Solubility of Anhydrite, CaSO4, in NaCl-H2O Solutions at High Pressures and Temperatures: Applications to Fluid-Rock Interaction   总被引：1，自引：0，他引：1  

NEWTON  ROBERT C.; MANNING  CRAIG E. 《Journal of Petrology》2005,46(4):701-716

Anhydrite solubility in H₂O–NaCl solutions was measuredat 6–14 kbar, 600–800°C and NaCl mole fractions(X_NaCl) of 0–0·3 in piston–cylinder apparatus.Solubilities were determined by weight changes of natural anhydritein perforated Pt envelopes confined with fluid in larger Ptcapsules. In initially pure H₂O at 10 kbar and 800°C, CaSO₄concentration is low (0·03 molal), though much largerthan at the same temperature and 1 kbar. Hematite-buffered experimentsshowed slightly lower solubilities than unbuffered runs. CaSO₄solubility increases enormously with NaCl activity: at 800°Cand 10 kbar and X_NaCl of 0·3, CaSO₄ molality is 200 timeshigher than with pure H₂O. Whereas CaSO₄ solubility in pureH₂O decreases with rising T at low T and P, the high-P resultsshow that anhydrite solubility increases with T at constantP at all X_NaCl investigated. The effects of salinity and temperatureare so great at 10 kbar that critical mixing between sulfate-richhydrosaline melts and aqueous salt solutions is probable at900°C at X_NaCl 0·3. Recent experimental evidencethat volatile-laden magmas crystallizing in the deep crust mayevolve concentrated salt solutions could, in light of the presentwork, have important implications regarding such diverse processesas Mount Pinatubo-type S-rich volcanism, high-f O₂ regionalmetamorphism, and emplacement of porphyry Cu–Mo ore bodies,where anhydrite–hematite alteration and fluid inclusionsreveal the action of very oxidized saline solutions rich insulfur. KEY WORDS: anhydrite; sulfur; solubility; metamorphic brines; granulites  相似文献   

On the Retrieval of Volcanic Sulfur Dioxide Emissions from GOME Backscatter Measurements     

W. Thomas  T. Ruppert  M. Van Roozendael  J. Verdebout  D. Balis  C. Meleti  C. Zerefos 《Journal of Atmospheric Chemistry》2005,50(3):295-320

We focus on the retrieval of volcanic sulfur dioxide (SO₂) emissions from an analysis of atmospheric UV backscatter spectra obtained by the Global Ozone Monitoring Experiment (GOME) spectrometer on board the ESA European Remote Sensing Satellite (ERS-2). Here, the last major eruptions of Mt. Etna on Sicily (Italy) in July/August 2001 and October/November 2002 provided an excellent opportunity to study the retrieval of SO₂ columnar amounts from ground-based, LIDAR and satellite measurements. Our study shows that the bulk of emitted SO₂ was confined in the troposphere, mainly between 700 hPa and 400 hPa which is confirmed by trajectory analysis, by LIDAR observations and AVHRR observations. The area of influence of Mt. Etna eruptions ranges from the Western Saharan Desert to Greece and the near east states and even down to the basin of Tschad, Africa. Our analysis revealed that information about the plume height of volcanic eruptions and aerosol parameters is necessary for a reliable quantitative retrieval of SO₂ from space-borne sensor data at periods perturbed by volcanic eruptions.  相似文献   

Isotopic evidence of TSR origin for natural gas bearing high H<Subscript>2</Subscript>S contents within the Feixianguan Formation of the northeastern Sichuan Basin,southwestern China   总被引：3，自引：1，他引：2  

Guangyou?ZhuEmail author  Shuichang?Zhang  Yingbo?Liang  Jinxing?Dai  Jian?Li 《中国科学D辑(英文版)》2005,48(11):1960-1971

The northeastern area of Sichuan Basin, southwestern China, is the area with the maximal reserve of natural gas containing higher hydrogen sulphide (H₂S) that has been found among the petroliferous basins of China, with the proven and controlled gas reserve of more than 200 billion cubic meters. These gas pools, with higher H₂S contents averaging 9%, some 17%, are mainly distributed on structural belts of Dukouhe, Tieshanpo, Luojiazhai, Puguang, etc., while the oolitic-shoal dolomite of the Triassic Feixianguan Fm. (T₁f) is the reservoir. Although many scholars regard the plentiful accumulation of H₂S within the deep carbonate reservoir as the result of Thermochemical Sulfate Reduction (TSR), however, the process of TSR as well as its residual geological and geochemical evidence is still not quite clear. Based on the carbon isotopic analysis of carbonate strata and secondary calcite, etc., together with the analysis of sulfur isotopes within H₂S, sulphur, gypsum, iron pyrites, etc., as well as other aspects including the natural gas composition, carbon isotopes of hydrocarbons reservoir petrology, etc., it has been proved that the above natural gas is a product of TSR. The H₂S, sulphur and calcite result from the participation of TSR reactions by hydrocarbon gas. During the process for hydrocarbons being consumed due to TSR, the carbons within the hydrocarbon gas participate in the reactions and finally are transferred into the secondary calcite, and become the carbon source of secondary calcite, consequently causing the carbon isotopes of the secondary calcite to be lower (−18.2‰). As for both the intermediate product of TSR, i.e. sulfur, and its final products, i.e. H₂S and iron pyrites, their sulfur elements are all sourced from the sulfate within the Feixianguan Fm. During the fractional processes of sulfur isotopes, the bond energy leads to the ³²S being released firstly, and the earlier it is released, the lower δ ³⁴S values for the generated sulphide (H₂S) or sulfur will be. However, for the anhydrite that participates in reactions, the higher the reaction degree, the more ³²S is released, while the less ³²S remains and the more δ ³⁴S is increased. The testing results have proved the process of the dynamic fractionation of sulfur isotopes.  相似文献   

1994-2006年长江三角洲和东北平原酸性气体浓度变化   总被引：6，自引：0，他引：6  

徐晓斌  林伟立  颜鹏  张忠华  俞向明 《气候变化研究进展》2008,4(4):195-201

 利用长江三角洲和东北平原地区大气本底站的二氧化硫（SO2）和氮氧化物（NOx）历史资料和近期取得的观测数据,探讨两个地区人为排放对这些气候相关酸性气体的不同贡献。从两种酸性气体过去和现在的浓度水平,估算了它们在两个地区的增长率,比较了NOx与SO2比值的不同变化趋势。结果表明,早在20世纪90年代中期,长江三角洲酸性气体污染水平已经较高,其后主要是NOx浓度显著升高,从而使该地区成为硫和氮污染并重的地区;东北平原酸性气体过去浓度很低,但这些气体以很高的速率增长,虽然目前浓度水平仍然比较低,但未来形势不容乐观。  相似文献   

蒸发岩中硫同位素的地球化学特征及其沉积学意义——以思茅盆地MZK- 3井为例   总被引：2，自引：0，他引：2  

苗忠英  郑绵平  张雪飞  张震  高运志 《地质学报》2019,93(5):1166-1179

思茅盆地目前是中国唯一的含古代固体钾盐矿床的沉积盆地,其钾盐形成时代、物源特征、海侵方向等多年来一直存在争议。本文依据海相硬石膏的形成条件、存在形式、同位素分馏机理,重点分析了盆地内MZK-3井蒸发岩硫同位素的地球化学特征。结果表明:①岩盐中的硬石膏在蒸发盆地析岩盐阶段即可形成,单独成层的硬石膏是由原始沉积的石膏经历了沉积埋藏升温进而脱水而成;②岩盐中硬石膏的硫同位素值具有"双峰"特征,分别为14‰～16‰和8‰～10‰或6‰～8‰,这体现了硫酸盐的双重来源——原始海水中的硫酸盐和陆源淡水输入的硫酸盐或火山活动提供的硫源;③硬石膏层的硫同位素在区域上具有对比性,结合~(87)Sr/~(86)Sr值的特征,认为其代表了海相的沉积环境;④硬石膏层的硫同位素值平面上由南向北降低,可能反映了在此方向陆源淡水或火山活动对蒸发岩盆地的影响逐渐增强,进而说明这可能也是海侵的方向。可见对硬石膏硫同位素的研究,不仅在沉积学上能揭示物源、沉积环境、海侵方向等信息,更能对研究区钾盐矿床勘查提供有益的参考。  相似文献   

滇东北镇雄硫磺矿区环境地质问题及其对策与意义     

张佳文  赵元艺  骆检兰  魏友华  方景玲  蔡剑辉  刘冠男  李小赛  崔宁  黄道袤  王蕊  郑权 《地球学报》2019,40(2):329-338

硫磺渣是硫磺矿区主要的矿业固废,其随意堆放可产生一系列的环境地质问题,并对山水林田湖草等自然资源、环境及人的健康构成较大危害。滇东北地区长期以硫铁矿为原料、以煤炭为燃料,土法炼硫生产硫磺,导致巨量硫磺渣堆积,产生了严重的环境地质问题。本文针对该地区镇雄县硫磺矿区,调查了小硫磺生产形成硫磺渣的规模和特征,梳理了该硫磺矿区主要环境地质问题及其对当地生态环境的影响,认为目前镇雄硫磺矿区存在的环境污染、自然资源破坏及可能形成的矿渣性泥石流等环境地质现状与过去40多年的小硫磺生产密切相关。基于以上认识,强调应结合矿业固废无害化、减量化和资源化技术政策,从资源回收利用、生态环境恢复、地质灾害防治和文化遗产保护方面探讨和提出镇雄硫磺矿区矿渣治理和生态修复的新理念和新对策。  相似文献   

Interplay of S and As in Mekong Delta sediments during redox oscillations   总被引：1，自引：1，他引：0  

Van T.H.Phan  Fabrizio Bardelli  Pierre Le Pape  Raoul-Marie Couture  Alejandro Fernandez-Martinez  Delphine Tisserand  Rizlan Bernier-Latmani  Laurent Charlet 《地学前缘(英文版)》2019,10(5):1715-1729

The cumulative effects of periodic redox cycling on the mobility of As,Fe,and S from alluvial sediment to groundwater were investigated in bioreactor experiments.Two particular sediments from the alluvial floodplain of the Mekong Delta River were investigated:Matrix A(14 m deep)had a higher pyrite concentration than matrix B(7 m deep)sediments.Gypsum was present in matrix B but absent in matrix A.In the reactors,the sediment suspensions were supplemented with As(Ⅲ)and SO_4~(2-),and were subjected to three full-redox cycles entailing phases of nitrogen/CO_2,compressed air sparging,and cellobiose addition.Major differences in As concentration and speciation were observed upon redox cycling.Evidences support the fact that initial sediment composition is the main factor controlling arsenic release and its speciation during the redox cycles.Indeed,a high pyrite content associated with a low SO_4~(2-)content resulted in an increase in dissolved As concentrations,mainly in the form of As(Ⅲ),after anoxic half-cycles;whereas a decrease in As concentrations mainly in the form of As(Ⅴ),was instead observed after oxic half-cycles.In addition,oxic conditions were found to be responsible for pyrite and arsenian pyrite oxidation,increasing the As pool available for mobilization.The same processes seem to occur in sediment with the presence of gypsum,but,in this case,dissolved As were sequestered by biotic or abiotic redox reactions occurring in the Fe—S system,and by specific physico-chemical condition(e.g.pH).The contrasting results obtained for two sediments sampled from the same core show that many complexes and entangled factors are at work,and further refinement is needed to explain the spatial and temporal variability of As release to groundwater of the Mekong River Delta(Vietnam).  相似文献   

硫氧同位素示踪污染物来源在济南岩溶水中的应用   总被引：1，自引：0，他引：1  

张海林  王重  逄伟  滕跃  齐欢 《中国地质调查》2019,6(1):75-80

近年来,济南岩溶水硫酸盐浓度逐年升高,为了对硫酸盐污染区域实施有效的防治措施,保障饮用水安全,识别硫酸盐的污染来源极其重要。在系统分析研究区水文地质条件的基础上,根据实际的采样测试数据,采用硫、氧(S、O)双同位素示踪技术,分析识别了济南趵突泉泉域硫酸盐的主要污染来源,并通过IsoSource质量守恒模型,估算了硫酸盐各污染来源的贡献率。结果表明: 泉域内硫酸盐主要污染来源有大气沉降、污水和土壤; 大气沉降来源贡献率最大,均值达到53.9%; 其次是污水来源,均值为31%; 土壤来源贡献率最小,均值为15.1%。该研究为北方岩溶区地下水硫酸盐来源的定量研究提供了一种新方法,为济南趵突泉泉域硫酸盐污染防治提供了科学依据。  相似文献   

煤中硫研究现状   总被引：8，自引：2，他引：6  

周春光  杨起  康西栋  汤达祯  刘大锰 《煤田地质与勘探》1999,27(1):16-20

从煤中的无机硫、有机硫、亲硫元素及煤中硫成因等四方面总结了煤中硫的研究现状。   相似文献   

华北晚古生代煤中有机硫的赋存状态及其成因   总被引：8，自引：0，他引：8  

康西栋  杨起  张瑞生  周春光  汤达祯  刘大锰 《地球科学》1999,24(4):413-417

为揭示煤中有机硫的赋存状态及其地质成因,采用电子探针微区分析和硫同位素分析技术对华北地区山西大同、太原西山、霍州以及安徽淮南４个矿区的８个层晚古生代的煤层进行了研究,海水的作用对有机硫的聚集起着十分重要的影响。煤的不同显微组分中有机硫的质量分数存在明显差异,镜质组中有机硫的质量分数高于其在惰质组的质量分数。硫在煤中的聚集是一个逐渐累积的过程,有机硫的聚集一般滞后于黄铁矿硫的聚集。泥炭沼泽条件控制着  相似文献