西太平洋海山玄武岩的岩石学特征及与上覆富钴结壳的关系     

赵海玲  范忠孝  王成  丁旋  莫兆  李长江  张振国  张静 《现代地质》2007,21(2):352-360

通过对西太平洋海山玄武岩和玄武质火山角砾岩的岩石学特征及其气孔充填物成分变化的研究,讨论了海山玄武岩与上覆富钴结壳的关系。富钴结壳的基岩火山岩主要为碱性玄武岩和玄武质火山角砾岩。碱性玄武岩中气孔充填物为S型和C型,S型和C型气孔充填物不共存在同一个气孔中。S型气孔充填物的物质成分富Si、Fe、K、Mg、Al,Co含量一般为0.17%~0.46%,其成分与碱性玄武岩的组成类似,其物质来源可能与碱性玄武岩有关。C型气孔充填物为O、Ca、C及少量Si、Al、Mg、Fe、K等元素,C型气孔充填物可能与海水中物质的沉积有关。由Si、Al、Fe、Mg、K等元素变化曲线反映出的S型气孔充填物沉积过程与富钴结壳早期的沉积过程具有相似的趋势,说明富钴结壳早期沉积物的物质来源可能与碱性玄武岩有关,富钴结壳物质来源可能是碱性玄武岩和海水共同作用的结果。  相似文献   

Determination of Major/ Minor and Trace Elements in Seamount Phosphorite by XRF Spectrometry   总被引：2，自引：0，他引：2  

Xiaohong Wang  Guohui Li  Qin Zhang  Yimin Wang 《Geostandards and Geoanalytical Research》2004,28(1):81-88

In this paper, a method developed to determine the major, minor and trace elements, including carbon and the four halogens, in seamount phosphorite involving a modern XRF spectrometry technique is described. Ultra-fine (99% v/v < 40 μm) powder samples (4 g) were directly pressed into pellets (Φ= 30 mm). For elements having an analytical line lower in energy than the energy of Fe Kα line absorption edge, the inter-element absorption-enhancement effects were corrected using an influence coefficient method. For the other elements, the matrix effects were corrected using the ratio of element peak to Rh Kα Compton peak (for I, Rh K|3 Compton peak was used instead). The relative standard deviation was smaller than 1.0% for the major elements (except C, Na and Cl). The detection limit levels of C, F, Cl, Br and I were 30, 20, 0.8, 0.2 and 0.3 (μg g⁻¹ respectively for 100 s count time of background. The accuracy of this method was tested by evaluating determinations on three certified reference materials. The direct analysis of major and minor elements in geological materials by pressed pellet without any chemical procedures makes XRF spectrometry a particularly environment-friendly analytical technique.  相似文献   

莫霍计划的回顾与展望     

吴婵  李海兵  姚永坚  张伙带  刘栋梁  尉建功 《地质学报》2022,96(8):2657-2669

“莫霍计划”是20世纪50年代末提出来的堪与“登月计划”相媲美的最宏伟的科学计划之一。它开启了大洋钻探的新篇章，拉开了探索大洋岩石圈的序幕。历经半个多世纪的深海探索，研究学者逐渐揭开了洋壳结构的复杂性和多变性，其中代表下洋壳层3的辉长岩乃至地幔岩剥露的大洋核杂岩，为莫霍钻的实施提供了捷径和优选区。本文综述了“莫霍计划”以来在洋壳结构、洋壳增生机制和大洋核杂岩方面的研究进展，通过分析国际上莫霍计划的选址和策略，结合我国南海洋壳的特征，初步提出“南海莫霍计划”的两个站位及策略：① 南海残余洋中脊附近的U1431孔，该孔已钻到玄武岩层，可通过重复钻进钻穿莫霍面；② 南海东缘残余扩张脊的管事海山，可能有下洋壳辉长岩剥露，可在该区域采取多阶段钻探钻穿莫霍面。  相似文献   

滇西南古特提斯石炭纪海山碳酸盐台地的层序地层学研究   总被引：4，自引：0，他引：4  

张海清  刘本培 《沉积学报》1997,15(4):18-23

应用露头层序地层学原理和方法，首次对滇西古特提斯（昌宁－孟连带）中海山碳酸盐台地的石炭系进行了研究。识别出６个三级层序，其中早石炭世晚期１个、威宁期３个、鱼塘寨组３个，顶部一个归属二叠纪。三级层序和相应的海平面变化旋回可以和黔南对比，但副层序厚度较大（黔南副层序小于１０ｍ，鱼塘寨１０～５０ｍ），碳、氧同位素普遍偏轻以及存在麦粒蜓带厚度变薄事件，造成这种现象的主要原因是两者之间经历了同样的冰川型全球海平面变化，但具有不同的大地构造背景.  相似文献   

基于SCI-E的国际海山生物多样性研究现状及研究热点解析   总被引：1，自引：1，他引：0  

郭琳  冯志纲  张均龙  张灿影  於维樱  王琳 《海洋科学》2016,40(4):116-125

为了解海山生物多样性研究领域的研究现状和研究热点,本文采用文献计量学的方法对1991~2014年海山生物多样性相关的SCI论文产出进行了分析。结果表明,美国是该领域发文量最多的国家,新西兰水和大气国家研究所是发文量最多的机构。关键词分析的结果显示,海山生物多样性领域的研究热点主要集中在新物种发现和分类学,涉及"hydrothermal vent"(热液喷口)、"mitochondrial DNA"(线粒体DNA)及"conservation(保护)"等关键词的研究近几年逐渐增多。研究结果同时表明我国在该领域的研究较少,研究力度有待加强。  相似文献   

Three Cobalt-Rich Seamount Crust Reference Materials: GSMC-1 to 3   总被引：1，自引：0，他引：1  

Xiaohong Wang  Yushu Gao  Yimin Wang  S.I. Andreev 《Geostandards and Geoanalytical Research》2003,27(3):251-257

A research project involving the preparation of three Co-rich crust reference materials (GSMC-1 to 3) has been preliminarily completed. The samples were collected from the eastern and central Pacific seamount zones and their main chemical composition is MnO₂. After the raw materials were dried in ambient air and at low temperature (60-100 C), they were ground in a ball mill to form a well-mixed powder. The proportion of particle size fractions of < 74 μm and < 3 μm was over 98% and 50% respectively. The homogeneity of the materials was tested using wavelength dispersive X-ray fluorescence spectrometry (WD-XRF). The relative standard deviation (% RSD) of the measurements for all the selected elements in forty sub-samples randomly taken from the bottles was less than 0.4%. Sixteen laboratories from Germany, Russia, France, Australia and China participated in the collaborative analysis programme. Fifty seven elements or constituents were analysed, and among those, forty six elements were certified in each sample. The sum of contents of the major and minor elements or components was 99.5% for GSMC-1, 99.6% for GSMC-2 and 99.2% for GSMC-3.  相似文献   

New, high resolution swath bathymetry of Gettysburg and Ormonde Seamounts (Gorringe Bank, eastern Atlantic) and first geological results     

G. de. Alteriis  S. Passaro  R. Tonielli 《Marine Geophysical Researches》2003,24(3-4):223-244

High resolution swath bathymetry of shallow water (< 200 m) oceanic seamounts is a relatively rare issue. During the recent Gorringe_2003 cruise over the Gorringe Bank (Eastern Atlantic) we collected multibeam bathymetry on the bank’s two shallow summits, Gettysburg and Ormonde in the –25/–400m depth range at a resolution rarely achieved over an oceanic seamount. We also carried out bottom samplings and ROV dives in the same bathymetric interval. The acquisition parameters and the characteristics of the echosounder employed allowed to generate a Digital Terrain Model (DTM) with metric spatial resolution upto 75–100 m depths. To ensure proper tidal corrections a tide-gauge was deployed at sea-bottom during the survey. DTM reveals for the Gettysburg Seamount an almost perfectly circular summit resulting from the blanket of bioclastic sediments over an igneous ‘core’ consisting of sheared and foliated serpentinites. The core is dissecated by N 10° W trending ridges elevating some tens of metres and filled in between by bioclastic sands. Both foliation and ridge patterns seem related to primary igneous fabric rather than later structural deformation. The overall circular shape confirms the origin of the seamount as a mantle serpentinite diapir in analogy with similar, but subduction-related, circular seamounts observed in the Bonin Trench (western Pacific). In contrast the Ormonde elongated summit follows the regional tectonic trend with a N 60° E active (seismogenic?) fault on its southeastern flank. Its basement morphology corresponds to the outcrops of igneous rocks chiefly consisting of gabbros, volcanic rocks and dyke intrusions. On both seamounts topographic profiles show that the ‘shelf’ area is somewhat convex rather than flat like that of ‘Pacific type’ guyots and is bordered by a depositional, locally erosional shelf break, located between –170 and –130 m. Various terraced surfaces and some geological evidence confirm previous observations and indicate relative sea-level oscillations with partial emersion of the two summits that seem occurred during the last glacial cycle (past 120 ka).  相似文献   

2014年冬季西太平洋雅浦海山与大洋海域大型浮游动物群落比较研究     

陶振铖  王延清  金鑫  李超伦 《海洋与湖沼》2020,51(4):919-930

2014年冬季对西太平洋雅浦Y3海山区和从西太平洋暖池区到黑潮源区之间的大洋海域的浮游动物进行了调查研究，分析了海山区和大洋海域大型浮游动物群落的物种组成、丰度和分布，并比较了两个海域大型浮游动物群落的差异，结合温度、盐度和叶绿素a浓度等环境因子数据，分析了海山对大型浮游动物群落的影响。结果表明，Y3海山区和大洋海域的大型浮游动物群落物种组成存在差异，二者的群落相似度系数为68.4%，两个海域的优势种/类群也不尽相同，海山区的优势种/类群是磷虾各期幼体、尖额磷虾和蛮𧊕，而大洋海域的优势种/类群分别是磷虾后期幼体、手磷虾、蛮𧊕、尖额磷虾和莹虾。大型浮游动物群落在海山区的平均丰度和最大丰度都要高于大洋海域，但海山区的生物多样性指数、均匀度指数和生物量占比都低于大洋海域，因而Y3海山对大型浮游动物群落的海山效应不明显。通过相关性分析和主成分分析结果可以看出，海山区的首要影响环境因子是盐度，而大洋海域则是温度；海山区和大洋海域的大型浮游动物丰度分别与200m层盐度和平均温度呈负相关关系，并且在两个调查海域均未发现大型浮游动物的丰度和生物量分布与叶绿素a浓度之间存在显著的相关关系。  相似文献   

麦哲伦海山区MA、MC、MD、ME、MF海山结壳基岩的岩石学   总被引：2，自引：0，他引：2  

朱克超 《海洋地质与第四纪地质》2002,22(1):49-56

麦哲伦海山区MA、MC、MD、ME、MF海山的结壳基岩类型主要有玄武岩、火山碎屑岩，其次为灰岩和磷块岩。玄武岩为蚀变玄武岩、橄榄玄武岩等，造岩矿物斜长石的成份多为拉长石和中长石，辉石多为普通辉石，橄榄石多已伊西石化。玄武岩的硅酸盐全分析表明，其P2O5含量普遍偏高，超出了玄武岩正常值范围；玄武岩的稀土分配模式与洋岛碱性玄武岩类型基本相似，但出现一定程度的Ce负异常，这是由于玄武岩中混有磷酸盐矿矿物的结果，经过成分校正后，化学成分分类上属碱性系列的碱性玄武岩。火山碎屑主要为玄武质火山碎屑岩，其中玄武质碎屑的矿成分及结构特征与玄武岩相似，玄武质火山碎屑岩的稀土分配模式与玄武岩的稀土分布模式基本相似，推测其与玄武岩为同一期火山喷发的产物。灰岩包括生物屑微晶灰岩、微晶生物屑灰岩等，多数灰岩具有不均匀的磷酸盐化现象，成为磷块岩。另一种类型的磷块岩，是由磷酸盐矿物交火山碎屑岩形成。磷块岩的稀土元素特征表现为稀土总量较高，Ce呈明显负异常。灰岩和火山碎屑岩的磷酸盐化作用对稀土元素的富集及Ce的亏损起了重要作用。  相似文献   

南海海山非均匀磁性反演   总被引：3，自引：0，他引：3  

金钟  徐世浙  李昭荣 《中国海洋大学学报(自然科学版)》2002,32(6):926-934

利用虚源法对南海海盆 1 6座实测海山进行了磁性反演。结果表明 ,南海海山非均匀磁化反演效果明显优于均匀磁化反演 ;南海海盆东部和西南部的海山运动方向相反 ,前者向北 ,后者往南 ;海山运移中的旋转形式两地也存在明显差异。  相似文献