辆地面力学理论,开展了底质土力学特性试验研究,建立了深海底质力学模型。根据深海重载作业采矿车样机结构参数,在大型动力学仿真软件Recurdyn中建立了仿真模型。通过直线行走多体动力学仿真与直线行走海试试验的对比,验证了仿真模型的准确性。在此基础上开展了采矿车样机在深海软底质上的多种行走工况动力学仿真,分析与评价其行走性能。结果表明,采矿车样机可以顺利完成转弯、爬坡、越障等基本功能。该研究成果可为深海采矿车海底行走性能评估提供理论参考,为深海采矿车和软底质的相互作用力学研究提供借鉴。  相似文献   

西南印度洋深海热液硫化物区沉积物微生物群落结构和固氮基因多样性   总被引：1，自引：0，他引：1  

吴月红  曹佚  王春生  吴敏  Aharon Oren  许学伟 《海洋学报(英文版)》2014,33(10):94-104

A sediment sample was collected from a deep-sea hydrothermal vent field located at a depth of 2 951 m on the Southwest Indian Ridge. Phylogenetic analyses were performed on the prokaryotic community using polymerase chain reaction（PCR） amplification of the 16 S rRNA and nifH genes. Within the Archaea, the dominant clones were from marine benthic group E（MBGE） and marine group I（MGI） belonging to the phyla Euryarchaeota and Thaumarchaeota, respectively. More than half of the bacterial clones belonged to the Proteobacteria, and most fell within the Gammaproteobacteria. No epsilonproteobacterial sequence was observed. Additional phyla were detected including the Actinobacteria, Bacteroidetes, Planctomycetes, Acidobacteria, Nitrospirae, Chloroflexi, Chlorobi, Chlamydiae, Verrucomicrobia, and candidate divisions OD1, OP11, WS3 and TM6, confirming their existence in hydrothermal vent environments. The detection of nifH gene suggests that biological nitrogen fixation may occur in the hydrothermal vent field of the Southwest Indian Ridge. Phylogenetic analysis indicated that only Clusters I and III NifH were present. This is consistent with the phylogenetic analysis of the microbial 16 S rRNA genes, indicating that Bacteria play the main role in nitrogen fixation in this hydrothermal vent environment.  相似文献   

东太平洋海隆深海热液区沉积物古菌多样性分析   总被引：1，自引：0，他引：1  

刘青  谢运标  陈逍遥  周梅先 《台湾海峡》2014,(4):516-524

采用PCR-RFLP方法对东太平洋海隆深海热液区3个站位沉积物中的古菌多样性进行了初步研究.结果显示,从古菌16S rRNA基因文库中随机挑取的296个阳性克隆分属奇古菌门（Thaumarchaeota,47.64%）、广古菌门（Euryarchaeota,44.93%）、泉古菌门（Crenarchaeota,6.77%）和未分类古菌（0.68%）,其中优势菌群为奇古菌门的亚硝化侏儒菌属（Nitrosopumilus,35.47%）和广古菌门的热原体纲（Thermoplasmata,27.03%）,DHVE3、DHVE5、DHVE6、MBGB和MBGE类群在沉积物样品中也均有发现.另外,3个站位沉积物中古菌类群组成存在差异,S5-TVG1站位样品文库的97个古菌克隆分属奇古菌门（49.48%）、广古菌门（49.48%）和泉古菌门（1.03%）,S14-TVG10站位样品文库的103个古菌克隆由奇古菌门（84.47%）和广古菌门（15.53%）组成,S16-TVG12站位样品文库的96个古菌克隆包括广古菌门（71.88%）、泉古菌门（19.79%）、奇古菌门（6.25%）和未分类古菌（2.08%）.研究结果表明,东太平洋海隆深海热液区沉积物中古菌多样性丰富,存在着许多新的古菌菌群;不同站位古菌菌群结构以及多样性存在差异,这与其所处环境的热液活动密切相关.  相似文献