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A number of studies have shown that development areas of weak deformation brittle series of tectonically deformed coal are often the favorable areas for coalbed methane development, and the distribution area of the mylonitic coal of ductile deformation is a danger zone of mine gas outburst. Therefore, faced with solving the key scientific issues and technical problems of the coal bed methane exploration and development and gas outburst prediction and evaluation, more and more attention has been paid to the research on tectonically deformed coal. This paper first systematically elaborated the main research progress on the concept and classification of tectonically deformed coals, their deformation characteristics, and the pore fissure structure and chemical structure. Then, it pointed out that there was a lack of research on the ductile deformation mechanism of coal, and this key scientific problem needs further research in the future. It seemed that the structural and geochemical process of chemical elements migration and accumulation during coal deformation was a new field which is worth exploring. Through refining stress sensitive elements, their distribution and evolution patterns in different stress-strain environments and different types of tectonically deformed coals might be revealed, and then they could become a predictive index which indicates the significance of distribution of tectonically deformed coals and gas outburst prediction. It was thought that geophysical response characteristics and research of detection theory and interpretation method of different types of tectonically deformed coal and gas enrichment area should be an important development direction in the future. 相似文献
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阿尔金山喀腊大湾地区变形岩石EBSD组构分析 总被引:4,自引:0,他引:4
岩石组构是指组成岩石的矿物在岩石中分布的各向异性,EBSD(Electron Back Scattered Diffraction)岩组分析就是运用电子背散射衍射技术测定岩石结构要素——岩石中矿物分布的规律性。本文作者运用EBSD技术方法,对阿尔金山喀腊大湾地区变形岩石的组构分析显示,花岗质糜棱岩和蚀变变形花岗岩中,石英变形机制是以中温I级柱面(10-10)0001和中高温II级柱面(10-10)0001滑移为主,少量为中低温底面(0001)11-20滑移;而在变形火山岩中,石英变形机制是以中低温底面(0001)11-20滑移系为主。在区域南北向剖面分布上,接近阿尔金北缘断裂和白尖山断裂的中北部变形温度较高,向南变形温度有逐渐降低的趋势。从岩石组构特点结合宏观构造分析,可以认为本区北段属于中—中深层次(15~25km,t=350~550℃,P=0.40~0.60GPa)的韧性变形,而中南段为中浅层次(10~15km,t=250~350℃,P=0.25~0.40GPa)的韧脆性变形。结合不同变形特点花岗岩的年代学资料,确定构造变形的时代为早古生代。上述特征与区域上发育板块碰撞带,且北部发育高压榴辉岩和蓝片岩的构造部位以及该构造变形带的演化历史相吻合。 相似文献
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黄河三角洲变形层理的研究 总被引:7,自引:2,他引:5
黄河三角洲发育了非常丰富的变形层理,规模不一,类型多样,成因复杂,概括起来有下列几种:泄水变形层理、重力滑动变形层理、流水牵引变形层理、沙波滑移变形层理、生物扰动变形层理、波浪改造变形层理及滑塌变形层理七种。其中以泄水变形层理和流水牵引变形层理最为常见和典型。泄水变形层理上表面往往有一乳头状或脊状的突起,有时中心有一泄水孔,与上下部层理呈突变接触。流水牵引变形层理具有五个特点:(1)变形层理之上经常可以见到没有层理或具平行层理的细泥砾(砂)层,或者逆行沙波、逆行爬升层理,显示了变形层理之上有高速水流作用;(2)有时可以看到褶曲状变形层理轴面向下游倾倒,但常常无规律可寻;(3)与上覆层理多为突变接触,与下伏层理突变或渐变接触,取决于变形强烈程度;(4)大部分变形强列,呈包卷状,囊状或管状;(5)分布稳定,有时可见多级组合产出。 相似文献
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重庆綦江奥陶系五峰组中—下部的黑色页岩中发育有一系列主要由阶梯状断层和其间的小型褶皱构成的同生变形构造(contemporaneous deformed structures),并可大致分为3个构造层段。沉积后—固结成岩前所形成的同生变形构造层之上为正常沉积的黑色页岩层。另外,在贵州桐梓五峰组距底部2.3m左右的黑色页岩中也发育有与綦江地区相似的、以小型褶皱为主的同生变形构造层,且此同生变形构造层上下为斑脱岩层。同生变形构造的发现,表明渝南—黔北地区奥陶纪晚期(五峰期)的沉积盆地为非平坦的古地貌,且曾发生过多期可能与火山运动相关的构造运动。 相似文献
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宝塔梁崩滑变形体位于陕西省安康市镇坪县城关镇菜村的宝塔梁陡坡上,地处南江河右岸。该崩滑体最早发现于1987年,至2008年1月,一直未发生明显的变形。2008年2月1日开始变形,2月23日,崩滑变形体前缘临沿江路的崩塌面宽度由原先的数米宽增至60~70m,且向陡崖上部延伸发展,陡崖不断地垮塌,完全阻断了沿江路,3~4月采取减载应急处理,其后基本没有再发生大的变形。在详细描述崩滑体变形特征和破碎程度的基础上,认为该崩滑体岩体呈散体或碎裂状,碎块间结合力差,属大型崩滑体。采用钻探、探井、浅层地震勘探、瑞雷波测试和室内试验等到多种方法,分析确定了变形体的形态、变形状态及其边界,给定了变形结构面及计算参数,并以此参数进行了稳定性验算。结果表明,该崩滑体Ⅰ-Ⅰ和Ⅲ-Ⅲ剖面处于欠稳定状态,Ⅱ-Ⅱ剖面处于基本稳定状态,总体处于欠稳定状态。研究结果在2009年7月崩滑变形体的复活变形中得到了验证。 相似文献
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As the mercury emitted from coal combustion can lead to serious environmental issues, researchers pay more attention to the content, distribution and occurrence of mercury in coal. In this paper, the content, distribution, and occurrence of mercury in the Permian tectonically deformed coals from Peigou Mine, Xinmi coalfield, Henan Province were investigated. A total of 18 bench samples were taken from No.2-1 coals seam in Peigou Mine, including 15 coal bench samples, two roofs and one floor. The mercury concentration, mineral composition, and main inorganic element content of 18 samples were determined by DMA-80 direct mercury analyzer, XRD, and XRF respectively. The results show that the mercury content ranges from 0.047 ppm to 0.643 ppm, with an average of 0.244 ppm. Though the coal seam has turned into typical tectonically deformed coal by the strong tectonic destruction and plastic deformation, the vertical distribution of mercury has remarkable heterogeneity in coal seam section. By the analysis of correlation between mercury and the main inorganic elements and the mineral composition in coal, we infer that majority of mercury mainly relates to pyrite or kaolinite. 相似文献
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Detailed micro-meso to macroscopic structural analyses reveal two deformation phases in the western limb of the Hazara-Kashmir Syntaxis(HKS). Bulk top to NW shearing transformed initially symmetrical NNE-SSW trending meso to macroscopic folds from asymmetric to overturned ones without changing their trend. Sigmoidal en-echelon tension gashes developed during this deformation,that were oblique to bedding parallel worm burrows and bedding planes themselves. Strain analyses of deformed elliptical ooids using the R_f/φ method constrain the internal strain patterns of the NNE-SSW structures. The principal stretching axis(S_3) defined by deformed elliptical ooids is oriented N27°E at right angles to WNW-ESE shortening. The deformed elliptical ooids in sub-vertical bedding vertical planes contain ooids that plunge ~70° SE due to NW-directed tectonic transport. Finite strain ratios are1.45(R_(xy)) parallel to bedding plane and 1.46(R_(yz)) for the vertical plane. From these 2D strain values, we derive an oblate strain ellipsoidal in 3D using the Flinn and Hsu/Nadai techniques. Strains calculated from deformed elliptical ooids average-18.10% parallel to bedding and-18.47% in the vertical plane.However, a balanced cross-section through the study area indicates a minimum of~-28% shortening.Consequently, regional shortening was only partially accommodated by internal deformation. 相似文献