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Tephra records from abyssal sediments off western Sumatra in recent 135 ka: evidence from Core IR-GC1

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Acta Oceanologica Sinica 2014年第12期33卷 75-80页

作者： QIU Zhongyan han xiqiu JIN Xianglong WANG Yejian ZHU Jihao Key Laboratory of Submarine Geosciences Second Institute of Oceanography State Oceanic Administration

Three volcanic ash layers were identified in a deep-sea Core IR-GC1 from the north-eastern Indian Ocean, adjacent to western Indonesian arc. They were dominated by glass shards with minor mineral crystals, such as plagioclase, biotite, and hornblende. According to the morphology and major element compositions of the representative glass shards, combined with theδ18O-based age, it is suggested that ash Layer A is cor-related to the youngest Toba tuff （YTT）, Layer B is supposed to be associated with a new eruption of Toba caldera in an age of 98 to 100 ka. Ash Layer C is different the geochemistry characteristics than those of Layer A and Layer B, suggesting that Layer C was not originated from Toba but registered another volcanic erup-tion event.

关键词： geochemistry glass shards youngest Toba tuff abyssal sediment

Evaluating a satellite-based sea surface temperature by shipboard survey in the Northwest Indian Ocean

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Acta Oceanologica Sinica 2016年第11期35卷 52-58页

作者： YANG Guang HE Hailun WANG Yuan han xiqiu WANG Yejian Ocean College Zhejiang University State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyState Oceanic Administration Key Laboratory of Submarine Geosciences Second Institute of OceanographyState Oceanic Administration

A summer-time shipboard meteorological survey is described in the Northwest Indian Ocean. Shipboard observations are used to evaluate a satellite-based sea surface temperature（SST）, and then find the main factors that are highly correlated with errors. Two satellite data, the first is remote sensing product of a microwave, which is a Tropical Rainfall Measuring Mission Microwave Imager（TMI）, and the second is merged data from the microwave and infrared satellite as well as drifter observations, which is Operational Sea Surface Temperature and Sea Ice Analysis（OSTIA）. The results reveal that the daily mean SST of merged data has much lower bias and root mean square error as compared with that from microwave products. Therefore the results support the necessary of the merging infrared and drifter SST with a microwave satellite for improving the quality of the SST. Furthermore, the correlation coefficient between an SST error and meteorological parameters, which include a wind speed, an air temperature, a relative humidity, an air pressure, and a visibility. The results show that the wind speed has the largest correlation coefficient with the TMI SST error. However, the air temperature is the most important factor to the OSTIA SST error. Meanwhile,the relative humidity shows the high correlation with the SST error for the OSTIA product.

关键词： shipboard survey sea surface temperature Northwest Indian Ocean Tropical Rainfall Measuring Mission Microwave Imager Operational Sea Surface Temperature and Sea Ice Analysis

Fractional crystallization processes of magma beneath the Carlsberg Ridge(57°–65°E)

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Journal of Oceanology and Limnology 2020年第1期38卷 75-92页

作者： ZONG Tong han xiqiu LIU Jiqiang WANG Yejian QIU Zhongyan YU Xing Key Laboratory of Submarine Geosciences and Prospection of Ministry of Education Ocean University of ChinaQingdao 266100China Key Laboratory of Submarine Geosciences State Oceanic Administration&Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China Ocean College Zhejiang UniversityZhoushan 316021China School of Oceanography Shanghai Jiaotong UniversityShanghai 200030China

Fractional crystallization of basaltic magma at variable depths influences strongly the geochemical compositions of mid-ocean ridge basalts(MORBs),especially at slow-spreading mid-ocean *** Carlsberg Ridge is a typical slow-spreading ridge located in the northwestern Indian *** this study,we conducted petrological,geochemical and modelling studies of MORBs collected along the Carlsberg Ridge from 57°-65°E to understand the fractional crystallization processes of magma and the controls on variations in MORB *** results show that the mantle sources beneath the Carlsberg Ridge are heterogeneous even on the local scale of a segment;such heterogeneity may be ubiquitous beneath the Carlsberg *** heterogeneity may be caused by the enriched components resulting in the"DUPAL"anomaly,whereas the effect of pyroxenite on mantle heterogeneity is *** parental melts experienced crystallization of olivine,plagioclase and clinopyroxene prior to eruption,which played a significant role in the major and trace element variations in MORBs from the Carlsberg *** liquid lines of descent(LLDs),deduced from the forward modelling of three parental magma compositions using the Petrolog3 program at pressures between 1 atm and 10 kbar,demonstrate that clinopyroxene joined the olivine and plagioclase *** over-enrichment in highly incompatible elements relative to LLDs may be caused by the processes of replenishment-tapping-crystallization in magma *** calculated crystallization pressures suggest that parental magmas beneath the Carlsberg Ridge experienced moderateto high-pressure crystallization and that crystallization beneath the slow-spreading Carlsberg Ridge may start at upper mantle depths.

关键词： fractional crystallization crystallization pressure mantle heterogeneity Carlsberg Ridge mid-ocean ridge basalt (MORB)

Distribution of large-scale detachment faults on mid-ocean ridges in relation to spreading rates

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Acta Oceanologica Sinica 2013年第12期32卷 109-117页

作者： YU Zhiteng LI Jiabiao LIANG Yuyang han xiqiu ZhanG Jie ZHU Lei Key Laboratory of Submarine Geosciences State Oceanic Administration The Second Institute of Oceanography State Oceanic Administration Institute of Oceanology Chinese Academy of Sciences China Ocean Mineral Resources Research and Development Association

Large-scale detachment faults on mid-ocean ridges （MORs） provide a window into the deeper earth. They have megamullion on their corrugated surfaces, with exposed lower crustal and upper mantle rocks, rela- tively high residual Bouguer gravity anomaly and P-wave velocity, and are commonly associated with ocean- ic core complex. According to 30 detachment faults identified on MORs, we found that their distances to the axis mostly range from 5 to 50 km, half-spreading rates range from 6.8 to 17 mm/a, and activity time ranges from recent to 3 Ma. Most of the detachment faults are developed on the slow spreading Mid-Atlantic Ridge （MAR） and ultra-slow spreading Southwest Indian Ridge （SWIRl, with the dominant half-spreading rates of 7-13 mm/a, especially 10-13 mm/a. Furthermore, they mostly occur at the inside corner of one segment end and result in an asymmetric seafloor spreading. The detachment faults on MORs are mainly controlled by the tectonism and influenced by the magmatism. Long-lived detachment faults tend to be formed where the ridge magma supply is at a moderate level, although the tectonism is a first-order controlling factor. At the slow spreading ridges, detachment faults tend to occur where local magma supply is relatively low, whilst at the ultra-slow spreading ridges, they normally occur where local magma supply is relatively high. These faults are accompanied by hydrothermal activities, with their relationships being useful in the study of hydrothermal polymetallic sulfides and their origin.

关键词： detachment faults oceanic core complex spreading rates distribution tectonism magmasupply hydrothermal vents

慢速扩张卡尔斯伯格脊远轴热液成矿作用的发现和意义

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大地构造与成矿学 2024年第5期48卷 1090-1108,I0001,I0002页

作者：严睿哲王叶剑杨铭周鹏蔡翌旸胡昕凯余星韩喜球自然资源部第二海洋研究所自然资源部海底科学重点实验室浙江杭州310012 浙江大学海洋学院浙江舟山316021

慢速扩张洋中脊是海底多金属硫化物勘查的重要地区,然而目前对离轴的大洋核杂岩(OCC)热液成矿作用的调查及认识非常有限。本文对卡尔斯伯格脊2.54°N附近一处离轴20 km处OCC采集的样品进行了详细的矿物学和元素地球化学研究。结果表明,... 详细信息

慢速扩张洋中脊是海底多金属硫化物勘查的重要地区,然而目前对离轴的大洋核杂岩(OCC)热液成矿作用的调查及认识非常有限。本文对卡尔斯伯格脊2.54°N附近一处离轴20 km处OCC采集的样品进行了详细的矿物学和元素地球化学研究。结果表明,蚀变玄武岩和石英角砾岩的矿物共生组合以及化学特征指示了高温热液蚀变与矿化过程,以及低温海底风化过程。从热液蚀变至矿化阶段,绿泥石化和黄铁矿化逐渐增强,部分亲石(Ca、Sr)、亲铜(Zn)和稀土元素迁出,Cu逐渐迁入。通过典型矿床黄铁矿对比分析发现,研究区蚀变玄武岩和石英角砾岩中的黄铁矿总体具有高Ni、Co和Se含量,以及高Ni/As值的特征,反映了高温和强还原的成矿流体性质,并受到深部超镁铁质围岩的影响。相比蚀变玄武岩中黄铁矿(PyⅠ),石英角砾岩黄铁矿(PyⅡ)更富集Co和Se,反映流体温度升高的趋势。此外,受到热液流体与海水混合作用等过程影响,在成矿后期Ag进一步在蚀变玄武岩黄铁矿中富集。本次研究证实了在远离脊轴的OCC区域,拆离断层的构造作用有利于深部热液矿化线索抬升至海床面,为慢速扩张洋中脊的硫化物资源分布规律与热液成矿机理等研究提供了新视角。

关键词：大洋核杂岩热液蚀变和矿化黄铁矿元素地球化学卡尔斯伯格脊

Lipid biomarker composition in surface sediments from the Carlsberg Ridge near the Tianxiu Hydrothermal Field

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Acta Oceanologica Sinica 2021年第8期40卷 53-64页

作者： Shengyi Mao Hongxiang Guan Lihua Liu xiqiu han Xueping Chen Juan Yu Yongge Sun Yejian Wang CAS Key Laboratory of Gas Hydrate Guangzhou Institute of Energy ConversionChinese Academy of SciencesGuangzhou 510640China Key Laboratroy of Submarine Geosciences&Second Institute of Oceanography Ministry of Natural ResourcesHangzhou 310012China School of Environmental and Chemical Engineering Shanghai UniversityShanghai 200444China Institute of Environmental and Biogeochemistry(eBig) School of Earth SciencesZhejiang UniversityHangzhou 310027China

Hydrothermal venting has a profound effect on the chemical and biological properties of local and distal seawater and sediments. In this study, lipid biomarkers were analyzed to examine the potential influence of hydrothermal activity on the fate of organic matter(OM) in surface sediments around Tianxiu Hydrothermal Field in the Carlsberg Ridge(CR), Northwest Indian Ocean. By comparing the biomarker distributions of the samples with that of other typical hydrothermal sediments in the mid ocean ridge, it is shown that the location of the samples is not affected by the hydrothermal activity. The relatively low abundances of terrestrial n-alkyl lipids and riverine1,15-C_(32) diol suggested a minor contribution of terrigenous OM to the study area. The bacteria contributed predominantly to sedimentary marine OM;however, other marine source organisms, e.g., eukaryotes(i.e.,phytoplankton and fungi) could not be completely neglected. The marine-originated biomarkers showed significantly variable distributions between the two sediments, suggesting different dynamic physical and biogeochemical processes controlling the fate of marine OM. This study identified various diagnostic biomarkers(5,5-diethyl alkanes, diols and β-OH FAs), which may have significant environmental implications for future works in this region.

关键词： Carlsberg Ridge Tianxiu Hydrothermal Field surface sediments biomarkers

Mineralogical and geochemical features of sulfide chimneys from the 49°39′E hydrothermal field on the Southwest Indian Ridge and their geological inferences

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Chinese Science Bulletin 2011年第26期56卷 2828-2838页

作者： TAO ChunHui LI HuaiMing HUANG Wei han xiqiu WU GuangHai SU Xin ZHOU Ning LIN Jian HE YongHua ZHOU JianPing Key Laboratory of Submarine Geosciences Second Institute of Oceanography State Oceanic Administration Hangzhou 310012 China Qingdao Institute of Marine Geology Qingdao 266071 China China University ofGeosciences (Beijing) Beijing 100083 China China Ocean Mineral Resources Research and DevelopmentAssociation Beijing 100860 China Woods Hole Oceanographic Institution Woods Hole MA 02543 USA

During January–May in 2007,the Chinese research cruise DY115-19 discovered an active hydrothermal field at 49°39′E/37°47′S on the ultraslow spreading Southwest Indian Ridge (SWIR).This was also the first active hydrothermal field found along an ultraslow-spreading *** analyzed mineralogical,textural and geochemical compositions of the sulfide chimneys obtained from the 49°39′E *** samples show a concentric mineral zone around the fluid *** mineral assemblages of the interiors consist mainly of chalcopyrite,with pyrite and sphalerite as minor *** the intermediate portion,pyrite becomes the dominant mineral,with chalcopyrite and sphalerite as minor *** the outer wall,the majority of minerals are pyrite and sphalerite,with few *** the outer margin of the chimney wall,the mineral grains become small and irregular in shape gradually,while minerals within interstices are *** features are similar to those chimney edifices found on the East Pacific Rise and Mid-Atlantic *** average contents of Cu,Fe and Zn in our chimney samples were 2.83 wt%,45.6 wt% and 3.28 wt%,*** average Au and Ag contents were up to 2.0 ppm and 70.2 ppm respectively,higher than the massive sulfides from most hydrothermal fields along mid-ocean *** rare earth elements geochemistry of the sulfide chimneys show a pattern distinctive from the sulfides recovered from typical hydrothermal fields along sedimentstarved mid-ocean ridge,with the enrichment of light rare earth elements but the weak,mostly negative,Eu *** is attributed to the distinct mineralization environment or fluid compositions in this area.

关键词：块状硫化物地球化学特征南印度洋热液场矿物学烟囱大西洋中脊稀土元素地球化学

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俯冲循环组分对大洋地幔不均一性的定量约束

地球科学 2022年第7期47卷 2616-2630页

作者：胡航余星韩喜球自然资源部第二海洋研究所自然资源部海底科学重点实验室浙江杭州310012 上海交通大学海洋学院上海200240

大洋地幔内部存在广泛的不均一性,其成因可有多种模式,其中俯冲循环作用对地幔组成的变化具有重要影响.为明确各循环组分对亏损地幔的改造作用及其在富集源区中的相对贡献,系统总结了不同循环组分(远洋沉积物、俯冲洋壳、陆壳)的平均微... 详细信息

大洋地幔内部存在广泛的不均一性,其成因可有多种模式,其中俯冲循环作用对地幔组成的变化具有重要影响.为明确各循环组分对亏损地幔的改造作用及其在富集源区中的相对贡献,系统总结了不同循环组分(远洋沉积物、俯冲洋壳、陆壳)的平均微量元素特征,计算了各循环组分在俯冲过程中经历的化学变化.基于改造后的循环组分,开展与亏损地幔源区的混合和熔融模拟.结果表明,HIMU型玄武岩可以由纯俯冲洋壳(≤10%)与亏损地幔(≥90%)混合形成的源区,经较低程度熔融(0.5%~1.5%)形成;而EMI型玄武岩可以由俯冲洋壳(≤10%)、俯冲剥蚀的下陆壳物质(≤3%)、亏损地幔(≥90%)混合形成的源区,经较低程度熔融(1%~2%)形成;EMII型玄武岩可以由俯冲洋壳(≤10%)、GLOSS-II(全球俯冲沉积物)或上陆壳物质(≤0.8%)与亏损地幔(≥90%)混合形成的源区,经较低程度熔融(1%~1.5%)形成.

关键词：地幔不均一性俯冲洋壳俯冲沉积物亏损地幔部分熔融地球化学

Comparative study on the mineralogy and geochemistry of sediments near active and inactive hydrothermal sites of Wocan hydrothermal field on Carlsberg Ridge, Northwest Indian Ocean

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Comparative study on the mineralogy and geochemistry of sedi...