检索结果-南通市图书馆

Acta Oceanologica Sinica 2015年第8期34卷 27-34页

作者： YANG Baoju ZENG Zhigang WANG Xiaoyuan seafloor hydrothermal activity laboratory of the key laboratory of marine geology and environment Institute of Oceanology Chinese Academy of Sciences University of Chinese Academy of Sciences

Si-Fe-Mn-oxyhydroxides dredged at the PACMANUS （Papua New Guinea-Australia-Canada-Manus） hydrothermal field, Eastern Manus Basin, have 87Sr/SSSr=0.708 079-0.708 581; eNd=5.149 833-6.534 826; 208pb/204pb=38.245-38.440; 207pb/204pb=lS.503-15.560; 206pb/204pb=lS.682-18.783. s7sr/sSSr isotope ratios are relatively homogeneous and close to the value of the surrounding seawater （0.709 16）. The content of Sr in the samples contributed by seawater was estimated to be 76.7%-83.1% of total amount. The mixing temperature of hydrothermal fluids and seawater were ranging from 53.2℃ to 72.2℃ and the hydrothermal activities were unstable when the samples precipitated. The eNd values of all the samples are positive, which differ from the values of ferromanganese nodules （crusts） with hydrogenic origin. Nd was mainly derived from substrate rocks leached by hydrothermal circulation and preserved the hydrothermal signature. Ph isotopic compositions of most samples show minor variability except Sample #9-2 that has relatively high values of Pb isotopes. The Pb may be derived from the Eastern Manus Basin rocks leached by the hydrothermal fluid. The slightly lower 28pb/204pb and 207pb/204pb values of the samples indicated that the hydrothermal circulation in PACMANUS was not entire and sufficient, or that hydrothermal circulation had transient changes in the past. Si-Fe-Mn-oxyhydroxides in the samples preserved the heterogeneities of local rocks.

关键词： Si-Fe-Mn-oxyhydroxides PACMANUS hydrothermal field Sr-Nd-Pb isotopes

Pourbaix diagrams to decipher precipitation conditions of Si-Fe-Mn-oxyhydroxides at the PACMANUS hydrothermal field

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2014年第12期33卷 58-66页

作者： YANG Baoju ZENG Zhigang WANG Xiaoyuan YIN Xuebo CHEN Shuai seafloor hydrothermal activity laboratory of the key laboratory of marine geology and environment Institute of Oceanology Chinese Academy of Sciences University of Chinese Academy of Sciences

Utilizing Si, Fe and Mn concentrations within the end-member PACMANUS hydrothermal fluid, Si-Fe-Mn-H2O Pourbaix diagrams were constructed at 300℃and 25℃. ThePourbaix diagrams show that the main Si, Fe and Mn oxides species precipitating from the hydrothermal fluid were SiO2, Fe（OH）3, Fe3（OH）8, Mn3O4, and Mn2O3at 25℃. During mixing of hydrothermal fluid with seawater, SiO2 precipitated earlier than Fe-Mn-oxyhydroxides because of the lower stability boundary. Then Fe（OH）2 precipitated first, followed by Fe3（OH）8 and Fe（OH）3, and last, small amounts of Mn3O4 and Mn2O3 precipitated. Fe（OH）3was readily de-posited in alkaline solution with little influence by Eh. There were many Si-Fe-Mn-concentric particles in the polished sections of the massive precipitates collected from PACMANUS. In the concentric nucleus and ellipsoid, Si oxides precipitated first before the hydrothermal fluid had mixed with seawater. In the concen-tric nucleus, after the precipitation of Si oxides, the increase of pH and Eh promoted the precipitation of Mn oxides around the Si oxides. In the large ellipsoid, the precipitation of Fe was divided into two periods. In the early period, increase of pH value of hydrothermal fluid produced by low-temperature convection and an input of a small volume of seawater promoted a small amount of Fe（OH）3 to precipitate in the Si-rich core. In the late period, after complete mixing with seawater and the resultant fluid was close to neutral or slightly alkaline in pH, Fe（OH）3was easily precipitated from the solution and distributed around the Si-rich core.

关键词： Si-Fe-Mn-oxyhydroxides PACMANUS hydrothermal field Pourbaix diagrams

Genesis of anhydrite in hydrothermally altered basalt from the East Pacific Rise near 13°N

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2013年第2期32卷 12-17页

作者： CHEN Shuai WANG Xiaoyuan YIN Xuebo ZHANG Guoliang seafloor hydrothermal activity laboratory of the key laboratory of marine geology and environment Institute of OceanologyChinese Academy of Sciences Graduate University of Chinese Academy of Sciences

This study reports the occurrence of anhydrite in hydrothermally altered pillow basalt （12°50.55＇N, 103°57.62＇W, water depth 2 480 m）, which may have been produced in the basalt during seawater-basalt interaction in the laboratory. The existence of anhydrite in the altered basalt indicates extensive high- temperature hydrothermal alteration at the surface of seafloor pillow basalt. Microprobe analysis shows significant chemical zoning in the hydrothermally altered pillow basalt, in which Ca, Si and A1 contents de- crease and P, Fe, Mn, Cr and S contents increase from fresh basalt to altered basalt. The negative correlation between Rb-Sr and Li-Sr, and negative correlation between Li-Ca and Rb-Ca in the high-temperature vent fuids show that these fluids underwent anhydrite precipitation before fluid jetting due to mixing with sea- water in the sub-seafloor. Based on these observations, we show that not all Ca in the anhydrite comes from basalt in the reaction zone, and that the basalts on the seafloor or in the upflow zone may also provide Ca for anhydrite.

关键词： anhydrite hydrothermal alteration pillow basalt East Pacific Rise 13°N

Characteristics of silicon and oxygen isotopic compositions of basalts near East Pacific Rise 13°N

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2013年第12期32卷 104-108页

作者： WANG Xiaoyuan ZHAO Huijing ZENG Zhigang YIN Xuebo CHEN Shuai MA Yao seafloor hydrothermal activity laboratory of the key laboratory of marine geology and environment Institute of OceanologyChinese Academy of Sciences Graduate University of Chinese Academy of Sciences

In this study, 13 groups of silicon and oxygen isotopes and major elements of the basalts near the East Pacific Rise 13°N are used to study the fractionation of silicon and oxygen isotopes. Among these data, δ30Si values of basalts vary from -0.4%o to 0.2%o with a mean value of δ30Si of （-0.18±0.22）%o. The δ180 values range from 4.1%o to 6.4%o with a mean δ180 value of （＋5.35±0.73） %0. Since the δ30Si values increase in the series of basalt-basaltic andesite- andesite, and δ180 values display a positive correlation with the SiO2 content, we propose that the fractionation of silicon and oxygen isotopes is influenced by the SiO2 content in igneous rocks. Compared with the igneous rocks from Manus Basin with clinopyroxene as their dominant mineral phase, MORBs in this study containing olivine and plagioclase as primary minerals have lower δ180 and δ30Si values, indicating that the fractionation of silicon and oxygen isotopes is also affected by different Si-O bridges in silicate minerals. Furthermore, our samples from the EPR are defined as E-MORB based on K/Ti ratios. Probably, the difference in δ30Si and δ30O between our samples and a normal MORB are cause by the enriched components in E-MORBs.

关键词： silicon and oxygen isotopes basalt East Pacific Rise near 13°N

Silicon and Oxygen Isotopic Composition of Igneous Rocks from the Eastern Manus Basin

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2014年第3期13卷 421-427页

作者： ZHAO Huijing ZENG Zhigang YIN Xuebo CHEN Shuai seafloor hydrothermal activity laboratory of the key laboratory of marine geology and environment Institute of Oceanology Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences

This paper reports silicon and oxygen isotopes of 20 kinds of igneous rocks and their major elements from the eastern Manus Basin. Combining silicon and oxygen isotopic data from other studies, we suppose that both δ30Si and δ18O values increase with the increasing of SiO2 content. It means that the fractionation of silicon and oxygen isotopes are affected by the silica content. The positive correlation between CaO/Al2O3 ratios and MgO and that between Si/Al and SiO2 content indicate that clinopyroxene is the predominant mineral phase in our samples. We suppose that the fractionation of silicon and oxygen isotopes are influenced by mineral fractional crystallization. Probably, it is due to their different silicon and oxygen bridges. In this study, the δ30Simean value=-0.17‰±0.17‰ and δ18Omean value= +6.07‰±0.57‰ are higher than normal δ30Si and δ18O values of mantle, and we propose that these igneous rocks in the eastern Manus Basin are affected by hydrothermal alteration.

关键词： Si isotope O isotope igneous rocks eastern Manus Basin

Geochemical and isotopic characteristics of volcanic rocks from the northern East China Sea shelf margin and the Okinawa Trough

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2010年第4期29卷 48-61页

作者： ZENG Zhigang YU Shaoxiong WANG Xiaoyuan FU Yongtao YIN Xuebo ZHANG Guoliang WANG Xiaomei CHEN Shuai seafloor hydrothermal activity laboratory of the key laboratory of marine geology and environment Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China Graduate School of Chinese Academy of Sciences Beijing 100049 China

Volcanic rocks both from the northern East China Sea （NECS） shelf margin and the northern Okinawa Trough are subalkaline less aluminous,and lower in High Field Strength Elements （HFSE）.These rocks are higher in Large Ion Lithophile Elements （LILE）,thorium and uranium contents,positive lead anomalies,negative Nb-Ta anomalies,and enrichment in Light Rare Earth Elements （LREE）.Basalts from the NECS shelf margin are akin to Indian Ocean Mid-Ocean Ridge Basalt （MORB）,and rhyolites from the northern Okinawa Trough have the highest 207 Pb/ 204 Pb and 208 Pb/ 204 Pb *** NECS shelf margin basalts have lower 87 Sr/ 86 Sr ratios,ε N d and σ 18 O than the northern Okinawa Trough silicic *** to 40 K– 40 Ar isotopic ages of basalts from the NECS shelf margin,rifting of the Okinawa Trough may have been active since at least 3.65–3.86 *** origin of the NECS shelf margin basalt can be explained by the interaction of melt derived from Indian Ocean MORB-like mantle with enriched subcontinental *** basalts from both sides of the Okinawa Trough may have a similar origin during the initial rifting of the Okinawa Trough,and the formation of basaltic magmas closely relates to the thinning of continental *** source of the formation of the northern Okinawa Trough silicic rocks was different from that of the middle Okinawa Trough,which could have been generated by the interaction of basaltic melt with an enriched crustal *** the Ryukyu island arc to East China,the Cenozoic basalts have apparently increasing trends of MgO contents and ratios of LREE to Heavy Rare Earth Elements （HREE）,suggesting that the trace element variabilities of basalts may have been influenced by the subduction of the Philippine Sea plate,and that the effects of subduction of the Philippine Sea plate on the chemical composition of basaltic melts have had a decreasing effect from the Ryukyu island arc to East China.

关键词： volcanic rocks geochemical characteristics northern East China Sea shelf margin Okinawa Trough

New insights into the origin of the bimodal volcanism in the middle Okinawa Trough： not a basalt-rhyolite differentiation process

在线全文

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2018年第2期12卷 325-338页

作者： Yuxiang ZHANG Zhigang ZENG Shuai CHEN Xiaoyuan WANG Xuebo YIN seafloor hydrothermal activity laboratory of the key laboratory of marine geology and environment Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China laboratory for marine Mineral Resources Qingdao National Laboratory for Marine Science and Technology Qingdao 266071 China University of Chinese Academy of Sciences Beijing 100049 China

In the middle Okinawa Trough （MOT）,rhyolites have been typically considered as products ofcrystallization differentiation of basaltic magma as afeature of bimodal volcanism. However, the evidence isinsufficient. This paper compared chemical trends ofvolcanic rocks from the MOT with fractional crystal-lization simulation models and experimental results andutilized trace element modeling combined with Rayleighfractionation calculations to re-examine fractional crystal-lization processes in generating rhyolites. Both qualitativeand quantitative studies indicate that andesites, rather thanrhyolites, originate by fractional crystallization frombasalts in the MOT. Furthermore, we established twobatch-melting models for the MOT rhyolites and proposedthat type 1 rhyolites are produced by remelting of andesiteswith amphiboles in the residue, while type 2 rhyolites arederived from remelting of andesites without residualamphiboles. It is difficult to produce melts with a SiO2content ranging from 62% to 68% either by magmaticdifferentiation from basalts or by remelting of andesites,and this difficulty might help account for the compositionalgap （Daly gap） for bimodal volcanism in the OkinawaTrough.

关键词： Okinawa Trough rhyolite andesite remelting fractional crystallization

Elemental and isotopic compositions of the hydrothermal sulfide on the East Pacific Rise near 13°N

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2010年第2期53卷 253-266页

作者： ZENG ZhiGang1,CHEN DaiGeng1,2,YIN XueBo1,WANG XiaoYuan1,ZHANG GuoLiang1,2 & WANG XiaoMei1,2 1 seafloor hydrothermal activity laboratory of the key laboratory of marine geology and environment,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China 2 Graduate School of Chinese Academy of Sciences,Beijing 100049,China 1. seafloor hydrothermal activity laboratory of the key laboratory of marine geology and environment Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China2. Graduate School of Chinese Academy of Sciences Beijing 100049 China

The mineralogical,elemental,and isotopic characteristics of a hydrothermal sulfide sample from one dredge station (12°42.30’N,103°54.48’W,water depth 2655 m) on the East Pacific Rise near 13°N were *** hydrothermal sulfide was composed mainly of sphalerite,chalcopyrite,and pyrite and was a Zn-rich sulfide;in layer ep-s-1,goethite formed by secondary oxidation was *** concentrations of rare elements,such as Li (0.15×10-6-0.30×10-6),Be (0.01×10-6-0.05×10-6),Zr (73.8×10-9-1344×10-9),Nb (8.14×10-9-64.7×10-9),Hf (2.54×10-9-28.0×10-9),and Ta (0.203×10-9-1.21×10-9),were far lower in the hydrothermal sulfide than in the ocean crust,whereas the content of Au was higher and the contents of Co,Ni,Sr,Cs,Ba,Bi,and U were *** correlations between Zn and Cr,Cd and Ga,Cu and P,P and In (R2 > 0.8) were positive,whereas those between Zn and Fe,Cu,and Ba (R2 > 0.8) were distinctly *** low-temperature mineral assemblages to high-temperature mineral assemblages,the spatial distributions of dispersive and rare elements (***,Li,Cs) in the hydrothermal sulfide displayed corresponding *** variations observed in some elements (e.g.,Cd,Cs,P) are controlled by Zn,Fe,and Cu sulfides,*** weathering accounts for the enrichment of V,Mn,and rare earth elements (REE) in the henna sulfide-oxidation layer that bears the secondary oxide mineral,leading to identical REE patterns for this layer (ep-s-1) and *** weathering also distinctly affects the correlations between the element ratios of the hydrothermal *** high-temperature mineral assemblages to low-temperature mineral assemblages,Fe content and δ 34S value of the hydrothermal sulfide increase gradually,and Zn content and lead isotopic ratios decrease gradually on the contrary,which indicate the influences of seawater on elements and the sulfur and lead isotopic compositions enhance gradually during the formation of hydrothermal sulfides.

关键词： variation element isotopic composition hydrothermal sulfide East Pacific Rise 13oN

Smectite formation in metalliferous sediments near the East Pacific Rise at 13°N

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2018年第9期37卷 67-81页

作者： RONG Kunbo ZENG Zhigang YIN Xuebo CHEN Shuai WANG Xiaoyuan QI Haiyan MA Yao seafloor hydrothermal activity laboratory of the key laboratory of marine geology and environment Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China laboratory for marine Mineral Resources Qingdao National Laboratory for Marine Science and Technology Qingdao 266071 China University of Chinese Academy of Sciences Beijing 100049 China

A 43 cm long E271 sediment core collected near the East Pacific Rise（EPR） at 13°N were studied to investigate the origin of smectite for understanding better the geochemical behavior of hydrothermal material after deposition.E271 sediments are typical metalliferous sediments. After removal of organic matter, carbonate, biogenic opal,and Fe-Mn oxide by a series of chemical procedures, clay minerals（〈2 μm） were investigated by X-ray diffraction,chemical analysis and Si isotope analysis. Due to the influence of seafloor hydrothermal activity and close to continent, the sources of clay minerals are complex. Illite, chlorite and kaolinite are suggested to be transported from either North or Central America by rivers or winds, but smectite is authigenic. It is enriched in iron, and its contents are highest in clay minerals. Data show that smectite is most likely formed by the reaction of hydrothermal Fe-oxyhydroxide with silica and seawater in metalliferous sediments. The Si that participates in this reaction may be derived from siliceous microfossils（diatoms or radiolarians）, hydrothermal fluids, or detrital mineral phases. And their δ30 Si values are higher than those of authigenic smectites, which implies that a Si isotope fractionation occurs during the formation because of the selective absorption of light Si isotopes onto Feoxyhydroxides. Sm/Fe mass ratios（a proxy for overall REE/Fe ratio） in E271 clay minerals are lower than those in metalliferous sediments, as well as distal hydrothermal plume particles and terrigenous clay minerals. This result suggests that some REE are lost during the smectite formation, perhaps because their large ionic radii of REE scavenged by Fe-oxyhydroxides preclude substitution in either tetrahedral or octahedral lattice sites of this mineral structure, which decreases the value of metalliferous sediments as a potential resource for REE.

关键词： metalliferous sediments smectite formation REE silicon isotope

Origin of a native sulfur chimney in the Kueishantao hydrothermal field, offshore northeast Taiwan

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2007年第11期50卷 1746-1753页

作者： ZENG ZhiGang1, LIU ChangHua1,2, CHEN ChenTung A3, YIN XueBo1, CHEN DaiGeng1,2, WANG XiaoYuan1,2, WANG XiaoMei1,2 & ZHANG GuoLiang1,2 1 seafloor hydrothermal activity laboratory of the key laboratory of marine geology and environment, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China 2 Graduate University of Chinese Academy of Sciences, Beijing 100049, China 3 Institute of marine geology and Chemistry, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, China 1. seafloor hydrothermal activity laboratory of the key laboratory of marine geology and environment Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China 2. Graduate University of Chinese Academy of Sciences Beijing 100049 China 3. Institute of marine geology and Chemistry National Sun Yat-Sen University Kaohsiung 804 Taiwan China

Analyses of rare earth and trace element concentrations of native sulfur samples from the Kueishantao hydrothermal field were performed at the seafloor hydrothermal activity laboratory of the key Labo-ratory of marine geology and environment, Institute of Oceanology, Chinese Academy of Sciences. Using an Elan DRC II ICP-MS, and combining the sulfur isotopic compositions of native sulfur samples, we studied the sources and formation of a native sulfur chimney. The results show, when comparing them with native sulfur from crater lakes and other volcanic areas, that the native sulfur content of this chimney is very high (99.96%), the rare earth element (REE) and trace element constituents of the chimney are very low (ΣREEseafloor fluid-andesite at the Kueishantao hydrothermal field was of short duration. The sulfur isotopic compo-sitions of the native sulfur samples reveal that the sulfur of the chimney, from H2S and SO2, originated by magmatic degassing and that the REEs and trace elements are mostly from the Kueishantao ande-site and partly from seawater. Combining these results with an analysis of the thermodynamics, it is clear that from the relatively low temperature (environment is favorable for formation of this native sulfur chimney in the Kueishantao hydrothermal field.

关键词： origin,native sulfur chimney,Kueishantao hydrothermal field,northeast Taiwan