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Clay minerals in Arctic Kongsfjorden surface sediments and their implications on provenance and paleoenvironmental change

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Acta Oceanologica Sinica 2018年第5期37卷 29-38页

作者： shi Fengdeng shi xuefa SU Xin FANG Xisheng WU Yonghua CHENG Zhenbo YAO Zhengquan School of Ocean Sciences China University of Geosciences (Beijing) Key Laboratory of State Oceanic Administration for Marine Sedimentology and Environmental Geology The First Institute of OceanographyState Oceanic Administration Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and Technology

Kongsfjorden is a typical fjord on the edge of the ice cap of the Arctic Svalbard-Barents Sea. Its inner bay is connected with a modern glacier front along the direction of the fjord axis with a significant gradient change in the parameters of hydrology, sedimentation, and biology. In summer, ice and snow melt-water and floating ice collapse continuously and thus transport the weathering products on the surrounding land into the sea. Thus Kongsfjorden is regards as a natural laboratory for the study of unique sedimentation in polar fjords under modern glacial-sea water conditions. In this study, fifty-two surface sediments were collected in Kongsfjorden for clay mineral analysis to study the sediment source and sediment-transport process. Our results indicate that clay minerals in the surface sediments from Kongsfjorden are mainly composed of illite, chlorite, and kaolinite, and no smectite is found. Rocks from different periods exposed extensively in the surrounding areas of Kongsfjorden provide an important material basis for clay minerals in the Kongsfjorden. Kaolinite may be mainly derived from the fluvial deposits, weathered from reddish sandstones and conglomerates during the Carboniferous *** is mainly derived from Proterozoic low-grade and medium-grade metamorphic phyllite, mica schist, and gneiss. While chlorite is mainly from Proterozoic low-grade metamorphic phyllite and mica schist. In the direction from the fluvio-glacial estuary to the sea of the glacier front of Kongsfjorden, illite increase gradually,and the content of kaolinite declines gradually. However, the change pattern of chlorite is insignificant, which may be related to the provenance. Kongsfjorden detritus is mainly transported by the fluvio-glacial streams and icebergs into the sea and deposited in the inner bay. Coarse sediments are rapidly deposited in the glacier front,estuary, and near-shore areas. Clay fraction begins to deposit significantly by 200–400 m after flowing into

关键词： Arctic Pole Kongsfjorden clay mineral provenance sedimentation

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Biomarker reconstruction of phytoplankton productiv-ity and community structure changes in the middle Okinawa Trough during the last 15 ka

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Chinese Science Bulletin 2008年第16期53卷 2552-2559页

作者： XING Lei ZHAO MeiXun ZHANG HaiLong LIU YanGuang shi xuefa Key Laboratory of Marine Chemistry Theory and Technology Ministry of Education Ocean University of China Qingdao 266100China Sate Key Laboratory of Marine Geology School of Ocean and Earth Science Tongji University Shanghai 200092 China Key Laboratory of Marine Sedimentology and Environmental Geology State oceanic AdministrationFirst Institute of Oceanography State Oceanic Administration Qingdao 266061 China

Biomarkers have been widely used to reconstruct phytoplankton productivity and community structure changes, and this method has been applied for the first time in the middle Okinawa Trough during the transition from the last deglaciation to the Holocene. The total content of all marine phytoplankton biomarkers, used as a total productivity indicator, reveals higher productivity during the deglaciation. The ratios of the biomarkers are used as community structure indicators which show that, compared with the Holocene, the contribution from haptophytes decreased while the contributions from diatoms and dinoflagellates increased during the deglaciation. The increased productivity during the deglacia- tion was likely caused by the stronger winter monsoon. Also increased nutrient supply from terrestrial sources contributes to the higher productivity due to lower sea-level, which is consistent with higher terrestrial biomarker (long-chain n-alkanols) content. These changes in the nutrient supply also con- tributed to the community structure changes in the Okinawa Trough.

关键词：浮游植物生物标记重建社区结构变化冰川消失

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A preliminary study on thermoluminescence characteristics of sediments from the North Pacific

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Acta Oceanologica Sinica 2007年第3期26卷 56-72页

作者： LU Huahua shi xuefa WU Yonghua YANG Gang WEI Jianwei REN Xiangwen Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China Key Laboratory of Marine Sedimentology and Environmental Geology First Institute of Oceanography State Oceanic Administration Qingdao 260061 China Graduate School Chinese Academy of Sciences Beijing 100049 China

Thirty-eight surficial deposit samples were collected from the equatorial North Pacific, and the natural thermoluminescence （TL） characteristics of both bulk and clay fraction samples （〈 2μm fractions） were studied by the FJ427 - AI automatic TL Dosimeter for the first time. With the measurements of clay mineral composition, element composition by XRD and ICP, the correlations between TL intensity and sedimentary environment proxies were analyzed, such as water depth, ratio of FeO to Fe2 O3 contents, LOI, and major clay mineral concentration, and it was found the bulk sample＇ s TL signal was stronger than the clay ones. Usually, increase in the clay components may result in the decrease of TL intensity. From the shape of TL curves, the pelagic sediments can be divided into two groups： the majority group has two glow peaks, in general, the first peak is broad and flat, but the second narrow and sharp; the minority group only has a single peak because the first is absent. The peak centers of TL curves are almost fixed, falling in the temperature sections 230 ~ 260 and 390 ~ 405℃ respectively. Lorentz model packed in the Origin 7.5 was chosen to deal with the TL curves. From the processing results, three parameters （H, C and A ） , corresponding to the height, center, and kurtosis of TL curve, were obtained to describe the curve characteristics. The correlations between TL curve parameters and sedimentary environment proxies were also calculated. On the basis of the above work, the relationship between TL characteristics and sediment type, mineral composition, sedimentary environment of surface sediments was discussed in the study area, and a conclusion is： sediments from the environment of shallower water, higher organic contents and weaker reductivity have stronger TL signals.

关键词： North Pacific surface sediments thermoluminescence sedimentary environment clay minerals

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Low-temperature alteration of oceanic island basalts and their contribution to transition metal circulation of the ocean

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Acta Oceanologica Sinica 2008年第2期27卷 35-54页

作者： BU Wenrui shi xuefa PENG Jiantang LIU Jihua Zhang Mingjie QI Liang Key Laboratory of Marine Sedimentology ＆ Environmental Geology First Institute of Oceanography State Oceanic Administration Qingdao 266061 China Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China College of Earth and Environmental Science Lanzhou University Lanzhou 730000 China

The major elements, rare earth elements （REE） and trace elements of four basalt samples from central and western Pacific ferro- manganese crust provinces have been analyzed using chemical methods and ICP - MS, respectively. The results indicate that the samples have been extensively altered and that the contents of their major elements have changed significantly. However, the similarity of REE partition patterns and trace element contents of basalt samples to those of fresh oceanic island basalts （OIB） indicate that the basalt samples originated as OIB. Because of low-temperature alteration, the contents of A1203 , Fe203 , MnO, K20 and P205 increased, while MgO and FeO decreased. Active components, such as magnesium and iron, were leached from OIB resulting in the relative enrichment of SiO2. The leaching of active components can cause the relative enrichment of REE, while the precipitation of LREE-rich ferromanganese oxides in vesicles and fissures not only causes an increase of REE contents, but also induces ＂fractionation＂ of LREE and HREE. Based on the enrichment mechanism of REE contents, the theoretical quantities of precipitated ferromanganese oxides and the depleted quantities of active components are calculated ： the depleted quantities of active components for the unit mass of fresh basalts vary in the range of 0.15 ～ 0. 657, and the precipitated quantities of ferromanganese oxides for the unit mass of fresh basahs vary in the range of 0. 006 ～ 0. 042. Of the major elements, the two most depleted are iron, and magnesium, with 18.28% ～ 70.95% of iron and 44.50% ～ 93.94% of magnesium in the fresh basalts was leached out. Theoretical calculation and geochemistry results both indicate that low-temperature alteration of basalts can supply abundant amount of metals to seawater, and may play an important role in ocean metal circulation.

关键词： oceanic island basahs ( OIB) low-temperature alteration ocean metal circulation theoretical calculation cobaltrich ferromanganese crusts

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The occurrence of gold in hydrothermal sulfide at Southwest Indian Ridge 49.6°E

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Acta Oceanologica Sinica 2012年第6期31卷 72-82页

作者： YE Jun shi xuefa YANG Yaomin LI Naisheng LIU Jihua SU Wenchao Institute of Oceanology Chinese Academy of SciencesQingdao 266007China First Insititute of Oceanography State Oceanic AdministrationQingdao 266061China Graduate University of the Chinese Academy of Sciences Beijing 100049China National Oceanographic Center Qingdao 266071China State Key Laboratory of Ore Deposit Geochemistry Chinese Academy of SciencesGuiyang 550002China

Massive sulfide precipitates found in the Southwest Indian Ridge （SWIR） 49.6°E hydrothermal field are enriched in gold. Here, the mineralogy and mineral chemistry of these massive sulfides to constrain the process of gold precipitation were studied. Sulfide samples in this field include lower- temperature Zn-rich sulfides and relative higher-temperature Fe-rich sulfides. Zn-rich sulfides are dominated by sphalerite-pyrite-chalcopyrite assemblages, with concentrations of gold ranging from 9.08 to 17.0 μg/g. Fe-rich sulfides consist mainly of pyrite-marcasite-isocubanite assemblages, with gold concentrations from 2.17 to 3.79 μg/g. The significant enrichment in gold within the lower- temperature Zn-rich sulfides and the effective separation of Zn and Fe in hydrothermal precipitates at the surface of this field are here interpreted to reflect the strong temperature dependence of gold transportation and deposition within the sulfides. In Zn-rich samples, large amounts of isolated native gold grains were identified. They were found mainly as inclusions up to 8 μm in diameter, occupying porous cavities in sphalerite or in the elevated iron content rim of sphalerite. The fineness of the gold ranged from 810 to 830. Unlike previously published results on other hydrothermal fields, these data show a low gold fineness values in SWIR 49.6°E. The FeS content of sphalerite associated with gold grains ranged from 3.2 mole % to 18.9 mole %. This was higher than in other fields, indicating that the sulfur activity is relatively low during the gold precipitation process and that sulfur activity may be one of the main factors affecting gold fineness in the SWIR 49.6°E hydrothermal field. Evidence regarding gold fineness and sulfur activity suggests that gold was quite likely transported as AuHS° rather than as a Au（HS）2- complex.

关键词： hydrothermal sulfide Southwest Indian Ridge occurrence of gold mineralogy

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Nature, Source and Composition of Volcanic Ash in Surficial Sediments Around the Zhongsha Islands

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Journal of Ocean University of China 2008年第2期7卷 154-160页

作者： YAN Quanshu shi xuefa WANG Xinyu Key Laboratory of Marine Sedimentology and Environment Geology State Oceanic Administration Qingdao 266100 P. R. China Guangxi Institute of Geological Survey Nanning 530023 P. R. China

Volcanic detrital sediments are a unique indicator for reconstructing the petrogenetic evolution of submarine volcanic terrains. Volcanic ash in surficial sediments around the Zhongsha Islands includes three kinds of volcanogenic detritus, i.e., brown volcanic glass, colorless volcanic glass and volcanic scoria. The major element characteristics show that bimodal volcanic activity may have taken place in the northern margin of the South China Sea, with brown volcanic glass and colorless volcanic glass repre- senting the mafic end-member and felsic end-member, respectively. Fractional crystallization is the main process for magma evolu- tion. The nature of the volcanic activity implies that the origin of volcanic activity was related to extensional tectonic settings, which is corresponding to an extensional geodynamic setting in the Xisha Trench, and supports the notion, which is based on geophysical data and petrology, that there may exist a mantle plume around the Hainan Island.

关键词： volcanic glass bimodal volcanic activity tectonic setting the South China Sea

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Trend analysis of sediment grain size and sedimentary process in the central South Yellow Sea

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Chinese Science Bulletin 2002年第14期47卷 1202-1207页

作者： shi xuefa CHEN Chunfeng LIU Yanguang REN Hong WANG Huiyan Key Lab of Marine Science and Numerical Modeling State Oceanic AdministrationQingdao 266061China First Institute of Oceanography State Oceanic AdministrationQingdao 266061China College of Marine Geosciences Ocean University of QingdaoQingdao 266003China

With the method of trend analysis of sediment grain size, the sediment transport trend of the fine-grained sediments area in the central South Yellow Sea was studied. The results demonstrated that there is a sedimentation center around the point of 123.4° E, 35.1°N, and the sediments outside the center are transported to it. The patterns of sediment transportation and deposition in the Yellow Sea should be controlled by cyclonic circulation (including the Yellow Sea Cold Water Mass) and cold water gyre. The study also showed that the method of trend analysis of sediment grain size has prospective utilization in the fine-grained sediment deposited area on large-scale continental shelf.

关键词： grain size trend analysis sediment transportation the central South Yellow Sea.

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The finding of natural GaN crystals in sediments from the East Pacific Ocean

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Chinese Science Bulletin 2006年第9期51卷 1101-1105页

作者： CHEN Jing shi xuefa ZHANG Haiping LUE Huahua FU Zhendong Electron Microscopy Laboratory School of Physics Peking University Beijing 100871 China Key Laboratory of Marine Sedimentology and Environmental Geo- logy First Institute of Oceanography State Oceanic Administration Qingdao 260061 China Graduate School of the Chinese Academy of Sciences Beijing 100049 China

The first finding of natural GaN crystals is reported in sediments from the East Pacific. They are identified by multiple micro-beam techniques such as TEM, EDS and EELS. Detailed examinations show that these GaN crystals are euhedral and authigenic, and belong to the hexagonal system (space group P63mc) with cell parameters: a = b = 0.3186 nm, c = 0.5178 nm. Structure data fit closely with those of the synthetic GaN crystals obtained from high-temperature and high-pressure experi- ments. Moreover, the nearly perfect euhedral form of the sample excludes the possible synthetic origin of the GaN crystals as artifacts with long transport. The sampling localities are located between the Clarion and Clipperton Fracture Zone in the East Pacific where ongoing hydrothermal activities, deformation, and volcanic eruptions are very intensive. It is sug- gested that the natural GaN crystals may form at relatively high-temperature and high-pressure condi- tions in geologic environments that have been af- fected by intense hydrothermal activities.

关键词：透射电子显微镜半导体 GaN 表面沉积太平洋

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Kr and Xe isotopic compositions of Fe-Mn crusts from the western and central Pacific Ocean and implications for their genesis

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Acta Oceanologica Sinica 2014年第8期33卷 26-33页

作者： BU Wenrui shi xuefa LI Li ZHANG Mingjie G.P.Glasby LIU Jihua Key Laboratory of Marine Sedimentology & Environmental Geology First Institute of OceanographyState Oceanic Administration School of Resources and Environment Lanzhou University Department of Geochemistry Geowissenschafliches Zentrum der Universitat G?ttingen (GZG)G?ttingen 37077Germany

Kr and Xe nuclide abundance and isotopic ratios of the uppermost layer of Fe-Mn Crusts from the western and central Pacific Ocean have been determined. The results indicate that the Kr and Xe isotopic composi-tions, like that of He, Ne and Ar, can be classified into two types： low3He/4He type and high3He/4He type. The low3He/4He type crusts have low84Kr and132Xe abundance, while the high3He/4He type crusts have high84Kr and132Xe abundance. The82Kr/84Kr ratios of the low3He/4He type crusts are lower than that of the air, while the83Kr/84Kr and86Kr/84Kr ratios are higher than those of the air. The Kr isotopic ratios of the high-er3He/4He type crusts are quite similar to those of the air. The128Xe/132Xe,130Xe/132Xe and131Xe/132Xe ratios of the low3He/4He type sample are distinctly lower than those of the air, whereas the129Xe/132Xe,134Xe/132Xe and136Xe/132Xe ratios are higher than those of the air. The low3He/4He type samples have the diagnostic characteristics of the MORB, with excess129, 131, 132, 134, 136Xe relative to130Xe compared with the solar wind. The128Xe/132Xe,130Xe/132Xe and131Xe/132Xe ratios of the high3He/4He type samples are slightly higher than those of the air, and the129Xe/132Xe,134Xe/132Xe and136Xe/132Xe ratios are qiute similar to those of the air. The noble gases in the Fe-Mn crusts are derived from the lower mantle, and they are a mixture of lower mantle primitive component, radiogenic component and subduction recycled component. The helium isotopic ra-tios of the low mantle reservoir are predominantly controlled by primitive He （3He） and U and Th radiogenic decayed He （4He）, but the isotopic ratios of the heavier noble gases, such as Ar, Kr and Xe, are controlled to different extent by recycling of subduction components. The difference of the noble isotopic compositions of the two type crusts is the result of the difference of the noble isotopic composition of the mantle source reservoir underneath the seamounts the crusts occurred, the noble gas

关键词： Fe-Mn crusts Kr and Xe isotopes mantle reservoir Pacific Ocean subduction recycling

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Clay mineral distribution characteristics of surface sediments in the South Mid-Atlantic Ridge

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Journal of Oceanology and Limnology 2023年第3期41卷 897-908页

作者： Qiannan HU Chuanshun LI Baoju YANG Xisheng FANG Huahua LÜ xuefa shi Jihua LIU Key Laboratory of Marine Geology and Metallogeny First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Laboratory for Marine Geology Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China

Clay minerals are usually considered as important indicators to identify sources in both terrigenous and marine *** particular,clay minerals in metalliferous sediments(MS)have long been studied in global oceans except in South Mid-Atlantic Ridge(SMAR)due to limited ***,32 MS and 34 non-MS(NMS)samples were analyzed to clarify the distribution characteristics and mineral compositions of clay *** the sediments were collected along the SMAR between 12°S and 27°*** removal of organic matter and carbonate,clay fractions(<2μm)were investigated by Xray diffraction(XRD)*** show that clay mineral assemblages of surface MS consist dominantly of smectite,less abundant illite,chlorite,and kaolinite in average weight percentage of 30%,21%,18%,and 16%,*** the other hand,clay mineral assemblages in the NMS consist mainly of illite,less abundant kaolinite,chlorite,and very scarce smectite in average weight percentage of 47%,29%,24%,and 0.2%,*** clay fractions in MS are mainly composed of amorphous or poorly crystallized Fe/Mn oxyhydroxides,clay mineral,quartz,and ***,the counterparts in the NMS are mainly composed of well-crystallized clay minerals,quartz,and plagioclase without the presence of Fe/Mn *** is suggested that most of the illite,kaolinite,and chlorite in both MS and NMS are likely aeolian dust in origin from South Africa *** addition,the abundance of kaolinite dominates the clay mineral assemblage at low latitudes,where the intensive chemical weathering of continental source rocks facilitating the formation of *** terms of smectite,it is indicated of authigenic origin in consideration of only smectite is available in several MS and the absence in ***,the MS samples with only smectite available are always accompanied by ***,it is assumed that most of smectite occurred in studied area is the results of interaction between hydrothe

关键词： metalliferous sediment South Mid-Atlantic Ridge(SMAR) clay mineral smectite

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