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| 1 | Major element,trace element,and Sr,Nd and Pb iso-tope studies of Cenozoic basalts from the South China Sea显示文摘The whole rock K-Ar ages of basalts from the South China Sea basin vary from 3.8 to 7.9 Ma, which suggest that intra-plate volcanism after the cessation of spreading of the South China Sea (SCS) is comparable to that in adjacent regions around the SCS, i.e., Leiqiong Peninsula, northern margin of the SCS, Indochina block, and so on. Based on detailed petrographic studies, we selected many fresh ba-saltic rocks and measured their major element, trace element, and Sr-Nd-Pb isotope compositions. Geochemical characteristics of major element and trace element show that these basaltic rocks belong to alkali basalt magma series, and are similar to OIB-type basalt. The extent of partial melting of mantle rock in source region is very low, and magma may experience crystallization differentiation and cu-mulation during the ascent to or storing in the high-level magma chamber. Sr-Nd-Pb isotopic data of these basaltic rocks imply an inhomogeneous mantle below the South China Sea. The nature of magma origin has a two end-member mixing model, one is EM2 (Enriched Mantle 2) which may be originated from mantle plume, the other is DMM (Depleted MORB Mantle). Pb isotopic characteristics show the Dupal anomaly in the South China Sea, and combined with newly found Dupal anomaly at Gakkel ridge in Arctic Ocean, this implies that Dupal anomaly is not only limited to South Hemisphere. In variation diagrams among Sr, Nd and Pb, the origin nature of mantle below the SCS is similar to those below Leiqiong peninsula, northern margin of the SCS and Indochina peninsula, and is different from those below north and northeast China. This study provides geochemical constraints on Hainan mantle plume. | YAN QuanShu SHI XueFa WANG KunShan BU WenRui XIAO Long | 2008 | Science China Earth Sciences2008，51，4： | 33 |
| 2 | Terrestrial carbon sinks in China and around the world and their contribution to carbon neutrality显示文摘Enhancing the terrestrial ecosystem carbon sink(referred to as terrestrial C sink) is an important way to slow down the continuous increase in atmospheric carbon dioxide(CO_(2)) concentration and to achieve carbon neutrality target.To better understand the characteristics of terrestrial C sinks and their contribution to carbon neutrality,this review summarizes major progress in terrestrial C budget researches during the past decades,clarifies spatial patterns and drivers of terrestrial C sources and sinks in China and around the world,and examines the role of terrestrial C sinks in achieving carbon neutrality target.According to recent studies,the global terrestrial C sink has been increasing from a source of (-0.2±0.9) Pg C yr^(-1)(1 Pg=1015g)in the 1960s to a sink of (1.9±1.1) Pg C yr^(-1) in the 2010s.By synthesizing the published data,we estimate terrestrial C sink of 0.20–0.25 Pg C yr^(-1) in China during the past decades,and predict it to be 0.15–0.52 Pg C yr^(-1) by 2060.The terrestrial C sinks are mainly located in the mid-and high latitudes of the Northern Hemisphere,while tropical regions act as a weak C sink or source.The C balance differs much among ecosystem types:forest is the major C sink;shrubland,wetland and farmland soil act as C sinks;and whether the grassland functions as C sink or source remains unclear.Desert might be a C sink,but the magnitude and the associated mechanisms are still controversial.Elevated atmospheric CO_(2) concentration,nitrogen deposition,climate change,and land cover change are the main drivers of terrestrial C sinks,while other factors such as fires and aerosols would also affect ecosystem C balance.The driving factors of terrestrial C sink differ among regions.Elevated CO_(2) concentration and climate change are major drivers of the C sinks in North America and Europe,while afforestation and ecological restoration are additionally important forcing factors of terrestrial C sinks in China.For future studies,we recommend the necessity for intensive and long-term ecosystem C monitoring over broad geographic scale to improve terrestrial biosphere models for accurately evaluating terrestrial C budget and its dynamics under various climate change and policy scenarios. | Yuanhe Yang Yue Shi Wenjuan Sun Jinfeng Chang Jianxiao Zhu Leiyi Chen Xin Wang Yanpei Guo Hongtu Zhang Lingfei Yu Shuqing Zhao Kang Xu Jiangling Zhu Haihua Shen Yuanyuan Wang Yunfeng Peng Xia Zhao Xiangping Wang Huifeng Hu Shiping Chen Mei Huang Xuefa Wen Shaopeng Wang Biao Zhu Shuli Niu Zhiyao Tang Lingli Liu Jingyun Fang | 2022 | Science China(Life Sciences)2022，65，5： | 32 |
| 3 | Petrologic perspectives on tectonic evolution of a nascent basin(Okinawa Trough) behind Ryukyu Arc: A review显示文摘Okinawa Trough is a back-arc, initial marginal sea basin, located behind the Ryukyu Arc–Trench System. The formation and evolution of the Okinawa Trough is intimately related to the subduction process of the Philippine Sea Plate beneath the Eurasian Plate since the late Miocene. The tectonic evolution of the trough is similar to other active back-arcs, such as the Mariana Trough and southern Lau Basin, all of which are experiencing the initial rifting and subsequent spreading process. This study reviews all petrologic and geochemical data of mafic volcanic lavas from the Okinawa Trough, Ryukyu Arc, and Philippine Sea Plate, combined with geophysical data to indicate the relationship between the subduction sources(input) and arc or back-arc magmas(output) in the Philippine Sea Plate–Ryukyu Arc–Okinawa Trough system(PROS). The results obtained showed that several components were variably involved in the petrogenesis of the Okinawa Trough lavas: sub-continental lithospheric mantle underlying the Eurasian Plate, Indian mid-oceanic ridge basalt(MORB)-type mantle, and Pacific MORB-type mantle. The addition of shallow aqueous fluids and deep hydrous melts from subducted components with the characteristics of Indian MORB-type mantle into the mantle source of lavas variably modifies the primitive mantle wedge beneath the Ryukyu and subcontinental lithospheric mantle(SCLM) beneath the Okinawa Trough. In the northeastern end of the trough and arc, instead of Indian MORB-type mantle, Pacific MORB-type mantle dominates the magma source. Along the strike of the Ryukyu Arc and Okinawa Trough, the systematic variations in trace element ratios and isotopic compositions reflect the first-order effect of variable subduction input on the magma source. In general, petrologic data, combined with geophysical data, imply that the Okinawa Trough is experiencing the 'seafloor spreading' process in the southwest segment, 'rift propagation' process in the middle segment, and 'crustal extension' process in the northeast segment, and a nascent ocean basin occurs in the southwest segment. | YAN Quanshu SHI Xuefa | 2014 | Acta Oceanologica Sinica2014，33，4： | 27 |
| 4 | Records of the East Asian winter monsoon from the mud area on the inner shelf of the East China Sea since the mid-Holocene显示文摘AMS14C dating and analysis of grain size,major elements and clay minerals were applied to Core MZ01 from the mud area on the inner shelf of the East China Sea.Based on the environmentally sensitive grain size,clay mineral and major element assemblages,the history of the East Asia winter monsoon since the mid-Holocene could be reconstructed.These three proxies,mean grain size(>9.71μm),chemical index of alteration(CIA)and ratio of smectite to kaolinite in particular,show similar fluctuation patterns. Furthermore,10 extreme values corresponding to the contemporary cooling events could be recognized since the mid-Holocene;these extreme values are likely to have been caused by the strengthening of the East Asia winter monsoon.The cooling events correlated well with the results of theδ18O curves of the Dunde ice core and GISP2,which therefore revealed a regional response to global climate change.Four stages of the East Asia winter monsoon were identified,i.e.8300-6300 a BP,strong and unstable;6300-3800 a BP,strong but stable;3800-1400 a BP,weak and unstable;after 1400 a BP,weak but stable. | LIU ShengFa SHI XueFa LIU YanGuang QIAO ShuQing YANG Gang FANG XiSheng WU YongHua LI ChaoXin LI XiaoYan ZHU AiMei GAO JingJing | 2010 | Chinese Science Bulletin2010，55，21： | 25 |
| 5 | Clay mineral composition and their sources for the fluvial sediments of Taiwan Residents rivers显示文摘Located at the collision boundary between the Philippine Sea Plate and the Eurasian Continental Plate,the island of Taiwan is generally recognized as an important example in the MARGINS Program Science Plan and 'source-to-sink' research because of its high tectonic activity,heavy rainfall and unique geography.Large suspended sediment loads are transported to the adjacent ocean by Taiwan Residents rivers every year,making Taiwan an important source of sediments into the adjacent seas and a natural laboratory for studying the systemic movement of fluvial sediments from source to sink.A detailed study on the clay mineral composition of surface sediments collected from the drainage basins of 12 Taiwan Residents rivers using X-ray diffraction methods was conducted.Our results indicated that the clay mineral assemblages consisted dominantly of illite(approximately 73%) and chlorite(approximately 24%),with lesser abundances of kaolinite(approximately 3%) and even lower levels of smectite from the Danshuei River sediments in northwestern Taiwan.The Jhuoshuei River sediments from western Taiwan contained clay mineral assemblages that consisted of illite(approximately 75%) and chlorite(approximately 25%),but they lacked kaolinite and smectite.In southwestern Taiwan,the clay mineral assemblages were dominated by illite(approximately 75%) and chlorite(approximately 23%),but had a low abundance of kaolinite(generally < 2%) and no smectite.The clay mineral assemblages in eastern Taiwan are obviously different from those in western parts of the island.The most noticeable difference is that the average abundance of chlorite in the Hualien River from eastern Taiwan was the highest(approximately 48%) of all the Taiwan Residents rivers.We concluded that,in general,the clay mineral assemblages in Taiwan Residents rivers were mainly composed of illite and chlorite with kaolinite and smectite being scarce,and these trends are different from those in China's mainland rivers.The clay mineral composition shown in this study was primarily determined by the properties of the bedrock,and the differential weathering intensities of the drainage area.The surface sediments in Taiwan's rivers showed a greater abundance of illite and chlorite because the outcropped rocks were mainly composed of Tertiary sedimentary rocks,especially sandstone,shale and slate,and show strong physical weathering.The relatively high relief and more abundant rainfall also caused the clay minerals in the fluvial sediments to be transported to the estuaries down rivers from the mountains and then delivered to the adjacent seas by currents and waves over a shorter time scale. | LI ChuanShun SHI XueFa KAO ShuhJi CHEN MinTe LIU YanGuang FANG XiSheng LUE HuaHua ZOU JianJun LIU ShengFa QIAO ShuQing | 2012 | Chinese Science Bulletin2012，57，6： | 23 |
| 6 | Trend analysis of sediment grain size and sedimentary process in the central South Yellow Sea显示文摘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. | SHI Xuefa CHEN Chunfeng LIU Yanguang REN Hong WANG Huiyan | 2002 | Chinese Science Bulletin2002，47，14： | 17 |
| 7 | Biomarker reconstruction of phytoplankton productiv-ity and community structure changes in the middle Okinawa Trough during the last 15 ka显示文摘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. | XING Lei ZHAO MeiXun ZHANG HaiLong LIU YanGuang SHI XueFa | 2008 | Chinese Science Bulletin2008，53，16： | 17 |
| 8 | Os isotopic compositions of a cobalt-rich ferromanganese crust profile in Central Pacific显示文摘187Os/188Os ratios in all sub-layers of the Co-rich ferromanganese crust MP5D17 from Line Seamount in Central Pacific have been systematically determined. The 187Os/188Os values in this crust are highly variable, ranging from 0.4262 to 1.0155. From the bottom to the top, the os-mium isotopic ratios of the crust display a regular variation trend, which correlates well with its changes in structure and texture in the vertical profile. In comparison with the evolu-tion curve of Os isotopic composition in seawater over the past 80 Ma, a similar evolution tendency can be found with respect to the Os isotopic composition of the crust in this study. It is preliminarily concluded that the crust MP5D17 began to grow at about 72 Ma, and underwent three growth hiatuses, corresponding to the geological ages of 64, 53 and 37 Ma, respectively. | FU Yazhou PENG Jiantang QU Wenjun HU Ruizhong SHI Xuefa DU Andao | 2005 | Chinese Science Bulletin2005，50，18： | 13 |
| 9 | Major and trace element geochemistry of the mid-Bay of Bengal surface sediments: implications for provenance显示文摘The major and trace elements in 110 surface sediment samples collected from the middle of the Bay of Bengal(mid-Bay of Bengal) are analyzed to investigate provenance. Si levels are highest, followed by Al, and the distributions of these two elements are identical. The average CIA*(chemical index of alteration) value is 72.07,indicating that the degree of weathering of the sediments in the study area is intermediate between those of sediments of the Himalayan and Indian rivers. Factor analyses and discrimination function analyses imply that the two main provenances are the Himalayan and the Indian continent. The inverse model calculation of the Tinormalized element ratios of the Bay of Bengal sediments indicate an estimated average contribution of 83.5%and 16.5% from the Himalayan and peninsular Indian rivers to the study area, respectively. The Himalayan source contributes more sediment to the eastern part of the study area, whereas the western part receives more sediment from the Indian Peninsula than did the eastern part. The primary mechanisms for deposition of sediments in the study area are the transport of Himalayan matter by turbidity currents and river-diluted water and the transport of Indian matter to the study area by a surface circulation in the Bay of Bengal, particularly the East India Coastal Current. | LI Jingrui LIU Shengfa FENG Xiuli SUN Xingquan SHI Xuefa | 2017 | Acta Oceanologica Sinica2017，36，3： | 12 |
| 10 | Potassium-argon/argon-40-argon-39 geochronology of Cenozoic alkali basalts from the South China Sea显示文摘Based on the isotopic chronologic results of Cenozoic alkali basalts from the South China Sea, the characteristics of volcanic activity of the South China Sea after spreading were studied. The potassium-argon ages of eight alkali basalt samples from the South China Sea, and the argon-argon ages of two samples among them are reported. Apparent ages of the whole rock are 3.80 to 7.91 Ma with an average value of 5.43 Ma (potassium-argon, whole rock), and there is little difference among samples at the same location, e.g., 4.76~5.78 Ma for location S04-12. The argon-argon ages for the two samples are 6.06 and 4.71 Ma, which lie within the age scope of potassium-argon method. The dating results indicate that rock-forming age is from late Miocene to Pliocene, which is consistent with erupting event for alkali basalts from adjacent regions of the South China Sea. Volcanic activities occur after the cessation of spreading of the South China Sea, which are controlled by lithospheric fault and the spreading center formed during the spreading period of the South China Sea. These dating results, combined with geochemical characteristics of these basalts, the published chronological data for the South China Sea and its adjacent regions, and the updated geophysical data near Hainan Island, suggest that after the cessation of spreading of the South China Sea, there occur widely distributing magmatic activities which primarily is alkali basalt, and the volcanic activity continues to Quaternary. The activity may be relative to Hainan mantle plume originated from core/mantle boundary. | YAN Quanshu SHI Xuefa YANG Yaomin WANG Kunshan | 2008 | Acta Oceanologica Sinica2008，27，6： | 11 |
| 11 | Geological comparative studies of Japan Arc System and Kyushu-Palau Arc显示文摘Based on the published data of structure geology,geochronology,petrology and isotope geochemistry,the authors of this paper have conducted studies on the tectonic evolution history of Japan arc system and Kyushu-Palau ridge(KPR) . The studies show that the initial Japan arc system was resulted from the subduction of ancient Pacific plate beneath Eurasian Plate in Permian. It was part of an Andean-type continental volcanic arc which occurred in the offshore in the east of Asian during late Mesozoic era. The formation of tertiary back-arc basin(Japan Sea) resulted in the fundamental tectonic framework of the present arc system. Since Quaternary the system has been lying at E-W compression tectonic setting due to the eastward subduction of Amur Plate. It is expected that Japan arc system will be juxtaposed with Asian continent,which is similar to the present Taiwan arc system. The origin of Philippine Sea Plate(PSP) is still in debate. Some studies argued that it is a trapped oceanic crust segment,while the others insisted that it is a back-arc basin accompanied with ancient IBM arc. However,it is all agreed that the tectonic evolution of PSP started since 50 Ma,i.e.,PSP has drifted from the site around equator at 50 Ma to the present site,and the subduction of PSP along Nankai trough-Ryukyu Trench beneath the Japan arc system during 6-2 Ma led to the formation of the present Ryukyu arc system. Of the PSP,the KPR has been found with the oldest rocks formed at 38 Ma. Combining with its geochemical characteristics of oceanic arc tholeiite,it is suggested that KPR is an intraoceanic volcanic arc,more specifically,a relic arc(i.e.,rear arc of the ancient IBM) after rifting of ancient IBM. In addition,Amami-Daito province is of arc tectonic affinity,but has been affected by mantle plume. Therefore,based on their respective tectonic evolution history and geochemical characteristics of rock samples,it is inferred that there is no genetic relationship between Japan arc system and KPR. It is noted that rocks reflecting continental crust basement feature have been collected on the northern tip of KPR,which may be related to the process of KPR accreting on Japan arc,but the arc-continent accretion process are still at initial stage of modern continental crust accretion model. However,due to the scarcity of data of the northern tip of KPR,crustal structure of this location and its adjacent Nankai trough need to be further constrained by geophysical studies in the future. | YAN Quanshu SHI Xuefa | 2011 | Acta Oceanologica Sinica2011，30，4： | 10 |
| 12 | Testing the mantle plume hypothesis: an IODP effort to drill into the Kamchatka-Okhotsk Sea basement显示文摘The great mantle plume debate(GPD) has been going on for ~15 years(Foulger and Natland, 2003;Anderson, 2004; Niu, 2005; Davies, 2005; Foulger, 2005; Campbell, 2005; Campbell and Davies, 2006),centered on whether mantle plumes exist as a result of Earth's cooling or whether their existence is purely required for convenience in explaining certain Earth phenomena(Niu, 2005). Despite the mounting evidence that many of the so-called plumes may be localized melting anomalies, the debate is likely to continue. We recognize that the slow progress of the debate results from communication difficulties.Many debaters may not truly appreciate(1) what the mantle plume hypothesis actually is, and(2) none of the petrological, geochemical and geophysical methods widely used can actually provide smoking-gun evidence for or against mantle plume hypothesis. In this short paper, we clarify these issues, and elaborate a geologically effective approach to test the hypothesis. According to the mantle plume hypothesis, a thermal mantle plume must originate from the thermal boundary layer at the core-mantle boundary(CMB), and a large mantle plume head is required to carry the material from the deep mantle to the surface. The plume head product in ocean basins is the oceanic plateau, which is a lithospheric terrane that is large(1000's km across), thick(>200 km), shallow(2–4 km high above the surrounding seafloors), buoyant(~1% less dense than the surrounding lithosphere), and thus must be preserved in the surface geology(Niu et al., 2003). The Hawaiian volcanism has been considered as the surface expression of a type mantle plume, but it does not seem to have a(known) plume head product. If this is true, the Hawaiian mantle plume in particular and the mantle plume hypothesis in general must be questioned. Therefore, whether there is an oceanic plateau-like product for the Hawaiian volcanism is key to testing the mantle plume hypothesis, and the Kamchatka-Okhotsk Sea basement is the best candidate to find out if it is indeed the Hawaiian mantle plume head product or not(Niu et al., 2003; Niu, 2004). | Yaoling Niu Xuefa Shi Tiegang Li Shiguo Wu Weidong Sun Rixiang Zhu | 2017 | Science Bulletin2017，62，21： | 8 |
| 13 | Distribution characteristics of magnetic susceptibility of the surface sediments in the southern Yellow Sea显示文摘The characteristic distributions of magnetic susceptibility (MS) are analyzed on the basis of susceptibility of 172 surface sediment samples in the southern Yellow Sea (SYS). The preliminary results are as follows: first, the distributions clearly correspond to different modern sediment assemblages in the continental sea, which indicates different sediment origins. With the 30 μCGS isoline being taken as demarcation line, the study area can then be divided into section H (high MS value area) and section L (low MS value area). Section H is mainly adjacent to land with two main sources of the Changjiang River and the Huanghe River.Section L is mainly an eddy sediment area, where Yellow Sea Cold Water is entrenched all the year round. The distribution pattern of MS could tell apart strong or weak hydrodynamic conditions and has a close relation to the circulation system in this area. At the areas of the SYS Circumfluent and northern East China Sea (NECS) Circumfluent (weak hydrodynamic), the MS has low values, while in the areas of Coastal Current (strong hydrodynamic), the values are high.At the same time, the oxidizing areas tend to take on higher MS, while the reducing areas have lower one. It seems safe to say that the MS in the continental sea reflects more of the sediment origin and sedimentary environment, which is different from that of loess, lake and surface soil as a climate proxy. | GE Shulan~(1,2,3), SHI Xuefa~1 & HAN Yibing~1 1. Key Laboratory of Marine Sedimentology and Environmental Geology, First Institute of Oceanography, State Oceanic Administration. Qingdao 266061. China 2. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029. China 3. Graduate School. Chinese Academy of Sciences, Beijing 100039. China | 2003 | Chinese Science Bulletin2003，48，B06： | 8 |
| 14 | Geochemistry and petrogenesis of Quaternary volcanism from the islets in the eastern Beibu Gulf: evidence for Hainan plume显示文摘Some of the islets in the eastern Beibu Gulf are covered by Quaternary volcano strata.The rock samples from these islets mainly consist of quartz tholeiites(at Shenjiandao),olivine tholeiites(at Linshidao and Xieyangdao)and alkali basalts(at Yangpubi and Jianshidao),and basically represent four periods of the Quaternary volcanism of Hainan Island and its adjacent regions.Except for the samples from Shenjiandao,most of the Quaternary volcanics of these islets belong to alkali magma series.The trace element characteristics of all of these samples show they are OIB(oceanic island basalt)-like,which implies that their deep geodynamic setting may be related to a mantle plume.The Sr-Nd-Pb isotopic compositions show that the mantle source beneath the Quaternary strata can be regarded as a result of binary mixing between a depleted,DMM(depleted MORB mantle)-like source and an enriched mantle type 2(EM2).The EM2 may be originated from the Hainan mantle plume,and has been metasomatized by carbonaceous fluids released from ancient recycled oceanic crust at an asthenospheric mantle level.These features,together with typical trace element ratios,reflect that the parent magma was not subjected to crustal contamination during its ascent to the surface.This study provides further petrological and geochemical evidence for the existence of the Hainan mantle plume. | LI Naisheng YAN Quanshu CHEN Zhihua SHI Xuefa | 2013 | Acta Oceanologica Sinica2013，32，12： | 7 |
| 15 | Growth ages of ferromanganese crusts from the western and central Pacific:Comparison between nannofossil analysis and ^(10)Be dating显示文摘Based on results of nannofossil analysis and 10Be dating in ferromanganese crusts M1-1 and A1-1 (no nannofossils were found in it),from the western and central Pacific respectively,it is found that the crust growth ages from nannofossil biostrati-graphy agree well with those based on 10Be isotope analysis. Both crusts have three growth layers,and the oldest layer was deposited in Miocene at about 12.80 Ma. The maximum,minimum,and average growth rates of crust A1-1 (from the central Pacific) are 8.11,1.92 and 3.47 mm/Ma,and those of crust M1-1 (from the western Pacific) are 2.93,0.47,and 0.94 mm/Ma. | CHENG Zhenbo SHI Xuefa WU Yonghua SU Xin LI Xiaoyan WANG Kunshan YANG Yongliang GE Shulan JU Xiaohua SHI Fengdeng M. Hiroyuki | 2006 | Chinese Science Bulletin2006，51，24： | 7 |
| 16 | The occurrence of gold in hydrothermal sulfide at Southwest Indian Ridge 49.6°E显示文摘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 lowertemperature 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 lowertemperature 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 AuHS0 rather than as a Au(HS)-2 complex. | YE Jun SHI Xuefa YANG Yaomin LI Naisheng LIU Jihua SU Wenchao | 2012 | Acta Oceanologica Sinica2012，31，6： | 7 |
| 17 | Turbidite and bottom-current evolution revealed by anisotropy of magnetic susceptibility of redox sediments in the Ulleung Basin,Sea of Japan显示文摘Anisotropy of magnetic susceptibility(AMS) from above and below 7.31 m in a core from the southern Ulleung Basin shows clear differences on an equal area projection of the lower hemisphere.Rather concentrated steep inclination of K 3 and horizontal inclination of K 1 and K 2(K1 ≥K2 ≥K3) are located within the upper part,and the latter two axes lie perpendicular to each other near the bedding plane.In contrast,random distribution of the three axes and extremely high value of shape parameters(Q=(K1-K2)/[(K1+K2)/2-K3]) are evident in the lower part,indicating complete destruction of the original sedimentary structure.This result is consistent with data from X-radiographs,which show numerous conglomerates,distortions and cleavages in the lower part.According to age models by Liu et al.(2010) and Zou et al.(2010),the bottom age at 7.31 m is 48 cal ka BP,and the time domain is discussed below.The degree of AMS(P) is low,1-1.08,and linearly related to the foliation(F)(R2 =0.95,N=176).The relationship between F and linearity(L) implies oblate aligning patterns that are typically sedimentary in origin.At least five redox couplets were found with the aid of S ratios and other rock magnetic parameters,and in most cases,the original signals of climate survived early diagenesis.The paleomagnetically reoriented AMS show corresponding changes with millennial events in the last 48 cal ka.Clearly tilted K 3 directions and reduction of P and F occurred within DO1-BA warm events,when melt water pulse 1A nd the YD cold event took place.The turbulent conditions therein,synchronous with coarsening of sediments,provide evidence of strong bottom currents and possible directional changes,as evidenced by different K3 tilting directions.A NE current direction in the last 4.5 cal ka is consistent with in situ measurements of bottom currents.Responses of AMS,mainly to climatic modulation,show on the one hand,the limited influence of diagenesis on rock magnetic signals and,on the other hand,the dramatic change of hydrodynamic conditions and terrigenous inputs during rapid sea level rise during the last deglaciation. | GE ShuLan SHI XueFa LIU YanGuang WANG KunShan ZOU JianJun DIAO JingYu ZHU ZhiWei WANG ChunJuan | 2012 | Chinese Science Bulletin2012，57，6： | 7 |
| 18 | Sm-Nd isotopic geochronologyof the Yinachang Fe-Cu-REE deposit at Wuding,Yunnan Province and its genetic significance显示文摘Sm-Nd isotope systematics of ores and fluorites places precise time constraints on REE mineralization of the Yinachang Fe-Cu-REE deposit in Yunnan Province which occur in the Proterozoic Kunyan group. The ore-related fluorites contain high abundant REE, and show a strong enrichment of LREE and a positive Eu anomaly, which is in marked contrast to post-ore fluorites that are HREE en-riched. The Sm-Nd isochron ages of the ores and fluorites are 1539±40 Ma and 1617±100 Ma, respectively, and calculated εNd(t) are ?4.6 and ?3.2. Accurate age determinations of the mineralization demonstrate that the REE mineralization took place during early Mesoproterozoic. Together with other geological evidence from the ore deposit, the primary REE-bearing ore-forming fluids are suggested to have been derived from the Enriched Mantle, and the Yinachang Fe-Cu-REE ore deposit is of volcanic exhalation- hydro-thermal sedimentary origin. This study also imply that the sudden large-scale REE mineralization in the Mesoprotero-zoic epoch may have been induced by alkaline-rich anoro-genic magmatism which occurred at marginal rifts of the continent in the Mesoproterozoic. | YANG Yaomin TU Guanzhi HU Ruizhong SHI Xuefa | 2005 | Chinese Science Bulletin2005，50，18： | 6 |
| 19 | Magnetostratigraphy of borehole EY02-2 in the southern Yellow Sea and its paleoenvironmental significance显示文摘Detailed rock magnetic and paleomag- netic studies have been undertaken on borehole EY02-2 (70m in length) in the southern Yellow Sea (SYS). The main Curie point revealed by magnetic susceptibility-temperature (k-T) curve is 580―600℃ indicating magnetite dominance. The hysteresis loop parameters show large variation of magnetic minera size in different sedimentary contexts: it is larger in subtidal sediment than in terrigenous sediment and even larger than in shallow sea sediment. This trend is correlative with distance to sediment source and dynamic strength. Magnetostratigraphic results show that the M/B polarity boundary (MBPB) is at 63.29m and there are at least 7 polarity transitions (Nr1-7) in Brunhes chron that can be tentatively correlated with 6 named polarity reversals. Three positive polarity reversals occur in late Matuyama chron and the early two may be the record of Kamikatsura happening in 886±3 kaB.P. Magnetic susceptibility (MS) and sediment grain size behave so differently in some sedimentary facies that certain big environmenta changes can be clearly revealed. Generally, the MS and grain size of subtidal and terrigenous sediments are larger than shallow sea sediments and MS value around 10×10?5SI and mean grain size of 7Φ seems to be indicators of shallow sea sediments of deep water depth. However, the frequently used excellen climatic proxies such as MS and grain size in loess and deep sea sediments fail to record such climatic cycles revealed by oxygen isotope in continental seaThe various sediment sources, sedimentation dy- namic and their complex changes between glacial and interglacial periods should be the cause of fail- ure. | GE Shulan SHI Xuefa ZHU Rixiang LIU Yanguang YIN Ping LIU Lejun | 2006 | Chinese Science Bulletin2006，51，7： | 6 |
| 20 | Distribution of major and trace elements in surface sediments of Hangzhou Bay in China显示文摘The Inductively Coupled Plasma Optical Emission Spectrometer was used to analyze sediment samples collected from the Hangzhou Bay to determine major and trace elemental concentrations. Based on these concentrations, the study area can be classified into three geochemical provinces. Province I covers the northern Hangzhou Bay area and contains high concentrations of Al_2 O_3 , Fe_2 O_3 , MgO, Na_2 O, K_2 O, MnO, Cr, Cu, Ni, Pb, V, Co and Zn. Province III is located in the western Hangzhou Bay, near the Qiantang River mouth, and contains high concentrations of SiO_2 , Na_2 O, P_2 O_5 , TiO_2 , Cr, Sr, Zr. Province II is located in the middle and eastern Hangzhou Bay, with the medium concentrations of major and trace elements. The results also demonstrate that the grain size is the dominating factor controlling the spatial variations of elemental concentrations, and the Changjiang River (Yangtze River) and Qiantang River sediments play an important role in the distribution of these elements. Anthropogenic impact on heavy metal concentrations (especially Cr, Sr and Zr) can be detected in the surface sediments near the Qiantang River mouth. | LIU Shengfa LIU Yanguang YANG Gang QIAO Shuqing LI Chaoxin ZHU Zhiwei SHI Xuefa | 2012 | Acta Oceanologica Sinica2012，31，4： | 5 |
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