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1.
准噶尔盆地腹部含氮—富氮天然气成因 总被引:12,自引:2,他引:12
通过对天然气地化特征、碳同位素、轻烃组成资料研究认为,准噶尔盆地腹部陆梁隆起古生界天然气具有高氮特征.其中陆南凸起石炭系和三叠系天然气为含氮天然气;石南凹陷石炭系天然气为富氮天然气.成因研究认为,这类天然气可能与岩浆岩侵入体有关.在此研究基础上,结合地质条件,推测气源为石南凹陷石炭系. 相似文献
2.
为了探讨荷花山铅锌矿控矿因素上与铜陵地区其它矿床异同,运用宏、微观相结合,地质观察研究同位素地球化学以及流体包裹体分析相结合的方法,通过地层岩性、地质构造、特定地质体及成矿流体的来源和性质等几个方面与成矿关系的比较,揭示了这种新类型矿床的控矿因素的特点是与岩浆关系不密切的低温热液、角砾岩控矿。得出了这种新类型矿床既具有铜陵地区其它矿床的控矿因素,同时也具有自己独特的控矿因素的结论。 相似文献
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论地球化学外能与内能的转换 总被引:1,自引:0,他引:1
岩石在地表条件下具有q值增大规律。岩浆岩和变质岩在地表条件下,吸收太阳等宇宙能转化成沉积岩;在地壳深处,沉积岩释放这些能量转化成岩浆岩或变质岩。能量的上述转换,是通过内生的低晶格能矿物与外生的高晶格能矿物负载者实现的;是通过硅、铝主导控制元素,以及氧、钠、钾、钙、镁和铁等实现的。外能补充内能并通过内能起作用,从而成为改造地球面貌的宏伟运动。 相似文献
6.
Trace contaminants in water, including metals and organics, often are measured at sufficiently low concentrations to be reported only as values below the instrument detection limit. Interpretation of these “less thans” is complicated when multiple detection limits occur. Statistical methods for multiply censored, or multiple-detection limit, datasets have been developed for medical and industrial statistics, and can be employed to estimate summary statistics or model the distributions of trace-level environmental data.We describe S-language-based software tools that perform robust linear regression on order statistics (ROS). The ROS method has been evaluated as one of the most reliable procedures for developing summary statistics of multiply censored data. It is applicable to any dataset that has 0 to 80% of its values censored. These tools are a part of a software library, or add-on package, for the R environment for statistical computing. This library can be used to generate ROS models and associated summary statistics, plot modeled distributions, and predict exceedance probabilities of water-quality standards. 相似文献
7.
Michael M Kimberley 《Computers & Geosciences》1980,6(3):237-266
SOLVUS is a FORTRAN IV program which utilizes experimental data to calculate a complete miscibility gap between two isostructural phases. This binodal curve and the corresponding spinodal curve are plotted on temperature-composition axes. A formulation of the excess Gibbs energy of mixing is required for the calculation. Three different formulations are used, that is the Margules, van Laar, and Scatchard-Hamer types, in alternate solvus calculations. The temperature dependences of parameters in the three formulations are fitted by least-squares regression to a hyperbolic tangent, given sufficient data, or else to a line. Sample calculations are presented for six systems, high albite-sanidine, halite-sylvite, calcite-siderite, pyrite-vaesite, oldhamite-niningerite, and oldhamite-alabandite. 相似文献
8.
四川盆地中侏罗统沙溪庙组是低油价形势下四川盆地天然气勘探的重要领域,但盆地内不同地区天然气来源尚不明确,影响下一步勘探部署决策,为此开展侏罗系沙溪庙组天然气地球化学特征及成因研究。结果表明:①沙溪庙组天然气属于干酪根降解气,甲烷含量>84%,含少量乙烷、丙烷等烃类气体及少量的氮气、二氧化碳等非烃气体,不含硫化氢,不同区域的天然气成熟度存在差别;②天然气δ13C1值为-39.2‰~-31.2‰、δ13C2值为-32.8‰~-22.3‰、δ13C3值为 -28.7‰~-19.5‰,天然气碳同位素未发生倒转,川西地区为煤成气,川中地区为油型气,川东地区为煤成气和油型气混合气,以油型气为主;③不同区域天然气δ13C1值、δ13C2值的差异,与其来源于不同类型烃源岩贡献比例大小有关。川西、川西南地区主力烃源岩为须五段煤系烃源岩,川中地区为下侏罗统湖相烃源岩,川东地区天然气来源于须五段和下侏罗统烃源岩。研究结果对四川盆地侏罗系沙溪庙组下一步天然气勘探部署决策具有重要的指导意义。 相似文献
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Estuarine sediments are often highly enriched in particle-reactive metal contaminants and because aquatic animals have often been shown to acquire metals predominantly from their diet, benthic animals feeding on deposited or resuspended sediments may also accumulate metals through this uptake pathway. Laboratory experiments were performed in which the surface deposit-feeding polychaete, Nereis succinea, was exposed to As(+ 5), Cd, and Cr(+ 3) in pore water or in estuarine sediments with and without enrichment with algal debris. These experiments generated metal uptake parameters (assimilation efficiency of ingested metal [AE], uptake rate constant of dissolved metal, efflux rate constants following dietary or aqueous metal exposures) used in a kinetic model of metal bioaccumulation. The model showed that > 97% of the body burden of these metals is accumulated through ingested sediment. The kinetic model was further modified to consider the geochemical fractionation of the metals in the sediments because metals bound to some fractions were shown to be unavailable to these polychaetes. The modified model substituted the AE term for each metal by the percentage of metal extracted in neutral and weak acid exchangeable fractions (termed “carbonex” fraction) multiplied by the slope of the regression between the metal AE and its fractionation in carbonex. The modified model generated predictions of As, Cd, and Cr body burdens in polychaetes at three different estuarine sites that matched independent field observations at these sites (r2 = 0.84 for sediments without organic enrichment, r2 = 0.87 with organic enrichment). Model predictions that relied on total metal concentrations showed weaker relationships (r2 = 0.11-0.50). This study adds to the evidence for the dominance of dietary uptake of metals in aquatic animals and identifies a key sedimentary fraction of metals that can account for bioavailability of sediment-bound metals. 相似文献