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1.
本文以宏观沉积学研究方法为主，辅助进行室内岩矿签定，编制沉积断面图和各种等值线图，在此基础上讨论了山西组煤层的沉积环境。并对煤层与聚煤沉积环境间的关系进行讨论。研究结果表明，泥炭沉积前和沉积期的沉积环境是影响煤层厚度和煤质的主要原因，泥炭沉积后的沉积环境仅在局部地区影响煤厚分布，而后期构造对煤厚影响程度较小。 相似文献
2.
Factors controlling the vegetation distribution and coal‐forming environments in a strike‐slip basin. The Pennsylvanian Peñarroya‐Belmez‐Espiel Basin,southern Spain 
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下载免费PDF全文 Coal‐forming environments require humid to perhumid conditions. Tectonics governs the size, location and availability of coal seams developed in such environments. While large Pennsylvanian paralic basins generated thick and continuous coal seams, many other small coeval basins, which were tectonically active, developed a puzzling succession, with carbonaceous deposits that varied in size, thickness and the nature of the coal‐forming flora. This study, conducted in the Peñarroya‐Belmez‐Espiel coalfield, a Variscan strike‐slip basin in the south of Spain, provides insights into this subject. The coal seams analysed, generated in different depositional environments, have quantitatively different palynological assemblages. Lacustrine coals are dominated by lycopsids; distal alluvial plain/marginal lacustrine coals are dominated by sphenophytes and tree ferns, and middle alluvial fan coals are dominated by sphenophytes, tree ferns and lycopsids. This means that when conditions were favourable for peat accumulation, peat accumulated regardless of the nature of the available flora. 相似文献
3.
华北晚古生代成煤环境与成煤模式多样性研究 总被引：23，自引：2，他引：23
华北晚古生代聚煤盆地存在活动体系成煤环境和废弃体系成煤环境。前者的海相成煤环境主要为泻湖泥炭坪,陆相成煤环境以三角洲平原沼泽意义最大。晚石炭世至晚二叠世,海相为主的成煤环境逐渐被陆相为主的成煤环境所取代,由盆缘到盆内成煤环境总体呈环带状展布。成煤环境差异性影响了成煤特点,这些成煤特点成为识别海、陆相煤层的显著相标志。华北晚古生代聚煤盆地在时间上和空间上存在成煤模式的多样性,以陆表海滨岸成煤模式、废弃碎屑体系成煤模式和浅水三角洲成煤模式为主。 相似文献
4.
A.B. Cadle B. Cairncross A.D.M. Christie D.L. Roberts 《International Journal of Coal Geology》1993,23(1-4)
The coal-bearing sediments and coal seams of the Karoo Basin, Southern Africa are described and discussed. The Karoo Basin is bounded on its southern margin by the Cape Fold Belt, onlaps onto the Kaapvaal Craton in the north and is classified as a foreland basin. Coal seams are present within the Early Permian Vryheid Formation and the Triassic Molteno Formation.The peats of the Vryheid Formation accumulated within swamps in a cool temperate climatic regime. Lower and upper delta plain, back-barrier and fluvial environments were associated with peat formation. Thick, laterally extensive coal seams have preferentially accumulated in fluvial environments. The coals are in general inertinite-rich and high in ash. However, increasing vitrinite and decreasing ash contents within seams occur from west to east across the coalfields. The Triassic Molteno coal seams accumulated with aerially restricted swamps in fluvial environments. These Molteno coals are thin, laterally impersistent, vitrinite-rich and shaly, and formed under a warm temperate climatic regime.Palaeoclimate, depositional systems, differential subsidence and basin tectonics influence to varying degrees, the maceral content, thickness and lateral extent of coal seams. However, the geographic position of peat-forming swamps within a foreland basin, coupled with basin tectonics and differential subsidence are envisaged as the primary controls on coal parameters. The Permian coals are situated in proximal positions on the passive margin of the foreland basin. Here, subsidence was limited which enhanced oxidation of organic matter and hence the formation of inertinitic coals. The coals in this tectonic setting are thick and laterally extensive. The Triassci coals are situated within the tectonically active foreland basin margin. Rapid subsidence and sedimentation rates occurred during peat formation which resulted in the preservation of thin, laterally impersistent, high ash, vitrinite-rich, shaly coals. 相似文献
5.
准噶尔盆地侏罗系八道湾组聚煤作用控制因素分析 总被引：11，自引：2，他引：9
从煤层厚度及其在层序地层格架中的平面展布特征入手,并在分析煤层在层序格架中的发育和分布规律的基础上,探讨了沉积环境、沉积体系演化和湖平面变化对陆相盆地---准噶尔盆地侏罗系层序Ⅰ(八道湾组的主体)聚煤作用的影响。河流泛滥平原、三角洲平原、湖湾等沉积环境的可容空间变化速率和泥炭堆积速率常能保持有利于泥炭沉积的平衡关系,从而成为富煤环境。实质上,沉积环境是聚煤作用控制因素的外在表现形式,而其最根本的控制因素则是可容空间变化速率。在本研究区,主要体现为湖平面变化对煤层分布的控制作用。 相似文献
6.
M. Mastalerz A.B. Stankiewicz G. Salmon E.P. Kvale C.L. Millard 《International Journal of Coal Geology》1997,33(4):275-299
Roof successions above two coal seams from the Mansfield Formation (Lower Pennsylvanian) in the Indiana portion of the Illinois Basin have been studied with regard to sedimentary structures, organic petrology and organic geochemistry. The succession above the Blue Creek Member of the Mansfield Formation is typical of the lithologies covering low-sulphur coals (< 1%) in the area studied, whereas the succession above the unnamed Mansfield coal is typical of high-sulphur coals (>2.%). The transgressive-regressive packages above both seams reflect the periodic inundation of coastal mires by tidal flats and creeks as inferred from bioturbation and sedimentary structures such as tidal rhythmites and clay-draped ripple bedforms. Geochemistry and petrology of organic facies above the Blue Creek coal suggest that tidal flats formed inland in fresh-water environments. These overlying fresh water sediments prevented saline waters from invading the peat, contributing to low-sulphur content in the coal. Above the unnamed coal, trace fossils and geochemical and petrological characteristics of organic facies suggest more unrestricted seaward depositional environment. The absence of saline or typically marine biomarkers above this coal is interpreted as evidence of very short periods of marine transgression, as there was not enough time for establishment of the precursor organisms for marine biomarkers. However, sufficient time passed to raise SO42− concentration in pore waters, resulting in the formation of authigenic pyrite and sulphur incorparation into organic matter. 相似文献
7.
Peter J. Crosdale Anatoly P. Sorokin Ken J. Woolfe David I. M. Macdonald 《International Journal of Coal Geology》2002,51(4)
Selected Tertiary coals from the Zeya–Buryea Basin, Far Eastern Russia, were investigated for aspects of their coal type, rank, depositional environment and post-depositional history. The coals have been examined in outcrop (lithotype logging), microscopically (maceral, reflectance and fluorescence), and geochemically (proximate analysis).Two laterally extensive coal-bearing horizons occur: one of Palaeocene age and the other of early Miocene age. The Palaeocene coals were investigated in active open-cut mines at Raichikhinsk and Yerkovtsi and the early Miocene deposit in an abandoned open-cut mine at Cergeyevka.Palaeocene coals at Raichikhinsk and Yerkovtsi were indistinguishable from each other macroscopically, microscopically, and geochemically. The deposits were sufficiently coalified that brightness logging could be undertaken. Dull coals, with numerous fusainous wisps, were dominant. Four dulling-up sequences, which represent stacked peat deposits, were observed at Raichikhinsk. At Yerkovtsi, only a small section of the middle of the seam, which was mostly dull and muddy coal, was investigated. Petrographically, these coals were dominated by inertinite group macerals, which is unusual in non-Gondwanan coals and rare in the Tertiary. Rank classification was problematic with volatile matter (VM) content of vitrain (daf), macroscopic appearance, and microscopic textures suggesting subbituminous B rank, but carbon content, moisture content and specific energy indicating a lignite rank.Notwithstanding complications of rank, estimates of the maximum-range burial depths were calculated. Taking the VM (daf) content of vitrain as 48%, burial depth estimates range from 900 m for a high geothermal gradient and long heating time to a maximum of 3300 m for a low geothermal gradient and short heating time. These estimates are maxima as the coal rank may be lower than implied by the VM.The Cergeyevka deposit is a soft brown coal. Limited sampling of the upper-most portion indicated a high moisture content (75% daf) and an unusual, hydrogen-rich geochemistry. Lack of identifiable liptinites using either reflected light or fluorescence microscopy suggested a significant bituminite component. Otherwise, the coals appear to be typical for the Tertiary. An estimate of 125 m maximum burial depth was obtained using the bed-moisture content of the coal, which is around the present burial depth.Comparison of present-day thicknesses with inferred burial depths suggests that at least 500 m of section is missing between the Palaeocene coals and the early Miocene coals.Palaeoenvironmental considerations suggest that fire played a significant role in the accumulation of the peats at Raichikhinsk and Yerkovtsi. At Cergeyevka, peat accumulation ended by drowning of the mire.Two tuff beds were recognised within the seam at Raichikhinsk and one in the seam at Yerkovtsi. Correlation of the tuff beds is uncertain but they should prove useful in regional coal seam correlation and interpreting coal depositional environments. Geochemical analysis by XRF was complicated by high loss-on-ignition (LOI) values. Despite extensive alteration, an acid igneous source is implied from the presence of free quartz and TiO2/Al2O3 ratios of 0.02 to 0.05. 相似文献
8.
依据沉积环境控制烃源岩发育理论,研究了琼东南盆地崖北凹陷崖城组煤系烃源岩的发育环境及主控因素,并建立了研究区崖城组煤系烃源岩的发育模式。崖城组煤系烃源岩主要形成于半咸水、还原-弱还原的扇三角洲平原河道间泥炭沼泽环境和半咸水、弱还原-弱氧化的潮坪潮上带-潮间带泥炭沼泽环境。沉积环境、古气候条件、相对海平面变化以及古构造控制煤系烃源岩的发育,其中沉积环境控制着煤系烃源岩中有机质类型、有机质丰度、显微组分及煤层的厚度,古气候条件提供了煤系烃源岩发育的物质基础,相对海平面变化影响着煤系烃源岩的展布及保存条件,古构造则是聚煤盆地形成、演化的主要控制因素。崖城组煤系烃源岩有两种发育模式,一是在扇三角洲平原河道间泥炭沼泽环境中水体的还原性起主导作用,二是在潮坪潮上带-潮间带泥炭沼泽中高生物生产率起主导作用。 相似文献
9.
陕甘宁地区位于华北地台西部,处于东西构造域的交接部位,是我国重要的含煤、油气区之一。受不同构造背景、海平面升降、沉积物供给等影响,其晚古生代沉积体系类型多样。通过对露头、岩心、测井响应及编图等分析研究,区分出了碳酸盐台地、障壁岛－湖潮坪、潮道－湖潮坪、河控三角洲、扇三角洲、河流、冲积扇、湖泊等沉积类型,阐明了各自的沉积特征。晚古生代沉积体系展布、充填演化与南北两侧的兴蒙海槽和秦祁海槽的构造活动密切相关：晚石炭世西缘拗拉槽重新复活,形成以潮道－湖潮坪沉积为主的海湾充填,充填受基底和盆缘断裂控制;早二叠世东西部海水汇合,本区统一于华北陆表海中,形成碳酸盐台地、障壁岛、浅水三角洲交互的含煤沉积;中二叠世至晚二叠世早期陆表海萎缩,本区演变为近海内陆坳陷充填,形成冲积扇、河流、三角洲、湖泊沉积;晚二叠世晚期陆表海消亡,本区转化为内陆坳陷,形成以湖泊沉积为主的河湖充填。砂储层发育取决于沉积环境,空间展布受控于古构造机制。 相似文献
10.
鄂尔多斯盆地南部延长组沉积体系和层序特征 总被引：29，自引：0，他引：29
鄂尔多斯盆地南部延长组沉积体系类型形成于不同的地质背景，物源方向和沉积环境也不同，因此沉积特征和分布规律差异较大。以主力含油层段长8油组为例，辫状河三角洲体系主要位于盆地西南缘较陡坡带，砂体为长石砂岩，以槽状层理构造发育、前三角洲中有重力流沉积为特征；重力流沉积主要分布在盆地南部渭北地区的长7油层段，以岩屑砂岩为主，形成于深湖环境中，发育的鲍玛组合层序有ABCE、ADE、AE和BCE型序列；东北方向水系形成了曲流河三角洲体系，主要位于盆地东北缓坡带上，三角洲分流河道伸展距离长，朵体规模大，以长石细砂岩为主，河口砂坝发育。 相似文献
11.
The present work is an attempt to establish the stable isotope database for Mesozoic to Tertiary coals from the Pannonian Basin, Hungary. Maceral composition, proximate analysis, sulphur form, sulphur isotopes (organic and pyritic), and carbon isotopes were determined. This database supports the assessment of the environmental risks associated with energy generation, the characterization of the formation and the distribution of sulphur in the coals used.The maceral composition, the sulphur composition, the C, S isotopic signatures, and some of the geological evidences published earlier show that the majority of these coals were deposited in freshwater and brackish water environments, despite the relatively high average sulphur content. However, the Upper Cretaceous, Eocene, and Lower Miocene formations also contain coal seams of marine origin, as indicated by their maceral composition and sulphur and carbon chemistry.The majority of the sulphur in these coals occurs in the organic form. All studied sulphur phases are relatively rich in 34S isotopes (δ34Sorganic = + 12.74‰, δ34Spyrite = + 10.06‰, on average). This indicates that marine bacterial sulphate reduction played a minor role in their formation, in the sense that isotopic fractionation was limited. It seems that the interstitial spaces of the peat closed rapidly during early diagenesis due to a regime of high depositional rate, leading to a relative enrichment of the heavy sulphur isotopes. 相似文献
12.
Romeo M. Flores 《Organic Geochemistry》1979,1(4):225-235
Detailed stratigraphic and sedimentological studies of the Tertiary Tongue River Member of the Fort Union Formation in the Powder River Basin, Wyoming, and the Cretaceous Blackhawk Formation and Star Point Sandstone in the Wasatch Plateau, Utah, indicate that the depositional environments of coal played a major role in controlling coal thickness, lateral continuity, potential minability, and type of floor and roof rocks.The potentially minable, thick coal beds of the Tongue River Member were primarily formed in long-lived floodbasin backswamps of upper alluvial plain environment. Avulsion of meandering fluvial channels contributed to the erratic lateral extent of coals in this environment. Laterally extensive coals formed in floodbasin backswamps of a lower alluvial plain environment; however, interruption by overbank and crevasse-splay sedimentation produced highly split and merging coal beds. Lacustrine sedimentation common to the lower alluvial plain, similar to the lake-covered lower alluvial valley of the Atchafalaya River Basin, is related to a high-constructive delta. In contrast to these alluvial coals are the deltaic coal deposits of the Blackhawk Formation. The formation consists of three coal populations: upper delta plain, lower delta plain, and ‘back-barrier’. Coals of the lower delta plain are thick and laterally extensive, in contrast to those of the upper delta plain and ‘back-barrier’, which contain abundant, very thin and laterally discontinuous carbonaceous shale partings. The reworking of the delta-front sediments of the Star Point Sandstone suggests that the Blackhawk-Star Point delta was a high-destructive system. 相似文献
13.
平沟矿区山西组潮控三角洲—河流沉积及聚煤特点 总被引：3，自引：0，他引：3
通过野外和室内研究,提出山西组形成于河流—潮控三角洲环境。河流沉积包括辫状曲流河和高弯度曲流河。潮控三角洲以潮汐沉积发育为标志,潮汐沙坝、潮河道构成其沉积骨架,揭示了沉积期仍受海水内泛影响。煤聚积发生在河道岸后边缘沼泽环境、废弃潮汐沙坝上发育起来的潮坪环境及分流间湾充填变浅形成的泥炭沼泽环境。总结了不同沉积环境的聚煤特点。 相似文献
14.
Gondwana coals of the Rio Bonito Formation (Paraná Basin) in Southern Brazil have generally large ash yields, so they could be better called coaly siltstones than coal. In addition, hummocky cross stratification (HCS) was found in several coal beds of the Rio Bonito Formation throughout the basin. In this formation, the frequent and close relationship between facies involving rocks generated by subaqueous gravity flows (diamictites) and coal itself provides an excellent depositional model based on resedimentary processes acting during deposition, as well as a stratigraphic rearrangement of the present units.In the State of Rio Grande do Sul (southern part of Paraná Basin), coals are actually prodelta deposits related to delta-front diamictite and conglomeratic sandstone with sigmoidal bedding. Coal-forming organic sediments would come from trees plucked by the floods, as indicated by the wood logs floating in the diamictite, and reworking of previous peat accumulations. Every coal layer is covered generally by paleosoil siltstones, which represent colonization at the top of the catastrophic flood deposit, ending a sedimentary cycle.In case of Brazilian coal settings, several authors recognized deltas (fan deltas or braid deltas). Here is particularly considered the general environment as a salted interior sea (lago mare, Hsü et al. sense).The present study will refer to three important lithostratigraphic units in the Carboniferous–Early Triassic cycle: the Itararé Group, the Rio Bonito Formation, and the Palermo Formation.Although the preferential mode of occurrence of HCS in shallow marine environments indicates a genesis attributed to storm action, other causes, such as catastrophic flooding, have been advanced. Mutti et al. [Mem. Sci. Geol. 48 (1996) 233] described flood-dominated deltaic systems with thick conglomerate, sandstone, and pelitic deposits, derived from small- to medium-scale fluvial systems and mountain-bordered drainage basins adjacent to the sea. In such settings, seaward sediment flow can increase dramatically when weather conditions can supply water in such amounts to produce catastrophic floods. Thick and laterally extensive sandstone lobes with HCS are the fundamental depositional elements of fan deltas and other river-dominated delta systems.Diamictites and coal together could be a result from Jökullhlaups—an Icelandic term for glacial outburst flood—in case of catastrophic floods coming from a melting mountain glacier, similar to the Columbia River Valley Scablands (15,000 BP) and in modern Iceland examples. 相似文献
15.
利用测井曲线对吉林省双阳盆地长岭区煤系地质沉积环境进行了深入研究，利用DLW曲线并参照HGG曲线建立了解释格架(沉积模式)。得出的结论是：双阳盆地长岭区煤系地层沉积环境主要为扇三角洲沉积和湖泊沼泽沉积。并对以往工作中对本区煤系地层的对比作了修正。 相似文献
16.
The Oligocene coals from the northeastern part of the Assam-Arakan basin show a gradual decrease in the content of moisture, volatile matter and oxygen with corresponding increase in carbon content and calorific value from the Foreland Shelf to the deeper part of the geosyncline, reflecting the coalification trends in this basin. It has been suggested that the oxygen was replaced by organic sulphur, thereby lowering the oxygen content in the coals. The coals are perhydrous in nature with a high sulphur content. The high volatile content, perhydrous nature and high sulphur content in the Oligocene coals, as well as the presence of streaky facies and a very fine clastics unit, indicate that they were probably deposited in a marine-influenced deltaic and lagoonal environment.The plots of carbon versus hydrogen on Seyler's coal band follow a trend which differs from that of Seyler's band of Carboniferous bright coals. The coalification of the Oligocene coals represents the lignitic stage, in the case of the Foreland Shelf, and near subbituminous stage in the deeper geosynclinal part of the basin. A more intense, and probably sudden, dynamic process was involved in bringing about higher coalification in Oligocene coal of the geosynclinal facies than in Foreland Shelf area. This is possibly due to intense mountain-building forces acting from the southeastern direction of the basin. 相似文献
17.
古河口湾沉积环境的恢复主要根据下列证据进行:1.淡化水证据:小个体薄壳生物组合和沉积物中低的硼含量;2.古地理位置处于古河流入海部位;3.潮汐能量大于河流能量,潮汐作用控制了主要沉积过程;4.沉积层序与现代河口湾层序可以类比。虽然河口湾生命短暂,沉积物常被改造,但一个时期的古代河口湾沉积物仍是可以被识别的。 相似文献
18.
中国煤中有机硫的分布及其成因 总被引：2，自引：0，他引：2
对来自全国26个省、市、自治区的290个煤样中有机硫的质量分数测试及研究,发现煤中有机硫质量分数基本分布在0%1.0%范围内。在低硫煤中硫分以有机硫为主,在高硫煤中以无机硫为主。中、高硫煤中,广西、湖南等地区很大一部分煤中硫分以有机硫为主。在所采集的样品中,高有机硫煤(有机硫>1%)均分布在华南、华北两大聚煤区,属于石炭、二叠纪煤。高有机硫煤中有机硫质量分数的变化与变质程度无明显关系。煤炭形成过程中海水作用的影响,是导致煤中有机硫含量偏高的最主要原因。 相似文献
19.
Shao Longyi Xiao Zhenghui Lu Jing He Zhiping Wang Hao Zhang Pengfei 《Frontiers of Earth Science》2007,1(1):106-115
The Qinshui basin in southeastern Shanxi Province is an important base for coalbed methane exploration and production in China.
The methane reservoirs in this basin are the Carboniferous and Permian coals. Their thickness is strongly controlled by the
depositional environments and the paleogeography. In this paper, sedimentological research was undertaken on the outcrop and
borehole sections of the Taiyuan and Shanxi formations in the Qinshui basin and the basin-wide lithofacies paleogeography
maps for these two formations have been reconstructed. The Taiyuan Formation is composed of limestones, aluminous mudstones,
siltstones, silty mudstones, sandstones, and mineable coal seams, with a total thickness varying from 44.9 m to 193.48 m.
The coal seams have a thickness ranging between 0.10 and 16.89 m, averaging 7.19 m. During the deposition of the Taiyuan Formation,
the northern part of the basin was dominated by a lower deltaic depositional system, the central and southern parts were dominated
by a lagoon environment, and the southeastern corner was occupied by a carbonate platform setting. Coal is relatively thick
in the northern part and the southeastern corner. The Shanxi Formation consists of sandstones, siltstones, mudstones, and
coals, with the limestones being locally developed. The thickness of the Shanxi Formation is from 18.6 m to 213.25 m, with
the thickness of coal seams from 0.10 to 10 m and averaging 4.2 m. During the deposition of the Shanxi Formation, the northern
part of the Qinshui basin was mainly dominated by a lower deltaic plain distributary channel environment, the central and
southern parts were mainly an interdistributary bay environment, and the southeastern part was occupied by a delta front mouth
bar environment. The thick coals are distributed in the central and southern parts where an interdistributary bay dominates.
It is evident that the thick coal zones of the Taiyuan Formation are consistent with the sandstone-rich belts, mainly located
in the areas of the northern lower deltaic plain and southeastern barrier bar environments, whereas the thick coal zones of
the Shanxi Formation coincide with the mudstone-rich belts, located in the areas of the central and southern interdistributary
bay environments.
Translated from Journal of Palaeogeography, 2006, 8(1): 43–52 [译自: 古地理学报] 相似文献
20.
陕渑煤田位于河南省的西部,其晚古生代煤系地层由晚石炭世太原组、早二叠世早期山西组和早二叠世晚期～晚二叠世早期石盒子群所组成。本文主要讨论太原组—3煤层形成的沉积环境和聚煤特征。—3煤沉积前的下部碎屑岩段为一套开阔型海岸碎屑潮坪体系沉积,发育潮坪以及与其共生潮道和潮沟。—3煤沉积后的灰岩段根据微相、沉积构造及其中所含的生物化石等可以确定是一套由潮间带到潮下低能带的向上变深的沉积序列。—3煤层厚度分布主要受其沉积前沉积环境的影响,其中主要潮道发育的地方以及潮坪上较低洼的地带,上覆煤层厚度小(0～0.50m),而在潮坪上其它地区,煤层则厚度大(一般大于0.50m)。—3煤硫分主要受其沉积时沉积环境和沉积后沉积环境的影响,煤层中夹有薄层混灰岩时,煤的疏分就增高。—3煤层硫分和灰分普遍高的原因是受其堆积后较深水碳酸盐沉积的影响所致。 相似文献