区域采样法测定水中硫酸根离子的研究

在分散度不同的区域内进行区域采样用于水中硫酸根离子的测定，结果令人满意。应用此方法测定硫酸根离子的线性范围为２００．０～３０００ｍｇ／Ｌ；进样频率为１２０次／ｈ；相对标准偏差为１．７０％     

EXPERIMENTAL STUDY ON EFFECTS OF HUMIDITY AND CHEMICAL COMPOSITION UPON IMAGINARY PART OF REFRACTIVE INDEX OF AEROSOL PARTICLES*

Experimental study is made of the relationship between the imaginary part of refractive index (IRI) of atmospheric aerosol particles and relative humidity,and between IRI and chemical element through the assay of chemical constituents of the particles.Evidence suggests that atmospheric humidity and aerosols' chemical ingredients have great effects on the IRI's and they should thus be considered in the research of the radiation properties of the particles in the atmosphere.     

Composition of Kerogen in Kupferschiefer from Southwest Poland

Thirty-seven Kupferschiefer samples from southwestern Poland were analyzed by microscopy, Rock-Eval approach and instrumental neutron activation analysis to understand the geochemical and morphological characteristics of kerogen present in the samples. The analytical results indicate that there are two different types of kerogens. One type was only subjected to thermal alteration processes, and the other was further oxidized after deposition of the sediment.In the oxidized samples migrabitumen was transformed into pyrobitumen. Rock-Eval analyses show a significant decrease in HI values in the oxidized samples and an increase in OI values in relation to the samples that were not influenced by oxidation. Variations in S2 versus Corg contents indicate a change in kerogen from Type II to Type III with progressing oxidation. The presence of pyrobitumen and the depletion of hydrogen in the altered kerogen allow one to conclude that the kerogen was used as hydrogen donor for thermochemical sulfate reduction(TSR).     

Isotopic evidence of TSR origin for natural gas bearing high H_2S contents within the Feixianguan Formation of the northeastern Sichuan Basin, southwestern China

Isotopic evidence of TSR origin for natural gas bearing high H2S contents 1961 As the hazardous component of natural gas, the ex-istence of H2S, due to its extremely strong toxicity and corrosivity, not only decreases the percentage of hy-drocarbon gas within natural gas and reduces its in-dustrial value, it also threatens each aspect of drilling and exploitation. It frequently causes serious safety accidents[1] and leads to the E&P cost and risk of natural gas with higher H2S contents be…     

我国砂岩型铀矿分带特征研究现状及存在问题

作为一种重要的国家战略资源,砂岩型铀矿床是当今世界上最重要的铀矿床类型之一。本文详细地介绍了砂岩型铀矿在国内外的分布特征及占比情况,并对外生地质作用矿床类型中表生流体作用形成的层间渗透砂岩型和潜水渗透砂岩型铀矿床进行了讨论,发现层间渗透砂岩型铀矿床在外表颜色、矿物组合以及地球化学等方面均具有明显的氧化-还原分带现象,此外,矿床内部还具有细菌分带现象。颜色分带在氧化带、氧化-还原过渡带以及还原带之间具有明显不同的特征;矿物组合在不同分带之间各不相同;地球化学分带表现为U、TOC含量以及Fe~(2+)/Fe~(3+)、Th/U比值在各分带之间差异较大。此外,硫酸盐还原菌、硫杆菌、铁细菌及硝化菌等细菌在不同分带之间的数量相差悬殊,而且硫酸盐还原菌数量与TOC呈明显正相关性。通过矿化带内的碳、硫同位素分析,发现硫酸盐还原菌参与了成矿过程,推测其可能是导致碳、硫同位素分馏的主要因素。总体来看,颜色分带、矿物分带、地球化学分带以及细菌分带均与氧化-还原分带呈耦合关系。本文通过总结层间渗透砂岩型和潜水渗透砂岩型铀矿床的成矿模式和当前分带研究中存在的问题,提出了由细菌、地球化学反应参与的砂岩型铀矿床成矿机理,以及未来亟需解决的若干关键科学问题。典型砂岩型铀矿床的分带现象在物、化、探、遥等领域的异常响应对寻找砂岩型铀矿床具有重要的指导意义。     

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.     

Hydrothermal Dolomite: A Review and PerspectiveEI北大核心CSCD

Hydrothermal dolomite commonly closely associates with oil-gas reservoirs and sediment-hosted Pb-Zn deposits, the Mississippi Valley-type (MVT) Pb-Zn deposits in particular. Host rocks of MVT deposits usually experienced extensive dolomitization, and indeed, hydrothermal dolomite is considered as a useful prospective indicator for MVT mineralization. However, genetic link between the hydrothermal dolomitization and MVT Pb-Zn mineralization is a matter of debate. This paper briefly reviewed the nomenclature and research history of hydrothermal dolomite, introduced the major geological, geochemical characteristics, and distribution of hydrothermal dolomite, spatial and possibly genetic relationship between hdyrothermal dolomite and hdyrothermal ore deposits and oil-gas reservoirs based on case studies including the occurrence of hydrothermal dolomites in MVT deposits in Southwest China. The temporal and genetic relationships between dolomitizaiton and thermal sulfate reduction, sulfide precipitation and thus the location of ore mineralization well worthy more attention, and comprehensive geological and isotope geochemical and state of art in situ techniques will contribute to understanding of the genesis of hydrotherml dolomite and the spatially related ore deposits and oil-gas reservoirs. © 2018, Science Press. All right reserved.     

火山活动与海侵影响下的典型湖相页岩有机质保存差异分析

黑色富有机质页岩是页岩油气生成和赋存的主要母体,是强还原环境水体的沉积产物,在其形成过程中,细菌硫酸盐还原作用(BSR)对水体环境影响明显,但BSR强度如何影响有机质的保存尚未得到关注。我国陆相湖盆富有机质泥页岩广泛发育,形成过程中常常伴随有火山活动或者海侵等事件,大量硫酸盐进入湖盆,改变水体的沉积环境,不同环境下BSR对黑色页岩有机质保存的影响明显不同。本次研究选取鄂尔多斯盆地延长组长7段页岩、松辽盆地青山口组和嫩江组页岩作为对象,同时与现代沉积物进行对比。研究表明,TOC与TS之间关系复杂,但细菌硫酸盐还原强度指数(SRI)与TOC呈现幂指数变化,且表现出两阶段变化的特征。当SRI大于1.375时,TOC整体偏低,指示了强硫酸盐还原作用消耗大量有机质;当SRI小于1.375时,TOC明显较高,指示了弱硫酸盐还原作用对有机质消耗相对较少,更有利于有机质保存。火山活动和海侵作用均向水体提供了大量硫酸盐,但对陆相湖盆页岩中有机质的保存影响不同。火山活动影响的长7段页岩SRI普遍小于1.375,BSR对有机质消耗相对弱,页岩TOC高。而受海侵影响的青山口组一段底部和嫩江组一段底部页岩SRI大于1.375,BSR过度消耗了大量有机质,使得页岩TOC偏低。嫩江组一段下部SRI指数更高,海侵强度更大,BSR反应更强,更不利于有机质保存。     

Wet deposition of excess sulfate at Macquarie Island, 54° S

Annual wet deposition of excess sulfate at Macquarie Island has been estimated from 5 months of rainwater composition data covering the Austral summer of 1985/86. The resulting figure of 2.1±0.6 mmol/m²/yr is at the low end of previous estimates of maritime excess sulfate deposition by precipitation. Within estimated uncertainty limits this figure is consistent with the DMS emission flux which would be predicted for latitude 50°–60° S, based solely on available Northern Hemispheric DMS measurements.Temporarily at the International Meteorological Institute, Stockholm University, S-106 91, Stockholm, Sweden.