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1.
N. V. Astakhova 《Oceanology》2013,53(6):686-701
The examination of polished sections of ferromanganese crusts from the Sea of Japan revealed abundant inclusions of small grains of base and precious metals: Ag, Pd, Pt, Au, Rh, Cu, Zn, Sn, P, Ni, Cr, Ti, Sb, As, W, and Mo. The metals occur in the form of native elements or intermetallic compounds, subordinate sulfides, sulfates, oxides, tungstates, and phosphides. The data on contents, occurrence forms, and distribution of these metals in the ore crusts from this region are discussed. 相似文献
2.
N. V. Astakhova 《Oceanology》2009,49(3):405-417
Thin mineral grains of nonferrous and precious metals (Ag, Au, Cu, Ni, Pb, Sn, Zn, Sb, Ti, W, Mo, and Ce) were revealed for the first time by SEM and microprobe studies of polished sections of iron-manganese crusts from the Sea of Okhotsk. The metals form native and intermetallic compounds; less frequently they form mineral oxides or sulfides. The conclusion was drawn that the main part of the native minerals represents a mechanical admixture in the ferromanganese crusts. 相似文献
3.
I. F. Gablina L. L. Demina O. B. Dmitrenko N. S. Os’kina E. A. Popova T. A. Khusid V. V. Shilov 《Oceanology》2011,51(3):476-490
The first thorough analysis of microfossils from ore-bearing sediments of the Ashadze-1 hydrothermal field in the Mid-Atlantic
Ridge sampled during cruise 26 of the R/V Professor Logachev in 2005 revealed the substantial influence of hydrothermal processes on the preservation of planktonic calcareous organisms,
as well as on the preservation and composition of the benthic foraminifers. From the lateral and vertical distribution patterns
and the secondary alterations of the microfossils, it is inferred that the main phase of the hydrothermal mineralization occurred
in the Holocene. Heavy metals (Cu, Co, Cr, and Ag) were accumulated by foraminiferal tests and in their enveloping Fe-Mn crusts.
The distribution of authigenic minerals replacing foraminiferal tests demonstrates local zoning related to the hydrothermal
activity. There are three mineral-geochemical zones defined: the sulfide zone, the zone with an elevated Mg content, and zone
of Fe-Mn crusts. 相似文献
4.
Iron–manganese formations and igneous rocks of submarine elevations in the Sea of Japan contain overlapping mineral phases (grains) with quite identical morphology, localization, and chemical composition. Most of the grains conform to oxides, intermetallic compounds, native elements, sulfides, and sulfates in terms of the set of nonferrous, noble, and certain other metals (Cu, Zn, Sn, Pb, Ni, Mo, Ag, Pd, and Pt). The main conclusion that postvolcanic hydrothermal fluids are the key sources of metals is based upon a comparison of the data of electron microprobe analysis of iron–manganese formations and igneous rocks dredged at the same submarine elevations in the Sea of Japan. 相似文献
5.
Carles Canet Rosa María Prol-Ledesma William L. Bandy Peter Schaaf Carlos Linares Antoni Camprubí Esperana Tauler Carlos Mortera-Gutirrez 《Marine Geology》2008,251(1-2):47-59
Marine hydrogenetically precipitated ferromanganese crusts are widespread in the Pacific Ocean. They occur as pavements coating volcanic or sedimentary hard-rock substrates, mainly on the slopes of seamounts, plateaus and hills in ocean basins and continental margins. We studied three ferromanganese crusts from one dredge haul from the Rivera Plate (western margin of Mexico), which are up to 15 mm thick and grow directly on a substrate of pillow basalt fragments. They consist of laminated, botryoidal, porous aggregates mostly of Fe and Mn oxyhydroxides and up to 10% silicates. XRD analysis showed the predominance of poorly crystallized mineral phases in the crusts that include Mn-feroxyhyte and vernadite, and an authigenic smectite-like clay. Detrital minerals probably derive from granodiorites of the eastern wall of the neighboring Middle America Trench. Scattered barite grains occur on the crust surface and suggest plume fall-out derived from hydrothermal vents, although a possible pelagic source cannot be dismissed. Ratios between major (Fe, Mn, Si) and trace (Co, Ni, Cu) elements reveal that such crusts are predominantly hydrogenetic in origin, although they show a hydrothermal influence that increases in the outer layers. Iron contents range from 16.2 to 25.2 wt.%, and manganese from 3.4 to 14.5 wt.%. The Fe/Mn ratio ranges from 1.6 to 7.0. The SiO2/Al2O3 ratio ranges from 4.3 to 6.6, indicating the presence of biogenic silica (radiolarians). The concentrations of copper (up to 383 ppm) and cobalt (up to 534 ppm) are significantly below those of the typical hydrogenetic crusts, whereas Ni (up to 1320 ppm) is about the same or slightly lower. REE normalized profiles and ΣREE values (486 to 732 ppm) match those reported for hydrogenetic crusts, but suggest a hydrothermal contribution for the later crust layers. The inferred crust growth rates using the Co-chronometer (44 and 229 mm/Myr) are higher than those reported for pure hydrogenetic crusts (mostly 1 to 6 mm/Myr), thus indicating an increasing hydrothermal influence. The highest growth rate (229 mm/Myr, corresponding to the outer crust layers) suggests a regional hydrothermal input of iron and manganese to seawater. The intensification of regional submarine hydrothermal activity began about 13,000 yr ago, and may be related to the tectonic activity in the complex junction of the Rivera, Cocos, Pacific and North America plates. 相似文献
6.
富Co铁锰结壳铂族元素与铼-锇同位素组成及其意义 总被引：13，自引：0，他引：13
用ICP－MS测定了太平洋富Co铁锰结壳铂族元素和铼－锇同位素组成。富Co铁锰结壳不仅异常富集铂族元素，而且铂族元素及其它亲铁元素的配发与陨石特征非常相似。铁锰结壳的铼－锇同位素组成明显有别于大陆地壳岩石，和K－T界线沉积物相似，接近陨石值。世界大洋范围内的富Co铁锰结壳均产于远离海底构造热液活动区，几乎不可能受到地幔源热液作用的直接影响。因此，富Co铁锰结壳中的铂族元素可能部分来源于地外物质。 相似文献
7.
Considerable effort has been expended in studying the Izu-Bonin Arc over the past 15 years. In particular, 43 dives of the Shinkai 2000 have been undertaken there to discover and evaluate the extent of submarine hydrothermal activity and mineraliza tion. Most effort has been focused on Myojin Knoll (23 dives), Suiyo Seamount (6 dives), and Kaikata Caldera (10 dives). The Izu-Bonin Arc is divided in two by the Sofugan Tectonic Line. Eight submarine caldera are located north of this line but only one is south of it. The physiography of the northern sector of the arc is quite different from that of the southern sector. Volcanic rocks from the northern sector are more acidic than those from the southern sector. Evidence for submarine hydrothermal mineralization has been observed at four seamounts along the Izu-Bonin Arc (Myojin Knoll, Myojinsho, Suiyo Seamount, and Kaikata Caldera), and submarine hydrothermal activity is evident at another three seamounts along the arc (Kurose Hole, Mokuyo Seamount, and Doyo Seamount). The most extensive submarine hydrothermal mineral deposit so far located on the Izu-Bonin Arc is the Sunrise deposit at Myojin Knoll. This deposit, at least 400 m in diameter and 30 m high, is associated with black smoker venting, inactive sulfide chimneys, massive sulfides, hydrothermal Mn crusts, and a hydrothermal vent fauna. The maximum recorded temperature of the hydrothermal vents there was 278°C. Some of the sulfide chimneys contained as much as 49 μg / g Au and 3,400 μg / g Ag. The sunrise deposit is one of the largest submarine volcanic massive sulfide deposits so far discovered in midocean ridge, backarc, or arc settings and has an estimated mass of 9 x 10 6 t. This deposit may be of the Kuroko-type. The discovery of the Sunrise deposit in 1997 gives hope that other, similarly large, sulfide deposits may be found in other caldera along the Izu-Bonin Arc. The geological variability along the arc, the high seismicity, the occurrence of active volcanism and submarine hydrothermal venting, and a proven submarine hydrothermal mineral potential coupled with the proximity of the region to Japan suggest that the Izu-Bonin Arc could profitably serve as a natural laboratory for the long-term monitoring of the seafloor. 相似文献
8.
西北太平洋多金属结核铂族元素地球化学特征 总被引：1，自引：0，他引：1
Polymetallic nodules and cobalt (Co)-rich crusts are enriched in platinum-group elements (PGEs),especially platinum (Pt) and may be important sinks of PGEs.At present,little information is available on PGEs in polymetallic nodules,and their geochemical characteristics and the causes of PGEs enrichment are unclear.Here PGEs of polymetallic nodules from abyssal basin in the Marcus-Wake Seamount area of the Northwest Pacific Ocean are reported and compared with the published PGEs data of polymetallic nodules and Co-rich crusts in the Pacific.The total PGEs (ΣPGE) content of polymetallic nodules in study area is 258×10~(–9) in average,markedly higher than that of Clarion-Clipperton Zone (CCZ) nodules (ΣPGE=127×10~(–9)) and lower than that of Co-rich crusts in the Marcus-Wake Seamount (ΣPGE=653×10~(–9)),similar to that of Co-rich crusts in the South China Sea(ΣPGE=252×10~(–9)).The CI chondrite-normalized PGEs patterns in different regions of polymetallic nodules and cobalt-rich crusts are highly consistent,with all being characterized by positive Pt and negative Pd anomalies These results,together with those of previous studies,indicate that PGEs in polymetallic nodules and Co-rich crusts are mainly derived directly from seawater.Pt contents of polymetallic nodules from the study area are negatively correlated with water depth,and Pt/ΣPGE ratios in nodules there are also lower than those of the Corich crusts in the adjacent area,indicating that sedimentary water depth and oxygen fugacity of ambient seawater are the possible important controlling factors for Pt accumulation in crusts and nodules. 相似文献
9.
Abstract Considerable effort has been expended in studying the Izu–Bonin Arc over the past 15 years. In particular, 43 dives of the Shinkai 2000 have been undertaken there to discover and evaluate the extent of submarine hydrothermal activity and mineralization. Most effort has been focused on Myojin Knoll (23 dives), Suiyo Seamount (6 dives), and Kaikata Caldera (10 dives). The Izu–Bonin Arc is divided in two by the Sofugan Tectonic Line. Eight submarine caldera are located north of this line but only one is south of it. The physiography of the northern sector of the arc is quite different from that of the southern sector. Volcanic rocks from the northern sector are more acidic than those from the southern sector. Evidence for submarine hydrothermal mineralization has been observed at four seamounts along the Izu–Bonin Arc (Myojin Knoll, Myojinsho, Suiyo Seamount, and Kaikata Caldera), and submarine hydrothermal activity is evident at another three seamounts along the arc (Kurose Hole, Mokuyo Seamount, and Doyo Seamount). The most extensive submarine hydrothermal mineral deposit so far located on the Izu–Bonin Arc is the Sunrise deposit at Myojin Knoll. This deposit, at least 400 m in diameter and 30 m high, is associated with black smoker venting, inactive sulfide chimneys, massive sulfides, hydrothermal Mn crusts, and a hydrothermal vent fauna. The maximum recorded temperature of the hydrothermal vents there was 278°C. Some of the sulfide chimneys contained as much as 49 μg/g Au and 3,400 μg/g Ag. The sunrise deposit is one of the largest submarine volcanic massive sulfide deposits so far discovered in midocean ridge, backarc, or arc settings and has an estimated mass of 9 × 106 t. This deposit may be of the Kuroko-type. The discovery of the Sunrise deposit in 1997 gives hope that other, similarly large, sulfide deposits may be found in other caldera along the Izu–Bonin Arc. The geological variability along the arc, the high seismicity, the occurrence of active volcanism and submarine hydrothermal venting, and a proven submarine hydrothermal mineral potential coupled with the proximity of the region to Japan suggest that the Izu–Bonin Arc could profitably serve as a natural laboratory for the long-term monitoring of the seafloor. 相似文献
10.
《Marine Geology》2006,225(1-4):145-156
Manganese oxide crusts were recovered from Baby Bare seamount in order to investigate the history of off-axis hydrothermal venting. Baby Bare is a small basement high protruding from a regional sediment cover on the eastern flank of the Juan de Fuca Ridge that acts as a focus for discharging crustal fluids. Stratabound Mn-oxide crusts were collected where warm venting has been observed near the seamount summit. Mn-oxide crusts are composed primarily of 10 Å manganate ± pyrolusite, with minor nontronite, saponite, and/or barite. These assemblage and chemical characteristics such as high Mn/Fe ratios and low trace metal and REE concentrations are indicative of a hydrothermal origin. Minimum ages for these deposits, calculated using growth rates (324 to ∼ 1800 mm/Ma) and estimated thicknesses of manganese outcrops, show that Baby Bare has been hydrothermally active for at least 0.5 Myr, and possibly since its formation (1.7–2.7 Ma). Hydrothermal manganese oxide crusts such as these from Baby Bare record interactions between the hydrothermal fluids and seawater and are important tools for estimating the longevity of off-axis hydrothermal activity. 相似文献
11.
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
12.
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
13.
P. Stoffers G. P. Glasby D. Stuben R. M. Renner T. G. Pierre J. Webb 《Marine Georesources & Geotechnology》2013,31(1):45-86
Abstract Hydrothermal iron‐rich crusts have been recovered from a number of hot spot volcanos including Crough Seamount, Pitcairn Volcanos 2 and 1, Cyana Seamount, Teahitia, Moua Pihaa, and Macdonald Seamount in the S. W. Pacific. Mineralogically, the crusts consists of ferrihydrite with traces of the weathering products of volcanic ash (feldspar, nontronite, pyroxene, and serpentinite). The iron oxyhydroxide phase has a mean particle size of 3–4 nm indicating rapid deposition. Electron microprobe studies have revealed the presence of filamentous iron‐silica deposits within the crusts reflecting the possible bacterial oxidation of iron from the hydrothermal fluids. The crusts display wide variability in composition both between individual sampling stations and between seamounts. Endmember analysis shows that the compositional data can be resolved into three endmembers: a Fe‐rich endmember, a light and heavy rare earth element endmember, and a Ba (barite)‐rich endmember. The Fe‐rich endmember appears to contain very low concentrations of most trace elements. For bulk samples, the composition of the iron‐rich crusts reflects dilution of the iron oxyhydroxide phase by volcanic ash and, to a lesser extent, a hydrogenous component. This is illustrated by the wide variability in SiO2 (11.1–71.3%) and Mn (0.01–1.21%) contents of the crusts. For iron‐rich crusts containing greater than 40% Fe, the Pitcairn crusts display lower contents of Pb, Ba, Mo, U, Th, As, and rare earth elements (REE) and lower cerium anomalies than those from Teahitia. REE profiles of crusts from each of the hot spot volcanoes are characterized by small negative cerium anomalies but pronounced positive europium anomalies. The low average La/Fe ratios of the crusts from the various seamounts (47–572 X 10‐6) and positive Eu anomalies of the crusts suggest rapid deposition of the iron oxyhydroxide near the hydrothermal vent. The high Fe/Mn ratio of vent fluids at hot spot volcanoes (8.5–5.6) may account for the formation of these iron‐rich crusts. The present data indicate that there may be differences in the nature of the iron‐rich crusts based on the depth of occurrence. This influences the temperature of the venting hydrothermal fluids and the possibility of occurrence of submarine phreatomagmatic eruptions. 相似文献
14.
The distributions of Fe, Mn, Zn, Cu, Ni, Co, Cr, Pb, As, Ag, Cd, Se, Sb, and Hg in 128 samples of tissues of the organisms that inhabit hydrothermal vent fields of the Mid-Atlantic Ridge (Menez Gwen, Snake Pit, and Rainbow) depending on the abiotic environmental parameters were studied. The majority of the elements studied showed direct correlations between their concentrations in the fluids released and in the tissues of hydrothermal organisms. A higher degree of bioaccumulation of metals was revealed in the Bathymodiolus mussels and Rimicaris shrimps from the Rainbow hydrothermal vent field as compared to their analogues from Menez Gwen and Snake Pit. This corresponds to the maximum concentrations of the majority of the metals studied in the Rainbow high-temperature hydrothermal fluids. The highest degree of bioaccumulation of heavy metals was found in gills of the symbiotrophic mussels Bathymodiolus and in maxillipeds of the ectosymbiotic shrimps Rimicaris, i.e., in the organs that function in dependence on chemosynthetic bacteria. Within the Rainbow vent field, the shrimps, which inhabit in biotopes with more high-temperature conditions and therefore are more strongly subjected to the influence of fluids, were found to contain higher metal contents than mollusks. The Fe-Mn hydroxide films that cover mussel shells might serve as important reservoirs of other metals related to Fe and Mn. 相似文献
15.
Shili Liao Chuanwei Zhu Jianping Zhou Weiyong Liu Junyu Yu Jin Liang Weifang Yang Wei Li Jia Liu Chunhui Tao 《海洋学报(英文版)》2021,40(5):105-113
The newly discovered East Longjing-2 hydrothermal field (ELHF-2) is located on the Dragon Horn oceanic core complex of the ultraslow-spreading Southwest Indian Ridge, approximately 12 km from the ridge axis. This study measured the chemical compositions of pyrite from ELHF-2 using a laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to investigate the genesis of the field. Three generations of pyrite were classified, and found that: Py1 and Py2, rich in V, Mn, U, and Se, occur in altered basalt debris and the silica alteration matrix, respectively. Py3 was mainly intergrown with chalcopyrite in quartz veins and had higher Cu, In, Ag, Sb, and Au contents than Py1 and Py2. Some elements, such as Au, Se, and Pb, are likely presented as direct substitution with Fe2+ in pyrite, while Cu, Zn, Co, Ni, and Ag probably occur both as direct substitution with Fe and as distributed micro- to nanoparticle-sized sulfides. Meanwhile, the occurrence of V, Mn, and U is likely presented as oxide inclusions. Trace element geochemistry suggested that the pyrite was formed under high-temperature conditions, and the ore forming elements were likely derived from ultramafic rocks. In addition, Py1 and Py2 were formed under higher water/rock ratio and higher temperature conditions, with more seawater involvement compared with Py3. The formation of ELHF-2 was probably driven by exothermic serpentinization reactions with an additional magmatic heat. This study shows that high-temperature hydrothermal circulation driven by magmatic activity can be developed on distal rift flank areas of magma-starved ultraslow-spreading ridges. 相似文献
16.
Atomic absorption spectroscopy (flame and graphite furnace techniques) and instrumental neutron activation analysis were used
for determining the Fe, Mn, Zn, Cu, Pb, Cd, Ag, Co, Cr, As, Se, Sb, Ba, Au, and Hg contents in 25 samples of different tissues
and whole organisms inhabiting the southern trough in the Guaymas Basin (Gulf of California) and in several samples of its
bottom waters. It is shown that the habitat environment of this hydrothermal field with high primary production of both photosynthetic
and bacterial chemosynthetic origin influences the Fe and Mn ratios in the waters of the microbiotopes and the distribution
patterns of the metals in the external and internal organs of the benthic animals. In the dominant specialized taxa, the maximal
bioaccumulation of metals is registered both in the organs related to bacterial chemosynthesis such as the trophosome of Vestimentifera
Riftia pachyptila and the gills of the vesicomyid clam Archivestica gigas and in other organs. The other organisms such as the mollusks Nuculana grasslei, actinias Paraphelliactis pabista, Actinaria, and Spongia and the crabs Munidopsis alvisca demonstrate high bioaccumulation properties as well. The metal concentration coefficient is highly variable ranging from
10 to 104. The changes in the molar Fe/Mn ratio values imply the partitioning of these two metals in the following migration succession:
microbiotope water-external organs-internal organs. 相似文献
17.
We study the distribution of Fe, Mn, Co, Ni, Cu, Zn, Cd, Hg, Ag, and Au in present-day and ancient bottom sediments in the
shelf, slope, and deep-trench areas of the northeast part of the Black Sea. The samples were taken in 1990 in the Crimean,
Kerch-Taman, and Caucasian regions. The revealed character of the fields of concentration of metals does not allow one to
establish exact regularities in the distribution of Mn, Co, and Cu with Fe. It is shown that the values of the ratios of concentrations
of metals increase in the following direction: Au/Cu → Zn/Cu → Co/Fe → Ni/Fe → Mn/Fe → Hg/Cu → Ag/Cu → Cu/Fe. The data on
Ag are presented for the first time. 相似文献
18.
利用等离子体发射光谱法、等离子体质谱法以及相态分析手段,对太平洋徐福海山富钴结壳稀土和铂族元素地球化学特征、赋存状态及富集机制进行研究。结果表明,富钴结壳稀土和铂族元素明显富集,其稀土总量为1 842～2 854 μg/g,铂族总量为144～1 180 ng/g,老壳层中稀土和铂族元素含量明显高于新壳层,这可能与老壳层发生磷酸盐化作用有关。轻稀土元素含量明显高于重稀土元素含量,呈现Ce正异常而Eu无异常,具有明显Ce富集特征。铂族元素之间发生了明显分异作用,PPGE含量明显高于IPGE,表现出明显Pt正异常而Pd负异常,具有明显Pt富集而Pd亏损特征。稀土元素赋存状态显示,新壳层中稀土元素主要赋存于铁氧化物相,其富集比例为65.40%～70.05%,老壳层中稀土元素主要赋存于残渣态,富集比例为62.27%～65.77%,这可能与残渣态中磷酸盐有关。铂族元素赋存状态显示,新壳层和老壳层中铂族元素都主要赋存于铁氧化物相,其富集比例为63.66%～69.51%,残渣态(29.20%～34.68%)对铂族元素也有一定的富集能力。富钴结壳稀土和铂族元素的富集推测为铁氧化物胶体粒子的吸附作用,受海水氧化性环境影响,可溶性Ce3+和Pt2+分别被氧化成不溶性Ce4+和Pt4+,沉淀被吸附到铁氧化物相中,从而造成富钴结壳稀土和铂族元素的富集。 相似文献
19.
尖顶海山和平顶海山是洋底海山的两种类型,同时也是富钴结壳资源赖以成长的主要载体,两者在地形上具有显著差别,资源状况和分布也不尽一致。以地形分类为基础,就中太平洋海山区两类海山结壳的成矿特征、宏微观构造、矿物和化学组成以及空间分布等进行了比对研究。研究认为,尖顶海山体积虽小,但地形演化连续,底层流及环境氧化性较强,有利于结壳的长期稳定生长,结壳厚度总体较大,富成矿元素和生物组分,远景成矿区域连续绵长。平顶海山山体巨大,顶部和斜坡陡崖区不利于结壳成长,底流活动只在山顶边缘和山脊地带表现突出,环境氧化性整体较弱,后期构造活动相对频繁,结壳总体厚度较小,铁,碎屑和热液组分含量较高,远景矿区相对狭窄。 相似文献
20.
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