共查询到20条相似文献，搜索用时 171 毫秒
1.
通过对黔西北阳关寨勘查地质勘查资料的综合分析,研究了该勘查区的构造特征以及对煤层赋存的影响。研究表明:勘查区构造特征主要表现为受燕山期应力作用的影响,形成的以NW向褶曲与断裂为主;勘查区的3条NW向褶皱改造了本区煤层的空间位置,形成了现如今该地区煤层埋藏起伏不平的埋藏形态,抬升了中部背斜轴部地区煤层埋深,有利于中部地区煤层的开采利用;勘查区内切割煤层的断层不仅限制了煤层空间发育位置,还改造了煤层的空间发育形态,破坏了煤层连续性。 相似文献
2.
在系统分析勘查区构造发育特征的基础上,结合勘查区瓦斯实测参数,以区域构造演化和勘查区构造的控制作用为基础,对勘查区的构造对瓦斯赋存控制作用进行了探讨。结果表明:勘查区的瓦斯赋存的特征严格受构造控制,断层倾向多与地层倾向大致一致,以逆断层为主。断层落差较大,导致煤系地层的不同程度重复或者缺失,浅部含煤地层的完整性被严重的破坏了。复杂的构造特征致使瓦斯赋存条件由轴部到两翼逐渐变差且南西翼好于北东翼。 相似文献
3.
杨家沟矿区大地构造位置处于扬子准地台黔北台隆遵义断拱与贵阳复杂构造变形区交接的毕节北东向构造变形区内,区内主要构造形态断层呈北北东向,褶皱的主要形态为东西向。矿区及附近出露地层有二叠系上统龙潭组、长兴(大隆)组,三叠系下统夜郎组、茅草铺组。主要含煤地层为龙潭组,可采煤层为K1、K2、K3煤层,可采煤层赋存于煤系地层中下部。煤系地层很少受F1断层影响,煤系地层沿走向倾向的产状变化不大,矿区求获的煤炭333+334?资源量总计6251万吨。研究结果对以后的地质勘查与开采提供可靠的数据。 相似文献
4.
朱楼勘查区位于安徽省砀山县,勘查区为全隐伏式井田。本区主体构造形迹的形成,主要受东部郯庐断裂的影响。由于郯庐断裂的左行平移和南北古地块及其附近东西向断裂的联合作用形成了北部收敛,南部撒开的徐淮弧形褶皱束,构成了本区基本构造格架。区内褶皱、断裂构造简单,通过对该区历年施工钻孔资料的整理和分析研究,认为区内地质构造对煤层的形态和分布有控制作用。通过对该区地质构造特征的研究,根据本区地质、构造等实际情况。为以后工程布置、矿山开采提供依据。 相似文献
5.
鄂尔多斯盆地西北部是鄂尔多斯盆地乃至整个内蒙古自治区的煤炭资源重要富集区,其拥有古生代石炭—二叠纪和中生代侏罗纪两类含煤岩系,储量丰富,煤种齐全,品质优良,是我国煤炭工业的重要战略基地。本文以地球动力学和煤田地质理论为指导,从煤系赋存角度出发,结合大地构造单元区划及赋煤单元区划,以地质构造控制煤系赋存状况为出发点,合理地划分了赋煤构造单元,建立了鄂尔多斯盆地西北部3级赋煤构造单元划分方案,详细论述了各赋煤构造单元的构造特征;总结了区内煤田构造特征,揭示了煤系赋存状况的分区分带特征。 相似文献
6.
漫赖勘查区位于东胜煤田的北部,具有含煤层数多、厚度不均、层间距不稳定等特点,利用勘查区波阻抗反演数据进行煤层追踪对比解释,准确圈定出区内煤层的赋存范围,并合理解释了煤层分叉、合并、尖灭及厚度变化等地质现象,取得了较为可靠的地质成果。 相似文献
7.
两淮煤田煤炭资源丰富,淮南煤田各矿井实测含气量介于0～25.85m~3/t之间,淮北煤田实测煤层气含量0～24.79m~3/t。两淮煤田煤储层含气饱和度总体偏高,煤层含气量高的部位多位于向斜的构造部位或煤储层埋深较大部位。淮南煤田煤储层的含气丰度相对淮北煤田整体较高,其中13-1煤层最高,含气丰度可达1×10~8m~3/km~2以上,但含气饱和度相对淮北煤田较低。煤层气含量的大小受多种因素的综合控制,与煤层的厚度、构造、煤的变质程度、埋深、围岩、岩浆作用水动力条件等因素有关,其中煤层厚度和构造因素对煤层气的富集起主导作用。 相似文献
8.
本文通过对老东山及其周边地区近年来地质找煤成果的分析,对老东山地区地质概况和煤层及煤质进行了分析和梳理,老东山地区总体分为F1断层上盘和下盘,上盘构造总体为一南东向倾斜的单斜构造形态,区内断层和褶皱发育,断层对煤层的赋存具有一定的切割破坏作用。下盘为总体为一南倾的单斜构造,被断层切割为不同深度的断块区。研究区含煤地层为侏罗系中统石门沟组(J2s)和大煤沟组(J2d),其中侏罗系中统石门沟组含可采煤层2层,属低灰、中硫、中高热量的长焰煤,大煤沟组含可采煤层1层,属低灰、中高硫、中高热量的不粘煤。 相似文献
9.
绍根煤田隶属于内蒙古自治区赤峰市阿鲁科尔沁旗境内,地理位置位于大兴安岭余脉南麓、松辽平原西缘,区域构造上位于阴山纬向构造带属南东、北西受断裂控制的山间断陷型盆地,为全掩盖型煤田。煤田分为四个矿区,分别为东区、西区、中区、和F1断层东侧区。煤的变质程度较低,本文依据野外施工资料对绍根煤田F1断层东侧矿区的成煤条件及煤质特征进行分析研究。 相似文献
10.
以地质勘查资料、煤质分析结果为依据,对新疆伊南煤田阿尔玛勒勘查区中——下侏罗统水西沟群煤中硫分、灰分组成特征及成因进行了探讨。研究结果表明:新疆伊南煤田阿尔玛勒勘查区中——下侏罗统水西沟群泥炭沼泽受淡水成煤环境影响,可利用的铁质与H2S反应生成硫铁化物含量较少,形成了该区特低——低硫煤的特点。同时,该区碎屑物供给较少,且由镜惰比可知,西山窑组煤层形成于高位沼泽,受地表水影响较小,从而形成了灰分产率低的特点。 相似文献
12.
在新构造运动中复活的阿尔金走滑断裂带制约着本区构造地貌的分布格局和发育过程.阿尔金山即是该断裂带所控制的断块发生强烈上升而成的差异性断决山地,以阿尔金山为轴成反对称分布的区域地貌格局也是阿尔金走滑断裂带发生大规模左旋平移和逆冲推覆的产物.本区构造地貌演化则经历了三个阶段,其间断块上升活动西强东弱并自西向东发展,因而形成阿尔金山西高东低的起伏形态. 相似文献
13.
Summary. Anisotropy of magnetic susceptibility measurements have been performed on 154 specimens taken from 25 different seams in the South Wales Coal Field, up to 24 samples per seam. The magnetic fabric determined is represented, in general, by oblate spheroids with minimum ( K c) AMS axes usually clustered at a near-vertical, or occasionally, near-horizontal pole which is normal to the magnetic foliation plane defined by great circle distributions of maximum ( K a) and intermediate ( K b) axes. The results suggest that the coalification process and variations in rank within the coal field are due to the combined effects of vertical compression and compaction resulting from variations in overburden pressure, and to horizontal compression, due to variations in tectonic thrusting during the Variscan Orogeny. Analysis of the AMS of closely spaced samples across a single anthracite seam shows no systematic variability in magnetic properties within the seam. 相似文献
14.
In situ stress is not only a vital indicator for selecting explorative regions of coalbed methane (CBM), but also a pivotal factor affecting CBM production. The present study explored whether in situ stress affected the development potential of CBM in western Guizhou, China. To this end, we collected injection/falloff well test data and gas content data from 70 coal seams in 28 wells. The study found that from top to bottom, strike slip fault stress fields (<?500 m), normal fault stress fields (500–1000 m) and strike slip fault stress fields (>?1000 m) were successively developed in western Guizhou. The distribution features of vertical permeability in western Guizhou are consistent with the stress fields' transformation location. The coal permeability in the western part in Guizhou presents a tendency of increase followed by decrease as a result of increased burial depth. The vertical development characteristics of coal seam gas content are controlled mainly by reservoir pressure, and the relationship between reservoir pressure and buried depth shows a linear increase. The CBM in western Guizhou is divided vertically into three development potential regions dependent on the characteristics of burial depth, permeability and gas content of coal seams. The most favorable vertical development potential region in western Guizhou is 500–1000 m. This region exhibits high gas content, high permeability and moderate burial depth, which are favorable for the production of CBM. These research results can provide basis for geological selection and engineering implementation of CBM in western Guizhou. 相似文献
15.
The status of seismic exploration work mapping the post-Caledonian strata in the Svalbard area is presented. Compressional wave velocities are very high throughout the area, around 4km/s in the Tertiary and Mesozoic layers. In the Permian section velocities exceed 5 km/s, with refraction velocities > 6 km/s in the calcareous rocks of the Gipsdalen Group (early Permian/Late Carboniferous). Apart from correlation with carbonate and chert lithology, high velocities reflect the high degree of consolidation and the low porosities of shales and sandstones in the post-Caledonian strata in Svalbard. In van Mijenfjorden seismic reflection events are observed down to 3–4 km depth and associated with Carboniferous and younger strata. The thickness of the Mesozoic layers in this part of the central Spitsbergen syncline seems to be greater than previously suggested, and there is an apparent eastward divergence between the Jurassic and the Triassic reflectors. In south-western Storfjorden, reflections interpreted to originate from Carboniferous and Permian strata might represent the seaward extension of the central Spitsbergen syncline. In the northern part of Storfjorden, carbonate layers within the Gipsdalen Group are interpreted to lie about one kilometre below the sea floor. A prominent fault zone in this area trends NNW-SSE, like the main structural elements on Spitsbergen. It shows block-faulting, presumably caused by extensional movement in late Devonian-Carboniferous time. 相似文献
16.
The enigma of the origin and development of plains-type folds, as they were christened in the early 20th Century, essentially has been solved. The folds, a considerable distance from the tectonic disturbance, were formed by draping of sediments over differentially displaced Precambrian basement fault blocks. These Precambrian basement fault blocks controlled the location, size, and shape of the folds. Forces were transmitted through the rigid basement causing readjustment along the indigenous fracture/fault pattern formed much earlier. In the U.S. Midcontinent, the crystalline basement is overlain by a thin veneer of sediments, and once the structures were formed, they continued to develop as evidenced by features in the overlying sediments. As the stress was transmitted through the basement and then relaxed, the fault blocks moved differentially in concert to these outside forces. Sediment compaction and nondeposition over structural topographic highs reacted accordingly to form the features as seen today. To determine the structural history, structural closure on different horizons on the anticline is plotted in their appropriate stratigraphic position at depth. This gives a compaction line for each tectonically coherent segment. Similar segments show a relatively straightline with offsets at major unconformities indicating breaks in the continuum. It is at these breaks that the section can be stretched until the compaction line matches as a continuum with the resulting gap giving the approximate amount of missing section for that part of the rock column. Conversely, the amount of closure on a structure at depth for each line segment can be estimated by extrapolating downward in that segment. This technique to determine depth of burial and thus the amount of missing stratigraphic section from well data at numerous locations has been compared with estimates made by other methods and the results are similar. Where no other data are available or for quick estimates, then, it is proposed that this approach will give reasonable results and that the values can be used as a constraint in basin modeling. 相似文献
17.
Summary. In 1985, 180 km of regional vibroseis profiles were acquired in the Carolinas and Georgia, southeastern United States, as part of the Appalachian Ultra-Deep Core Hole (ADCOH) Site Study. The data quality is excellent, with large-amplitude reflections from faults and crystalline rocks, lower Palaeozoic shelf strata and from within autochthonous Grenville basement. The profiles image the subsurface more clearly than other available data and allow the possibility of alternative interpretations of important elements of the tectonic framework of the southern Appalachians. The major points in the interpretation are: 1) The Blue Ridge master decollement is at a depth of 2-3 km beneath the Blue Ridge. This thrust increases in dip just NW of the Brevard fault zone. 2) The Brevard fault zone appears to splay from the master decollement at 6 km (2.2 s) near Westminster, S.C., and defines the base of the crystalline Inner Piedmont allochthon. 3) Below the Blue Ridge thrust sheet are images of duplex and imbricate structures ("duplex tuning wedges") connected by other thrust faults that duplicate shelf strata to a thickness of 4–5 km. 4) Subhorizontal reflections from depths of 6 to 9 km may be from relatively undisturbed lower Palaeozoic strata as suggested by others. 5) Eocambrian-Cambrian(?) rift basins in the Grenville basement are also imaged. The ADCOH data were originally recorded with 14–56 Hz bandwidth and 8 s length, but an extended Vibroseis correlation was used to produce 17 s data length revealing reflections from within the upper crust. Below 8 s, reflections from within the Grenville basement become weak, but are observable as late as 13 s; however, these Moho (?) reflections are generally short segments. 相似文献
18.
With increasing demands for coal resources, coal has been gradually mined in deep coal seams. Due to high gas content, pressure and in situ stress, deep coal seams show great risks of coal and gas outburst. Protective coal seam mining, as a safe and effective method for gas control, has been widely used in major coal-producing countries in the world. However, at present, the relevant problems, such as gas seepage characteristics and optimization of gas drainage borehole layout in protective coal seam mining have been rarely studied. Firstly, by combining with formulas for measuring and testing permeability of coal and rock mass in different stress regimes and failure modes in the laboratory, this study investigated stress–seepage coupling laws by using built-in language Fish of numerical simulation software FLAC3D. In addition, this research analyzed distribution characteristics of permeability in a protected coal seam in the process of protective coal seam mining. Secondly, the protected coal seam was divided into a zone with initial permeability, a zone with decreasing permeability, and permeability increasing zones 1 and 2 according to the changes of permeability. In these zones, permeability rises the most in the permeability increasing zone 2. Moreover, by taking Shaqu Coal Mine, Shanxi Province, China as an example, layout of gas drainage boreholes in the protected coal seam was optimized based on the above permeability-based zoning. Finally, numerical simulation and field application showed that gas drainage volume and concentration rise significantly after optimizing borehole layout. Therefore, when gas is drained through boreholes crossing coal seams during the protective coal seam mining in other coal mines, optimization of borehole layout in Shaqu Coal Mine has certain reference values. 相似文献
19.
The geodynamic processes in the western Mediterranean are driven by both deep (mantle) processes such as slab‐rollback or delamination, oblique plate convergence and inherited structures. The present‐day deformation of the Alboran Sea and in particular the Nekor basin area is linked to these coeval effects. The seismically active Nekor basin is an extensional basin formed in a convergent setting at the eastern part of the Rif Chain whose boundaries extend both onshore and offshore Morocco. We propose a new structural model of the Nekor basin based on high‐resolution offshore data compiled from recent seismic reflection profiles, swath bathymetry acquisitions and industrial seismic reflection profiles. The new data set shows that the northern limit of the basin is oriented N49° with right‐stepping faults from the Bousekkour–Aghbal fault to the sinistral Bokkoya fault zone. This pattern indicates the presence of an inherited left‐lateral basement fault parallel to the major inherited Nekor fault. This fault has been interpreted as a Quaternary active left‐lateral transfer fault localized on weak structural discontinuities inherited from the orogenic period. Onshore and offshore active faults enclose a rhombohedral tectonic Nekor Basin. Normal faults oriented N155° offset the most recent Quaternary deposits in the Nekor basin, and indicate the transtensional behaviour of this basin. The geometry of these faults suggests a likely rollover structure and the presence at depth of a crustal detachment. Inactive Plio‐Quaternary normal faults to the east of the Ras Tarf promontory and geometries of depocentres seem to indicate the migration of deformation from east to west. The local orientations of horizontal stress directions deduced from normal fault orientations are compatible with the extrusion of the Rifian units and coherent with the westward rollback of the Tethyan slab and the localization of the present‐day slab detachment or delamination. 相似文献
20.
A structural map of Oscar II Land compiled using black and white, stereo-pair air photos and other available information sources suggests the existence of three structural zones within the deformed platform cover strata. The western zone consists of basement involved overthrusts of complex geometry in the north large-scale folds of platform cover strata with a stepped, down to the east profile in the south. The central zone consists primarily of folds within Kapp Starostin Fm. and overlying Triassic strata that likely formed above a subhorizontal décollement within Gipshuken Fm. strata. Farther to the east thrusts emplace Permian Kapp Starostin Fm. strata over Triassic strata. This zone probably represents stratigraphic climb of the basal decollement. Conservative estimates of shortening for the central and eastern zones are in the 15-25% range. The contribution of the western zone structures to overall Tertiary shortening depends on the geometry of faults underlying the stepped folds and is uncertain at present. Changes along strike are in part due to differential levels of erosion and changes in transport direction, but also probably important was variable thickness of the platform cover strata involved (less to the north) and the availability of incompetent horizons along which thrust-fiats could form. Two areas with anomalous structural trends may represent oblique ramps. 相似文献
|
