煤形成环境及其与斯蒂芬期聚煤盆地的构造活动.doc

19河南理工大学毕业设计 附录2 外语文献煤形成环境及其与斯蒂芬期聚煤盆地的构造活动Dennis L. Nielson Gamma法国南部的塞文山脉煤盆地位于东南部法国山岳的中心，以前的研究主要针对于它的地层，岩石学，煤的化学成份，煤炭岩石学和地质构造。这项研究的目标将强调位于山脉之间的法国山岳的中心盆地在构造形式和煤炭形成晚期沉淀环境之间的关系, 在中国类似第三纪煤炭盆地形成，煤炭缝厚度和范围基本上由早期的构造活动控制。 1.塞文山脉煤炭盆地区域性的结构盆地北部的煤系露头厚度达到2500米。盆地南部的覆盖了一系列的中世纪地层.两个主要的断层中间夹有50 公里宽煤盆地。 盆地被划分成西部(研究区域)和 一个东部次级盆地。 西部次级盆地在这项调查研究中被划分为三个部分，从北到南分别为：地堑，由于断层而形成的鄂图曼地垒和洛杉矶巨大的深谷地堑。 本文重点研究位于塞文山脉盆地西北部的煤的特征和范围和碎屑物的范围，和他们的与早期的构造活动的关系。 2.地层学结构在斯蒂芬期的一系列盆地沉积的顺序由岩屑组成的岩石决定，包括：砾岩或角砾岩，粗砂岩，粉砂岩，泥岩和煤缝合线。沉积的序列从底部到顶部可以分为六个地层单位地层学的结构是除了边缘断层以外的各种不同沉淀的环境和他们的相互关系的分布范围的结果。盆地腹部断层例如： 断层也影响了个体的地理分布和不对称地堑的发育。大型的地堑和煤缝合线的范围，以及早期和后期的层序都与边缘和盆地腹部的断层有关。 重要煤层在序列的中间部分被集中。3.塞文山脉煤盆地煤的层序目前分析的煤的层序是以大量的地质区域钻芯和老的矿层补充日志为基础。从薄的部分观察和统计处理获得的沉积学数据来完成古地理学和史前环境的解释。有不充足的图解数据和地层学的起源的相互作用来归纳地层层序。3.1 第一阶段：单位沉积物 单位形成于在早期的次级盆地。主要冲积扇系统以洛杉矶巨大深谷地堑为中心。近扇形和中扇形的沉积由角砾岩聚结和粗砂岩控制，包含的片麻岩和石英的碎片最大直径达到40cm。近扇形和中扇形沉积主要集中在研究区域的西部，接近维勒福尔断层并进一步向东延伸。巨大的扇形由沙质和泥质的沉积物组成。除了接近佩特努断层，一些小扇形聚集物被沉积了下来，在东部盆地冲积扇发育不足，并且包括细颗粒的沉积，。在这个阶段期间， 佩特努断层和与西部边缘断层一起控制了各种沉积的范围。 3.2 第二阶段：理查得单位的沉积物 沉积还发生在洛杉矶巨大深谷地堑，并向东部和西部延伸。扇形的沉积延伸着西部的边缘延伸，又回到维勒福尔断层，以减少连续沉积物的区域和厚度。巨大的冲积扇，由沙质沉积物组成，在洛杉矶巨大深谷地堑东部和西部边缘发育并沿着NE-SE方向加宽了。在洛杉矶巨大深谷地堑的中心，沼泽在冲积扇平原前面位置开育，泥煤富集在沼泽的中央部分。泥煤富集区域下面覆盖了单位的厚实的冲积扇聚集物。对应的厚实煤层迅速地沿佩特努断层向东西方向分裂，并控制了煤炭富集区域的发育。 3.3第三阶段：整个盆地的沉积在这个阶段，沉积发生在整个盆地，反映了增加的范围和下陷的比例。沿着西部边缘到盆地的东部边缘冲积扇控制了南部的地堑，佩特努断层形成了巨大的扇形沉积。泥炭沼泽在扇形平原的前缘沉积下来。而泥炭的沉积物被暂时的分开，形成了一些侧面变化的薄煤层。一些小型的沼泽在扇形和昌普斯村之间发育，形成了非常薄的煤层，而巨大的扇形砂质沉积控制了北部的地堑北部盆地。在拉维多地堑的北部，古地层成为冲积扇体系的标志层，沉积物暗示了出现在超级盆地西部的扇形沉积，而古河流的方向暗示了三角洲向中东部迁移，也暗示了东部边际碎屑的来源。砂质沉积物都出现在巨大三角洲的中部地区。沼泽在东部超级盆地的恰莫和昌普斯断层之间的冲积扇平原上广泛发育。在拉维多地堑的西部边际的保罗因断层非常活跃，从而形成了半地堑构造。 在鄂图曼地垒，大颗粒的碎屑体也发育在西部，而且向东部逐渐变薄，在地垒的东部，沉积物和砂质沉积物形成了次级砂岩。3.4 第四个阶段：巨大的波美单位沉积在洛杉矶巨大的深谷地堑，冲积扇只发育在次级盆地的东北部分，碎屑物来源于东部，在特努和墨菲斯特断层之间，发育了广阔的河流沼泽体系，泥煤在洪水冲积平原被积累起来。形成了邻近和平行于活跃的墨菲斯特断层的煤炭富集区域。在拉维多地堑，扇体被限制在北和西部，与先的阶段相比较扇体的范围和组成物的颗粒粒度都减小了。形成的大面积的沼泽代替了冲积扇平原中的扇形砂质沉积，从而形成了几个煤系地层。在鄂图曼地垒，冲积扇也被限制在东西部地区，并沿着鄂图曼村发育。在东部的泥煤沼泽，发育了一些薄煤系地层。 3.5 第五个阶段：陆明特单位的沉积物洛杉矶巨大的深谷地堑冲积扇发育在东北部边缘，受到特努和墨菲斯特断层的构造控制，在扇体中主要由粗大的砂岩和碎石组成的，但没有大的鹅卵石。在地堑的中央，埋藏着两个大的富煤区域，周围是由分选良好的花岗质砂岩组成。沼泽和花岗质砂岩区域从西南向东北方向移动。在狭窄的墨菲斯特和帕鲁贝断层的凹陷区域，发育了一些煤系地层，每一层的平均厚度不到1米。在洛杉矶闻密得地堑，扇体的中心和附近区域主要分布在北部边缘，沿着构造运动形成的保罗因和帕鲁贝断层西部边际由扇体颗粒状含砂沉积和次级粗糙沉积物组成。泥炭沼泽发育在中心和东部地带，周围是黑色鱼鳞状含钙质或铁的油页岩浅湖沉积物。沿着湖的西岸发育了一个小的完整的三角洲体系。碎屑物来自洛杉矶保罗因地堑的西部边缘。沼泽沿着浅湖的冲积平原延伸，在那里形成了薄的煤系地层，一些小型的冲积扇沿着西部边缘发育。3.6 第六个阶段：理查德单位的沉积物 巨大的洛杉矶深谷地堑沉积只发生在昌普斯北部，而冲蚀发生在南部，小型的冲积扇沿着东北部的边缘发育，在其它的地区主要由粗糙的沉积物组成，与第五阶段相比，泥炭沼泽和煤富集区域向东北方向移动。拉维多地堑的西部上升，且没有沉积物形成。在第五阶段形成的三角形的湖变成狭长型区域并且由大颗粒的长石砂岩沉积形成。沿着西部边缘，一个被淹没的扇开三角洲被合并成一个中央湖。这个复合体大约有100米厚，并且表现为完全的反向分级的矿床。河岸由粗糙的岩石组成，在这个阶段期间，当保罗因断层的活动减少时，卡马斯断层的活动却非常频繁，从而形成了一个向东的急倾斜的和一个向西的缓慢倾斜的半分离的地堑构造，鄂图曼地垒主要是由分类良好的长石砂岩沉积形成。在第六个阶段的结束时，文塞山脉盆地的西部和北部上升而且沉积结束了。 4.塞文山脉盆地的构造活动像其它的被断开的盆地一样，盆地腹部的强度和样式的变化程度以及塞文山脉盆地边缘断层影响和控制成煤环境。以洛杉矶巨大的深谷地堑北部的盆地做为的例子和基础来研究洛杉矶巨大的深谷地堑南部盆地的断层，我们谈论结构框架的演变， 盆地腹部的构造运动和它对沉积物变化特征及煤的形成的影响。可以看到在中早期的斯蒂芬期，换言之，也就是在斯蒂芬期的第三沉积阶段和第四个盛大波美单位在盆地演变期间，在西部边缘的防水断层的剧烈运并且控制了粗糙碎屑体的空间分布。在东部的边缘没有断层发育。盆地的构造是一个半地堑形式，这个含有砂岩和聚集的粗糙的碎屑沉积物的南部断层发育。这种粗糙的碎屑体呈透镜状，使断层加厚并且与维班克断层平行所以显然它受到断层的控制。这种大块的粗糙碎屑体由粗糙变为光滑，这种岩石从沉积的砂岩变成粗粉砂岩、泥岩和煤层。这个断层的北部断盘是由粗砂岩，粉砂岩，泥岩和煤层组成。在斯蒂芬期的中晚期，也就是第五个沉积阶段，扇体主要分布在变成了拉维多地堑的北部边缘，并且被保罗因和卡马斯断层贯穿。在这个时期，东部和西部的边缘断层控制着地层结构并形成了结构上对称的拉维多地堑。在斯蒂芬期的晚期，也就是第六个沉积阶段，由粗糙的沉积物形成的扇形三角洲的圆形突出部分在卡马斯断层和斯诺丁断层区域有良好的发育,古老河流方向暗示了扇形三角洲的叶部来源于东部，在这个阶段，卡马斯断层北部边缘构造运动剧烈，而保罗因断层西部的构造运动缓慢，从而使拉维多地堑东部下滑，西部剧烈下滑的半地堑。5.结论 在上文中对斯蒂芬期煤炭盆地的详细的结构和沉积地层的研究解释了盆地的环境演变并且叙述了煤炭的形成过程。在斯蒂芬期塞文山脉盆地的东北部地区，泥煤沼泽形成了在冲积扇系统的末端部分，并被限制在与边缘断层有关的盆地边缘。由于剧烈的盆地外的构造运动导致了轻微的下陷和后来碎屑物的快速的填充，泥煤发展和不保护开采是罕见的。构造运动的暂时停止能使泥炭发育，并能使沉积物广泛的覆盖河系。 在洛杉矶巨大的深谷地堑，煤炭形成环境经历了从早期和晚期的斯蒂芬期阶段沼泽冲积扇系统到进入中期的沼泽冲积湖上的系统阶段，连接与对应盆地发展和消失的三个构造阶段的演变。 煤炭沼泽范围转变，富集煤炭区域和冲积层是由盆地腹部和边缘断层控制的。冲积扇聚成团身体发行和极限准许容易地重建少量的缺点的活动和提高来源地区。另一方面，碎屑物和沉积的有机物之间线性和严格的限制暗示了盆地腹部断层活动的改造。从沉积特征推断的构造的说明与以构造分析为基础的构造演变是一致的，并且通过盆地的空间和时间推断的古应力场和他变化。河南理工大学毕业设计 外语文献Coal forming environments and their relationship to tectonic activity in the Cevennes Stephanian coal basinDennis L. Nielson GammaThe Stephanian C6vennes coal basin is located in the southeastern part of the French Massif centra1Previous studies focused on its stratigraphy，sedimentary petrology，coal chemistry ， coal petrology and structural geology. The aim of this study is to highlight the relationships between the tectonic patterns and the sedimentary environments of coal formations in the late Hercynian interm ontane basins of the Massif central in France , resemble the Tertiary coal basins in China where the occurrence, distribution and the thickness of the coal seams are essentially controlled by early tectonic activity 1.Regional framework of Cevennes coal basin The coal measures are up to 2500 m thick and outcrop in the northern part of the basinMesozoic strata cover the stephanian series in the southern basinThe two main faults Villefort and Crvennes borde the 50km2 wide coal basinThe basin is divided into a western (study area)and an eastern subbasinsThe western subbasin was investigated in this study is divided with three areas，respectively from north to south：La Vernarede graben， Portes horst and La GrandCombe graben，by the Paulin and Chamarit faultsThis paper focuses on the characteristics and distribution of the coal and clastics distribution in the northwestern part of the Crvennes coal basin，their palaeoenVimnmentale setting and their relationships with the early tectonic activity 2.Stratigraphic famework The Stephanian series of the basinfill sequence are dominated by detrital rocks including conglomerates or breccias，coarse and fine grained sandstones，sihstones，mudstones and coal seams The depositional sequence canbe divided into six lithostratigraphic units from bottom to top ： Strriles infde La ForSt unit； Ricard unit； Strriles supde La Foret unit； GrandBaume unit； Luminieres unit； Champclauson unitThe stratigraphic framework is a result of the distribution of various depositional environments and their mutual relationships Besides the marginal faults，intrabasinal faults such as the Peyraube fault and Malperthus fault also controlled the distribution of units，and the development of asymmetric grabenTh at the distribution of the coarsegrained bodies an d coal seams，in both the lower and the upper parts of the sequence are related to the marginal and intrabasinal faultingThe important mineable coal seams are concentrated in the middle part of the sequence 3.Coal bearing sequences in the Cevennes basin The analysis of coal bearing sequences presented here is based on a large amount of geologiical field sections drill cores and well logs complemented by sections in ancient mining galeriesThe paleogeographical and paleoen vironmental interpretations were performed using farther inform ation derived from thin section observations and statistical processing of sedimentological dataCorrelations within the basin are discussed using poor biostrati graphical data and genetic stratigraphy induced sequences.31 The first stage：deposition of the Strriles infde la Foret unit The Strriles infde la Forget unit form ed at the beginning of the opening of the sub-basinMainly alluvial fan systems started at the center of the La Grand-Combe grabenThe near-fan and middle-fan deposits are dominated by breccias，conglomerates and coarsegrained sandstones，containing gneiss and quartz fragments with a maxdiameter up to 40 cmNear-and middlefan mainly developed in the west part of the study area，close to the marginal Villefort fault and advanced eastwardThe far-fan was dominated by sandy and muddy sedimentsIn the eastern basin alluvial fans are poorly developed，and consist of finegrained sediments，except close to the Peyraube fault where some small fan conglomerate bodies were depositedDuring this stage，the Peyraube fault and together with the western marginal faults，controlled the distribution of the various sediments 32 The second stage：deposition of the Ricard unit The deposition still occurred in the La Grand-Combe graben，but extended both towards eastwards and west-mentwardThe fan conglomerate，well-developed along the western margin，drew back to the Villefort fault，with decreasing of both deposition area and thickness of the seriesThe farfan，composed of sandy sediments，developed at the eastern and western margins of the La Grand-Combe graben and widened along a NESE directionIn the central part of La Grand-Combe graben，swamps developed in forefan plain position，with peat enrichment in the central part of the swampThe peat enrichment zone is just covering the underlying extra-thick fan-conglomerate of the Strriles infde la Foret unitThe corresponding thick coal seams thin rapidly an d pinch out both eastwards and westwards and also split westwards，along the Peyraube fault, which controlled the development of the coal enrichment zone 33 The third stage：deposition of the Strriles sup During this stage，deposition occurred throughout the whole basin，reflecting the increased extent and rate of subsidenceAlluvial fans dominated in the southern La Grand-Combe graben，from the western bo rder and along the eastern margin of the basin，where large fan conglomerates were controlled by the Peyraube faultPeat swamps settled in the forefan plainThe accumulation of peat，however，was episodically interrupted，resulting in the formation of several thin coal seams with lateral variations in thicknessSome shortlived swamps developed between fans to the south of Champclauson Village，in which very thin coal seams and streaks formed ，while wide-spread deposition of farfan sandy sediments dominated the northern basin of La Grand-Combe graben To the north in the La Vernarede graben，distinct lithostratigraphic units are recognizable as part of alluvial fan systemsBreccias and conglomerates indicate the nearand middle-fan facies occur in the western part of the sub- basinThe paleocurrent directions indicate that the fans moved towards the central and eastern parts，implying a source of clastics in the western marginSandy sediments are representative of the far-fan central partSwamps developed acrl0ss alluvial fan plains between the Comas and Chamafit faults in the eastern sub-basinThe great number 0f thin coal seams interbedded with clastic bands and pinching out laterally is significant of rapid variations in depositional environmentThe Paulin fault at the western margin was active in the La Vemarede graben，and controlled the spatial distribution of coarsegrmned clastic bodiesThe Com as fault at the eastern margin is much less active1eading to a semigraben structure.In the Portes horst,Cofirse-grained clastic bodies also developed in the westem part，and thined eastwardsTo the east of Portes villageconglomerates and sandy conglomerates dominated with subordinate sandstones34 The fourth stage：deposition of the Grand-Baume unitIn the La Grand-Combe grabent the alluvial fans are confined to the northeastern part of the sub-basin，with clastics originating from the east.Between the Thrrond and Malperthus faults, extensive riverswamp systems developedPeat mainly accumulated in alluvial flood plainsThe coal enrichment zones formed close to and parallel to the active Malperthus faultIn the La Vemarede graben，the fan bodies are confined to the northern and western parts，while their extent and the grain size of their constituent were reduced，in comparision with the preceding stage Widely developed swamps mainly replaced far-fan sandy sediments over the alluvial fan plains，leading to a few mineable coal seams In the Portes horst，alluvial fan bodies are also confined to the northwestem part，and far-fans developed close to the Portes villageIn the peat swamps to the east，some minor thin seams developed 35 The fifth stage：deposition of the Luminieres unit In the La Grand-Combe graben alluvial fan bodies，tectonically controlled by the Th6rond and the Malperthus faults，developed at the northeastem margin. Conglomerates and gravelly coarse-grained sandstones without large pebbles are dominant in these bodiesIn the central part of the graben，swamps with two coal enrichment zones are dominant，surrounded by well sorted arkosesThe swamp and arkose areas( and in moved from the southwest to the northeastIn the narrow trough between the Malperthus and Peyraube faults， several mineable coal seams developedeach having an average thickness of less than 1 m In the La Vemarede graben，near and middle fan bodies are mainly distributed at the northern margin，along the tectonically active Paulin and Com as faultsThe western margin was dominated by farfan fine-grained sandy sediments，with subordinate coarse sedimentsPeat swamps developed in the central and eastem parts，enclosing shallow lacustrine black oil shales with fish fragments and calcareous or ferruginous concretionsAlong the western shore of the lake a small but complete delta system developedClastics originated from the western margin of the La Vemariede grabenSwamps spread over the alluvial plain in a shallow lake，in which poor minable coal seams formed.The western margin of the Portes horst was uplifted and emerged，while sandy sedimentation dominated in the central part，and wide swamps in the eastern part，leading to the formation of several thin mineable coal seams Small alluvial fan groups grew along the eastern margin 36 The sixth stage：deposition of the Ricard unit In the La Grand-Combe graben deposition occurred only north to ChampclausonWhile erosion took place to the southSmall alluvial fans developed along the northeastern margin，and fine grained sediments dominated the other depositional regionsCompared with the fifth stage，peatswamps and coal enrichment zones shifted towards the northeast The western part of the La Vemarede graben uplifted and no deposits form edThe triangular shape of the lake formed in the fifth stage changed into an elongated area in which fine-grained arkoses were depositedAlong the western margin，a submerged fan-delta complex prograded into the central lakeThis complex is about 100 m thick，and shows a complete reverse-graded beddingTh e coarser part is composed of coarsegrained sandstones，gravel-bearing coarse-grained sandstones and rounded conglomerates During this stage，Comas fault was very active while along the Paulin fault activity decreased，resulting in a semi-graben structure，with a steep eastward slope and a gentle westward slope .Well-sorted arkose deposition dominated in the Portes horst At the end of the sixth stage，the north-western part of the Crvennes basin uplifted and Stephanian deposition ended 4.Tectonic activity of C6vennes basin As in other faulted basinthe variations in the intensity and style of the intrabasinal and marginal faults of the Crvennes basin influenced and controlled the coa1forming envomments. Taking the La Vemarede graben in the northern basin as an example and based on the study of faults in the La Grand-Combe graben in the southern basin，farther we discuss the evolution of structural framework，the activity of the intrabasin faults and their iniluence on the sedimentary regime and formation of coa1 It can be seen that during early-middle Stephanian the third deposition stage of the Stieriles supde La Foret unit and the fourth deposition stage of the Grand-Baume unit during basin evolution，the Paulin fault at the western margin moved intensely and controlled the spatial distribution of the coarse clastic bodies At the eastern margin no fault was developedThe structural framework of the basin is a half-graben pattern，with W erbrouck fault having a strike of N125。dip of N35。and dip angle of about 80。In the south wall of this fault coarse clastic sediments consisting of sandstone and conglomerate developedThis coarse clastic body shows a lenticular shape thickening towards this fault and runs horizontally parallel to the Werbrouck fault，so clearly it was controlled by the faultThe grain size of this coarse calstic body changed from coarse to fine towards the south，and its rocks from conglomates，sandstones to finegrained sihstone，mudstone and coal seamsThe north wall of this fauh is composed of fine-grained sandstone，sihstone，mudstone and coal seamsAt the end of middle Stephanian and during late Stephanian，iethe fifth deposition stage of the Luminieres unit，the nearand middlefan bodies were distributed on the northern margin of the La Vemarede graben，where the Paulin fault and the Comas fault intersectedDuring this stage，both east and west marginal faults controlled the stratigraphic framework and resulted in the nearly symmetrical structural framework in the La Vemarede grabenAt the end of Stephanian ，i ethe sixth deposition of the Champclauson unit，fan-delta lobes constructed by coarse sediments were well developed at the region where the Comas fault and the The rond faultThe paleocurrent directions indicate that the fan-delta lobe came from the eastDuring this stage，the eastern marginal Comas fault moved intensely and the western