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1.
南海铁锰结核(壳)的元素地球化学研究   总被引:1,自引:0,他引:1  
本文利用南海11个铁锰结核(壳)样品的化学分析资料,研究了铁锰结核(壳)中Fe,Mn,Cu,Co,Ni,Pb,Zn,Cr,K,Na,Ca,Mg,Si,P,Al,Ti,Sr,Ba及∑REE的元素地球化学特征。结果表明:(1)铁锰结核(壳)以高Fe,∑REE,低Mn,Cu,Co,Ni等元素为主要特征;(2)铁锰结核(壳)中Fe,Mn间无明显相关,而Fe与∑REE,∑Ce,∑Y呈弱的正相关,Mn与∑REE,∑Ce,∑Y呈明显的正相关,结壳中Fe,Mn与Si,Al,Cu Co Ni呈负相关;(3)结核(壳)中Mn/Fe与Cu/Ni,Ce/La呈负相关,Mn/Fe主要受Mn控制;(4)结核(壳)中Fe,∑REE等元素主要来自南海陆源中酸性岩类的风化、淋滤和沉积。  相似文献   

2.
Regional variation of Mn, Fe, Co, Ni and Cu in ferromanganese oxides (nodules and crusts) in the central south Pacific is related to primary productivity, oxygen minimum layer, and calcium carbonate compensation depth. The largely latitudinal influence of these environmental parameters on nodule and crust composition reflects their predominantly latitudinal variation. Primary productivity is the principal regional environmental control, influencing diagenetic enrichment of these elements in nodules through its effect, mediated by the CCD, on supply and concentration of labile organic matter vs. carbonate remains to the sediments. It influences hydrogenetic enrichment of these elements in nodules and crusts through its effect, mediated by the oxygen minimum layer (mainly in the case of crusts), on their export from surface waters.The elements’ varying susceptibility to being scavenged or organically bound influences the contrasting composition of diagenetic vs. hydrogenetic ferromanganese oxides, which is further influenced by depth. Hydrogenesis is the fundamental process governing nodule and crust formation, superimposed on which is diagenesis under specific circumstances; both are subject to intermittent interruption, diminution and augmentation by changes in environmental parameters. Application of regionally operative environmental controls locally explains local compositional variations and helps refine exploration criteria for economically viable nodules and crusts.  相似文献   

3.
A column concentration-high resolution inductively coupled plasma mass spectrometry (ICP-MS) determination was applied to measure the total dissolved concentrations of Fe, Co, Ni, Cu and Zn in seawater collected from the subarctic North Pacific (~45°N) and the Bering Sea in July–September 1997. Total adsorbable Mn was determined on board by column electrolysis preconcentration and chemiluminescence detection. The vertical profiles for Fe, Ni and Zn were nutrient-like. The deep water concentration of Fe was ~0.5 nM in the northeast Pacific (18°-140°W) and increased to ~1 nM in the northwest Pacific (161°E) and ~2 nM in the Bering Sea (57°N, 180°E). The deep water concentrations for Ni and Zn in the Bering Sea were also 1.3–2 times higher than in the North Pacific. The profiles for Co and Cu were examined in the subarctic North Pacific, and results obtained were consistent with previous reports. There was a significant correlation between the concentrations of Co and Mn except for surface mixed layer. The profiles for total adsorbable Mn were similar to the reported profiles for total dissolvable Mn. The deep water concentration of Mn in the Bering Sea was also 4 times higher than in the North Pacific. Iron and zinc were depleted in surface water of the subarctic North Pacific. The relationship between these trace elements and nutrients suggests that these elements could be a limiting factor of phytoplankton productivity. In the Bering Sea, surface water contained ~0.3 nM of Fe. The Zn concentration, which was less than the detection limit in surface water, increased at shallower depths (~30 m) compared with the subarctic North Pacific. These results imply a higher flux of Fe and Zn to surface water in the Bering Sea. This in turn may cause the ecosystem in the Bering Sea characterized by a dominance of diatoms and high regenerated production.  相似文献   

4.
Oceanic, non-hydrothermal ferromanganese crusts and nodules are variably enriched in Mn, Fe, Co, Cu, Ni and Zn. Comparison of the content of these elements in crusts and nodules with the level of primary productivity in the South Pacific Ocean suggests that primary-producer-mediated complexation of several of these elements by organic ligands in solution may contribute to explaining a pattern of distinctive associations observed between compositional variations for these elements in these deposits and variations in the level of primary productivity.  相似文献   

5.
Thirty-three bulk ferromanganese nodules from the sediment–water interface of siliceous sediment domain from the Central Indian Ocean Basin were analyzed for 50 elements including 6 new (Be, As, Se, Sn, Sb, and Bi) using inductively coupled plasma–mass spectrometer. The Mn/Fe ratio and triangular plot (Fe-Mn-{Cu+Ni+Co?×?10}) suggest that ferromanganese nodules are of hydrogenetic, early diagenetic, and diagenetic origin. In the ferromanganese nodules, Mo, Sb, Bi, and As are highly enriched ~320, 160, 90, and 50 times compared with upper continental crust, respectively. A majority of the elements such as Be, Sc, Ti, V, Co, As, Se, Sr, Y, Zr, Nb, Sn, rare earth elements (REEs), Pb, Bi, P, Th, U, Hf, and Ta are associated with Fe, whereas, Cu, Ni, Zn, Mo, Li, Ga, Sb, Mg, and Cs are associated with Mn in the ferromanganese nodules. Redox proxies such as U/Th (0.14) and Mo/Mn (0.0019) ratio in the ferromanganese nodules suggest their formation under oxic conditions.  相似文献   

6.
过渡金属元素Cu、Co、Ni在铁锰结核(壳)中富集的控制因素   总被引:7,自引:0,他引:7  
在不同生成环境下生成的铁锰结核(壳)吸收不同的过渡金属元素。在成岩作用形成的铁锰结核中,Cu、Ni主要以锰相形式存在,而Co则以铁相的形式存在;在水成作用形成的铁锰结核(壳)中Cu、Co、Ni均以锰相的形式存在。这些过渡金属元素在成岩作用形成的结核中的存在与铁锰结核(壳)中锰矿物和铁的氧化物、氢氧化物的晶体化学特征密切相关,而在水成作用形成的铁锰结核(壳)中的富集与锰矿物和铁的氧化物、氢氧化物的晶体化。学特征关系不大。同时铁锰结核(壳)中锰矿物和铁的氧化物、氢氧化物又严格地受结核(壳)的生成环境的制约,因此,过渡金属元素Cu、Co、Ni在铁锰结核(壳)中的富集在一定程度上受结核(壳)生成环境的控制。  相似文献   

7.
Manganese nodule distribution is primarily influenced by seafloor topography. Nodule distribution at 479 locations vis‐à‐vis seabed topography is studied by superimposing sampling location on the topographic profile and assigning appropriate domain (hilltop, valley, slope, or plain) for the sampling location. Highest mean abundance is observed at the valleys (6.94 kg /m2), followed by hilltops, slopes, and least on plains. Frequency distributions are regular (Gaussian) on plains, whereas on valleys and hilltops they are irregular (Rayleigh type). Fe and Co content is highest in nodules from hilltops and lowest in those from plains. Conversely, Mn, Cu, and Ni content is highest on plains and least on valleys. Fe: Mn and Co: Mn are negatively correlated in all the domains. Mn and total metal content (Ni + Cu + Co) show direct relationship in all the domains. An inverse relation between nodule abundance and composition is found. Cluster analysis on chemical and abundance data shows two distinct groups in all domains. Abundance and Fe and Co content typically form one group, while all other elements form another group. Genesis of nodules depends on the availability of supply of transition elements to the abyssal environment, maintenance of nodules in the sediment‐water interface, and sedimentation rates.  相似文献   

8.
单连芳 《海洋与湖沼》1995,26(5):494-501
于1986-1099年由海洋四号调查船的HY4-861,871,881三个航次采集的锰结核样品中选出37个以老结核或老结核碎块为核心的结核,进行研究,划分出3个结核世代,并大致确定其生长期:第一世代结核的生长期是在早中新世(〈20Ma);第二世代结核形成于早中新世-晚中新世(〉6Ma);第三世代结核的生长期是在上新世-第四纪。同时对老、新世代结核的矿物成份和化学成份进行成析,并得出,老世代结核比新  相似文献   

9.
为探究大洋富钴结壳的元素地球化学特征和赋存状态,以西太平洋麦哲伦海山群5个富钴结壳样品为研究对象,通过X射线衍射法、等离子体发射光谱法、等离子体质谱法及相态分析手段,分析了富钴结壳的矿物组成、主量元素和稀土元素含量。结果表明,富钴结壳样品主要结晶矿物为水羟锰矿,次要矿物包括石英、斜长石和钾长石,同时含有大量非晶态铁氧/氢氧化物。富钴结壳样品中Mn和Fe含量最高, Mn为16.87%~26.55%, Fe为14.34%~18.08%。富钴结壳明显富集稀土元素,其稀土总量为1 287~2 000μg/g,Ce含量为632~946μg/g,约占稀土总量的50%;轻稀土含量为1 037~1 604μg/g,重稀土含量为249~395μg/g,轻稀土元素明显高于重稀土元素。稀土元素配分模式呈现Ce正异常而Eu无异常,具有Ce富集特征。麦哲伦海山群富钴结壳是水成沉积成因,基本没有受到海底热液活动和成岩作用的影响。元素赋存状态与其矿物相密切相关, Na、K、Ca、Mg和Sr主要赋存于碳酸盐相, Mn、Ba、Co和Ni主要赋存于锰氧化物相, Fe、Al、P、Ti、Cu、Pb、V、Zn、Zr和REE主要...  相似文献   

10.
本文主要研究太平洋CC区多金属结核CCA33,CCB29,CCC50,CCC14生长过程中锰、铁、镍、铜的通量(FMn),FFe,FNi,FCu)的变化规律.研究表明:1.结核生长过程中Mn,Fe,Ni和Cu的通量都是波动性的;2.FMn与FFe,FNi,FCu均呈正相关性;3.结核的元素通量与结核的成因类型和生长阶段密切相关,并记录了海底缺氧事件;4.结核的元素通量存在区域性差异,是沉积环境不同的反映。  相似文献   

11.
12.
The contents of Fe, Mn, Cu, Co, Ni, Pb and Zn in the seaiment associated with manganese nodules from the Northern Central Pacific Ocean and in their acid-soluble fractions were determined and correlations among the elements and between the trace metals and environmental parameters were discussed. It has been found that the contents of Mn, Cu and Ni in the sediment are one order of magnitude higher than those in the common sediment. As shown in the manganese nodules, they may mainly derive from seabed. The contents of all trace metals in the sediment are obviously governed by Fe-and Mn-oxides, organic matter, seawater depth, particle size and Eh. Multi-element correlation equations were developed for all trace metals. The trace metals in acid-soluble fraction of the sediment were also much higher than ihose of common sediment and negatively correlated with water depth, implying the possible influence of carbonate speciation.  相似文献   

13.
Ferromanganese crusts comparable with central Pacific occurrences with respect to thickness and extension have been discovered at the Tropic Seamount in the subtropical NE Atlantic. A comparison with typical hydrogenetic crusts from a central Pacific seamount revealed lower concentration of the Mn phase with Mn, Co, Ni, Zn, and Cu but a strongly increased terrigenous input of Fe, Pb, Al, and Si in the Atlantic crusts. Growth rates are increased compared with the Pacific crusts, and crust ages average at 10 My. The old phosphatized crust generation that started to grow about 20 My ago on the Pacific seamounts is not pronounced at the Tropic Seamount. The typical hydrographic and morphological parameters for hyrogenetic crust growth have also been found at the Tropic Seamount, which implies that the Tropic Seamount crusts have developed according to the hydrogenetic growth model. There are no indications of hydrothermal influence.  相似文献   

14.
In the present paper, iodine(I), iron(Fe), manganese(Mn), cobalt(Co), phosphorus(P) and calcium(Ca)contents in three ferromanganese crusts from the Pacific Ocean are measured by spectrophotometric method and inductively coupled plasma atomic emission spectrometers(ICP-AES) to investigate the contents and distribution of iodine in ferromanganese crusts. The results show that iodine contents in three crusts vary between 27.1 and 836 mg/kg, with an average of 172 mg/kg, and the profile of iodine in the three crusts all exhibits a two-stage distribution zone: a young non-phosphatized zone and an old phosphatized zone that is rich in I, P and Ca. The iodine content ratios of old to young zone in MP5D44, CXD62–1 and CXD08–1 are 2.3, 3.4 and 13.7, respectively.The boundary depths of two-stage zone in MP5D44, CXD62–1 and CXD08–1 locate at 4.0 cm, 2.5 cm and 3.75 cm,respectively, and the time of iodine mutation in three crusts ranges from 17–37 Ma derived from 129 I dating and Co empirical formula, which is consistent with the times of Cenozoic phosphatization events. The present study shows that the intensity of phosphatization is the main responsible for the distribution pattern of iodine in the crusts on the basis of the correlation analysis. Consequently, iodine is a sensitive indicator for phosphatization.  相似文献   

15.
A widespread distribution of hydrothermal and hydrogenetic manganese deposits is described in the results of the Hakurei‐Maru cruises conducted in the Bonin Arc areas of the West Pacific from 1984 to 1989. Manganese deposits occur in the active volcano chains, back‐arc basins, remnant back‐arc ridges, and oceanic seamounts.

The hydrogenetic iron‐manganese deposits commonly form earthly black crusts and nodules on the topographic highs of inactive ridges and old seamounts, sometimes as thick as 10 cm. They are always composed of the iron‐manganese mineral vernadite. Co and Ni contents are relatively high in the crusts from the seamounts in the open Pacific Ocean (up to 1.1% Co and 1.0% Ni). Two generations of distinct chemistry and texture are typical of these crusts, which can be compared to reported thick crusts from the Central Pacific seamounts.

The hydrothermal deposits, characterized by dense, submetallic, and gray appearance, are dominant in the recent and also in past submarine volcanoes of the island‐arc systems. Evidence of past hydrothermal activity was ascertained as fossil hydrothermal manganese deposits inside the hydrogenetic nodules or beneath the hydrogenetic crusts over the Tertiary island arc. Their component minerals are considered to be todorokite and bimessite (stable and contractible upon dehydration), having almost negligible amounts of Fe, Si, Al, Ni, Co, Zn, Pb, Cu, etc. In the small model site, the Kaikata Seamount hydrothermal area, the presumably recent hydrothermal activity has yielded thin slabs of pure manganate deposits growing downward within volcanic and sand layers.

Early diagenetic influence is negligible on nodules of this area.  相似文献   

16.
Between 1980 and 1984 extensive studies were carried out in the Baltic Sea on trace metals (Cd, Co, Cu, Fe, Hg, Mn, Ni, Pb and Zn) in water, suspended matter and sediments. The results enabled the influence of different factors on metal distribution patterns to be considered. The vertical profiles of dissolved and particulate metals in waters of the central deep basins reflect influences caused by oxygen deficiency and anoxic conditions in near-bottom water layers. Peculiarities at Station BY15 in the Gotland Deep included high dissolved Fe, Mn and Co concentrations and remarkable enrichment of Zn (0.64%), Cd (51 μg g−1) and Cu (0.15%) in particulate matter from the anoxic zone. Manganese-rich particles were accumulated above this layer.In fine-grained soft sediments below anoxic deep waters, maximum contents of Cd, Cu and Zn were observed, relative to other coring sites, between Bothnian Bay and Lübeck Bight. The Hg content in sediments probably reflects the joint flocculation with organic matter. Land-based sources seem to play the leading part for maximum lead contents.  相似文献   

17.
全球三大洋海山钴结壳资源量估算   总被引:8,自引:0,他引:8  
钴结壳具有Co、Ni、Cu和Mn及其他金属的潜在矿产资源和储存在结壳层中古环境信息的双重意义。与深海多金属结核和热液硫化物矿床相比,具有较高Co、Ni和Pt含量的海山钴结壳有可能成为商业勘探的潜在目标。为合理地估算出全球三大洋海山钴结壳资源量,基于我国西太平洋海山钴结壳拖网采样调查资料和对太平洋海山钴结壳资源分布规律和钴结壳矿区圈定参数指标的深入研究,按海山不同高度、不同洋壳年龄赋予不同结壳厚度,进而计算出全球三大洋海山钴结壳分布面积为3 039 452.14km2和干结壳资源量为(1 081.166 1~2 162.332 2)×108 t。太平洋海山钴结壳分布面积为2 123 087.12km2和干结壳资源量为(513.244~1 026.488)×108 t,大西洋海山钴结壳分布面积为512 509.74km2和干结壳资源量为(116.503 2~233.006 4)×108 t,印度洋海山钴结壳分布面积为403 855.28km2和干结壳资源量为(81.484 9~162.969 8)×108 t。三大洋海山钴结壳的Mn、Co、Ni和Cu金属量分别为(138.848 0~277.696 0)×108 t,(3.967 6~7.935 2)×108 t、(2.793 6~5.587 2)×108 t和(0.825 1~1.650 2)×108 t。根据钴结壳的Co含量、Co通量和厚度相关分析,所赋予的钴结壳厚度占理论推测厚度的6.10%~12.20%,这与Ku等得出"钴结壳生长时间约占其整个生命史4%"的认识非常相近。三大洋海山钴结壳实测厚度与赋值厚度对比分析表明,太平洋海山钴结壳赋值厚度平均值为1.87cm,实测厚度平均值为1.77cm,相对误差为5.35%,大西洋和印度洋相对误差分别为18.18%和23.23%。研究数据表明按海山高度和洋壳年龄所赋的钴结壳厚度基本合理,估算出的钴结壳资源量基本可靠。本文首次估算出三大洋海山钴结壳资源量,为整个海盆和三大洋海山钴结壳资源量估算提供了新方法。  相似文献   

18.
The major and minor element compositions of a suite of abyssal sea-floor ferromanganese nodules and associated sediments from the eastern central Pacific have been used to examine inter-element relationships and the mineralogy of the nodules, the relationship between the composition of nodules and their associated sediments and regional variations in composition with respect to likely modes of formation of such deposits. Apart from Mn and Fe, significant proportions of the total Ti, Ca, Mg, K, Ba, Sr, Th and Y and almost all the P, As, Ce, Co, Cu, Mo, Ni, Pb, Zn and Zr are present in the oxide fractions of the nodules. The Mg, Ba, Cu, Mo, Ni and Zn contents are significantly correlated with the Mn content, while Ti, P, As, Pb, Sr, Y and Zr are similarly correlated with the total Fe content.Nodules from the northeastern tropical Pacific have Mn/Fe ratios higher than those in the oxide fractions of their associated sediments, todorokite as the principal Mn phase and relatively high concentrations of minor elements associated with Mn. Nodules from the south central Pacific have Mn/Fe ratios similar to those in the oxide fractions of the associated sediments, δ-MnO2 as the only Mn-phase, and relatively high concentrations of minor elements associated with Fe. There appears to be a smooth gradation in composition in the tropical Pacific between these two end members.The regional compositional variation is interpreted as a reflection of different sources of metals for, and different growth mechanisms of, sea-floor nodules. The oxide precipitate from sea water consists of δ-MnO2, has a relatively low Mn/Fe ratio and minor element contents related to the total Fe and Mn(δ-MnO2) content. The oxide precipitate forming in areas of very low sedimentation as a result of diagenetic remobilisation in the surface sediment consists of todorokite, and has a high Mn/Fe ratio and enhanced metal content in the Mn-(todorokite)phase. Available information on the morphology and compositional variation of individual nodules from the tropical Pacific corroborates these contrasting metal sources and suggests that they can be resolved on the scale of an individual oxide concretion.  相似文献   

19.
The anthropogenic contribution of trace metals to settling particulate matter (SPM) and surficial sediments was determined on the high-energy continental shelf adjacent to Sydney, Australia. Settling particulate matter and surficial sediment was collected in the vicinity of a major sewage outfall and at five control sites on the middle shelf (80-100 m water depth). Sediment traps were deployed on 10 occasions for up to 2 weeks during the summer and winter of 1995 and SPM was analyzed for Ag, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn. Cobalt, Fe, Mn and Ni act conservatively in SPM and in sediments regionally and are used as normalizing elements to determine anthropogenic enrichment. Surficial sediments and SPM are enriched in Ag, Cr, Cu, Pb and Zn near a major ocean outfall and at four of the five control sites, although sewage particles contribute < 5% of trace metals in the total sample. Silver is the most sensitive trace metal tracer for establishing the presence of sewage particulate matter. Sewage particulate matter flux near the outfall was estimated using a two end-member mixing model and is below 0.5 g m(-2) day(-1) during all deployment periods. The mean sewage particulate matter flux at sampling locations 30 km and 60 km north of the outfall are <0.13 g m(-2) day(-1) and <0.01 g m(-2) day(-1), respectively, indicating an efficient dispersal of anthropogenic material on this high energy continental shelf.  相似文献   

20.
本文研究了盐场海芽孢杆菌(Marinibacilluscampisalis)与大洋铁锰结核的相互作用过程,以及海洋微生物在铁锰结核形成中的作用。实验选取从深海沉积物中分离培养的盐场海芽孢杆菌(Marinibacillus campisalis)和大洋铁锰结核样品进行相互作用实验,设置有菌组和无菌组,培养过程中间隔取样分析。运用X射线荧光光谱(XRF)分析测定大洋铁锰结核元素组成,通过电感耦合等离子体发射光谱(ICP-OES)和电感耦合等离子体质谱(ICP-MS)测定反应过程中Fe、Mn、Co、Ni、Cu等离子浓度的变化,通过透射电镜(TEM)、扫描电镜(SEM)和能谱仪(EDS)观察并分析微生物表面情况,利用X射线衍射(XRD)分析手段测定铁锰结核矿物组成的变化。实验进行1天内细菌处于对数生长期,有菌组的Fe、Mn等离子浓度增加; 2—7天内细菌处于稳定期, Fe、Mn等离子浓度有一定程度降低,但总体浓度均大于无菌组的离子浓度,金属离子被吸附在菌体表面,新形成了简单的含Fe化合物和矿物;实验结束后,XRD分析结果显示样品的矿物含量,如菱铁矿、赤铁矿和针铁矿等有轻微程度的增加。研究表明盐场海芽孢杆菌(Marinibacilluscampisalis)能够促进释放铁锰结核中的Fe、Mn等元素,同时对释放出的金属离子又有富集作用,并能够诱导新矿物的形成。本研究为深入了解铁锰结核的生物成因提供了新的依据。  相似文献   

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