Deep-Sea Cobalt Crusts Water Jet Cutting Ability

Deep-sea cobalt crusts water jet cutting method is proposed to avoid cutter impact load. With simulation calculations and experimental tests, water jet system parameters and its cutting ability were studied. Simula-tion results show that working pressure, ejection range and ejection angle of water jet system are main parameters of its cutting ability. Its important degree is in turn the working pressure, ejection range and ejection angle. Increasing water jet system working pressure is the most effective way to improve its cutting ability. When water jet working pressure is constant, in order to improve its cutting ability, the ejection range should be less than 4mm (four times of nozzle diameter) and the ejection angle should be about 13o. Experimental results show that there is a threshold pressure during water jet cutting cobalt crusts simulation material. With the increase of water jet working pressure, its cutting ability increases dramatically. With the increasing of water jet ejection range, its cutting ability decreases sharply. The optimal ejection angle is about 13o

An Effective Method to Determine the Distribution Boundary of Cobalt-Rich Fe-Mn Crusts on a Guyot: Synchronous Application of Sub-bottom Profiling and Deep-Sea Video Recording

Determining the upper boundary of the cobalt-rich crust distribution of a guyot is important for estimating the mineral resources available, however, it has also long been an unsolved question. Correlations between the sub-bottom structures, revealed by sub-bottom profiling, and crust distribution can be revealed for the first time by the synchronous application of sub-bottom profiling and deep-sea video recording. The lower boundary of the sediment corresponds with the upper boundary of the crust. By analysis of these two kinds of data, the lower boundary of the sediment can be determined; therefore, the upper boundary of the crust distribution can be deduced. According to this method of analysis, the upper boundary of water depth of crust distribution of a seamount in the western Pacific is about 1 560 m.

Morphological description and population structure of an ophiuroid species from cobalt-rich crust seamounts in the Northwest Pacific:Implications for marine protection under deep-sea mining

Many seamounts are covered with cobalt-rich ferromanganese crusts,and are increasingly attracting interest for the potential extraction of valuable mineral resources from deep seabed environments.However,the impacts of potential mining activities on the vulnerable seamount ecosystem remain unclear.To enhance the understanding of connectivity in benthic invertebrate populations in the Northwest Pacific,several seamounts were surveyed and biological samples collected.In the present study,the ophiuroid species Ophioplinthaca defensor is reported for the first time from four deep seamounts in the Northwest Pacific,and described,providing more detailed morphological diagnosis characters.To assess the population structure of the species between and within seamounts,two mitochondrial markers(COI and 16 S)were sequenced.In total,20 haplotypes from 32 COI sequences and 8 haplotypes from 3716 S sequences were recovered.The star-shaped TCS networks and nonsignificant pairwise population differences reveal the absence of distinct population structures between and within seamounts.In addition,the O.defensor population seemed to have undergone a demographic expansion in history.This is the first study on the genetic population structure of a benthic invertebrate from seamounts in the Northwest Pacific,and this results suggest a potentially high,long distance dispersal capacity in O.defensor between seamounts,which could inform the development of the Regional Environmental Management Plans for the cobalt-rich crust seamounts in the area.

Distribution characteristics of seamount cobalt-rich ferromanganese crusts and the determination of the size of areas for exploration and exploitation

In 2001, the International Seabed Authority （ISBA） initiated the consideration relating to the Regulations for Prospecting and Exploration for Hydrothermal Polymetallic Sulphides and Cobalt-rich Ferromanganese Crusts in the Area at its 7th session. Since then, the consideration of the Regulations has been mainly focused on the size of areas to be allocated for exploration and exploitation of the crusts. This paper, based on the investigation data and the analysis of the distribution characteristics of the crusts, suggests a model for determining the size of areas for exploration and exploitation of the crusts, taking into account various factors such as production scale, crust thickness and grade, mineable area proportion, recovery efficiency, exploration venture, and so on. Through the modeling, the paper suggests that the exploration area （the area covered by each application for approval of a plan of work for exploration of cobalt-rich crusts） shall be 4 856 km2 and the exploitation area （the mine site area） shall be 1 214 km2, for 20 years of 1 million wet tonnes annual production.

Calcareous Nannofossils and Molecular Fossils in Cobalt-rich Crusts and their Response to the P/E Global Event

A biostratigraphic study on calcareous nannofossils from the CM3D06 Co-rich ferromanganese crust from the Magellan seamounts in the northwestern Pacific enabled estimation of depositional age. The bio-imprinting of calcareous nannofossils and other fossil species suggests six age ranges for the nannofossils： late Cretaceous, late Paleocene, （early, middle, late） Eocene, middle Miocene, late Pliocene, and Pleistocene. Gas chromatography （GC） and gas chromatography-mass spectrometry （GC-MS） were used to test the Co-rich crusts, and a variety of molecular fossils were detected, such as chloroform bituminous ＂A＂ , n-alkane, isoprenoid and sterol. Peak carbon and molecular indices （such as C23-/C24＋, CPI, Pr/Ph, Pr/nC17, Ph/nCxs and j13C） indicate that the parent organic matter is dominated by marine phytoplankton and thallogen whereas there is little input of terrestrial organic matter. Researches on calcareous nannofossils, molecular fossils and molecular organic geochemistry data reveal that the Paleocene/Eocene （P/E） global event is recorded in the cobalt- rich crusts from the northwestern Pacific Ocean. A succession of biomes can be observed near the 85 mm boundary （about 55 Ma）, i.e., the disappearance of the late Cretaceous Watznaueria barnesae and Zigodicus spiralis, and Broisonia parka microbiotas above the P/E boundary, and the bloom of Coccolithus formosus, Discoaster multiradiatus, Discoaster mohleri and Discoaster sp. below the boundary. Typical parameters of molecular fossils, such as saturated hydrocarbon components and carbon-number maxima, Pr/Ph, Pr/C17, Ph/C18, distribution types of sterols, Ts/Tm ratios and bacterial hopane, also exhibit dramatic changes near the P/E boundary. These integrated results illustrate that the biome succession of calcareous nannofossils, relative content of molecular fossils and molecular indices in the cobalt-rich crusts near the 85 mm boundary faithfully record the P/E global event.

Biomineralization of organic matter in cobalt-rich crusts from the Marcus–Wake Seamounts of the western Pacific Ocean

Organic matter in cobalt-rich crust （CRC） from the Marcus-Wake Seamounts of the western Pacific Ocean, Sample CM1D03, has been analyzed to understand the source, geochemistry and mineralization of organic matter, and the mineralization environment. Biomarkers, includingn-alkanes, isoprenoids, terpanes and sterols, have been detected in various layers of the CRC sample, using gas chromatography （GC） and gas chromatography-mass spectrometry （GC-MS）. The content of organic carbon （OC） and its stable isotope （δ13C）, and the combined features of the biomarkers show that the mineralized organic matter in CM1D03 CRC was mainly derived from microorganisms and lower plankton （e.g., bacteria and algae, respectively） from marine surface water, with some terrestrial higher plant components. The ratio of chloroform bitu-men ＂A＂： OC was high in the CRC, between 10.51 and 20.66, showing significant migration characteristics of n-alkanes. Four mineralization categories of organic matter were recognized based on GC chromatograms ofn-alkane molecules： （1） primitive type （bacteria and algae）, which is characterized by moderately mature ofn-alkanes preserving the original characteristics of the organic matter from microorganisms and lower plankton; （2） microbial degradation type, which is characterized by low contents ofn-alkanes and rising baseline in the chromatogram, with the ＂bulge＂ being the products of organic matter by biodegradation; （3） organic matter migration type, which is characterized by low carbon number ofn-alkanes withnC18 as the main peak carbon, without odd even predominance, and low concentrations of isoprenoids and hydro-carbons with high carbon number; and （4） organic matter hydrothermal type, which is characterized by relatively low concentration of small molecular weightn-alkanes, pristane, and phytane, accompanied by higher concentration ofn-alkanes with carbon number greater thannC18. This study shows that biomarkers can record controlling factors of mineralization and their variation.

Geochemistry of rare earth elements in cobalt-rich crusts from the Mid-Pacific M seamount

Rare earth elements（REEs） and major elements of 25 cobalt-rich crusts obtained from different depths of Mid-Pacific M seamount were analyzed using inductively coupled plasma-atomic emission spectrometer and gravimetric method.The results showed that they were hydrogenous crusts with average ∑REE content of 2084.69 μg/g and the light REE（LREE）/heavy REE（HREE） ratio of 4.84.The shale-normalized REE patterns showed positive Ce anomalies.The total content of strictly trivalent REEs increased with water depth.The Ce content and LREE/HREE ratios in Fe-Mn crusts above 2000 m were lower than those below 2000 m.The change in REE with water depth could be explained by two processes：adsorptive scavenging by setting matters and behaviors of REE in seawater.However, the Ce abundance took no obvious correlation with water depth reflects the constant Ce flux.The Ce in crusts existed mainly as Ce（IV）, implying that the oxidative-enriching process was controlled by kinetic factors.

Resources calculation of cobalt-rich crusts with the grid subdivision and integral method

On the basis of three geological models and several orebody boundaries, a method of grid subdivision and integral has been proposed to calculate and evaluate the resources of cobalt-rich crusts on the seamounts in the central Pacific Ocean. The formulas of this method are deduced and the interface of program module is designed. The method is carried out in the software ＂Auto mapping system of submarine topography and geomorphology MBChart＂. This method and program will possibly become a potential tool to calculate the resources of seamounts and determine the target diggings for China＇ s next Five-year Plan.

Noble Gas Isotopic Compositions of Cobalt-rich Ferromanganese Crusts from the Western Pacific Ocean and Their Geological Implications

Noble gas isotopic compositions of various layers in three-layered （outer, porous and compact layers） cobalt-rich ferromanganese crusts and their basaltic and phosphorite substrates from the western Pacific Ocean were analyzed by using a high vacuum gas mass spectrum. The analytical results show that the noble gases in the Co-rich crusts have derived mainly from the ambient seawater, extraterrestrial grains such as interplanetary dust particles （IDPs） and wind-borne continental dust grains, and locally formation water in the submarine sediments, but different noble gases have different sources. He in the crusts derives predominantly from the extraterrestrial grains, with a negligible amount of radiogenic He from the eolian dust grains. Ar is sourced mainly from the dissolved air in the seawater and insignificantly from radiogenic Ar in the eolian continental dust grains or the formation water. Xe and Ne derive mainly from the seawater, with minor amounts of extraterrestrial Xe and Ne in the IDPs. Compared with the porous and outer layers, the compact layer has a relatively high 4He content and lower 3He/4He ratios, suggesting that marine phosphatization might have greatly modified the noble gas isotopic compositions of the crusts. Besides, the 3He/4He values of the basaltic substrates of the cobalt-rich crusts are very low and their R/R. ratios are mostly 〈0.1 R., which are similar to that of phosphorite substrates （0.087 R.）, but much lower than that of fresh submarine MORB （8.75±14 Ra） or seamount basalts （3-43 Ra）, implying that the basaltic substrates have suffered strong water/rock interaction and reacted with radiogenic ^4He and P-rich upwelling marine currents during phosphatization. The trace elements released in the basalt/seawater interaction might favor the growth of cobalt-rich crusts. The relatively low ^3He/^4He values in the seamount basalts may be used as an important exploration criterion for the cobalt-rich ferromanganese crusts.

Optimal control of cobalt crust seabedmining parameters based on simulated annealing genetic algorithm

Under the condition of the designated collection ratio and the interfused ratio of mullock, to ensure the least energy consumption, the parameters of collecting head （the feed speed, the axes height of collecting head, and the rotate speed） are chosen as the optimized parameters. According to the force on the cutting pick, the collecting size of the cobalt crust and bedrock and the optimized energy consumption of the collecting head, the optimized design model of collecting head is built. Taking two hundred groups seabed microtopography for grand in the range of depth displacement from 4.5 to 5.5 era, then making use of the improved simulated annealing genetic algorithm （SAGA）, the corresponding optimized result can be obtained. At the same time, in order to speed up the controlling of collecting head, the optimization results are analyzed using the regression analysis method, and the conclusion of the second parameter of the seabed microtopography is drawn.

Cobalt crust recognition based on kernel Fisher discriminant analysis and genetic algorithm in reverberation environment

Recognition of substrates in cobalt crust mining areas can improve mining efficiency.Aiming at the problem of unsatisfactory performance of using single feature to recognize the seabed material of the cobalt crust mining area,a method based on multiple-feature sets is proposed.Features of the target echoes are extracted by linear prediction method and wavelet analysis methods,and the linear prediction coefficient and linear prediction cepstrum coefficient are also extracted.Meanwhile,the characteristic matrices of modulus maxima,sub-band energy and multi-resolution singular spectrum entropy are obtained,respectively.The resulting features are subsequently compressed by kernel Fisher discriminant analysis(KFDA),the output features are selected using genetic algorithm(GA)to obtain optimal feature subsets,and recognition results of classifier are chosen as genetic fitness function.The advantages of this method are that it can describe the signal features more comprehensively and select the favorable features and remove the redundant features to the greatest extent.The experimental results show the better performance of the proposed method in comparison with only using KFDA or GA.

Ecological functions of uncultured microorganisms in the cobaltrich ferromanganese crust of a seamount in the central Pacific are elucidated by fosmid sequencing

Cobalt-rich ferromanganese is an important seafloor mineral and is abundantly present in the seamount crusts. Such crusts form potential hotspots for biogeochemical activity and microbial diversity, yet our understanding of their microbial communities is lacking. In this study, a cultivation-independent approach was used to recover genomic information and derive ecological functions of the microbes in a sediment sample collected from the cobalt-rich ferromanganese crust of a seamount region in the central Pacific. A total of 78 distinct clones were obtained by fosmid library screening with a 16S rRNA based PCR method. Proteobacteria and MGI Thaumarch-aeota dominated the bacterial and archaeal 16S rRNA gene sequence results in the microbial community. Nine fosmid clones were sequenced and annotated. Numerous genes encoding proteins involved in metabolic functions and heavy metal resistance were identified, suggesting alternative metabolic pathways and stress responses that are essential for microbial survival in the cobalt-rich ferromanganese crust. In addition, genes that participate in the synthesis of organic acids and exoploymers were discovered. Reconstruction of the metabolic pathways revealed that the nitrogen cycle is an important biogeochemical process in the cobalt-rich ferromanganese crust. In addition, horizontal gene transfer （HGT） events have been observed, and most of them came from bacteria, with some occurring in archaea and plants. Clone W4-93a, belonging to MGI Thaumarch-aeota, contained a region of gene synteny. Comparative analyses suggested that a high frequency of HGT events as well as genomic divergence play important roles in the microbial adaption to the deep-sea environment.

Distribution and Classification of Cobalt-Rich Crust

Based on the on the spot investigation and related data, cobalt rich crust is mainly distributed in the low latitude area near the equator, mostly within 20°S to 20°N, especially 5°-15°(S and N). The analysis of the microtopographic and microphysicognomy features shows that crusts are often present in the complicated topographic regions such as seamount slopes, convex parts of seamounts and joint faults, of which the ideal region is seamount slopes in water depth of 1 500-2 500 m. The authors analyze the relation of the crusts and their bedrock, bedrock type, crust thickness and occurrence, and then attempt to classify the crusts as different types.

机器学习:海底矿产资源智能勘探的新途径

海底蕴藏着丰富的关键矿产资源,是当前研究的热点,也是未来产业新领域。随着海洋探测技术的不断进步,海底矿产勘探的数据量和数据维数急剧增加,给数据处理与解释带来了巨大困难和挑战。面对海量数据,传统的数据解释与分析方法暴露出许多问题。机器学习以其强大的自学能力,为无法解决或难以解决的问题提供了一系列智能分析决策方案,提高了数据分析的效率,是海底矿产资源智能勘探的新途径。近年来,机器学习在地球科学领域获得了广泛的关注和研究。为此,围绕机器学习技术应用于海底资源勘探技术,本文首先简要介绍了机器学习中经典的模型算法,然后详细阐述了机器学习在海底能源矿产和金属矿产两个方面的应用现状,最后总结了机器学习在海底矿产智能勘探领域的应用前景,指出了现有研究中存在的问题,提出了解决方案和未来的发展方向。

西太平洋维嘉海山埋藏型富钴结壳生长速率初步研究

富钴结壳是一种水成成因,生长在海底岩石或岩屑表面的皮壳状铁锰氧化物和氢氧化物,主要分布于CCD以上、最低含氧层(OMZ)中或以下800~2500 m水深之间的类叠层石结构,具典型的层状结构,奇特的韵律性生长剖面蕴含着其生长过程中所保留下来的比较完整的古海洋演化和古环境信息(任江波等,2013;王彦美等,2017)。

声学探测技术在富钴结壳勘探中的应用及展望

富钴结壳是深海固体矿产之一,其资源潜力巨大,已成为世界各国竞相调查的重要对象。声学探测技术作为一种海洋地球物理探测技术,因其在大面积调查和局部连续精细勘探方面的独特优势,在富钴结壳资源调查中得到了广泛应用。在搜集整理国内外相关文献的基础上,概述了富钴结壳的分布特征,分析传统勘探方法的不足,系统介绍多波束、侧扫声呐、浅地层剖面、原位高频测厚等声学探测技术在富钴结壳勘探中的应用现状。通过比较分析国内外声学探测技术发展现状以及未来富钴结壳勘探需求,提出3点未来发展趋势:开发一体化声学探测技术以实现海底特性的综合性测量;综合利用深海潜水器以实现近底高精度探测;深度融合大数据和人工智能技术以实现海量声学数据的智能化处理。

海洋有色金属矿产地球物理勘探进展

随着对海洋矿物资源的勘探研究,人们意识到多金属结核、富钴结壳和多金属硫化物等是具有战略意义的海洋有色金属矿产。近年来,随着地球物理勘探技术的发展,勘探深度逐渐从浅海过渡到深海,加深了人们对深部有色金属资源的认识,深海有色金属资源逐步成为世界各国关注的热点。近十年来,我国在深海矿产资源领域的研究取得了一系列的重要进展。首先,本文主要介绍国内外海洋有色金属矿产的勘探现状,并且在原理基础、正反演技术方法等方面回顾了适用于深海环境的地球物理勘探方法的发展。然后,结合我国在太平洋的多金属结核勘探区、富钴结壳勘探区和在西南印度洋中脊的多金属硫化物矿勘探区的研究进展,归纳了海洋有色金属矿产的地球物理勘探方法及实例分析。

大洋富钴结壳研究进展及展望

富钴结壳是一种重要的海底矿产资源,具有独特的经济价值和科学意义,其不仅富含Mn、Co、Ni、Cu、PGE和REY等金属,而且在反演新生代以来古海洋环境记录等方面扮演着独特的角色。锰氧化物(MnO_(2)·xH_(2)O)和铁羟基氧化物(FeOOH)是构成富钴结壳的主要矿物,矿物颗粒十分微小(纳米级)。水羟锰矿和水钠锰矿具有层状结构且层电荷为负,通过吸附阳离子来补偿。前人通过连续浸出实验、元素相关性统计分析、吸附实验和拓展X射线吸收精细结构(EXAFS)光谱广泛研究了微量元素在矿物中的赋存状态,确定了微量元素在锰氧化物矿物中主要存在三种类型络合物:共六边(edge-sharing)、共双角(double-corner sharing)和共三角(triple-corner sharing)。综合研究表明,在最低含氧带之下铁锰氧化物(氢氧化物)从海水沉淀到周围海山坚硬基岩上形成富钴结壳的机制主要是无机胶体化学反应和矿物表面反应。最后针对已有的相关研究现状以及富钴结壳研究面临的挑战,富钴结壳的成矿物质来源及演化、微量元素富集机制、蕴含的古海洋信息等问题仍需要进一步深入探讨。

麦哲伦海山群富钴结壳元素地球化学特征及赋存状态

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1287~2000μg/g,Ce含量为632~946μg/g,约占稀土总量的50%;轻稀土含量为1037~1604μg/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主要赋存于铁氧化物相,部分Al和K赋存于残渣态。该研究对于西太平洋麦哲伦海山群富钴结壳的成矿理论研究提供了科学依据。

Nanometer properties of oceanic polymetallic nodules and cobalt-rich crusts

An ammonia leaching process was utilized to extract Co, Ni and Cu from oceanic polymetallic nodules, whereas an acid leaching process was utilized to extract Co, Ni, Cu, Zn and Mn from cobalt-rich crusts. Both processes produced nanometer materials-ammonia leaching residue and acid leaching residue. A systematic study was conducted on the phase, composition and physicochemistry properties of these residues. The result shows that both residues contain a large amount of nanometer minerals. Ammonia leaching residue mainly consists of rhodochrosite, with the average grain diameter of 17.9 nm; whereas the acid leaching residue mainly consists of well-developed bassanite, with the average grain deameter of 9.5 nm. The bassanite also has a microporous structure, the volume of the pore space is 1.23×10-2 mL/g. Both the ammonia and acid leaching residues have a large specific surface area, and they display a strong adsorption capacity to saturate sodium chloride vapour, N2 and SO2. Both residues have high