南海东北部硫酸盐还原-甲烷厌氧氧化界面——海底强烈甲烷渗溢的记录   总被引：4，自引：0，他引：4  

陆红锋  刘坚  陈芳  程思海  廖志良 《海洋地质与第四纪地质》2012,(1):93-98

南海东北部沉积物顶空气甲烷含量较高,海底存在明显的甲烷渗溢现象。该海域6个沉积物岩心的孔隙水硫酸盐浓度和顶空气甲烷含量随深度变化而变化,出现明显的硫酸盐-甲烷互相消耗区域,硫酸盐和甲烷浓度均急剧下降。HD109、HD170、HD196A、HD200、HD319和GC10等6个岩心的硫酸盐还原-甲烷厌氧氧化界面(SMI)分别位于704、911、728、636、888、792cm处,完全落入全球水合物区富甲烷环境的SMI深度范围之内。强烈的甲烷渗溢过程使得硫酸盐-甲烷互相消耗作用加剧,并形成浅的SMI。浅的SMI显示了东北部存在强烈的甲烷渗溢活动以及强烈的甲烷厌氧氧化作用,具有天然气水合物成藏的典型特征。  相似文献   

Rickettsia-like organism infection associated with mass mortalities of blood clam, Tegillarca granosa, in the Yueqing Bay in China     

ZHU Zewen  XU Ting  HE Zhongyang  WU Xinzhong  WU Liuji  MENG Qingguo  HUANG Jiaqing 《海洋学报(英文版)》2012,31(1):106-115

A series of mass mortalities of the cultured blood clam, Tegillarca granosa, occurred in the Yueqing Bay of China from 2005 to 2009. An obligate intracellular prokaryote, designated as rickettsia-like organism (RLO), was frequently found in the moribund or dead blood clam sample during ultrastructural examination. These organisms were usually round, ellipsoid or occasionally dumbbell-shaped, ranged from approximately 0.28 to 0.71 μm in size and had a trilaminar cell wall. Two reproductive modes of organisms, transverse binary fission and budding, were observed. The organisms were able to form eosinophilic inclusions. Most inclusions were found within epithelial and connective tissues of the mantle, gills and digestive tube. The biological and morphological characteristics indicate that these organisms may belong to the family Rickettsiaceae. RLOs exhibited significant pathogenicity. Cytopathological examinations revealed extensive necrosis and destruction in the infected cell. The degree of tissue destruction was positively related to the number of RLO inclusions in the tissues, and the cytopathological effects were positively related to the number of intracellular RLO. RLOs and their inclusions were discovered throughout different disease areas and in different time periods. The infection intensity of the RLOs was positively correlated with the mortality rate of clams. Therefore, RLO infection might be associated with mass mortalities of cultured blood clams in the Yueqing Bay.  相似文献   

Geochemistry of fluid inclusions from Linglong gold deposit in Shandong，China     

ZHAO Yongyue  WANG Li  YANG Heting 《世界地质(英文版)》2012,15(1):26-34

By means of microscopy and laser Raman spectroscopy,the authors studied the fluid inclusions in petrography.The results show that there exist three-phase CO2 -bearing and two-phase aqueous inclusions in gold ore;the fluid of NaCl-H2O--CO2 system went through immiscibility in ore-forming process.Ore-forming fluids were of low salinity(0.82%-5.40%NaCleqv),low density(0.54-0.93 g/cm3);mineralization tempera-ture were concentrated in 320℃--340℃,with ore-forming pressure in 62-126 MPa and mineralization depth in 6.34-9.35 km.The fluid inclusions in quartz are generally characterized by a small amount of CO2 and N2.Combined with recent results of the isotopic analysis for fluid inclusions and dating data,it was indicated that the main ore-forming fluids derived mainly from source of mantle-derived fluids with a small amount of magmatic fluid and meteoric water.The genetic type was mesothermal gold deposits involved by mantle-derived fluids.  相似文献   

二连盆地群低煤阶煤层气成藏模式——以霍林河盆地为例     

韩兵  张明  刘旺博 《煤田地质与勘探》2012,40(1):24-28

为了建立断陷盆地的低煤阶煤层气成藏模式,从二连盆地群的霍林河盆地地质条件与煤层气地质特征入手,探讨该类盆地煤层气富集规律。研究结果显示:霍林河盆地煤层厚度可达80 m,煤层含气量为1.6~5.62 m3/t,瓦斯风化带深度为450~500 m;煤层的分布特征受同沉积构造与沉积环境控制,盆地内部小型凹陷与隆起决定着煤层的发育位置和煤层埋藏深度,基底的整体抬升确定了瓦斯风化带的位置;翁能花向斜与西南部向斜处,煤层厚度和埋藏深度均较大,煤层顶底板岩性为泥岩,其受到后期构造影响小,是煤层气成藏的有利地带。   相似文献   

闽江口芦苇湿地土壤甲烷产生与氧化能力研究   总被引：3，自引：0，他引：3  

王维奇  曾从盛  仝川 《湿地科学》2008,6(1):60-68

用室内干土培养法对闽江口芦苇(Phragmites australis)湿地土壤甲烷产生与氧化能力进行了研究。结果表明:①在30℃培养条件下,培养5 d与培养12 d、19 d的湿地土壤甲烷产生率具有显著差异(n=8,p<0.05),而培养12 d与培养19 d的湿地土壤甲烷产生率差异不显著(n=8,p>0.05),随着培养时间的增加,湿地土壤甲烷产生率逐渐减小;②不同土层平均甲烷产生率范围为0.028 2~0.123 3μg/(g.d),0~5 cm土层的甲烷产生率最高,与其他土层的甲烷产生率具有显著差异(n=3,p<0.05),其他土层间的甲烷产生率差异不显著;③在30℃下培养19 d后,湿地土壤甲烷产生受到抑制,将培养温度升高至35℃,其甲烷产生率未发生明显变化,而随后葡萄糖的添加,明显地促进了湿地土壤甲烷的产生;④湿地土壤甲烷的产生能力与土壤pH、Eh和全氮显著相关(n=8,p<0.05),与盐度也存在相关关系,与有机碳含量的相关性不显著;⑤30℃培养条件下,0~10 cm土层甲烷氧化能力最强,且甲烷氧化能力与甲烷产生能力密切相关。  相似文献   

A JÖKULHLAUP FROM A LAURENTIAN CAPTURED ICE SHELF TO THE GULF OF MEXICO COULD HAVE CAUSED THE BØLLING WARMING     

ULF ERLINGSSON 《Geografiska Annaler: Series A, Physical Geography》2008,90(2):125-140

Since the rapid rate of global warming at the onset of the Bølling interstadial became evident, its cause has been under debate. It coincides closely in time with a strong global transgression called meltwater pulse 1a. One attempt at solution says that a meltwater pulse of Antarctic origin could cause an increase in North Atlantic Deep Water formation, and thus give rise to the Bølling interstadial. However, others have disputed that Antarctic meltwater would have that effect, and furthermore, the start of the Bølling interstadial is not even associated with an increase in North Atlantic Deep Water. A controversial hypothesis says that some Laurentian meltwater came from a jökulhlaup (sub-glacial outburst flood), but no study has yet shown unequivocally that sufficient amounts of water could be stored under the ice. Furthermore, according to all available data a melt-water pulse from the Laurentian ice would give rise to strong cooling, not warming. Nevertheless, meg-afloods appear instrumental in accumulating the Mississippi Fan, created entirely during the Quaternary period, and dramatic climate changes are characteristic of this period. This paper presents a hypothetical chain of events, building on the published literature and simple calculations, to investigate whether the order of magnitude is reasonable. The hypothesis is that a jökulhlaup from a Laurentian captured ice shelf flowed out through the Mississippi, boosted the Gulf Stream, reinvigorated the North Atlantic circulation, and as a result triggered the Bølling warm phase.  相似文献   

CH4-H2O体系流体包裹体均一过程激光拉曼光谱定量分析   总被引：6，自引：2，他引：4  

陈勇周瑶琪  刘超英颜世永 王强 《地学前缘》2005,12(4):592-596

对南黄海盆地二叠纪地层中某石英脉中的CH4-H2O体系流体包裹体均一过程进行了激光拉曼光谱定量分析。利用甲烷与水的拉曼峰面积比值计算不同温度下流体包裹体中水溶液相中甲烷的浓度,除了在100℃附近出现最小值,随温度增加甲烷浓度呈指数增大。包裹体在214℃完全均一,均一时甲烷的浓度为0·1347mol/L。同时利用甲烷的拉曼特征对流体包裹体均一过程的内压变化作了分析。压力变化可以分为三个区间:19~100℃,随温度升高压力增大;100~150℃压力随温度升高减小;150℃之后压力迅速增大。均一温度下的内压为21·92MPa。流体包裹体内压的变化主要是由甲烷溶解行为和封闭体系的热力学特征决定的。实验表明激光拉曼光技术可以作为定量分析含甲烷流体包裹体的一种有效方法。  相似文献   

甲烷水合物CO2置换开采研究现状与展望     

王小文  刘昌岭  李淑霞  孙建业 《海洋地质前沿》2013,(12):25-31

天然气水合物广泛存在于海底沉积物和大陆永冻区,是一种潜在的能源资源。CO2置换法开采天然气水合物,不仅可以从水合物藏中开采出天然气,还能够使空气中的CO2以水合物的形式长期埋存于地下。本文从可行性、微观机理及影响因素等方面,总结了甲烷水合物CO2置换法开采的研究现状,论述了目前研究中存在的问题及不足,并对以后的研究工作提出了一些展望和建议。  相似文献   

楚雄盆地六苴砂岩型铜矿床成矿流体性质及演化     

吴海枝  韩润生  吴鹏 《吉林大学学报(地球科学版)》2016,46(2):398-411

六苴铜矿床是中国南方中、新生代红层盆地中典型的陆相砂岩型铜矿床,具有明显的"金属矿物分带"及"浅色和紫色砂岩过渡带控矿"两大特征。为探讨该矿床流体演化及成矿机制,本文以矿化类型及成矿期次划分为基础,进行了详细的流体包裹体特征、显微测温及成分分析研究。研究结果表明,六苴铜矿床成矿作用主要经历成岩期和改造期两个时期,改造期分早、晚两阶段。两期次的流体包裹体均以纯液相型和富液型盐水包裹体为主,流体均一温度具有先升高后降低的演化趋势,温度范围分别为:96~164℃、108~227℃、94~159℃;而盐度(w(NaCl))差别不大,改造期比成岩期略低,范围分别为2.7%~16.7%、2.1%~13.8%、1.2%~13.5%,总体属中低温-中低盐度盆地卤水。包裹体岩相学观察与激光拉曼气相成分测试表明,成岩期含少量烃类包裹体,而改造期含少量CO₂包裹体。两期包裹体群体成分也有一定差异:挥发分具有从还原性富有机质的CH₄端元向相对氧化的CO₂端元演化的特点;离子成分由富SO₄^2-(-Cl^-)-Ca²⁺-K⁺型向富Cl^--Na⁺型转变。成岩期流体演化形成了砂岩铜矿层状产出的浸染状或纹层状矿(化)体,改造期的构造流体在层状矿(化)体基础上进一步演化形成受构造控制的条带状、脉状富矿体(脉)。  相似文献   

宁武盆地煤岩静态力学特征研究     

林海  张宇  程远方  陈磊  郑玉辉  张振活  凡帆  董海东  涂海海 《煤田地质与勘探》2014,42(6):50-54

井壁失稳是目前制约煤层气规模化开发的关键问题之一。由岩石力学理论可知,煤岩的力学强度是井壁稳定性的决定因素之一。通过对宁武盆地煤岩进行系统力学研究,利用应力摩尔圆法求出宁武盆地主力煤岩的内摩擦角、内聚力等强度参数;建立横波与纵波幂律关系曲线,动态弹性模量与静态弹性模量间线性关系曲线及动静态泊松比间线性关系曲线,得出煤岩静态弹性参数以直接反应地层力学性质,解决了勘探开发中声波测井所得动态弹性参数无法真实反映地层力学特点的技术问题。   相似文献