三峡库区巫山县翠屏小区岩溶引起的地质灾害危险性研究   总被引：2，自引：1，他引：1  

张加桂  殷跃平  蔡秀华  李洪涛  孙党生 《地球学报》2008,29(4):495-501

三峡库区移民迁建中发现的岩溶问题是一个重大工程地质问题。巫山县城翠屏小区是较早发现有确切岩溶证据的地方,研究证实小区三叠系嘉陵江组灰岩普遍遭受了强烈的岩溶作用。不同部位具有不同的岩溶特点和强度,在纵向上,从山顶到坡脚岩溶作用有增强的趋势;从地表向深部,有局部强烈岩溶层位。岩溶作用在小区产生了顺坡或顺层延伸的溶洞和深部蜂窝状溶孔。岩溶作用在小区形成了脖颈状溶蚀槽地、槽状谷地、溶蚀台地和与地貌相关的"飞雁状"褶皱、岩溶正断层及帚状密集节理带。岩溶过程中伴随着其他外营力作用,它们的相互耦合形成各种次生岩土体。岩溶轻则引起岩体质量降低,重则可能导致地面不均匀沉降、地裂缝、滑坡、崩塌、泥石流及地面塌陷地质灾害。  相似文献   

Structural evolution of the Bayanhongor region, west-central Mongolia     

Soichi Osozawa  Gonchig Tsolmon  Uondon Majigsuren  Jargalan Sereenen  Shigeaki Niitsuma  Naoyoshi Iwata  Terry Pavlis  Bor-ming Jahn 《Journal of Asian Earth Sciences》2008,33(5-6):337-352

Most of previous models suggest that the Central Asia Orogenic Belt grew southward in the Phanerozoic. However, in the Bayanhongor region in west-central Mongolia, volcanic arc, accretionary prism, ophiolite, and passive margin complexes accreted northeastward away from the Baydrag micro-continent, and hence the region constitutes the southwestern part of a crustal-scale syntaxis close to the west. The syntaxis should be original, because presumably reorientation due to strike-slip faulting can be ignored. It is reconfirmed that the Baydrag eventually collided with another micro-continent (the Hangai) to the northeast. A thick sedimentary basin developed along the southern passive margin of the Hangai micro-continent. This region is also characterized by an exhumed metamorphosed accretionary complex and a passive margin complex, which are both bounded by detachment faults as well as basal reverse faults which formed simultaneously as extrusion wedges. This part of the Central Asia Orogenic Belt lacks exhumed crystalline rocks as observed in the Himalayas and other major collisional orogenic belts. In addition, we identified two phases of deformation, which occurred at each phase of zonal accretion as D1 through Cambrian and Devonian, and a synchronous phase of final micro-continental collision of Devonian as D2. The pre-collisional ocean was wide enough to be characterized by a mid-ocean ridge and ocean islands. Two different structural trends of D1 and D2 are observed in accretionary complexes formed to the southwest of the late Cambrian mid-ocean ridge. That is, the relative plate motions on both sides of the mid-ocean ridge were different. Accretionary complexes and passive margin sediments to the northeast of the mid-ocean ridge also experienced two periods of deformation but show the same structural trend. Unmetamorphosed cover sediments on the accretionary prism and on the Hangai micro-continent experienced only the D2 event due to micro-continental collision. These unmetamorphosed sediments form the hanging walls of the detachment faults. Moreover, they were at least partly derived from an active volcanic arc formed at the margin of the Baydrag micro-continent.  相似文献   

顾及DEM误差自相关的坡度计算模型精度分析   总被引：11，自引：1，他引：10  

刘学军  卞璐  卢华兴  朱莹 《测绘学报》2008,37(2):0-249

基于DEM的坡度计算,其误差来源于DEM误差、DEM结构和坡度计算模型。在顾及DEM误差自相关的前提下,对四种DEM坡度计算模型进行了分析和评价。研究表明,三阶不带权差分能给出较高的坡度计算精度;在局部窗口中,格网点数量越多,坡度计算越准确;等权比不等权的坡度计算模型更准确;DEM误差自相关结构形式对坡度计算无影响。进一步的理论分析和试验分析还表明：DEM误差自相关性的存在,不仅能够改善地形分析的精度,也能改善DEM自身精度。  相似文献   

煤矿区沉降与遥感监测方法探讨   总被引：2，自引：0，他引：2  

宁树正万余庆  孙顺新 《中国煤炭地质》2008,20(1):10-12

以晋城市煤矿区沉降研究为例,介绍了应用遥感图像调查与数字高程模型相结合的方法进行煤矿区沉降研究及监测。监测结果表明,沉降区主要集中在该区域的西北部,沉降区面积较大,沉降原因是大矿开采3#煤层,导致地面沉降,只有2处沉降由小煤矿开采9#煤层引起。经验证,具体位置虽有差异,但沉降区基本与实际吻合。依据当前合成孔径雷达干涉测量技术的发展,对煤矿区遥感综合监测方法进行了讨论。  相似文献   

新密市白石沟井田二1煤层充水因素分析     

王军强  崔蓓蕾 《中国煤炭地质》2008,(7):38-42

白石沟井田是近年来探明的大巾型井田,位于五指岭-白寨背斜东端之南翼,新密-新郑复向斜之北翼．岗亚腰断层和梁山断层之间的地垒构造上,其基本构造形态为-向东倾伏的宽缓背斜。二叠系下统山西组二1煤为主要开采煤层,探明二1煤资源量7206×10^7t。分析了井田含水岩组及其富水性,对断层带及其富水特征进行了研究,从矿床（二1煤层）充水的水源、通道、机理三个方面分析了矿床充水因素,指出二1煤层的主要充水水源为该煤层底板的石炭系岩溶裂隙-承压水,充水通道为断层带和灰岩的岩溶裂隙发育带,充水机理为矿压及高水头压力冲破煤层底板阻水层阻力,形成底鼓,迅速突水。认为该井田水文地质勘查类型为三类二型,提出了排除与隔离地表水体,预留防水安全煤柱,灌浆辅助采掘的井田突水防范措施。  相似文献   

甘肃大泉水——白沙岘矿区含煤地层及煤层赋存特征     

李玉畅 《中国煤炭地质》2008,(11):9-11

大泉水-白沙岘矿区位于甘肃省景泰县境内,在大地构造位置上处于北祁连加里东褶皱带东段,区内含煤地层为下石炭统靖远组和上石炭统羊虎沟组,属海陆交互相含煤沉积,根据岩性、岩相特征可划分为两个沉积旋回。该矿区主要可采煤层煤．层组赋存于羊虎沟组,厚1．71～9．00m,沿走向由西向东厚度变小,在大泉水井田可采厚度主要分布在V线以西,其东区段只是零星分布且不可采;在白沙岘井田煤层总厚度为2．99～5．15m,厚度变化小,属稳定煤层。煤：层组赋存于靖远组,仅分布在大泉水井田,厚1．33～8．88m,沿走向由西向东呈长透镜体状,西段和中段煤层发育较好．V线以东区段煤层变薄并出现无煤区。  相似文献   

Actinic flux and photolysis frequency comparison computations using the model PHOTOGT     

Carsten Blindauer  Vladimir Rozanov  John Philip Burrows 《Journal of Atmospheric Chemistry》1996,24(1):1-21

The accurate radiative transfer model GOMETRAN, initially designed to yield radiances at TOA in the wavelength range 240–790 nm, has been extended to allow for the computation of actinic fluxes down to 175 nm and for the calculation of photolysis frequencies in the atmosphere. The capability of the extended model PHOTOGT (PHOTOGOMETRAN) is demonstrated in a number of successful comparison studies both with recent experiments (ground-based, balloonborne, airborne) and model calculations of radiances, actinic fluxes and photolysis frequencies in the stratosphere and troposphere. In an atmospheric case study, the impact of new quantum yield data for the O₃ » O₂+O(¹ d) photodissociation channel on the photolytic production of O(¹ d) atoms in the lower atmosphere has been quantified.  相似文献   

华南二叠－三叠系的事件地层与生物地层界线   总被引：10，自引：1，他引：9  

王成源 《地层学杂志》1994,18(2):110-118,145

华南二叠－三叠系界线研究应严格区分事件地层界线与生物地层界线。“界线粘土”层的底界即为事件地层界线。生物地层界线定义不能与“混生层”或“过渡层”的概念连在一起。长兴煤山忠心大队剖面是最好的二叠－三叠系全球界线层型剖面点（ＧＳＳＰ）。二叠－三叠系生物地层界线定义为ＨｉｎｄｅｏｄｕｓｐａｒｖｕｓＭｏｒｐｈｏｔｙｐｅ１的首次出现,其位置就在长兴剖面界线层（混生层）２的内部,比事件地层界线高１５ｃｍ。ＨｉｎｄｅｏｄｕｓｐａｒｖｕｓＭｏｒｐｈｏｔｙｐｅ１的首次出现,即为长兴阶的顶界。  相似文献   

DEM高程基准转换方法及应用     

李月华  孙超 《北京测绘》2021,35(2):217-221

随着数字高程模型(DEM)在电力行业的广泛应用,电力地图需求部门对数字高程模型的要求越来越高。针对在数字高程模型生产中,电力业主方提供的立体模型高程基准不统一的问题,本文提出了基于特征数据的DEM基础转换方法。该方法在进行DEM制作过程中采用先采集特征数据,后转换特征数据高程基准的方式,实现了DEM成果的高程基准的转换,并进行了实验验证。结果表明,通过对比转换前后的DEM成果位置精度,验证了该方法的正确性。  相似文献   

珠江口盆地西江主洼油气差异分布机制     

刘培  张向涛  林鹤鸣  杜家元  冯进  陈维涛  梁杰  贾培蒙 《吉林大学学报(地球科学版)》2021,51(1):52-64

西江主洼是珠江口盆地一个低勘探程度洼陷，油气差异聚集特征明显，但其机理不清。本文在断陷盆地油气成藏理论指导下，利用研究区地质、地球物理和地球化学等资料，开展了烃源岩、断盖组合、储集体系和运聚模式等方面的研究。结果表明，裂陷期沉降、沉积中心有序迁移，造成主力烃源岩自东向西由文四段迁移至文三段、文一+二段，控制东、西部油气差异分布。恩平组区域性泥岩发育且晚期断裂缺乏，导致油气纵向上更易聚集于下构造层；区域泥岩减薄尖灭或晚期断裂切开盖层的区域，上构造层有一定油气分布。"源-汇"类型从宏观上控制储层优劣，影响下构造层油气富集程度；"仓储"运移是控制上构造层油气规模聚集的主要模式。下构造层古近系应作为重点部署方向，东部围绕文四段、西部围绕文三段、文一+二段烃源岩构成的含油气系统展开；上构造层勘探需关注珠海组，在隆起周边寻找具备"仓储"运移模式的有利区带。  相似文献