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Independent magma system underneath micro non-transform discontinuity: geochemical evidence of magma from Daxi area， Carlsberg Ridge

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Journal of Earth Science 2024年

作者： hang Hu xiqiu han Yejian Wang Zhongyan Qiu Tong Zong Jiqiang Liu Honglin Li Xing Yu Key Laboratory of Submarine Geosciences， & Second Institute of Oceanography， Ministry of Natural Resources Ocean College， Zhejiang University College of Architectural Engineering， Weifang University

The discontinuities of a ridge， defined by the geophysical properties， often coincides with geochemical variations in lava， highlighting the relationship between ridge discontinuity and the underlying magmatic system. This study presents bathymetric， geophysical， and basaltic geochemical data from the Daxi-non transform discontinuity (NTD) and adjacent segments. The Daxi-NTD is a typical micro-NTD， with an offset less than 15 km. Within the NTD， a neo-volcanic ridge has emerged， with an active hydrothermal system suggesting an underlying magmatic system. The study examines mantle composition， melting degree， crystallization pressure， and melt extraction processes beneath Daxi-NTD. Comparative analysis reveals that basalts in the Daxi area undergo extensive differentiation， characterized by higher crystallization pressure and lower melting degree compared to the adjacent segments. We propose that Daxi-NTD hosts an independent magmatic system， where melt migrates vertically through the magmatic system rather than laterally from the adjacent segment center. This approach aids in understanding of the magmatism along slow-spreading ridges and provides insights into the geodynamics and tectonic evolution of younger ridge system.

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卡尔斯伯格脊天休洋脊段的深部岩浆过程:来自洋中脊玄武岩中单斜辉石结晶条件的约束

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岩石学报 2024年第7期40卷 2203-2214页

作者：颉炜谭文睿韩喜球余星李谋王志朗姜翰费小倩河海大学海洋学院自然资源部海洋灾害预报技术重点实验室南京210024 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杭州310012 浙江省海洋科学院杭州310000 自然资源部海洋空间资源管理技术重点实验室杭州310000

洋中脊玄武岩(MORB)是了解洋中脊的热状态、岩浆供给及演化过程的绝佳研究对象。本文对中国大洋49航次第五航段(DY49V)在西北印度洋卡尔斯伯格脊天休热液区周边获得的拖网(49V-DR02)玄武岩样品进行了详细的岩石学和矿物学研究,并利用单... 详细信息

洋中脊玄武岩(MORB)是了解洋中脊的热状态、岩浆供给及演化过程的绝佳研究对象。本文对中国大洋49航次第五航段(DY49V)在西北印度洋卡尔斯伯格脊天休热液区周边获得的拖网(49V-DR02)玄武岩样品进行了详细的岩石学和矿物学研究,并利用单斜辉石-熔体温压计对玄武岩中单斜辉石的结晶温度和压力进行了估算,用以探讨天休热液区所在洋脊段的深部岩浆过程。结果表明,所研究的玄武岩样品属于拉斑质N-MORB,其中单斜辉石呈鳞片状、树枝状或骸晶状微晶,主要为普通辉石和透辉石。单斜辉石-熔体温压计计算结果显示天休洋脊段单斜辉石结晶温度为1153~1225℃,结晶压力在0.08~0.64GPa范围内,相当于2.6~21.1km的深度,但主要集中在10~16km深度。这说明单斜辉石的结晶温度相对集中,但结晶深度范围变化很大,从浅层上洋壳区域到大洋岩石圈地幔区域均有单斜辉石结晶作用发生,但主要集中在大洋岩石圈地幔区域,暗示天休洋脊段下方洋壳内可能不发育熔体透镜体或岩浆房。天休洋脊段单斜辉石如此深的结晶深度指示天休洋脊段岩石圈地幔厚度厚,地幔部分熔融产生岩浆的终止深度深。在该洋脊段10~16km深处富含高温熔体,为天休热液系统的热液循环提供深部热源。

关键词：卡尔斯伯格脊天休热液区 MORB 单斜辉石岩浆深部过程

洋中脊弯折带的构造-岩浆耦合作用:西北印度洋中脊火山锥及断层分布的约束

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岩石学报 2024年第7期40卷 2215-2224页

作者：党牛余星韩喜球吴招才邱中炎王叶剑李洪林自然资源部海底科学重点实验室自然资源部第二海洋研究所杭州310012 福建师范大学地理科学学院福州350007 浙江大学海洋学院舟山316021

洋中脊作为全球火山活动最活跃的区域之一,岩浆以裂隙式喷发为主,同时也存在中心式喷发火山锥。本文基于西北印度洋中脊大洋24航次的船载多波束地形数据,选择具有特殊空间位置和构造属性的北部弯折带作为研究靶区,应用定量地貌学方法分... 详细信息

洋中脊作为全球火山活动最活跃的区域之一,岩浆以裂隙式喷发为主,同时也存在中心式喷发火山锥。本文基于西北印度洋中脊大洋24航次的船载多波束地形数据,选择具有特殊空间位置和构造属性的北部弯折带作为研究靶区,应用定量地貌学方法分析火山锥形态特征与空间分布,探索区域火山作用与构造活动的耦合关系。结果表明,火山锥沿洋脊纵向上的分布主要受控于岩浆供应量,但段内其横向上的分布不仅与岩浆供应量有关,还决定于火山锥岩浆通道的形成。火山锥的分布与断层分布密切相关,断层分布密集,易于火山锥通道的形成。弯折带的洋脊段除了受扩张力外,还受到北东方向的应力作用,使弯折带南翼发育有更密集的断层,更高的火山锥密度。该应力效应的产生与非洲板块的北东向推移、印度板块的逆时针旋转以及弯折带效应本身有关。火山锥形态特征与空间分布,对于理解洋中脊区域构造演化以及火山活动过程具有重要价值。

关键词：火山锥分布特征构造-岩浆背景定量地貌学西北印度洋中脊

西北印度洋卡尔斯伯格脊卧蚕热液羽流影响区古菌群落动态变化特征

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微生物学报 2024年第6期64卷 1848-1863页

作者：巫苑桢韩喜球谢倩魏铭聪余娟上海交通大学海洋学院上海200240 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

【目的】热液羽流在浮力上升和非浮力侧向迁移过程中与背景海水不断进行物质和能量的交换。因海底热液活动和洋流的流速流向均存在动态变化性,热液羽流的高度、物理化学参数和微生物群落也随时空发生演化。然而,由于缺乏热液羽流的长期... 详细信息

【目的】热液羽流在浮力上升和非浮力侧向迁移过程中与背景海水不断进行物质和能量的交换。因海底热液活动和洋流的流速流向均存在动态变化性,热液羽流的高度、物理化学参数和微生物群落也随时空发生演化。然而,由于缺乏热液羽流的长期监测和时序取样,微生物群落(尤其是古菌)的多样性及其时空演化尚不清楚。【方法】2018年7月−2019年6月,在卧蚕1号热液喷口东南300 m处放置了一套带有2个沉积物捕获器(分别距海底300 m和40 m)和一个浊度仪(距海底150 m)的锚系潜标,对热液羽流和热液羽流下方颗粒物沉降区的近底水样进行了为期18个月的观测和时序采样。本研究采用16S rRNA基因高通量测序技术研究了水样中古菌群落的多样性,以了解羽流层和近底沉降层古菌群落结构的特征与时空演化。【结果】热原体纲(Thermoplasmata)、甲烷八叠球菌纲(Methanosarcinia)和甲烷杆菌纲(Methanobacteria)等热液来源古菌,当浊度异常值较高时,它们的丰度也增加。从空间上看,热液羽流区和近底沉降区古菌群落结构在门和纲水平上具有相似性,但在目水平上表现出差异性,而且各主要类群的相对丰度也存在差异,其中热原体纲在羽流层中的丰度普遍高于近底沉降层,而氨氧化古菌和甲烷八叠球菌纲在沉降层的丰度较高。【结论】卧蚕热液区东南300 m热液羽流层和近底沉降层均受到了热液的影响,羽流层受热液影响的程度相对更显著,而近底沉降层除了受到一定程度的热液影响外,还可能受到了再悬浮沉积物的影响。热液贡献大小的动态变化和底层沉积物再悬浮可能是造成热液区近端水体古菌群落时空异质性的主要因素。本研究深化了对热液影响区古生菌群落结构及其月际尺度时空分布特征的认识。

关键词：卧蚕1号热液区热液羽流古菌时空演化印度洋

东太平洋海隆海底热液蠕虫管道矿化特征及其成因

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地球科学 2024年第1期49卷 224-237页

作者：罗礼涛王叶剑蔡翌旸董传奇韩喜球成都理工大学沉积地质研究院四川成都610059 自然资源部海底科学重点实验室自然资源部第二海洋研究所浙江杭州310012 上海交通大学海洋学院上海200240

热液管状蠕虫生物矿化现象在海底热液喷口区发育广泛,但蠕虫管道矿化和风化氧化过程及其控制因素知之甚少.对采自东太平洋海隆热液蠕虫矿化管道样品开展了高分辨率矿物学和元素分布研究.结果表明,样品具有以胶状黄铁矿为主的多圈层矿化... 详细信息

热液管状蠕虫生物矿化现象在海底热液喷口区发育广泛,但蠕虫管道矿化和风化氧化过程及其控制因素知之甚少.对采自东太平洋海隆热液蠕虫矿化管道样品开展了高分辨率矿物学和元素分布研究.结果表明,样品具有以胶状黄铁矿为主的多圈层矿化结构,分为快速(F型)和慢速矿化(S型)两种类型.相比“S型”样品,“F型”的管壁更厚,同心层的数量少、间隙小、厚度均一.这主要受矿物沉淀速率的影响,即矿物的快速沉淀加快了蠕虫管道生长和矿化.此外,“F型”样品外壁分布的草莓状黄铁矿,表明纳-微米晶硫化物矿物的定向生长是形成胶状黄铁矿带的重要中间途径.而“S型”管壁从内到外具有氧化程度逐渐增加、胶状黄铁矿逐渐减薄的显著特征,指示样品同时受到了后期低温、富Fe-Si热液流体和低温海水风化氧化作用的影响.本项研究为理解现代海底热液系统的管状蠕虫矿化机制提供了新见解.

关键词：海底热液管状蠕虫矿物学管道圈层结构硫化物矿化风化氧化

Turbidite Events Recorded in Deep-sea Core IR-GC1 off Western Sumatra： Evidence from Grain-size Distribution

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Acta Geologica Sinica(English Edition) 2017年第4期91卷 1448-1456页

作者： QIU Zhongyan han xiqiu WANG Yejian Key Laboratory of Submarine Geoseiences Second Institute of Oceanography State Oceanic Administration Hangzhou 310012 China

Sediment core IR-GC1, from the abyssal basin of the Indian Ocean off Sumatra, may provide important information on depositional events related to earthquakes and tsunamis. In this study, based on a combination of grain-size analysis with lithological studies and oxygen isotope stratigraphy, seven deep-sea turbidite layers were identified, corresponding to seven turbidity events that occurred at 128- 130, 105-107, 98-100, 86-87, 50-53, 37-41 and 20-29 ka. The sediments of the turbidite deposits are characterized by coarse grain sizes, poor sorting, wide kurtosis, bimodal frequency distributions and clear depositional variations. Particle size grading is also an important signature of deep-sea turbidite deposits and can be used as an indicator to identify turbidite layers. Possible triggering mechanisms for the turbidite events include tsunamis, earthquakes, volcanic eruptions and sea-level changes.

关键词： grain size turbidite deep-sea core Indian Ocean

Source and nature of ore-forming fluids of the Edmond hydrothermal field,Central Indian Ridge:evidence from He-Ar isotope composition and fluid inclusion study

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Acta Oceanologica Sinica 2017年第1期36卷 101-108页

作者： WANG Yejian han xiqiu QIU Zhongyan Key Laboratory of Submarine Geosciences Second Institute of OceanographyState Oceanic AdministrationHangzhou 310012China

To understand the source and nature of the ore-forming fluids of the Edmond hydrothermal field on the Central Indian Ridge, we studied the He-Ar isotope composition and fluid inclusions of the hydrothermal *** results show that the sulfide samples contain noble gases He, Ne, Kr, and Xe with their abundances in between those of air-saturated water（ASW） and mid-ocean ridge basalt（MORB）. The ^3He/^4He ratio varies from1.3 to 8.7 Ra（n=10, average： 5.1 Ra）, whereas the ^40Ar/^36Ar ratio is from 285.3 to 314.7（n=10, average： 294.8）. These results suggest that the He was derived from a mixture of MORB with variable amounts of seawater, but the Ar in the ore-forming fluids trapped in the sulfides is predominantly derived from seawater. The fluid inclusions of barite have a wide range of homogenization temperatures and salinities varying from 163℃ to 260℃ and 2.6 wt%to 8.5 wt% Na Cl equiv., respectively. It is suggested that the ore-forming fluids were produced by phase separation, which agreed with the present-day vent fluid study.

关键词： fluid inclusion helium and argon isotopes phase separation massive sulfides Central Indian Ridge

Precipitation of Calcite Veins in Serpentinized Harzburgite at Tianxiu Hydrothermal Field on Carlsberg Ridge(3.67°N),Northwest Indian Ocean:Implications for Fluid Circulation

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Journal of Earth Science 2020年第1期31卷 91-101页

作者： Yang Chen xiqiu han Yejian Wang Jianggu Lu School of Earth Sciences Zhejiang UniversityHangzhou 310027China Key Laboratory of Submarine Geosciences State Oceanic AdministrationSecond Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China

Serpentinization and calcite precipitation of mantle peridotites exhumed along detachment faults at the slow-to ultraslow-spreading centers can provide important clues to the hydrothermal alteration *** Tianxiu hydrothermal field is a new-found active and ultramafichosted hydrothermal vent site along the Carlsberg Ridge,Northwest Indian *** types of calcite veins are recognized in serpentinized harzburgite samples collected from the seafloor at the water depth of 3 500 m(3.67°N/63.83°E) and 400 m north of Tianxiu hydrothermal *** veins Ⅰ occur in the fractures that cut through mesh texture in the highly serpentinized harzburgite,while calcite veins Ⅱ precipitate within the mesh texture in the relatively weaker serpentinized *** veins show similar δ13CPDB(+0.54‰ and +0.58‰) but different δ18OPDB(-16.67‰ and +4.46‰) values,suggesting that they were derived from the same carbon source but precipitated at different *** the deep seawater temperature of 2℃as the precipitation temperature of the calcite veins I,the equilibrium δ18OV-SMOW of calcite-precipitating fluid was calculated to be 1.78‰,which is close to the average δ18OV-SMOW value(1.74‰) of vent fluid samples from the ultramafic-hosted hydrothermal systems *** formation temperature of calcite veins Ⅱ is inferred to be approximately 134℃,based on the calculated δ18OV-SMOW *** temperature differences of calcite precipitation probably resulted from the fluid cooling conductively and mixing with seawater along the presumed fractures during slow *** low-temperature calcite postdates the mesh texture,while the high-temperature calcite may precipitate under relatively low water/rock ratios,alkaline and reduced conditions among the mesh texture,which is revealed by the geochemical ***,it is suggested that they both have been influenced by hydrothermal fluids and the sampling site is near the discharge zone of hydrothermal circulati

关键词： calcite veins serpentinized harzburgite isotopes geochemical models Carlsberg Ridge

Origin and nature of cold seep in northeastern Dongsha area,South China Sea:Evidence from chimney-like seep carbonates

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Chinese Science Bulletin 2013年第30期58卷 3689-3697页

作者： han xiqiu YANG KeHong HUANG YongYang Key Laboratory of Submarine Geosciences State Oceanic Administration Second Institute of Oceanography State Oceanic Administration Guangzhou Marine Geological Survey

The occurrence of seep carbonates is one of the characteristic features for cold seep sites at continental *** carbonates documented the venting history of methane-rich *** to the chemoherm carbonates and carbonate pavements which formed on the sediment-water interface,chimney-like seep carbonates precipitated around fluid conduits below the sediment-water interface therefore better recording information of the past fluid flow and *** the chimney-like seep carbonate samples from the northeastern Dongsha area of the South China Sea were studied to understand the origin and nature of the venting fluids and their potential relationship with gas hydrate deposits underneath the *** on the occurrence,morphology,petrology,mineralogy and C-and O-isotope compositions,combined with present and past bottom water temperatures and the timing of methane release events,the oxygen isotopic fractionation between calcite and water were used to estimate the equilibriumδ18O values of the precipitating ***δ13C values ranging from 56.33‰to 42.70‰V-PDB and thus clearly show that the studied chimneys were mainly derived from biogenic methane *** calculated equilibriumδ18O values of the precipitating fluids ranged from 1.9‰0.3‰to 0.6‰0.3‰V-SMOW,with an average of 1.4‰0.3‰V-SMOW which is heavier than those of seawater even at the last glacial *** is considered that the formation of chimney-like carbonates was closely related to methane hydrate dissociation in the *** methane hydrates contributed as much as45.7%of water to the venting *** is suggested that the climate and environmental changes(***-level lowering,down-cutting canyons and mass wasting)are the major mechanisms maybe responsible for the destabilization of methane hydrates in the study *** extensive occurrence of seep carbonates indicates that a large amount of the methane released from methane hydrate dissociation has been effectively captured

关键词：冷泉碳酸盐岩南海东北部群岛海域中国南海烟囱东沙性质甲烷水合物