Phylogenetic Diversity of Microorganisms from Chemocline of the Meromictic Soda Lake Doroninskoe(Zabaikalie,Russia)

正1 Introduction Many soda and salt lakes are characterized by the formation of the meromictic conditions under which a part of the water column is not involved in the annual process of mixing(Mac Intyre,Melack,1982).This creates an     

Thermodynamic Evaluation of Mineral Balance in Water Thickness of the Soda Lake Doroninskoe(Eastern Transbaikalia,Russia)

正In recent years,lakes,including salted,attract the attention of researchers,also when reconstructing last climate changes using the bottom sediments(Solotchina et al.,2008,et al.).In this case the different geochemical     

Vertical Distribution of Bacteria in Doroninskoe Lake(Zabaikalie,Russia):Paradigm of Dominance

正1 Introduction Prokaryotes are key organisms in aquatic ecosystems as they play animportant role in the biogeochemical cycling of elements.Investigations on the relationships betweenthe diversity of microbial community and environmentalfactors offer useful information that bothleads to understanding of the process of element     

中国现代陆生蜗牛壳体碳氧同位素组成的分布特征及其气候响应

陆生蜗牛壳体碳氧同位素组成记录了环境气候信息,是地质历史时期古环境和古气候重建的一个良好指标。文章在前人对现生蜗牛壳体碳氧同位素的环境意义研究基础上,通过增加对不同气候条件下的新疆地区（受西风带控制）、川西地区（受印度季风控制）以及东北地区（东亚季风北端）的现生蜗牛碳氧同位素组成进行测试分析,结合中国其他地区已有数据,总结探讨所有研究区已有蜗牛壳体碳氧同位素组成的分布规律及影响因子,回归分析蜗牛壳体碳氧同位素组成与降水量、温度、湿度、蒸发量及干燥度等5个气候因子之间的关系。得出以下研究结果：全国范围内的蜗牛壳体碳同位素组成与年均降水量、年均相对湿度具有明显负相关关系,与年均蒸发量及干燥度具明显正相关关系,年均温度大于9.5℃采样点的蜗牛壳体碳同位素与温度呈负相关关系;蜗牛壳体氧同位素组成与各种气候因子之间的关系比较复杂而显示无明显的相关性,可能由于不同区域蜗牛壳体氧同位素对不同气候因子的响应程度不同,也可能是由于蜗牛壳体氧同位素与温度的关系在不同区域存在差异导致。总之,蜗牛壳体碳同位素较为忠实地记录了有效降水引起C3植被同位素变化的信息,而对蜗牛壳体氧同位素记录的信息的解读还不明晰,仍需更多研究。     

Carbon and Oxygen Isotopic Composition of Surface-Sediment Carbonate in Bosten Lake (Xinjiang, China) and its Controlling Factors

Bosten Lake is a mid-latitude lake with water mainly supplied by melting ice and snow in the Tianshan Mountains. The depositional environment of the lake is spatially not uniform due to the proximity of the major inlet and the single outlet in the western part of the lake. The analytical results show that the carbon and oxygen isotopic composition of recent lake sediments is related to this specific lacustrine depositional environment and to the resulting carbonate mineralogy. In the southwestern lake region between the Kaidu River inlet and the Kongqi River outlet, carbon isotope composition (δ13C) values of the carbonate sediment (-1‰ to -2‰) have no relation to the oxygen isotope composition of the carbonate (δ18O) values (-7‰ to -8‰), with both isotopes showing a low variability. The carbonate content is low (<20%). Carbonate minerals analyzed by X-ray diffraction are mainly composed of calcite, while aragonite was not recorded. The salinity of the lake water is low in the estuary region as a result of the Kaidu River inflow. In comparison, the carbon and oxygen isotope values are higher in the middle and eastern parts of the lake, with δ13C values between approximately +0.5‰ and +3‰, and δ18O values between -1‰ and -5‰. There is a moderate correlation between the stable oxygen and carbon isotopes, with a coefficient of correlation r of approximately 0.63. This implies that the lake water has a relatively short residence time. Carbonate minerals constitute calcite and aragonite in the middle and eastern region of the lake. Aragonite and Mg-calcite are formed at higher lake water salinity and temperatures, and larger evaporation effects. More saline lake water in the middle and eastern region of the lake and the enhanced isotopic equilibrium between water and atmospheric CO2 cause the correlating carbon and oxygen isotope values determined for aragonite and Mg-calcite. Evaporation and biological processes are the main reasons for the salinity and carbonate mineralogy influence of the surface-sediment carbonate in Bosten Lake. The lake water residence time and the CO2 exchange between the atmosphere and the water body control the carbon and oxygen isotope composition of the carbonate sediment. In addition, organic matter pollution and decomposition result in the abnormally low carbon isotope values of the lake surface-sediment carbonate.     

咸水湖泊沉积物中正构烷烃及其氢同位素组成与成因

青海湖是我国最大的内陆咸水湖泊,对这种湖泊沉积物中正构烷烃及其氢同位素进行了分析,研究了沉积物中正构烷烃及其同位素组成,并且与青海湖水生植物及其周围陆生植物的研究结果进行了对比,研究了它们的成因.结果显示了青海湖表层和柱状沉积物中正构烷烃分布都是类似的,其特征反映了它们起源于湖泊周围陆生草本植物.青海湖表层沉积物中正构...     

Carbon and Oxygen Isotopic Composition of Surface‐Sediment Carbonate in Bosten Lake (Xinjiang,China) and its Controlling Factors

Bosten Lake is a mid-latitude lake with water mainly supplied by melting ice and snow in the Tianshan Mountains. The depositional environment of the lake is spatially not uniform due to the proximity of the major inlet and the single outlet in the western part of the lake. The analytical results show that the carbon and oxygen isotopic composition of recent lake sediments is related to this specific lacustrine depositional environment and to the resulting carbonate mineralogy. In the southwestern lake region between the Kaidu River inlet and the Kongqi River outlet, carbon isotope composition (δ13C) values of the carbonate sediment (?1‰ to ?2‰) have no relation to the oxygen isotope composition of the carbonate (δ18O) values (?7‰ to ?8‰), with both isotopes showing a low variability. The carbonate content is low (<20%). Carbonate minerals analyzed by X-ray diffraction are mainly composed of calcite, while aragonite was not recorded. The salinity of the lake water is low in the estuary region as a result of the Kaidu River inflow. In comparison, the carbon and oxygen isotope values are higher in the middle and eastern parts of the lake, with δ13C values between approximately +0.5‰ and +3‰, and δ18O values between ?1‰ and ?5‰. There is a moderate correlation between the stable oxygen and carbon isotopes, with a coefficient of correlation r of approximately 0.63. This implies that the lake water has a relatively short residence time. Carbonate minerals constitute calcite and aragonite in the middle and eastern region of the lake. Aragonite and Mg–calcite are formed at higher lake water salinity and temperatures, and larger evaporation effects. More saline lake water in the middle and eastern region of the lake and the enhanced isotopic equilibrium between water and atmospheric CO2 cause the correlating carbon and oxygen isotope values determined for aragonite and Mg–calcite. Evaporation and biological processes are the main reasons for the salinity and carbonate mineralogy influence of the surface-sediment carbonate in Bosten Lake. The lake water residence time and the CO2 exchange between the atmosphere and the water body control the carbon and oxygen isotope composition of the carbonate sediment. In addition, organic matter pollution and decomposition result in the abnormally low carbon isotope values of the lake surface-sediment carbonate.     

博斯腾湖碳酸盐和同位素组成的全新世古环境演变高分辨记录及与冰川活动的响应

本文通过对在新疆南部塔里木盆地北缘博斯腾湖采集的一根953cm的岩心进行了早全新世以来的古气候重建。对BSTC2000岩心进行了碳酸盐矿物组成、Ca/1000Sr,有机质TOC,C/N和C/S分析,并结合BSTC2000岩心附近的一个沉积物剖面的孢粉资料,利用多指标重建了8500aBP以来的古气候变化特征。在2个平行岩心中对保存的植物叶片、草籽,以及全有机质进行了9个AMS14C年代测定。8500～8100aBP气候冷湿,钻孔位置为河流-滨湖相环境,沉积物中有3层泥炭层。从8100～6400aBP,气温升高,湖泊扩张,气候暖湿,湖泊可能为最高湖面时期。而从6400～5100aBP湖泊稍微下降,气候变冷。在中全新世晚期从5100～3100aBP气候变得高温干旱,但其间的4400～3800aBP有短暂的气候变冷,早期大量的冰雪融水补给博斯腾湖,使得湖泊水位上升。湖泊的第二个高湖面期是5200～3800aBP。在3100～2200aBP气候冷湿,由于蒸发减弱而湖泊有所扩张,湖泊在3100至2800aBP期间是最后一次短暂的高湖面期。这次短期高湖面后,湖泊由于较长时期的低温而引起的供水减少,湖泊收缩。从2200～1200aBP,气候变得干热,湖泊收缩。尽管从1200aBP以来,温度有所下降,气候变得暖干,湖泊又开始有所上升,但是没有达到博斯腾湖出水口孔雀河的海拔高度。     

胶东金成矿区岩石氧氢同位素地球化学背景初探

本文对胶东区域与金矿有关的各主要地质体氧氢同位素组成背景进行研究，给出了燕山早期“玲珑”中粗粒二长花岗岩（滦家河型花岗岩）氧氢同位素背景值为δ１８Ｏ＝７．８％，δＤ＝－１１０‰；燕山晚期郭家岭（型）斑状花岗闪长岩背景值为δ１８）＝１０．０‰；昆嵛山复式岩基背景值为δ１８Ｏ＝８．５‰，δＤ＝－９０‰。胶东群变质岩各岩性段δ１８Ｏ＝５．１－１１．３‰，δＤ＝－８１－－９６‰，表明其源岩既有幔源中基性组     

广西西北部二叠系——三叠系界线碳、氧同位素组成异常及其意义

我国广西西北部平果太平剖面二叠系－三叠系界线处为保存良好的海相碳酸盐岩沉积，根据牙形石化石带推断，该剖面在二叠系－三叠系界线处的连续沉积性良性。在该界线附近处，碳同位素组成发生了突然的负向波动，δ^13C从1．3‰－2．2‰（PDB）降至－0．9‰－－0．2‰，波动范围达2．8‰，进入下三叠统后一直呈负向发展；氧同位素组成波动虽不与碳同位素组成同步，但趋势相同，在二叠系－三叠系界线处达到最小值－8．2‰，下降幅度达2‰。这种同位素组成的波动已在我国西藏，浙江等的同时代的沉积中发现，此外，还在中东，北美洲，欧洲等地的二叠系－三叠系界线处发现，因此，它可以成为大区域及至洲际之间的二叠系－三叠系界线对比标志，这同时表明，二叠纪末期的重大地质事件发生的时间短，影响范围大，几乎是全球性的。     

Hydrochemistry of Salt Lakes in Southeastern Transbaikalia(Russia) in the Time of Arid Phase of Climate Change at the Beginning of the XXI Century

正1 Introduction In the south of Eastern Transbaikalia in the border area with China and Mongolia,there are at least 300 saline without outlet lakes.They are confined to the semi-arid zone Daurian steppes with pronounced continental salinization processes and are mostly located on the bottoms of the intermountain basins.Their origin is related to evaporative concentration of fresh waters lakes filling.     

加氢和TSR反应对天然气同位素组成的影响

天然气形成过程中的加氢作用和 TSR 反应是有机-无机相互作用的重要方式。相邻水体和深部来源的氢,是天然气形成的重要氢源,塔里木盆地天然气的甲烷氢同位素组成明显表现出不同沉积水体对甲烷氢同位素的控制作用,大宛105～25井和阿克1井具有深部流体加氢的特征;TSR 反应中硫同位素在不同反应阶段和反应过程具有不同的分馏特征,这种特征在四川盆地高舍硫天然气中具有很好的表现,TSR 反应硫同位素分馏一般小于20‰,而单体硫、黄铁矿和硫酸盐矿物等其它反应过程的产物硫同位素分馏不明显。     

Isotopic composition of dissolved boron and its geochemical behavior in a freshwater-seawater mixture at the estuary of the Changjiang （Yangtze） River

The isotopic composition of dissolved boron, in combination with the elemental concentrations of B, Cl and salinities in freshwater-seawater mixed samples taken from the estuary of the Changjiang River, the largest one in China, was investigated in detail in this study. Brackish water and seawater samples from the estuary of the Changjiang River were collected during low water season in November, 1998. Boron isotopic compositions were determined by the Cs2BO^＋2-graphite technique with a analytical uncertainty of 0.2‰ for NIST SRM 951 and an average analytical uncertainty of 0.8‰ for the samples. The isotopic compositions of boron, expressed in δ^11B, and boron concentrations in the Changjiang River at Nanjing and seawater from the open marine East Sea, China, are characterized by δ^11B values of -5.4‰ and 40.0‰, as well as 0.0272 and 4.43 mg B/L, respectively. Well-defined correlations between δ^11B values, B concentrations and Cl concentrations are interpreted in terms of binary mixing between fiver input water and East Sea seawater by a process of straightforward dilution. The offsets of δ^11B values are not related to the contents of clastic sediment and to the addition of boron. These relationships favor a conservative behavior of boron at the estuarine of the Changjiang River.     

珠江口盆地珠江组碳酸盐岩碳同位素组成负偏的成因意义

在岩芯观察、铸体薄片以及阴极发光分析的基础上,测定了珠江口盆地珠江组碳酸盐岩的碳氧同位素组成,获取判别流体性质的地球化学信息,探究其成岩意义。研究结果表明:1珠江组碳酸盐岩全岩样品的δ~(13)C(PDB)值主体分布在0‰±2‰之间,与该时期底栖有孔虫的碳同位素值接近,反映了与早中新世同期海水碳源一致的特征;2珠江口盆地东沙隆起流花地区部分钻井中存在碳同位素明显偏负并且胶结物发育的样品,全岩δ~(13)C(PDB)值可低至-7.2‰,碳氧同位素之间以及碳同位素与岩石中胶结物的含量之间均显示出良好的正相关关系(相关系数在0.6以上),碳同位素偏负伴随着氧同位素变轻,表明碳同位素的偏负是由胶结物造成的;3成岩演化序列分析以及块状亮晶方解石单矿物的碳氧同位素分析进一步证实了是由晚期胶结物造成碳同位素的偏负,埋藏成岩过程中有机酸的作用可能是造成碳同位素偏负的主要原因。     

Magmatic Nature of Mineralizing Fluids in the Solnechnoye Sn Deposit (Russia) Deduced from Isotopic (H,O) Compositions of Tourmaline

In this paper, we present new isotopic (H, O) data of fluids in tourmalines from the large Sn deposit at Solnechnoye (Far East Russia). These data indicate that the deposit formed by fluid‐rock interactions in a hydrothermal system where the mineralizing fluid was mainly magmatic and to a lesser extent meteoric. This is in agreement with a magmatic fluid model. Our interpretation of the new isotopic data is consistent with earlier findings of the studies on fluid‐rock interactions that magmatic fluids form larger Sn deposits than exogenic fluids. We propose that isotopic (H, O) data of fluids in tourmaline, rather than those in quartz, muscovite, or chlorite, support robust interpretation on the nature of mineralizing fluids associated with Sn deposits.     

塔北隆起深层海相油藏中原油及族组分碳同位素组成的纵向分布特征及其地质意义

利用MAT252同位素质谱仪分析了塔里木盆地塔北隆起深层海相油藏中原油及族组分的碳同位素组成。研究表明该区深层海相油藏中原油的全油碳同位素组成主要受生源控制,受热力作用影响较小;而在继承生源的碳同位素组成的基础上,热力作用将对原油族组分的碳同位素组成及其逆转和分馏产生重要影响。总的趋势是随着油藏埋藏深度的增大和热力作用的加强,饱和烃组分的碳同位素组成逐渐变重,而沥青质组分的碳同位素组成不断变轻,族组分碳同位素逆转程度和分馏程度有所加强,并出现饱和烃﹥芳烃﹥非烃﹥沥青质的整体逆转现象。塔北隆起深层海相原油族组分的碳同位素组成的纵向变化特征,可以反映出热力作用对原油稳定性的影响。     

塔里木盆地东部地区天然气地球化学特征及成因探讨(之一)

塔里木盆地是世界上勘探程度较低的大型盆地之一。近年来在该盆地中进行了大规模的油气勘探,发现了一系列的油、气田,其油、气资源量近似1∶1,说明在该盆地中天然气资源非常丰富。该盆地已发现的天然气主要分布在塔里木盆地东部地区的塔北隆起、塔中隆起和库车拗陷。天然气主要与凝析油及原油伴生。该盆地天然气组分分析表明,已发现的天然气藏绝大多数烃类气体含量大于65%;非烃气体CO₂含量小于5%,N2含量小于10%。一些天然气中N2含量达25%到35%。在塔北隆起油气藏中天然气的干湿指数(C₁/C₂+比值)具有从东到西降低的趋势,天然气中N₂含量具有从东到西升高的趋势,天然气甲烷的碳同位素组成也具有由东到西变轻的趋势,结合该区的地质背景可知造成这一趋势的主要因素可能是由于该区下古生界烃源岩热演化程度具有东高西低的特征。     

Cryptophyta Flagellates of Meromictic Lakes Shira and Shunet(Khakassia,Russia):Mechanisms of Vertical Distribution and Trophic Role

正1 Introduction Many of the stratified lakes are characterized by the presence of large populations of cryptomonads in their chemocline zones(Reynolds,1992;Gervais et al,2003;Pedro's-Alio'et al.,1995).These populations are adapted to low light intensity and high sulfide concentration;they have a mixotrophic ability and form the so-called"deep chlorophyll maxima"(Gervais,1998;Marsha"and Laybourn-Parry,2002).A similar Cryptomonas sp.     

The source of sulfur in sulfide deposits in the Siberian Platform traps (from isotope data)

The source of sulfur in giant Norilsk-type sulfide deposits is discussed. A review of the state of the problem and a critical analysis of existing hypotheses are made. The distribution of δ³⁴S in sulfides of ore occurrences and small and large deposits and in normal sedimentary, metamorphogenic, and hypogene sulfates is considered. A large number of new δ³⁴S data for sulfides and sulfates in various deposits, volcanic and terrigenous rocks, coals, graphites, and metasomatites are presented. The main attention is focused on the objects of the Norilsk and Kureika ore districts. The δ³⁴S value varies from -14 to + 22.5‰ in sulfides of rocks and ores and from 15.3 to 33‰ in anhydrites. In sulfide-sulfate intergrowths and assemblages, δ³⁴S is within 4.2-14.6‰ in sulfides and within 15.3-21.3‰ in anhydrites. The most isotopically heavy sulfur was found in pyrrhotite veins in basalts (δ³⁴S = 21.6‰), in sulfate veins cutting dolomites (δ³⁴S = 33‰), and in subsidence caldera sulfates in basalts (δ³⁴S = 23.2-25.2‰). Sulfide ores of the Tsentral’naya Shilki intrusion have a heavy sulfur isotope composition (δ³⁴S = + 17.7‰ (n = 15)). Thermobarogeochemical studies of anhydrites have revealed inclusions of different types with homogenization temperatures ranging from 685 °C to 80 °C. Metamorphogenic and hypogene anhydrites are associated with a carbonaceous substance, and hypogene anhydrites have inclusions of chloride-containing salt melts. We assume that sulfur in the trap sulfide deposits was introduced with sulfates of sedimentary rocks (δ³⁴S = 22-24‰). No assimilation of sulfates by basaltic melt took place. The sedimentary anhydrites were “steamed” by hydrocarbons, which led to sulfate reduction and δ³⁴S fractionation. As a result, isotopically light sulfur accumulated in sulfides and hydrogen sulfide, isotopically heavy sulfur was removed by aqueous calcium sulfate solution, and “residual” metamorphogenic anhydrite acquired a lighter sulfur isotope composition as compared with the sedimentary one. The wide variations in δ³⁴S in sulfides and sulfates are due to changes in the physicochemical parameters of the ore-forming system (first of all, temperature and P_ch4) during the sulfate reduction. The regional hydrocarbon resources were sufficient for large-scale ore formation.