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1.
准噶尔盆地头屯河地区侏罗系陆相层序包含4种沉积:(1)冲积扇平原湿地中的砾石质河流沉积(八遭湾组),其特征提示在湿地中发育了规模不同的大河道(深3—5m,宽1OOm左右)及较小的分流或决口河道(深2m以下,宽6—30m)。(2)沙质低弯度河沉积,晚三工河、早西山窑、头屯河及齐古组沉积期的河流沉积属之。其特点是河道相与河间相间的界线清楚,提示河道在某一段时期固定于平原的特定地带;河道规模受古气候和构造的制约;气候干旱化和构造抬升(如头屯河组沉积时期),侵蚀基面降低,河流动力增加,因而河流规模变大,反之变小;晚头屯河组沉积期的干旱气候存在暂时性河道。(3)三角洲前缘沉积(河口中坝),见于八道湾、三工河及喀拉扎组中。(4)开阔湖相沉积,以三工河组厚的页岩层序为代表。 砂岩成分逆向反映源区剥蚀顺序。下侏罗统富含泥质岩屑,表示天山上古生界浅变质及沉积层系被剥蚀。自下而上,碎屑中稳定矿物增加,粒度变细,反映源区由于剥蚀而后退。中—上侏罗统砂岩成分演化方向不同于下侏罗统,可能与三工河组沉积末期盆地边缘构造回春有关。在Q-F-L三角图中,侏罗系样品大都落在构造区之间,反映陆相盆地充填物的混合来源。下—中侏罗统的煤既有原地生成,亦有重要的他生类型。 相似文献
2.
利用露头剖面及钻孔资料对贵州省乐平统（上二叠统）含煤岩系层序-古地理及聚煤规律进行研究。根据海相标志层向陆地方向延伸范围所反映的海平面规律,将贵州省乐平统划分为3个三级复合层序（CSⅠ、CSⅡ、CSⅢ）和相应的低位、海侵及高位层序组,层序CSⅠ相当于龙潭组下段中下部,层序CSⅡ相当于龙潭组下段上部及龙潭组上段下部,层序CSⅢ相当于龙潭组上段上部及长兴组。通过分析地层厚度、石灰岩含量、砂泥比、煤层厚度等参数变化规律,恢复3个层序的岩相古地理。贵州省乐平世海侵方向均来自研究区东部,物源来自西部的康滇高地,贵州省地区乐平统自西向东发育有陆相冲积平原、过渡相三角洲及潮坪-潟湖、海相碳酸盐台地以及深水盆地等古地理单元,总体上贵州省乐平世经历了CSⅠ的海侵、CSⅡ的海退及CSⅢ的持续海侵过程,在贵州西部地区,各古地理单元总体上有CSⅠ向陆、CSⅡ向海、CSⅢ又持续向陆的迁移规律。聚煤作用以CSⅢ最强,CSⅡ次之,CSⅠ较差。聚煤中心分布在过渡相三角洲平原及潮坪古地理单元,且有随区域性的海侵海退而迁移。CSⅠ的聚煤中心主要分布在发耳和纳雍地区,CSⅡ的聚煤中心主要分布在黔西南普安—六盘水及织金一带,CSⅢ的聚煤中心主要分布在六盘水、盘县及织金地区。这些聚煤规律分析结果可为煤炭及煤层气资源的勘探开发提供理论支持。 相似文献
3.
山西静乐舍科勘查区主要含煤地层为上石炭统太原组和下二叠统山西组,通过对区内地质成果分析,本区太原组沉积环境由河控三角洲到潟湖、潮坪交替出现,期间发育两次碳酸盐台地,岩性主要以灰岩、泥岩、中粗砂岩和粉、细砂岩为主,含主要可采煤层9煤层;山西组主要为三角洲平原分流河道相、泛滥盆地相和泥炭沼泽相,以砂岩、粉砂岩、砂质泥岩为主,含主要可采煤层4-1、4煤层;4-1号煤层属大部可采的较稳定煤层,4和9号煤层属全区可采的较稳定煤层;本区主要煤类均为焦煤,资源量丰富,煤质较好,具有较高的开发价值。 相似文献
4.
阳泉矿区煤系地层形成于海陆交互相的过渡环境,其煤层的形成、赋存、厚度变化、分布均受沉积环境的控制和影响。根据分析成煤环境、预测煤层赋存变化情况,为煤炭资源补勘和开采生产提供指导 相似文献
5.
Cyclic characteristics of coal-bearing sediments in the Bochumer Formation (Westphal A 2) Ruhrgebiet, Germany 总被引：1，自引：0，他引：1
SATYENDRA M. CASSHYAP 《Sedimentology》1975,22(2):237-255
Cyclic characteristics of the Bochumer coal measures have been studied statistically using first-order embedded Markov chain analysis on data from thirty-two boreholes. Separate tally matrices which were made for the Lower, Middle and Upper units by summing the tally matrices for all the boreholes, were used to produce various transition probability matrices, which were then subjected to the chi-square test. Results strongly suggest that the Bochumer succession was deposited by a Markovian mechanism, and that the sequence represents cyclic sedimentation. The preferential upward transition path for lithologic changes that can be derived in the total area and in individual logs is: coal\rightarrow shale\rightarrowsiltstone\rightarrowsandstone\rightarrowsiltstone\rightarrowrooty bed\rightarrowcoal. Among the noteworthy features are a two-way transition between siltstone and sandstone, which implies frequent interbedding of the two lithologies, and the transition, up out of siltstone to rooty beds. There are, however, minor variations, locally, either by way of subsidiary transitions or in the extent to which the above transitions can be followed. When tested for stationarity through time and space, the Markov chain analysis yields results which show the upward sequence of lithologic states (facies) to be stationary at individual localities, but non-stationary when the entire data are tested for the whole area. The relationship of the number of coal-bearing cycles to total thickness of strata and average thickness of coal-cycles is examined using linear regression. Significant positive relationships are present between the number of cycles and total thickness, and significant negative correlations occur between the number of cycles and their average thickness. The results of the study have been used to infer sedimentological evolution of the succession and sediment cyclicity. Environmentally, the Bochumer cycles fit suitably into the concept of deltaic cycles. 相似文献
6.
青海聚乎更矿区不仅赋存丰富的煤炭资源,同时也是全球陆域中纬度高海拔地区天然气水合物的首要发现地,同时也是我国非常规天然气(煤层气和页岩气)勘探开发的潜在热点地区,且天然气水合物勘探的层位主要为中侏罗世含煤岩系。通过对青海聚乎更矿区中侏罗世含煤地层野外露头、钻孔岩心、测井等资料整理分析的基础上,对研究区内中侏罗世含煤岩系沉积时期的沉积环境及古地理进行了分析。以定量和定性分析相结合的方法对研究区岩相古地理进行重建。以钻孔沉积相分析为基础,结合单因素分析多因素综合作图法及研究区目的层段沉积相断面图分析,最终恢复各段沉积期的岩相古地理格局。木里组下段岩性主要为细砾岩、含砾粗砂岩及粗砂岩等粗粒岩性,分析认为木里组下段主要发育辫状河沉积;木里组上段随着水体的不断加深,发育形成 了研究区主采的下1、下2煤层,该段主要以三角洲沉积为主,同时研究区西南区域发育滨浅湖沉积;江仓组上段沉积时期,水体进一步加深,成煤环境逐渐变差,发育形成多套薄煤层,以三角洲沉积为主,西南区域的滨浅湖沉积范围进一步扩大;江仓组上段是发现水合物的主要层段,其岩性主要以油页岩、暗色泥岩等为主,含有典型的湖泊沉积的瓣鳃类化石,为湖泊沉积。总体上,聚乎更矿区在中侏罗世经历了辫状河、三角洲平原、三角洲前缘、滨浅湖、半深湖-深湖的持续变深的演化过程。 相似文献
7.
河南济源晚三叠世—中侏罗世陆相地层 总被引：4，自引：1，他引：4
<正> 河南济源西承留一带晚三叠世—中侏罗世地层分布广泛、出露良好,化石丰富。60年代,河南省地质局石油队和区测队等做过区测工作,建立了地层系统。1979至1985年,笔者等在“河南省中生代含煤地层及找煤方向”课题研究时,研究地层的岩性及化石群特征,将本区晚三叠世—中侏罗世地层自下而上分为椿树腰组(T_(3ch)~1)、谭庄组(T_(3t)~2)、鞍腰组(J_(1a))、杨树庄组(J_(2y))和马凹组(J_(2m)),分述如下: 相似文献
8.
Mustafa Bozcu 《International Journal of Earth Sciences》2010,99(4):851-861
The Büyük Menderes and Gediz (Ala?ehir) grabens are two significant segments of the Western Anatolian extensional province. They merge around Buldan-Sar?caova in the east. Outcropping Neogene sedimentary units in this area display a rather complex structure. This paper summarizes the importance and meaning of the data obtained during a detailed investigation of the Neogene units and aims to improve our understanding of the neotectonic evolution of Western Anatolia. The Buldan-Sar?caova Neogene sequence is composed of three different sedimentary units: (1) the Lower Unit, (2) the Middle Unit, and (3) the Upper Unit. The Lower Unit crops out on the Buldan horst which is located between the Büyük Menderes and Ala?ehir grabens. The sequence starts as a coarse conglomerate and sandstone (?salar Formation) and continues as lagoonal-lacustrine mudstone, interbedded with coal seams and shales (Bostanyeri Formation) and also with lacustrine limestones. The age of this succession is Lower-Middle Miocene. The development of the basin is structurally controlled by NNW-trending normal faults. The Middle Unit begins with a conglomerate–mudstone sequence (K?z?lburun Formation), followed by a sandstone–mudstone–marl sequence (Sarayköy Formation). A lacustrine limestone–marl unit occurs at the top (Aktepe Formation). Some thin gypsum lenses and layers are observed in the Sarayköy Formation. The unit contains some brackish-water fossils. The rocks of the Middle Unit crop out mostly at the low altitudes of the Buldan horst, i.e. the southeast piedmont, around the junction of the Büyük Menderes and the Gediz grabens. The Middle Unit was deposited in fluvial and lacustrine environments during the Late Miocene–Pliocene period. These rocks were formed in response to the uplift of the Buldan horst. The Upper Unit, which is composed of conglomerates, was deposited within the Büyük Menderes Graben–Gediz Graben depressions as alluvial fill. 相似文献
9.
青海聚乎更矿区是全球陆域中纬度地区天然气水合物的首要发现地,水合物储存层位主要为该矿区三露天井田的中侏罗世含煤岩系。依据钻孔岩心及测井曲线,对该矿区三露天井田含煤岩系进行沉 积环境分析,在单孔沉积相及沉积相断面图分析的基础上,重建研究区的岩相古地理格局。木里组下段岩性主要为细砾岩、含砾粗砂岩及粗砂岩等粗粒岩石,以辫状河为主的沉积环境;木里 组上段岩性以厚层砂岩与厚层煤层互层为特征,反映了水体逐渐加深的过程中发育三角洲为主的沉积环境;江仓组下段以细粒砂岩及泥岩互层夹薄煤层为特征,反映水体进一步加深过程中的三角洲前缘和滨浅湖环境;江仓组上段以油页岩、暗色泥岩为主,含有瓣鳃类化石,反映湖泊为主的沉积环境。 相似文献
10.
库泰盆地是印度尼西亚最大、最深的第三系含油气盆地,也是该国最主要的产油气盆地。盆地经历了断陷期、拗陷期和反转期三个发育阶段,充填的第三系沉积物厚度达14 km。盆地发育四套烃源岩,其中,中中新统三角洲平原煤和三角洲前缘碳质泥岩是滨浅海区有效烃源岩,上中新统富含碳质碎屑浊积岩是深水区有效烃源岩;油气纵向上主要富集于中中新统、上中新统及上新统,平面上主要富集于背斜构造中。综合分析认为,深海平原区上中新统斜坡扇、盆底扇砂岩是下库泰盆地潜在勘探领域,渐新统—下中新统是三马林达复背斜带有利勘探领域,始新统盆地边缘上超尖灭砂体是上库泰盆地潜在勘探领域,始新统—中新统台地生物礁是库泰盆地深层潜在勘探领域。 相似文献
11.
川西坳陷中侏罗统的千佛崖、沙溪庙组是重要的油气勘探层位。通过沉积特征分析和对比,砂泥百分含量平面变化研究,建立了各亚段的沉积古地理面貌及可能的砂体叠合分布区。结合有利相带特征研究认为,千佛崖组的河床亚相或滨湖滩环境形成的砂、砾岩储集体具有相对较好的物性条件,沙溪庙组的储集砂体主要为辫状河道及三角洲前缘分流河道砂体,其它微相类型砂体较少见,在此基础上预测出了有利地区。 相似文献
12.
D. R. Chesnut 《International Journal of Coal Geology》1996,31(1-4)
Coal production has been an important economic factor in the Central Appalachian Basin. However, regional stratigraphic and structural relationships of the coal-bearing rocks of the basin have been poorly understood due to numerous separate nomenclatural schemes employed by various states. In order to estimate coal resources and understand mechanisms controlling the distribution of coal within the basin, a reliable geologic framework is necessary. Seven detailed cross sections across the Central Appalachian Basin were constructed in order to examine the stratigraphic and structural framework of the coal-bearing rocks in the basin. The cross sections were based on more than 1000 oil and gas well logs, measured sections, and borehole information from Kentucky, Ohio, Tennessee, Virginia and West Virginia.The cross sections revealed three main points discussed here: southeast thickening of the Pennsylvanian strata, uncomfortable northwestward onlapping relationship of Lower Pennsylvanian strata over underlying Lower Pennsylvanian and Mississippian strata and regional continuity of beds. The cross sections, geologic mapping, coal-resource studies, extensive new highway exposures and the occurrence of tonstein beds indicate that many coal beds and marine strata are laterally extensive, albeit locally variable across the basin. Certain quartzose sandstone bodies are also extensive over large areas of the basin.Existing stratigraphic nomenclature schemes obscured the geologic framework of the basin, so a new unified nomenclature scheme was devised to better describe stratigraphic features of the basin. The new stratigraphic nomenclature, now only formalized for Kentucky, was based on key stratigraphic units that proved to be extensive across the basin. Lower and Middle Pennsylvanian rocks are now recognized as the Breathitt Group (the Breathitt Formation was elevated to group rank). The Breathitt Group was subdivided into eight coal-bearing formations by relatively thick marine strata, and, in the lower part of the Breathitt Group, by quartzose sandstone formations. The new coal-bearing units are formally ranked as formations and, in ascending order, are the Pocahontas, Bottom Creek, Alvy Creek, Grundy, Pikeville, Hyden, Four Corners and Princess Formations. The quartzose sandstone units are also formally ranked as formations and are, in ascending order, the Warren Point, Sewanee, Bee Rock and Corbin Sandstones. The sandstone formations were previously recognized units in some states, but have been extended (formally in Kentucky) across the basin. The key stratigraphic marine units are formally ranked as members, and are, in ascending order, the Betsie Shale Member, the Kendrick Shale Member, Magoffin Member and Stoney Fork Member. 相似文献
13.
14.
通过野外地质露头和钻孔岩心观察以及对大量钻孔岩心编录和测井解释资料的综合统计分析,笔者将伊犁盆地南缘西段中下侏罗统水西沟群划分出4个大的沉积体系:八道湾组(J1b)的冲积扇沉积体系、三工河组—西山窑组一段的辫状河三角洲沉积体系、西山窑组二段至三段的浅湖沼泽沉积体系和西山窑组四段至五段的曲流河三角洲沉积体系。文中详细讨论了伊犁盆地南缘西段水西沟群各沉积体系的沉积相特征,研究了水西沟群沉积体系及沉积相与砂岩型铀矿的成矿关系,指出辫状河三角洲沉积体系是砂岩型铀矿成矿最有利的沉积体系,三角洲前缘河口坝及席状砂亚相、三角洲平原辫状河流亚相、扇中-扇端亚相及三角洲平原分流河道亚相是砂岩型铀矿主要的控矿沉积相。 相似文献
15.
珲春盆地是吉林省重要聚煤盆地,分析古近纪珲春组的沉积古地理,总结其层序格架下聚煤规律,可以为研究区煤炭和煤层气资源的勘探规划提供理论依据。基于区域地质、钻孔岩心和测井资料,对珲春组岩相类型、沉积体系、层序–古地理和聚煤特征进行分析。结果表明,珲春组共发育砾岩、砂岩、粉砂岩、泥岩和可燃有机岩5类岩石类型和12种岩相类型。根据区域不整合面、河流下切谷冲刷面和沉积体系转换面等3类层序界面,将珲春组划分为3个三级层序,建立了珲春组等时地层格架。基于各三级层序内的地层厚度、砂岩厚度、砂泥比和煤层厚度分布,恢复了各层序岩相古地理,认为珲春组共发育冲积扇、辫状河、辫状河三角洲和湖泊4类沉积体系,具体包括12类沉积亚相和13类沉积微相,物源主要位于研究区的南北两侧。在各层序地层格架内,珲春盆地煤层展布具有明显规律性。层序Ⅰ—Ⅲ,聚煤作用先增强后减弱,厚煤层主要发育在湖侵体系域和高位体系域等碎屑沉积体系明显减弱时期。珲春组主要有3个聚煤中心,分别位于研究区西部八连城地区、南部板石地区和东部的54-9钻孔附近。聚煤中心和地层沉积中心有较好的对应关系,且两者从层序Ⅰ—Ⅲ呈现出由盆地西部向东部再向西部迁移的趋势,成煤古地理单元主要为扇端漫流沉积、辫状河河漫滩、辫状河三角洲平原分流间湾及湖泊滨湖亚相。 相似文献
16.
四川盆地雷口坡组膏盐岩成因及膏盐盆迁移演化与构造意义 总被引：4，自引：0，他引：4
通过详细的岩石学特征分析,结合区域分布,研究了四川盆地中三叠统雷口坡组的膏盐岩成因,进而讨论了其反映的膏盐盆迁移和演化及构造指示意义。雷口坡组总体存在两种岩性组合和分布特征的膏盐岩,一类出现于雷一段—雷三段下亚段沉积时,表现为纹层状膏盐岩夹块状膏盐岩,厚度较小,横向分布稳定,属于泻湖成因;另一类出现在雷三段中亚段—雷四段中亚段沉积时,以块状硬石膏岩和石盐岩为主,厚度差异巨大,横向变化较快,并且膏盐岩沉积中心出现向西、向北迁移的趋势,与早期的膏盐岩形成了鲜明对比,属于膏盐盆成因。由此反映出构造信息,四川盆地中三叠世雷口坡期的构造应力场总体处于由张应力向挤压应力转换,其中,雷一段—雷三段下亚段沉积时盆地总体处于构造平静期,为张应力向挤压应力转换的过渡期;相比而言,雷三段中亚段—雷四段中亚段沉积时为构造活跃期,盆内北西—南东向和北东—南西向应力挤压趋于活跃,新的沉降中心形成,强烈的蒸发作用使得膏盐岩在凹地快速沉积,并随挤压的阶段性活跃,发育向北、向西迁移趋势的雷三段中亚段、雷三上亚段、雷四段下—中亚段沉积期三期膏盐盆,川西凹陷的形成与演化从雷三段中亚段沉积期已经开始发育,并在雷四段下—中亚段沉积期已具雏形。这些认识为四川盆地雷口坡组膏盐岩成因研究提供了新基础参考信息。 相似文献
17.
鱼卡煤田是青海省重要的煤炭资源基地,主要含煤地层为中侏罗统。区内含煤地层角度不整合于奥陶系上统滩间山群之上。根据野外实剖地质剖面岩性特征自下而上划分为侏罗系中统大煤沟组、上统采石岭组、红水沟组。其中大煤沟组分为下含煤段、砂岩段、上含煤段、页岩段;采石岭组分为下部砂岩段、上部砂泥岩段。大煤沟组与以往划分的大煤沟组、石门沟组相当。 相似文献
18.
Irfan U. JAN Shahid IQBAL Sarah J. DAVIES Jan A. ZALASIEWICZ Michael H. STEPHENSON Michael WAGREICH Muhammad HANEEF Muhammad HANIF Sajjad AHMAD 《《地质学报》英文版》2017,91(3):1063-1078
The Upper Carboniferous—Lower Permian(Upper Pennsylvanian-Asselian) Tobra Formation is exposed in the Salt and Trans Indus ranges of Pakistan.The formation exhibits an alluvial plain(alluvial fan-piedmont alluvial plain) facies association in the Salt Range and Khisor Range.In addition,a stream flow facies association is restricted to the eastern Salt Range.The alluvial plain facies association is comprised of clast-supported massive conglomerate(Gmc),diamictite(Dm)facies,and massive sandstone(Sm) Hthofacies whereas the stream flow-dominated alluvial plain facies association includes fine-grained sandstone and siltstone(Fss),fining upwards pebbly sandstone(Sf),and massive mudstone(Fm) Hthofacies.The lack of glacial signatures(particularly glacial grooves and striatums) in the deposits in the Tobra Formation,which are,in contrast,present in their timeequivalent and palaeogeographically nearby strata of the Arabian peninsula,e.g.the AI Khlata Formation of Oman and Unayzah B member of the Saudi Arabia,suggests a pro-to periglacial,i.e.glaciofluvial depositional setting for the Tobra Formation.The sedimentology of the Tobra Formation attests that the Salt Range,Pakistan,occupied a palaeogeographic position just beyond the maximum glacial extent during Upper Pennsylvanian-Asselian time. 相似文献
19.
山东济阳石炭-二叠系煤成气储层沉积研究 总被引：3，自引：0，他引：3
在建立层序地层格架的基础上进行煤成气储层沉积学研究。储集在二叠系砂岩(属于致密砂岩)储层内的煤成气藏成为重要的天然气藏。济阳地区上石盒子组万山段、奎山段和孝妇河段,发育河流相、湖泊滨岸相为主要特色的砂质沉积,是煤成气主要储集层。主要储层沉积相为河道滞留与边滩组成的河道充填。煤成气储集空间主要是次生孔隙。本区石炭-二叠系砂岩成岩作用强烈,原生粒间孔保存较少,大部分的粒间孔隙是由于后期溶蚀作用形成的。这种次生的粒间孔隙充填在粒间孔隙之间的杂基或胶结物后期经溶蚀作用形成。二叠系气藏的直接盖层主要是下石盒子组的河漫相、山西组及太原组的三角洲平原和湖沼相沉积的泥岩、煤和炭质泥岩。 相似文献
20.
以准噶尔盆地南缘韭菜园子沟剖面中二叠统芦草沟组野外露头为研究对象,结合该地区芦草沟组沉积时期坳陷湖盆的沉积特征和大套灰黑色油页岩的发育背景,对芦草沟组上部砂体进行了观察描述和沉积分析。在露头剖面上,芦草沟组以灰黑色油页岩为主,但笔者首次在该组上部发现了厚约60m的砂岩,其与上覆红雁池组灰黑色油页岩呈整合接触,具有明显的深水沉积背景。通过对该套砂体的岩石类型划分与沉积现象解析,共识别出2大类10种砂泥岩类型,明确了牵引流和浊流共同发育的特征。该套砂体中可识别出深水扇的3种沉积亚相和相应沉积微相,由3期富砂型湖泊深水扇叠置形成。结合此次露头观察与特征描述,分析了研究区由厚层砂岩到泥砂岩互层的演化过程,并建立了芦草沟组富砂型湖泊深水扇沉积模式。这个典型露头的沉积解剖,是对准噶尔盆地南缘芦草沟组深水沉积体系研究的有益补充。 相似文献