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Classification of seamount morphology and its evaluating significance of ferromanganese crust in the central Pacific ocean

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Acta oceanologica Sinica 2006年第2期25卷 63-70页

作者： CHU Fengyou SUN Guosheng MA Weilin LI Shoujun QIAN Xinyan ZHAO Hongqiao Laboratory of Submarine Geosciences of State oceanic Administration Hangzhou 310012 China Second Institute of oceanography State Oceanic Administration Hangzhou 310012 China Institute of Marine mineral Resource College of Geoscience Jilin University Changchun 130026 China

Using the SeaBeam technology, the morphology of seamount and its relation to the formation of cobalt-rich crust in the central Pacific ocean were surveyed during the cruise in 2003 for marine mineral resources. The result shows that seamounts can be divided morphologically into the spire seamount and the fiat topped seamount. These two types of seamount bear great differences in their landform, lithology and cobalt-rich crust. On the upper portion of the fiat topped seamount, the fiat top and the sharp escarpments are unfavorable to the growth of crust, and, consequently, the crusts here are mostly laminar or gravelly, their thicknesses generally show great variations, and the consecutive ore body often develops in its deep water region. On the spire topped seamount, however, the fiat area is small, and its gradient is constant without large variation from the top to the bottom. This favors the growth of cobalt-rich crust and often leads to consecutive tabular ore body of medium thickness, occurring on the spire topped seamount from the shallow water region to the deep water region. The cobalt-rich crust on the spire topped seamount is much better than that on the fiat topped seamount for the crust abundance, crust coverage and number of ore-occurrences within unit area. Furthermore, the crust on the spire topped seamount is rich in cobalt, nickel, manganese elements of high economic value. Because the crust with high quality ore often occurs in the shallow water region on the spire topped seamount, it can be mined and use more easily in the future.

关键词： central Pacific ocean spire topped seamount flat topped seamount cobalt-rich crest evaluating significance

The mineral Composition and Sources of the Fine-Grained Sediments from the 49.6?E Hydrothermal Field at the SWIR

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Journal of ocean University of china 2020年第1期19卷 60-68页

作者： ZHANG Wenqiang SUN Xiaoxia FAN Dejiang LIU Ming JIA Qi YANG Zuosheng Key Laboratory of Submarine Geosciences and Technology MOEOcean University of ChinaQingdao 266100China Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and TechnologyQingdao 266061China

We used the X-ray diffraction method to determine systematically the mineral phases in bulk sediment samples and acid undissolved residuals of the fine-grained fraction of the surface sediments from the 49.6°E hydrothermal field at the Southwest Indian Ridge(SWIR)and discussed the mineral sources of the surface *** results showed that the surface sediments in this region were composed of calcareous ooze,and calcite was the dominant *** sediments also contained quartz,feldspar,clay minerals,pyroxene,sphalerite,barite,serpentine,and *** quartz,feldspar,and clay minerals were exogenous minerals that mainly originated from the Namib and Kalahari deserts in southern *** pyroxene,serpentine,magnetite,sphalerite,calcite,and barite were endogenous minerals from weathering of seafloor basement rocks and seafloor hydrothermal *** sulfide particles in the sediments were mainly deposited from upwelling plumes.

关键词： Southwest Indian Ridge surface sediment mineral source hydrothermal

Enhanced cold active lipase production by metagenomic library recombinant clone CALIP3 with a step-wise temperature and dissolved oxygen level control strategy

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Chinese Journal of Chemical Engineering 2016年第9期24卷 1263-1269页

作者： Zhuhua Chan Runping Wang Fan Yang Runying Zeng State Key Laboratory Breeding Base of Marine Genetic Resource Third Institute of OceanographySOAXiamen 361005China South china Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center Guangzhou 510000China

A metagenomic library recombinant clone CAPL3, an Escherichia coli strain generated by transformed with metagenomic library from deep-sea sediments, can efficiently produce cold active lipase. The effects of both temperature and dissolved oxygen（DO） on cold active lipase production by batch culture of metagenomic library recombinant clone（CAPL3） from deep-sea sediment were investigated. First, a two-stage temperature control strategy was developed, in which the temperature was kept at 34 ℃ for the first 15 h, and then switched to30 ℃. The cold active lipase activity and productivity reached 315.2 U·ml^-1and 8.08 U·ml^-1·h^-1, respectively,increased by both 14.5% compared to the results obtained with temperature controlled at 30℃. In addition, different DO control modes were conducted, based on the data obtained from the different DO control strategies and analysis of kinetics parameters at different DO levels. A step-wise temperature and DO control strategy were developed to improve lipase production, i.e., temperature and DO level were controlled at 34℃, 30% during 0–15 h;30 ℃, 30% during 15–18 h, and 30 ℃, 20% during 18–39 h. With this strategy, the maximum lipase activity reached 354.6 U·ml^-1at 39 h, which was 28.8% higher than that achieved without temperature and DO control（275.3 U·ml^-1）.

关键词： Deep-sea sediments Metagenomic library Cold active lipase Step-wise temperature and DO control strategy

Evolving patterns of the fluids within the TAG hydrothermal field

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Science china Earth Sciences 2009年第1期52卷 29-37页

作者： LI HuaiMing ZHAI ShiKui YU ZengHui TAO ChunHui CHU FengYou Department of Marine Geoscience Ocean University of ChinaQingdao 266100China Key Laboratory of Submarine Geosciences State Oceanic AdministrationHangzhou 310012China Second Institute of oceanography State Oceanic AdministrationHangzhou 310012China

The mixing of seawater/hydrothermal fluid within the large seafloor hydrothermal sulfide deposits plays a key role in the formation processes of the sulfide deposits. Some issues attract considerable attentions in the study of seafloor hydrothermal system in recent years, such as the relationships among different types of vent fluids, the characteristics of chemical compositions and mineral assemblages of the hydrothermal deposits and their governing factors. Combined with the measured data of hydrothermal fluid in the TAG field, the thermodynamic model of mixing processes of the heated seawater at different temperatures and the hydrothermal fluid is calculated to understand the precipitation mechanism of anhydrite and the genetic relationships between the black and white smoker fluids within the TAG mound. The results indicate that the heating of seawater and the mixing of hydrothermal fluid/seawater are largely responsible for anhydrite precipitation and the temperature of the heated seawater is not higher than 150°C and the temperature of the end-member hydrothermal fluid is not lower than 400°C. Based on the simulated results, the evolving patterns of fluids within the TAG deposit are discussed. The mixed fluid of the end-member hydrothermal fluid and the seawater heated by wall rock undergoes conductive cooling during upflowing within the deposit and forms “White Smoker” eventually. In addition, the end-member hydrothermal fluid without mixed with seawater, but undergoing conductive cooling, vents out of the deposit and forms “Black Smoker”.

关键词： seafloor hydrothermal system mixing process evolving patterns of fluids TAG hydrothermal field

Interlinking the Hotspot Track in the Arctic and its Implications for Paleo-plate Reconstrution

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Acta Geologica Sinica(English Edition) 2017年第3期91卷 822-831页

作者： LIU Zhonglan LI Jianghai LIU Chiheng LI Weibo ZHANG Hongwei The Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of EducationSchool of Earth and Space SciencesPeking University Lamont Doherty Earth Observatory Columbia University Institute of Oil & Gas Peking University

The Siberian-Icelandic hotspot track is the only preserved continental hotspot track. Although the track and its associated age progression between 160 Ma and 60 Ma are not yet well understood, this section of the track is closely linked to the tectonic evolution of Amerasian Basin, the Alpha-Mendeleev Ridge and Baffin Bay. Using paleomagnetic data, volcanic structures and marine geophysical data, the paleogeography of Arctic plates （Eurasian plate, North American Plate, Greenland Plate and Alaska Microplate） was reconstructed and the Siberian-Icelandic hotspot track was interlinked between 160 Ma and 60 Ma. Our results suggested that the Alpha-Mendeleev Ridge could be a part of the hotspot track that formed between 160 Ma and 120 Ma. During this period, the hotspot controlled the tectonic evolution of Baffin Bay and the distribution of mafic rock in Greenland. Throughout the Mesozoic Era, the aforementioned Arctic plates experienced clockwise rotation and migrated northeast towards the North Pacific. The vertical influence from the ancient Icelandic mantle plume broke this balance, slowing down some plates and resulting in the opening of several ocean basins. This process controlled the tectonic evolution of the Arctic.

关键词： hotspot track large igneous province paleogeography reconstruction Alpha-Mendeleevridge the Arctic

Geochemistry of mafic rocks and melt inclusions and their implications for the heat source of the 14.0°S hydrothermal field, South Mid-Atlantic Ridge

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Chinese Journal Of Geochemistry 2014年第4期33卷 325-335页

作者： LI Bing SHI Xuefa YANG Yaomin YE Jun GAO Jingjing ZHENG Wenqin Key Laboratory of Marine Sedimentology and Environmental Geology First Institute of Oceanography State Oceanic Administration National Deep Sea Center State Oceanic Administration Institute of Geochemistry Chinese Academy of Sciences

Fresh rocks sampled from the 14.0°S hydrothermal field of the South Atlantic Ridge can be divided into two categories: olivine-gabbro and basalt. The olivine-gabbro is composed mainly of three types of minerals: olivine, clinopyroxene and plagioclase, while a multitude of melt inclusions occur in the plagioclase phenocrysts of the basalts. We analyzed the whole-rock, major and trace elements contents of the basalts, the mineral chemistry of phenocrysts and melt inclusions in the basalts, and the mineral chemistry of olivine-clinopyroxene-plagioclase in the olivine-gabbro, then simulated magma evolution within the crust using the COMAGMAT program. The whole-rock geochemistry shows that all the basalts exhibit typical N-MORB characteristics. In addition, the mineral chemistry characteristics of the olivine-gabbro(low-Fo olivine, low-Mg# clinopyroxene, high-Ti O2 clinopyroxene, low-An plagioclase), show that strong magma differentiation occurred within the crust. Nevertheless, significant discrepancies between those minerals and phenocrysts in the basalts(high-Fo olivine, high-An plagioclase) reflect the heterogeneity of magma differentiation. High Mg#(≈0.72) melt inclusions isobaric partial crystallization simulations suggest that the magma differentiation occurred at the depth shallower than 13.03 km below the seafloor, and both the vertical differentiation column shows distinct discrepancies from that of a steady-state magma chamber. Instead, a series of independent magma intrusions probably occurred within the crust, and their corresponding crystallized bodies, as the primary high-temperature thermal anomalies within the off-axis crust, probably act as the heat source for the development of the 14.0°S hydrothermal system.

关键词：熔融包裹体大西洋中脊地球化学热液区热源基性岩矿物化学岩浆演化

Identification of five strains of antarctic bacteria producing low-temperature lipase

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Acta oceanologica Sinica 2004年第4期23卷 717-723页

作者： YANGXiuxia LINXuezheng BIANJi SUNXiuqin HUANGXiaohang FisheriesCollege OceanUniversityofChinaQingdao266071China／／FirstInstituteofOceanographyStateOceanicAdministrationQingdao266061China FirstInstituteofoceanography StateOceanicAdministrationQingdao266061China

Five strains of antarctic bacteria producing extracellular low-temperature lipase are screened from seawater collectedby CTD during the Chinese 18th Antarctic Scientific Expedition. Their phylogenetic positions on the basis ofamplification, comparison and analysis of almost complete 16S rDNA sequence are determined by neighbor-joininganalysis. Phylogenetic analysis indicates that all of these five strains belong to g-proteobacteria. The strains 11102 and 92 are classified as genus Pseudoalteromonas sp. and genus Psychrobacter sp. respectively. The strains 25101, 2221 and 1281 are classified as genus Moritella sp.

关键词： antarctic bacteria low-temperature lipase 16S rDNA phylogenetic analysis

Numerical simulation for fluids mixing within seafloor hydrothermal sulfide deposit:taking the Trans-Atlantic Geo-Traverse (TAG) field for example

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Acta oceanologica Sinica 2010年第1期29卷 33-41页

作者： LI Huaiming ZHAI Shikui TAO Chunhui YU Zenghui CHU Fengyou Key Laboratory of Submarine Geosciences State Oceanic Administration Hangzhou 310012 China College of Marine Geoscience Ocean University of China Qingdao 266100 China

The formation mechanism of the large hydrothermal sulfide deposit is a complex geological process involving many controlling factors. Mixing between hydrothermal fluid and seawater plays a key role in this process. The results of the ocean Drilling program （ODP） indicate that mixing of the evolved seawater and hydrothermal fluid, which is wildly developed within the Trans-Atlantic Geo-Traverse （TAG） hydrothermal deposit, governs the internal structure and chemical compositions of the deposit to great extent. Taking the TAG field for example, the mixing processes of hydrothermal fluid with the seawater heated to different extent are calculated, so as to discuss the impact of hydrothermal fluid/seawater mixing on the formation process of the sulfide deposit. The results indicate that：（1） mixing between the heated seawater and hydrothermal fluid derived from the deep deposit is largely responsible for the wild precipitation of anhydrite within the TAG hydrothermal deposit; （2） 330-310℃ is a special temperature range in the mixing process; （3） the mixing and hydrothermal processes in different zones of the TAG hydrothermal deposit （TAG-1, TAG-2 and TAG-5, etc.） have been discussed based on the simulated results.

关键词： hydrothermal sulfide deposit mixing process TAG hydrothermal field numerical simulation

Geochemical Features of Sulfides from the Deyin-1 Hydrothermal Field at the Southern Mid-Atlantic Ridge near 15?S

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Journal of ocean University of china 2017年第6期16卷 1043-1054页

作者： WANG Shujie LI Huaiming ZHAI Shikui YU Zenghui CAI Zongwei Key Laboratory of Submarine Geosciences and Prospecting Techniques Ministry of EducationCollege of Marine Geosciences Ocean University of China Qingdao 266100 P. R. China Key Laboratory of Submarine Geosciences Second Institute of Oceanography State Oceanic AdministrationHangzhou 310012 P. R. China

In this study, geochemical compositions of elements in sulfide samples collected from the Deyin-1 hydrothermal field near the 15?S southern Mid-Atlantic Ridge(SMAR) were analyzed by the X-ray fluorescence spectrometry(XRF) and inductively coupled plasma mass spectrometry(ICP-MS) to examine the enrichment regulations of ore-forming elements and hydrothermal mineralization. These sulfide precipitates can be classified macroscopically into three types: Fe-rich sulfide, Fe-Cu-rich sulfide and Fe-Zn-rich sulfide, and are characterized by the enrichment of base metal elements along with a sequence of Fe>Zn>Cu. Compared with sulfides from other hydrothermal fields on MAR, Zn concentrations of sulfides in the research area are significantly high, while Cu concentrations are relatively low. For all major, trace or rare-earth elements(REE), their concentrations and related characteristic parameters exhibit significant variations(up to one or two orders of magnitude), which indicates the sulfides from different hydrothermal vents or even a same station were formed at different stages of hydrothermal mineralization, and suggests the variations of chemical compositions of the hydrothermal fluid with respect to time. The hydrothermal temperatures of sulfides precipitation decreased gradually from station TVG10(***10) to ***12, and to ***11, indicating that the precipitation of hydrothermal sulfides is subjected to conditions changed from high temperature to low temperature, and that the hydrothermal activity of study area was at the late stage of a general trend of evolution from strong to weak. The abnormally low concentrations of REE in sulfides and their similar chondrite-normalized REE patterns show that REEs in all sulfides were derived from a same source, but underwent different processes of migration or enrichment, or sulfides were formed at different stages of hydrothermal mineralization. The sulfides collected from the active hydrothermal vent were mainly attrib

关键词： southern Mid-Atlantic Ridge Deyin-1 hydrothermal field hydrothermal sulfide geochemistry of element mineralization