EPR 9°～10°N L喷口黑烟囱体形成环境重建:来自矿物学及铅-210年龄的限制

为了重建EPR 9°～10°N L喷口的形成环境,采用矿物学、地球化学及年代学的方法,对黑烟囱体的矿物组成、矿物结构、元素剖面分布以及黑烟囱体内外层铅-210测年进行了研究.矿物学观察表明,该喷口烟囱体内壁主要由方黄铜矿组成,而外壁则主要由硬石膏组成.铅-210测年结果表明,烟囱体形成于EPR 9°～10°N区域内1991年的火山喷发事件之后,并有较低的生长速率,约为0.3 cm/a.结合该喷口及其附近A喷口已发表资料认为,该烟囱体开始生长是由于蒸气相流体引起的,其后期受到卤水相流体的影响,而且流体温度应不小于330℃.     

Geochemical characteristics of stable isotopes from hydrothermal chimneys in the Mariana Trough, West Pacific Ocean

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烟囱模型动力试验研究

烟囱结构的地震反应及其破坏机理是地震工程界长期讨论的问题，对高耸烟囱结构的模型试验研究是研究此工程问题的重要方法，作者通过对45m和180m高大烟囱结构的动力模型试验，对烟囱结构的地震反应及其破坏机理进行了模型试验研究，得出了有意义的结论，为这一问题的理论研究提供了有力的依据。     

贵州省镍钼钒多金属矿成矿地质特征及其控制因素

贵州省的镍钼钒多金属矿分为岩浆熔离型铜镍矿、热液型多金属矿床中的镍钼钒矿、沉积型镍钼钒矿和次生淋滤型镍钼矿等4种矿化类型。文章重点介绍了沉积型镍钼钒矿的成矿地质特征,分析了其成矿条件及找矿标志,探讨了黑色岩系底部镍钼钒多金属矿层的成因机理,提出了"白烟囱"型的成硅(磷)、成矿、生物爆发的形成机制和被动大陆边缘构造、岩相古地理、深部岩浆岩及断裂构造等控制因素。     

珠江口盆地深水区白云凹陷气烟囱特征及成藏模式

以高分辨率三维地震资料为基础,结合地震属性,在珠江口盆地深水区白云凹陷识别出了大量的气烟囱现象。气烟囱可分为根部、过路区和顶部三个组成单元,各个单元具有不同的地震异常特征,主要通过同相轴的侧向变化,振幅、频率、连续性的局部增强和减弱,AVO响应以及它们的组合来识别。气烟囱根部是气体释压的初始部位,是气源供应区;过路区是流体泄压所经过的区带,在整个气烟囱结构的空间中占有主体地位;顶部常形成气藏。对白云凹陷建立了气烟囱顶部聚集和侧翼聚集两种气藏成藏模式,它们均由古近系文昌组—恩平组的河湖相沉积提供烃源。     

南海北部深水盆地流体活动系统及其成藏意义

根据高精度的3D和2D地震资料,对南海北部深水盆地的流体活动系统的类型、影响因素和它们之间的演化关系进行了研究.南海北部深水区存在着包括:泥火山、泥底辟、气烟囱、管状通道、多边形断层和构造断层等多种类型的流体活动系统.根据地震反射特征,可以把它们划分为断层有关的流体活动系统和柱状流体活动系统两大类.研究发现研究区内的流体活动系统主要受构造和沉积两方面的影响.并且,气烟囱、泥底辟和泥火山存在着单向演化的关系,可以从是否有沉积物参与运移及是否喷出海底将它们区分开来.最后,本文探讨了流体活动系统对深水油气和天然气水合物成藏的重要影响,建立了南海北部流体活动系统的存在模式.     

Methane hydrate recycling offshore of Mauritania probably after the last glacial maximum

To what extent methane liberated from marine hydrate will enter the ocean during a warmer world is unknown. Although methane release due to hydrate dissociation has been modelled, it is unclear whether or not methane will reach the seafloor during a warmer world and therefore contribute to oceanic and atmospheric budgets. Here we show, using a new three-dimensional (3-D) seismic dataset, that some hydrate deposits surround the gas chimneys passing through the HSZ. Bottom water warming since the last glacial maximum (LGM) is interpreted to cause hydrate dissociation but critically some of the released methane was not vented to the ocean. The released gas caused seal failure and free gas entered the hydrate stability zone (HSZ) through vertical gas chimneys to where new hydrate accumulations formed. This process is a new evidence for methane recycling and could account in part for the lack of methane in ice core records that cover warming events during the late Quaternary. This research provides new insight into how methane could be recycled rather than vented during a warmer world.     

REE and Sr-Nd isotope characteristics of hydrothermal chimney at Jade area in the Okinawa Trough

Hydrothermal chimney is a product of hydrothermal activity on the seabed. Chimney samples dredged from Jade hydrothermal area in Izena depression of the Okinawa Trough, are characterized by relatively enriched light rare earth elements (LREE) and strongly positive Eu anomalies. ^87Sr/^86Sr and ^143Nd/^144Nd of these samples are exactly between those of seawater and of acidic pumice, averaged at 0.708928 and 0.512292, respectively. These characteristics imply that the main source of hydrothermal sulfide at Jade area is possibly the undersurface acidic rocks. The mineralizing mechanism can be summarized as follows: Large amount of mineralized material would be leached out and LREE-enriched hydrothermal solution would be subsequently produced as a result of thermo-chemical exchange reaction between acidic volcanic rocks and heated seawater that penetrated in advance from upper water mass. The spurting out from the seabed and quickly crystallizing in the seawater of hydrothermal solution are responsible for the formation of Cu-Zn sulfide and barite-amorphous SiO2 minerals that are characterized by enriched LREE and positively strong Eu anomalies.     

太平洋三海区热液烟囱物的地球化学标型特征研究

以成因矿物学的理论和方法，运用电子探针、中子活化、常规化学分析和稳定同位素分析等多种地球化学实验测试技术，较系统地研究了太平洋三区四地热液烟囱物的地球化学组成和变化，揭示了研究区不同热液喷发类型中的地球化学标型特征。高温热液类型的硫化物，由高温热液矿物组成，除本身富合Fe，Zn，Cu，Pb等金属元素外，氧同位素换算温度也表现最高或中高；中低温热液类型的烟囱物，金属元素合量较低，氧同位素换算温度也表现较低。由此论证了不同标型特征的热液矿物地球化学特征与热液喷发环境之间相互依存的紧密关系。     

Mineralization of a Proterozoic Sulfide Black Smoker Chimney and Thermophilous Microorganisms in Eastern Hebei, China

A sulfide black smoker chimney exists in the Gaobanhe seabed exhalation massive sulfide deposit in the Xingiong-Kuancheng secondary fault basin of the Proterozoic Yaniiao rift trough in Hebei Province, taking the shape of mounds, individually about 2-3 cm high. Abundant fossils of thermophilous bacteria and algae in perfect preservation are found in the ore surrounding the black smoker chimney. Scanning electron microscopy （SEM） and molecular biomarker studies on the microorganismai ore fabric show that the microorganism in the sulfide ore is in fact a sedimentary product of probiotic bacteria and algae. In the special food chain based on black smoker chimney at ancient seabed- thermophilous bacteria, the thermophilous bacteria and algae reproduce in large quantity. Intermittently erupting of fluid from the chimney creats conditions for formation of sulfide deposit. In the process of exhalation action of hot fluid, thermophilous bacteria and algae grow and reproduce around the sulfide black smoker chimney, absorbing mineralizing substances brought by the fluid. Massive sulfide deposits are formed in this process of absorption of seabed black smoker chimney exhalation-mineralizing fluid pulsation-thermophilous microorganism.