Mud volcanism and fluid geochemistry in the Cheleken peninsula,western Turkmenistan     

《Marine and Petroleum Geology》2014

A geological and geochemical study has been carried out to investigate the relationships between major mud volcano structures and deep fluid migration in the Cheleken peninsula, in the South Caspian Basin. The fluid geochemistry allowed the origin and migration of the saline waters and the hydrocarbons to be deduced along with the regional source and reservoir rocks. The emitted waters formed by the mixing of deep highly saline water from the main source rocks of the Maykop Fm with the Caspian-like pore water contained in the Pliocene reservoirs. The water composition is very similar to that emitted by the mud volcanoes in Azerbaijan, allowing comparisons to be done between the reservoirs in the western and eastern sides of the South Caspian Basin. The associated oil is derived from a mixed type II/III kerogen deposited in a sub-oxic marine environment and generated during the early oil window. The oil biomarkers indicate that the source rock is the Maykop Fm., as previously determined for the other areas of the South Caspian Basin.The spontaneous emissions, showing different morphologies, are mainly aligned along normal and transtensive fault systems, which provide effective pathways for rapid fluid ascent from deep reservoirs to the surface.  相似文献   

桑沟湾及附近海域表层沉积物碳氮同位素分析及有机质来源   总被引：1，自引：0，他引：1  

夏斌  崔毅  陈碧鹃  崔正国  曲克明  马菲菲 《海洋学报(英文版)》2014,33(12):48-57

Naturally existing stable carbon and nitrogen isotopes are important in the study of sedimentary organic matter sources. To identify the sources of sedimentary organic matter in Sanggou Bay and its adjacent areas, which is characterized by high-density shellfish and seaweed aquaculture, the grain size, organic carbon(OC), total nitrogen(TN), carbon and nitrogen isotopic composition(δ13C and δ15N) of organic matter in the surface sediment were determined. The results showed that, in August, sedimentary OC and TN ranged from 0.17% to 0.76% and 0.04% to 0.14%, respectively. In November, OC and TN ranged from 0.23% to 0.87% and 0.05% to 0.14%, respectively. There was a significant positive correlation between OC and TN(R=0.98, P0.0001), indicating that OC and TN were homologous. In August, the δ13C and δ15N of organic matter varied from-23.06‰ to-21.59‰ and 5.10‰ to 6.31‰, respectively. In November, δ13C and δ15N ranged from-22.87‰ to-21.34‰ and 5.13‰ to 7.31‰, respectively. This study found that the major sources of sedimentary organic matter were marine shellfish biodeposition, seaweed farming, and soil organic matter. Using a three-end-member mixed model, we estimated that the dominant source of sedimentary organic matter was shellfish biodeposition, with an average contribution rate of 65.53% in August and 43.00% in November. Thus, shellfish farming had a significant influence on the coastal carbon cycle.  相似文献   

荣成天鹅湖越冬大天鹅粪便的重金属水平     

王峰  周毅  杨红生 《海洋科学》2014,38(6):1-4

为对大天鹅(Cygnus cygnus)保护及湖区管理提供基础数据,作者于2011年11月~2012年3月研究了山东荣成天鹅湖越冬大天鹅食物来源及其粪便的重金属水平。结果表明:所选择的食物来源中,Zn、As和Cr在硬毛藻(Chaetomorpha linum)中含量最高,Cd在大叶藻(Zostera marina L.)叶片中含量最高,Pb在大叶藻根茎中含量最高,Cu在石莼(Ulva pertusa)中含量最高,Hg在小麦(Triticum aestivum)中含量最高;水生植物来源的粪便中Cd含量极显著高于陆地植物来源的粪便,陆地植物来源的粪便中Cr,Pb和Hg含量显著高于水生植物来源的粪便;摄食小麦苗可能造成大天鹅对Cd和Hg的积累。  相似文献   

云南建水水草冲铜矿矿床地质特征及成矿物质来源     

刘军港 《地质与勘探》2014,50(5):840-854

本文通过研究云南建水水草冲铜矿地质特征、围岩玄武岩和矿石矿物的微量元素、S、C、O同位素的组成,示踪了该矿床的成矿物质来源和性质。研究结果表明,云南建水水草冲铜矿位于滇东南哀牢山变质体北侧,容矿围岩为峨眉山玄武岩,矿体受北东向逆断层及其次级断裂控制,延深大于延长,形状不规则,矿体内多夹灰岩角砾及矿化玄武岩角砾,矿石矿物主要为黄铜矿,矿化蚀变以硅化、碳酸盐化、绿泥石化为主。水草冲铜矿黄铜矿与黄铁矿稀土元素具有相同的稀土元素组成与含量,ΣREE平均为1.901×l0-6,富集轻稀土元素,轻重稀土元素比(LREE/HREE)平均为8.188,（La/Yb）N值平均为10.259;δEu值平均为0.977;Ce呈现弱负异常,δCe值平均为0.808。黄铁矿中的Co/Ni比值为0.835,显示水草冲铜矿床为中温热液矿床;黄铁矿的Y/Ho比值平均为38.23,表明水草冲铜矿床的成矿流体为混合来源。结合黄铁矿的稀土微量元素特征,推断水草冲铜矿床的成矿流体是Cl多于F的流体。S的来源复杂,黄铁矿δ34SCDT（‰）的变化范围（18.3~29.4）与海水硫酸盐(海相蒸发岩)的δ34S值接近或略低;黄铜矿δ34SCDT（‰）变化范围是-0.5~10.1,表明有深部硫的参与。δ13C V-PDB（0.9‰~2.6‰）,δ18O V-SMOW（14.3‰~15.9‰）反映了方解石流体可能为热液循环萃取沉积岩地层混合形成。综上,推测成矿物质为后期构造热液萃取围岩（玄武岩和灰岩等）所得,其中铜主要来自于玄武岩本身,而硫的来源以地层硫为主。  相似文献   

广西苍梧社垌石英脉型钨钼多金属矿床流体演化及来源示踪     

张志强  陈懋弘  莫建明  肖柳阳  黄智忠  罗军  区朝辉 《岩石学报》2014,30(1):281-291

广西苍梧社垌矿床是大瑶山隆起南侧新发现的一个大型斑岩-矽卡岩-石英脉型钨钼多金属矿床。本文重点对其中的石英脉型矿床进行了研究,依据脉体穿插关系及矿物共生组合将成矿过程划分为I石英-黄铁矿阶段、II石英-白钨矿-辉钼矿阶段、III石英-多金属硫化物阶段以及IV石英-方解石-萤石阶段,其中II和III阶段为主成矿阶段。从早到晚,均一温度逐渐下降(第一阶段550℃→370℃,第二阶段370℃→330℃,第三阶段330℃→210℃,第四阶段190℃→150℃),流体密度逐渐上升(0.61g/cm3→0.72g/cm3→0.82g/cm3→0.94g/cm3),盐度先升后降(第一阶段5.86%～8.55%NaCleqv,第二阶段4.49%～43%NaCleqv,第三阶段0.53%～46.37%NaCleqv,第四阶段0%～12.85%NaCleqv)。激光拉曼成分分析显示,社垌石英脉型矿床的成矿流体属于H2O-NaCl体系,但是该体系的流体成分在成矿前后发生了较大的变化,反映第I阶段以氧化环境为主,(II、III、)IV阶段则为还原环境。氢氧同位素研究显示成矿流体来自于岩浆水,后期大气降水的加入导致矿质发生沉淀。此外金属硫化物的δ34S组成(-3.8‰～+1.7‰)平均为-0.46‰,接近于零值,也表明为岩浆来源。引起矿质沉淀的主要原因是流体混合导致的温度下降等环境条件的改变。总体而言,社垌石英脉型钨钼多金属矿床的成矿流体主要来自岩浆热液,为中高温、中低盐度、低密度的NaCl-H2O流体体系,钨钼等多金属成矿与区内加里东期岩浆作用密切相关。  相似文献   

基于饮水标准的矿山水源人体健康风险--以云南个旧锡矿区某矿坑水源为例     

黄玉  ;蔡保新  ;王宇  ;李昊熹 《中国区域地质》2014,(8):1260-1266

饮水水源水质的人体健康安全是水源是否安全的首要问题。在调查锡矿矿坑水作为个旧市A镇及B矿段锡矿生活区饮用水源情况的基础上,应用国际辐射防护委员会和美国环保署推荐的风险评估模型,开展饮用水的人体健康风险评价。结果表明,水源中重金属致癌物质所引起的健康危害较高,风险值超过了国际辐射防护委员会推荐的最大可接受风险水平,其中以Cr6＋和As的致癌风险最大,应优先控制;非致癌物质所引起的健康风险较小,风险值在10-8以下,远低于推荐的最大可接受风险水平。虽然水中重金属含量符合相关标准要求,但是长期饮用对人体存在健康风险。  相似文献   

The Converter Mechanism of Particle Acceleration and Its Applications to the Unidentified Egret Sources     

E. V. Derishev  F. A. Aharonian  V. V. Kocharovsky  Vl. V. Kocharovsky 《Astrophysics and Space Science》2005,297(1-4):21-30

We discuss the properties of gamma-ray radiation accompanying the acceleration of cosmic rays via the converter mechanism. The mechanism exploits multiple photon-induced conversions of high-energy particles from charged into neutral state (namely, protons to neutrons and electrons to photons) and back. Because a particle in the neutral state can freely cross the magnetic field lines, this allows to avoid both particle losses downstream and reduction in the energy gain factor, which normally takes place due to highly collimated distribution of accelerated particles. The converter mechanism efficiently operates in relativistic outflows under the conditions typical for Active Galactic Nuclei, Gamma-Ray Bursts, and microquasars, where it outperforms the standard diffusive shock acceleration. The accompanying radiation has a number of distinctive features, such as an increase of the maximum energy of synchrotron photons and peculiar radiation beam-pattern, whose opening angle is much wider at larger photon energies. This provides an opportunity to observe off-axis relativistic jets in GeV–TeV energy range. One of the implications is the possibility to explain high-latitude unidentified EGRET sources as off-axis but otherwise typical relativistic-jet sources, such as blazars.  相似文献   

不同蛋白源饲料对褐点石斑鱼幼鱼血细胞发生的影响     

王赛  陈刚  张健东  纪多亮  吴灶和  周晖 《广东海洋大学学报》2011,(6):9-19

以全鱼粉作为唯一蛋白源(D1),用豆粕替代10%、20%鱼粉(D2、D3),玉米蛋白粉替代10%鱼粉(D4),啤酒酵母替代10%鱼粉(D5),配制5组等氮等能饲料,每种饲料设置3个实验组,进行56 d的养殖实验。通过血液和组织涂(印)片、细胞染色和显微观察,研究人工培育的褐点石斑鱼幼鱼外周血液白细胞的分类组成,头肾、脾脏、体肾和肝脏等4种组织中各类血细胞的发生情况,以及不同蛋白源饲料对褐点石斑鱼血细胞发生的影响。结果表明:褐点石斑鱼外周血液中的白细胞由淋巴细胞(53.30%±4.66%)、血栓细胞(35.69%±3.85%)、嗜中性粒细胞(10.34%±3.14%)、单核细胞(0.28%±0.36%)、浆细胞(0.24%±0.34%)和嗜酸性粒细胞(0.15%±0.27%)组成;组织印迹片中,未成熟的红细胞、淋巴细胞和粒细胞主要在头肾印迹片中出现,未成熟的单核细胞主要在头肾和脾脏印迹片中出现,血栓细胞在肝脏印迹片中数量最多,推断褐点石斑鱼幼鱼主要的造血组织是头肾,其次是脾脏;在4种组织中均观察到浆细胞,在体肾印迹片中观察到嗜碱性粒细胞,在肝脏印迹片中观察到巨噬细胞,在头肾印迹片中还观察到巨大原红细胞。显微观察和数据统计分析的结果都表明,投喂5种蛋白源不同的配合饲料,未对褐点石斑鱼4种组织中血细胞的发生情况造成显著影响。  相似文献   

Changes to sediment sources following wildfire in a forested upland catchment,southeastern Australia     

Hugh G. Smith  Gary J. Sheridan  Patrick N. J. Lane  Philip J. Noske  Henk Heijnis 《水文研究》2011,25(18):2878-2889

Few investigations link post‐fire changes to sediment sources and erosion processes with sediment yield response at the catchment scale. This linkage is essential if downstream impacts on sediment transport after fire are to be understood in the context of fire effects across different forest environments. In this study, we quantify changing source contributions to fine sediment (<63 µm) exported from a eucalypt forest catchment (136 ha) burnt by wildfire. The study catchment is one of a pair of research catchments located in the East Kiewa River valley in southeastern Australia that have been the subject of a research program investigating wildfire effects on runoff, erosion, and catchment sediment/nutrient exports. This previous research provided the opportunity to couple insights gained from a range of measurement techniques with the application of fallout radionuclides ¹³⁷Cs and ²¹⁰Pb_ex to trace sediment sources. It was found that hillslope surface erosion dominated exports throughout the 3·5‐year post‐fire measurement period. During this time there was a pronounced decline in the proportional surface contribution from close to 100% in the first six months to 58% in the fourth year after fire. Over the study period, hillslope surface sources accounted for 93% of the fine sediment yield from the burnt catchment. The largest decline in the hillslope contribution occurred between the first and second years after fire, which corresponded with the previously reported large decline in sediment yield, breakdown of water repellency in burnt soils, substantial reduction in hillslope erodibility, and rapid surface vegetation recovery. Coupling the information on sediment sources with hillslope process measurements indicated that only a small proportion of slopes contributed sediment to the catchment outlet, with material derived from near‐channel areas dominating the post‐fire catchment sediment yield response. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Variations in sediment sources and yields in the Finger Lakes and Catskills regions of New York     

Gregory N. Nagle  Timothy J. Fahey  Jerry C. Ritchie  Peter B. Woodbury 《水文研究》2007,21(6):828-838

The proportional contributions of stream bank and surface sources to fine sediment loads in watersheds in New York State were quantified with uncertainty analysis. Eroding streamside glacial drift, including glaciolacustrine deposits, were examined to help explain variations in the proportional contributions made by bank erosion. Sediment sources were quantified by comparing concentrations of the bomb‐derived radionuclide ¹³⁷Cs in fluvial sediment with sediment from potential source areas such as agricultural soils, forest soils and stream banks. To compare sediment sources in streams containing abundant deposits of fine‐grained glacial drift with watersheds that lacked moderate or extensive streamside deposits, samples were taken from 15 watersheds in the region. The mean contribution of bank erosion to sediment loads in the six streams with glaciolacustrine deposits was 60% (range 46–76%). The proportional contribution of bank erosion was also important in one stream lacking glaciolacustrine deposits (57%) but was less important in the remainder, with contributions ranging from 0 to 46%. Data from this study on the varying contributions of bank erosion and data from past studies of sediment yield in 15 watersheds of New York State suggest that eroding streamside glacial deposits dominate sediment yield in many watersheds. In other watersheds, past impacts to streams, such as channelization, have also resulted in high levels of bank erosion. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献