利用石膏产状研究汶东盐湖相沉积与烃源岩特征   总被引：1，自引：1，他引：0  

刘庆  张林晔  宋国奇  宋长玉  王茹 《高校地质学报》2009,15(3):371

根据石膏矿物类型和产状以及其它相标志,对汶东凹陷汶ZK16 钻孔的古近系盐湖相地层进行了沉积相分析,并结合有机地球化学分析,对不同沉积相的烃源岩开展了地球化学评价。汶东凹陷石膏矿物组合较好的反映了古盐湖沉积环境、水深、盐度和底水含氧量等的变化,不同的石膏矿物组合对应着不同的沉积相和不同质量的烃源岩,其中干化泥坪相和盐化泥坪相石膏矿物组合以分散胶结状和结核状为主,其烃源岩有机质丰度较低,发育非烃源岩到差烃源岩;干盐湖相石膏矿物组合以肠状石膏和透镜状石膏为主,烃源岩有机质丰度较高,发育好到优质烃源岩;而深水盐湖相石膏矿物以纹层状石膏为主,烃源岩有机质丰度高,总体达到优质烃源岩的标准。据此,建立了盐湖相烃源岩的发育模式。该模式对于中国第三系盐湖烃源岩,特别是高演化程度的盐湖相烃源岩原始烃源岩类型研究具有重要的指导意义。  相似文献   

Calibration of a hysteretic model for glass fiber reinforced gypsum wall panels     

Maganti Janardhana  P. Robin Davis  S. S. Ravichandran  A. M. Prasad  D. Menon 《地震工程与工程振动(英文版)》2014,13(2):347-355

Glass fi ber reinforced gypsum(GFRG) wall panels are prefabricated panels with hollow cores, originally developed in Australia and subsequently adopted by India and China for use in buildings. This paper discusses identifi cation and calibration of a suitable hysteretic model for GFRG wall panels fi lled with reinforced concrete. As considerable pinching was observed in the experimental results, a suitable hysteretic model with pinched hysteretic rule is used to conduct a series of quasi-static as inelastic hysteretic response analyses of GFRG panels with two different widths. The calibration of the pinching model parameters was carried out to approximately match the simulated and experimental responses up to 80% of the peak load in the post peak region. Interestingly, the same values of various parameters(energy dissipation and pinching related parameters) were obtained for all fi ve test specimens.  相似文献   

新疆乌苏地区新近系石膏脉特征及形成过程          下载免费PDF全文

杨少春  赵晓东  刘桓  向奎 《高校地质学报》2014,20(3):425

基于野外地质调查及采集样品的微观分析,文中详细研究了新疆乌苏地区新近系发育的石膏脉特征,并从古沉积环 境、成岩作用、风化作用和溶盐水注入期次等方面分析了石膏脉的形成过程。该区石膏脉发育形态特殊,主要是由两横两 纵4条线状主控石膏脉派生出的各种产状石膏脉组成,呈龟壳状。通过分析认为该石膏脉的形成过程共经历过4个阶段,炎 热的古沉积环境为沉积大量的石膏矿物奠定了基础,先成岩后胶结的成岩作用为石膏脉形成提供了必要条件,加上强烈的 风化作用和多期地表溶盐水注入和析出,形成了现今的龟壳状结构石膏脉。该套石膏脉的存在为推测盆地中心可能存在天 然储层裂缝改造区提供线索,并对西北地区新近纪干旱沉积环境具有一定的指示意义。  相似文献   

Origins of High H_2S-bearing Natural Gas in China   总被引：2，自引：0，他引：2  

ZHU Guangyou  ZHANG Shuichang  LIANG Yingbo  DAI Jinxing  LI Jian Research Institute of Petroleum Exploration  Development  China National Petroleum Corporation  Beijing 《《地质学报》英文版》2005,79(5):697-708

Natural gas containing hydrogen sulphide （H2S） has been found in several petroliferous basins in China, such as the Sichuan Basin, Bohai Bay Basin, Ordos Basin, Tarim Basin, etc. Natural gas with higher HES contents （HES 〉5 % mol.） is mostly distributed in both the gas reservoirs of Dukouhe, Luojiazhai, Puguang and Tieshanpo, which belong to the Triassic Feixianguan Formation in the northeastern Sichuan Basin and those of the Kongdian-Shahejie formations in the northeastern Jinxian Sag of the Jizhong Depression, Bohai Bay Basin. In the Sichuan Basin, the HES contents of natural gas average over 9% and some can be 17 %, while those of the Bohai Bay Basin range from 40 % to 92 %, being then one of the gas reservoirs with the highest H2S contents in the world. Based on detailed observation and sample analysis results of a total 5000 m of core from over 70 wells in the above-mentioned two basins, especially sulfur isotopic analysis of gypsum, brimstone, pyrite and natural gas, also with integrated study of the geochemical characteristics of hydrocarbons, it is thought that the natural gas with high HES contents resulted from thermochemical sulfate reduction （TSR） reactions. Among them, the natural gas in the Feixianguan Formation resulted from TSR reactions participated by hydrocarbon gas, while that in the Zhaolanzhuang of the Jinxian Sag being the product of TSR participated by crude oil. During the consumption process of hydrocarbons due to TSR, the heavy hydrocarbons were apt to react with sulfate, which accordingly resulted in the dry coefficient of natural gas increasing and the carbon isotopes becoming heavier.  相似文献   

兰州盆地石膏g=2.004峰平均寿命的估算   总被引：2，自引：0，他引：2  

刁少波  业渝光  隋卫东  李孝泽 《地球学报》2004,25(2):209-212

用热活化技术 ,对兰州盆地庄浪河剖面野狐城组地层中石膏样品的g=2.004峰ESR信号进行了平均寿命的估算。实验结果表明 ,一级动力学方程可能不适于g=2.004峰ESR信号平均寿命的估算。研究中采用几种方法估算了g=2.004峰ESR信号平均寿命 ,并进行了比较。用双二级动力学双活化能模式估算石膏g=2.004峰ESR信号在20℃时平均寿命为2.22×108a。  相似文献   

中国北方宁南盆地古近纪晚期咸化湖盆演化及其区域地质意义   总被引：1，自引：0，他引：1  

吴小力  李荣西  胡建民  程敬华  赵帮胜  刘福田  李得路  覃小丽  李佳佳  刘博彪 《地质学报》2017,91(4):954-967

本文以宁南盆地北部的贺家口子清水营组剖面为研究目标,对古近纪晚期清水营组的岩性特征、石膏主元素地球化学特征和泥岩有机地球化学特征进行研究,结果表明:清水营组岩性以灰绿-紫红色泥岩、石膏及二者互层为主,可划分为8个二级沉积旋回和3个一级沉积旋回。石膏中CaO含量反映了咸化湖盆中石膏的化学沉积作用,Al_2O_3等为陆源碎屑来源,清水营组下段为盐湖深水环境沉积的纯净石膏;中段石膏沉积的水体较浅。清水营组下段地层泥岩TOC和生烃潜量(S_1+S_2)较高,说明在咸化湖盆演化早期气候较湿润、水体较深;而泥岩降解潜力相对小,反映有机质以高等植物来源为主,陆源输入较多。在此研究基础上,认为宁南盆地清水营组沉积包括:蒸发岩的沉积和碎屑岩的沉积;咸化湖盆演化尚未达到钾盐等盐岩沉淀的高浓缩阶段。咸化湖盆演化主要经历了早期封闭深水盐湖发育阶段、中期封闭浅水盐湖鼎盛阶段和晚期开阔浅水盐湖消亡阶段。宁南盆地古近纪晚期咸化湖盆演化与盆地的持续构造沉降和各次级沉积坳陷最终连为统一的湖泊这一重大区域沉积事件有明显的响应关系。  相似文献   

石膏ESR测年信号g=2.004峰热稳定性的初步研究   总被引：1，自引：0，他引：1  

刁少波  业渝光  李孝泽  隋卫东 《海洋地质与第四纪地质》2004,24(3):97-102

用热活化技术,对甘肃兰州盆地和临夏盆地石膏样品的测年信号稳定性,以及石膏转化为干石膏的脱水情况进行了研究.根据干石膏在不同温度下的等温退火实验,应用双二级动力学和双活化能模式,估算出干石膏中陷阱电子g=2.004峰的平均寿命在20 ℃时为1.78×107a.  相似文献   

河西走廊花海古湖泊全新世白云石的发现及其环境意义   总被引：4，自引：3，他引：1  

李卓仑  陈晴  王乃昂  李育  吕行行 《湖泊科学》2013,25(4):558-564

通过对河西走廊花海古湖泊沉积物的X衍射分析发现,全新世期间有明显的白云石沉积.岩性、沉积过程、石膏以及Fe3+含量的变化表明,花海湖全新世白云石沉积环境以还原环境为主,即还原环境利于白云石的形成,为白云石的成因研究提供了新的证据.白云石作为碳酸盐矿物,可以反映湖水盐度,但并非直接指示了湖水的咸化.随着湖水盐度的进一步增加,在硫酸盐型湖泊中,白云石含量随盐度的增加而相应减少,表明利用白云石分析湖水盐度时需要结合其他矿物进行分析.结合石膏含量的变化,花海湖全新世时期白云石含量的变化可以揭示该区域湖水盐度的变化.在10.478.87 cal ka B.P.早全新世时期,湖水的盐度较高,气候由干向湿转变;8.87 cal ka B.P.时期,有大量石膏沉积,显示了湖水盐度的进一步升高,气候干旱;随后湖水相对淡化,气候湿润;5.50 cal ka B.P.至今,沉积出现间断,气候逐渐干旱.  相似文献   

The role of gypsum and/or dolomite dissolution in tufa precipitation: lessons from the hydrochemistry of a carbonate–sulphate karst system          下载免费PDF全文

David Domínguez‐Villar  Juan A. Vázquez‐Navarro  Kristina Krklec 《地球表面变化过程与地形》2017,42(2):245-258

The precipitation of freshwater carbonates (tufa) along karstic rivers is enhanced by degassing of carbon dioxide (CO₂) downstream of karstic springs. However, in most karstic springs CO₂ degassing is not enough to force the precipitation of tufa sediments. Little is known about the role of dissolution of gypsum or dolomite in the hydrochemistry of these systems and how this affects the formation of tufa deposits. Here we present a monitoring study conducted over a year in Trabaque River (Spain). The river has typical karst hydrological dynamics with water sinking upstream and re‐emerging downstream of the canyon. Mixing of calcium–magnesium bicarbonate and calcium sulphate waters downstream of the sink enhances the dissolution of carbonates and potentially plays a positive role in the formation of tufa sediments. However, due to the common‐ion effect, dissolution of dolomite and/or gypsum causes precipitation of underground calcite cements as part of the incongruent dissolution of dolomite/dedolomitization process, which limits the precipitation of tufa sediments. Current precipitation of tufa is scant compared to previous Holocene tufa deposits, which likely precipitated from solutions with higher saturation indexes of calcite (SIcc values) than nowadays. Limited incongruent dissolution of dolomite/dedolomitization favours higher SIcc values. This circumstance occurs when waters with relatively high supersaturation of dolomite and low SO₄^2? composition sink in the upper sector of the canyon. In such a scenario, the process of mixing waters enhances the exclusive dissolution of limestones, preventing the precipitation of calcite within the aquifer and favouring the increase of SIcc values downstream of the springs. Such conditions were recorded during periods of high water level of the aquifers and during floods. This research shows that the common‐ion effect caused by the dissolution of gypsum and/or dolomite rocks can limit [or favour] the precipitation of tufa sediments depending on the occurrence [or not] of incongruent dissolution of dolomite/dedolomitization. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

喀喇昆仑林济塘盆地铅锌矿床容矿地层的海相沉积环境：源于侏罗系灰岩微量元素和石膏硫同位素的约束     

唐俊林 《地质与勘探》2020,56(6):1134-1144

近年来,喀喇昆仑地区林济塘中生代沉积盆地内发现了火烧云超大型铅锌矿等众多铅锌矿床,以往对该地区的沉积环境以及其成矿相关性缺乏详细探讨。本文开展了林济塘盆地内侏罗系灰岩微量元素和石膏硫同位素分析,以揭示铅锌矿床容矿地层的沉积环境及其与成矿的相关性。研究发现,盆地内侏罗系灰岩中Ba、V、Ni、Cu、Co、Th、Co、Sr元素及比值特征显示其形成于海相,石膏硫同位素δ34S 值为14.89‰~20.63‰,与同期海水相一致。表明该盆地内铅锌矿床的容矿地层形成于干热气候条件下的海相沉积氧化环境。  相似文献