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1.
豫西济源中三叠世油房庄组下部发育曲流河沉积,以细砂、粉砂和粉砂质泥岩为主,局部含泥砾和粗砂岩。根据Miall的岩相分类法,油房庄组发育有17种岩相,主要有Sts、Sps、Sws、Fh、Fr、Fc、Ch和Cr等,可归纳为代表曲流河不同发展阶段的7种岩相组合类型。根据岩相类型和沉积构造特征,曲流河沉积识别出3个沉积亚相和8个沉积微相,其中河道亚相包括河道滞留沉积微相和边滩沉积微相;堤岸亚相包括天然堤沉积微相和决口扇沉积微相;洪泛平原亚相由近端洪泛平原沉积微相、远端洪泛平原沉积微相、永久性河漫湖泊微相和暂时性河漫湖泊微相组成。研究区河流曲率P为0.64,属于低弯度曲流河沉积。 相似文献
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广西北海涠洲岛第四纪湖光岩组的风暴岩 总被引：6，自引：1，他引：5
广西北海涠洲岛第四纪湖光岩组以碎屑岩为主, 内发育渠筑型、丘状或洼状交错层理、平行层理等典型的风暴沉积构造.湖光岩组的风暴岩包括3种岩相类型: A.底部具渠筑型、内部具块状层理或递变层理的砾岩、砂砾岩或含砾砂岩; B.具丘状、洼状交错层理或平行层理的砂岩; C.具浪成交错层理的砂岩.这些岩相组合成典型的A -B -C风暴沉积序列, 它们分别代表在风暴作用期间风暴流(A)、风暴浪(B) 和正常波浪(C) 的沉积.晚更新世北海涠洲岛地区位于低纬度的浅海沉积背景下, 上更新统湖光岩组以正常浪及面之上的浅海背景粗火山碎屑和砂沉积为主.湖光岩组风暴岩的发现反映该区晚更新世位于风暴作用频繁的5°~ 2 0°的低纬度地区.风暴沉积发育于正常浪及面之上的浅海地带, 涠洲岛是一个风暴作用控制的浅海陆架.因此风暴岩对解释晚更新世北部湾的古地理和古气候具有重要意义 相似文献
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春晖油田位于准噶尔盆地西北缘哈山（即“哈拉阿拉特山”）地区,主要含油层系为侏罗系八道湾组,对沉积相及有利储集层分布规律的研究制约着春晖油田的勘探工作。为此,根据野外露头、钻井、测井、取心及分析测试资料等,对春晖油田八道湾组开展了沉积相和有利砂体分布分析。研究结果表明,研究区八道湾组一段一砂组沉积时期,气候温暖潮湿,来自西北方向的多个物源形成的湿地扇沉积在研究区相互叠置,可识别出为扇根、扇中、扇缘3种亚相和6种岩石相（扇根砾岩相,扇中辫状河道砂砾岩相、辫状河道粗砂岩相、辫状河道细砂岩相,扇缘泥岩相和碳质泥岩及煤层相）;扇中粗砂岩相、细砂岩相为油气聚集的优势岩相带,亦是油气运移的优势通道,它决定了油气富集规模及油藏边界。 相似文献
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从新疆叶城剖面砂岩和砾岩组分看西昆仑山的剥蚀历史 总被引：7，自引：0，他引：7
叶城晚新生代山前盆地沉积序列由中新统乌恰群,上新统阿图什组和上新统-更新统西域组构成。乌恰群岩性为细粒泥岩夹砂岩,阿图什组为砂岩夹薄层砾岩,西域组为粗粒砾岩。中新世的沉积以细颗粒泥岩和砂岩为主,表明物源区较远,古流域坡度较小,搬运距离较长。叶城剖面碎屑岩粒度总体上是沿剖面向上逐渐变粗,到上新统的阿图什组时,开始出现砾石沉积,砂岩的岩屑成分增加,成熟度降低,反映西昆仑山已经开始有规模地隆升。西域组的沉积标志着作为物源区的西昆仑山已有相当的高度。西域组砾石成分在剖面下部以沉积岩为主,向上过渡为沉积岩和深变质岩为主,反映了源区的沉积盖层首先被剥蚀,随着山系的隆升,基底岩石(深变质岩和侵入岩)也被暴露和剥蚀。 相似文献
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滇中中元古代昆阳群因民组碎屑风暴岩及其意义 总被引：16，自引：1，他引：15
滇中地区中元古代昆阳群因民组以碎屑岩为主,内发育典型的风暴沉积构造 (包括渠铸型、丘状交错层理和洼状交错层理、递变层理等 )。风暴沉积主要包括 4种岩相类型 :A -具口袋构造的递变层理砂岩段。B -具丘状或洼状交错层理的砂岩段。C -具均质层理的粉砂岩、泥质岩段。D -具水平层理的泥质岩段。上述岩相A、B、C分别代表风暴流作用 -风暴浪作用 -风暴后期的快速悬浮沉积 (事件沉积 ),D代表风暴过后缓慢悬浮沉积 (背景沉积 ),它们组合成不同的风暴沉积序列。滇中地区昆阳群风暴沉积的发现表明中元古代大气圈、水圈及其相互作用与现今近似;中元古代滇中地区位于低纬度 (5 - 30°)的风暴作用带。该沉积对于解释因民组递变层砂岩的成因、证实昆阳群的地层层序也具有重要意义。 相似文献
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Late Neogene loess deposition in southern Tarim Basin: tectonic and palaeoenvironmental implications 总被引：2，自引：0，他引：2
Uplift of the Tibetan Plateau during the late Cainozoic resulted in a thick apron of molassic sediments along the northern piedmonts of the Kunlun and Altyn Mountains in the southern Tarim Basin. Early Neogene sediments are characterised by sandstone, siltstone and red mudstone, representing floodplain to distal alluvial fan environments. The Early Pliocene Artux Formation consists of medium-grained sandstone and sandy mudstone with thin layers of fine pebbly gritstone. The Late Pliocene to Early Pleistocene Xiyu Formation is dominated by pebble to boulder conglomerate typical of alluvial fan debris flow deposits. Sedimentological investigation, together with grain size and chemical analyses of siltstone bands intercalated with sandstone and conglomerate in the Xiyu and Artux Formations, point to an aeolian origin, suggesting desertic conditions in the Tarim Basin by the Early Pliocene. The onset of aeolian sedimentation in the southern Tarim Basin coincided with uplift of the northern Tibetan Plateau inferred from the lithofacies change from fine-grained mudstone and sandstone to coarse clasts. Tibetan Plateau uplift resulted in the shift of sedimentary environments northwards into the southern Tarim Basin, and could well have triggered the onset of full aridity in the Taklimakan region as a whole. 相似文献
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北大巴山志留系滔河口组火山碎屑岩相序、组构特征及古火山作用环境分析 总被引：6，自引：0，他引：6
志留系滔河口组是一套发育于北大巴山地区的火山岩-火山碎屑岩-沉积岩组合。在1:10000地质填图和大比例地质剖面实测基础上,通过详细的火山碎屑岩相序和组构分析,本文在滔河口组火山-地层中共识别和划分出22个岩相,5个相组合类型。区域岩相测量与对比揭示,滔河口组火山-沉积宏观序列自下而上由玄武岩相(一般下部为块状粗粒/细粒玄武岩相、上部为枕状玄武岩相)、凝灰角砾岩相、再沉积富辉石火山碎屑砾岩相、无结构或叠瓦状凝灰质粗砾岩相、凝灰质砂岩相、生物灰岩相或泥岩相构成。岩相组合横向变化显示滔河口组古火山活动西强东弱,火山活动类型为斯托柏林型(Strombolian-type eruption)喷发。相对地,研究区西部火山-沉积序列发育较为完整。滔河口组的地层序列与岩石组合与板内火山活动产物相似,本文认为北大巴山地区志留系滔河口组火山岩-火山碎屑岩-沉积岩组合形成于洋岛或海山构造环境,是板内拉伸作用的产物。 相似文献
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The late-orogenic Archaean Duparquet, Kirkland and Stormy basins of the Canadian Superior Province are characterized by bounding crustal-scale faults and abundant porphyry stock emplacement. Lava flows and pyroclastic deposits are restricted to the Kirkland and Stormy basins, and coarse clastic detritus characterizes the Duparquet basin. Seven distinct lithofacies are identified: (1) mafic volcanic, (2) felsic volcanic, (3) pyroclastic, (4) volcaniclastic, (5) conglomerate-sandstone, (6) sandstone-argillite
conglomerate), and (7) argillite-sandstone
tuffaceous sandstone). The mafic and felsic volcanic lithofacies represent effusive lava flows, the pyroclastic lithofacies is formed of subaerial surge and airfall deposits and the volcaniclastic lithofacies is composed of reworked volcanic debris. The conglomerate-sandstone lithofacies is interpreted as alluvial fan, fan delta or proximal braided stream deposits, whereas the sandstone-argillite lithofacies is consistent with sandy-dominated flood- or braidplain deposits. A dominantly shallow-water lacustrine setting is inferred for the argillite-sandstone lithofacies. These different lithofacies record the basin history and can be used to identify basin-forming processes. Lithofacies stacking and rapid lateral changes of lithological units in conjunction with interformational unconformities and basin margin faults suggest tectonically induced sedimentation. Volcanism can also influence basin evolution and the delicate balance between erosion, sedimentation, and prevalent transport processes is affected by volcanic input. Catastrophic influx of pyroclastic material facilitated mass-wasting processes and formation of non-confined hyperconcentrated flood flow deposits account for local congestion of alluvial or fluvial dispersal patterns. Confined stream flow processes govern sedimentation during intravolcanic phases or prominent tectonic uplift. In addition, climate which controls the weathering processes, and vegetation which stabilizes unconsolidated material, affects the transport and depositional process. A CO2-rich aggressive weathering, humid Archaean atmosphere favours traction current deposits and an absence of vegetation promotes rapid denudation. Although tectonism is the prevalent long-term controlling factor in restricted basins, the effects of volcanism, climate and lack of vegetation can also be detected. 相似文献
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Purbasha Bhattacharya Sarbani Patranabis-Deb 《Journal of the Geological Society of India》2016,87(3):287-307
The Meso to Neoproterozoic succession in the western Chattisgarh basin around Rajnandgaon has been classified into coarse siliciclastic dominated proximal and fine siliciclastic-carbonate dominated distal assemblages. The proximal assemblage, the Chandarpur Group, unconformably overlies the Neoarchean to Paleoproterozoic Dongargarh- Kotri volcanics (c.2.2-2.3 Ga), Bengpal Granite (c.2.5-2.6 Ga) and BIF of the Dalli-Rajhara Group (~2.4 Ga). The Chandarpur Group consists of 15-20 m thick conglomerate and feldspathic sandstone at the basal part of the succession, which is mapped as a lateral equivalent of the Lohardih Formation. The coarse clastics, conglomerate succession gradationally passes up to ~280 m thick succession of supermature sandstone, the Kansapathar Formation. The thick mudstone dominated heterolithic unit, the Gomarda Formation and its lateral equivalent, the Chaporadih Formation is not present in the western part of the Chattisgarh basin. The fine siliciclastic-carbonate assemblage of the Raipur Group conformably overlies the Chandarpur Group. The Raipur Group consists of Charmuria Limestone (~320 m), Gunderdehi Shale (~450 m), Chandi Limestone (~ 550 m) with Deodongar Member (~50 m) and Tarenga Shale. The sediments of Chandarpur Group were deposited in a shallow marine environment with occasional fluvial input in a relatively fluctuating sea level. The palaeoshoreline was NW-SE oriented with an open sea towards north which remained same throughout the deposition of the Chandarpur-Raipur sequence. It has also been inferred that the Lohardih Formation and the Kansapathar Formation represents a rifting phase followed by a stable subsidence stage when the basin evolved into a large epicontinental sea. The sequences further display signatures of passive margin sedimentation with multiple events of carbonate-shale rhythmite deposition. 相似文献
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Recycling and chemical weathering in tectonically controlled Mesozoic–Cenozoic basins of New Zealand
P.L. CORCORAN 《Sedimentology》2005,52(4):757-774
Sedimentation in molasse basins is controlled by tectonics, however, recycling and chemical weathering play a critical role in the compositional evolution of a sedimentary succession. The Cretaceous to Pliocene molasse deposits of Central Otago, New Zealand are excellent examples of tectonically related deposits that were governed by the effects of chemical weathering and recycling. Preserved in fault-controlled basins floored by flysch deposits of the Otago Schist, the clastic successions contain ubiquitous unconformities and lithofacies consistent with alluvial, fluvial and lacustrine depositional settings. Textural analysis of Central Otago sandstones establishes a general quartz enrichment and increased mixing of angular and well-rounded quartz varieties up-section, consistent with a history of sediment recycling. Rare earth element (REE) patterns, which reflect upper crustal compositions, are similar for the flysch-type Otago Schist (Permian–Early Cretaceous), a palaeo-weathering profile, and the overlying molasse deposits. The development of quartz arenites is also consistent with high degrees of chemical weathering, and erosion of the schist basement, which contains numerous quartz veins. Although recycling has occurred, SiO2 and TiO2 do not consistently show a negative correlation over time. This reflects erosion of previously deposited quartz-rich sediment and the Otago weathering profile, which produced an inverse stratigraphy. CIA values range from 52 for lithic-rich, coarse-grained sandstones and polymictic conglomerate matrices, to 93 for coarse-grained to pebble-rich quartz arenites. Individual samples were split into finer- and coarser-grained pairs (<2·5φ and 2·5 to −1φ) and were analysed separately. The results show that finer-grained samples contain higher REE abundances and less SiO2, but the coarser-grained Miocene–Pliocene samples have higher CIA values than their finer-grained counterparts. These coarse-grained deposits are quartz-rich and plot erratically on tectonic discrimination diagrams, implying that using SiO2-poor samples is more reliable for geochemical analysis. Overall, the petrographic and geochemical results indicate that the main factors controlling the composition of the Central Otago molasse deposits were source composition, chemical weathering and recycling. Studies of this nature can be conducted in Archaean tectonically controlled molasse basins that are affected by similar allocyclic factors. 相似文献
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C. W. Kwon S.-I. Park J. Park J.-H. Oh B. C. Kim 《Australian Journal of Earth Sciences》2013,60(6):865-880
Sedimentological characteristics and zircon provenance dating of the Babulu Formation in the Fohorem area, Timor-Leste, provide new insights into depositional process, detailed sedimentary environment and the distribution of source rocks in the provenance. Detrital zircon sensitive high-resolution ion microprobe (SHRIMP) U–Pb ages range from Neoarchean to Triassic, with the main age pulses being Paleozoic to Triassic. In addition, the maximum deposition ages based on the youngest major age peak (ca 256–238 Ma) of zircon grains indicate that the basal sedimentation of the Babulu Formation occurred after the early Upper Triassic. The formation consists predominantly of mudstone with minor sandstone, limestone and conglomerate that were deposited in a deep marine environment. These deposits are composed of six lithofacies that can be grouped into three facies associations (FAs) based on the constituent lithofacies and bedding features: basin plain deposits (FA I), distal fringe lobe deposits (FA II) and medial to distal lobe deposits (FA III). The predominance of mudstone (FA I) together with intervening thin-bedded sandstones (FA II) suggest that the paleodepositional environment was a low energy setting with slightly basin-ward input of the distal part of the depositional lobes. Discrete and abrupt occurrences of thick-bedded sandstone (FA III) within the FA I mudstone suggests that sandstone originated from a collapse of upslope sediments rather than a progressive progradation of deltaic turbidites. This combined petrological and geochronological study demonstrates that the Babulu Formation in the Fohorem area of the Timor-Leste was initiated as a submarine lobe system in a relatively deep marine environment during the Upper Triassic and represents the extension of the Gondwana Sequence at the Australian margin. 相似文献
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Mrinal Kanti Roy Syed Samsuddin Ahmed Tapas Kumar Bhattacharjee Sultan Mahmud Md. Moniruzzaman Md. Masidul Haque Sudip Saha Md. Ismail Molla Pulin Chandra Roy 《Journal of the Geological Society of India》2012,80(3):409-419
The Dupi Tila Formation is composed of yellow to light brown medium to very fine moderately hard to loose sandstone, siltstone, silty clay, mudstone and shale with some conglomerates with clasts of petrified wood. The lithofacies of matrix supported conglomerate, trough cross bedded conglomerate, massive sandstone, trough cross bedded sandstone, planar cross bedded sandstone, ripple cross laminated sandstone-siltstone, flaser laminated sandstone-shale, lenticular laminated sandstone-siltstone-shale, parallel laminated sandstone-siltstone, wavy laminated shale, parallel laminated blue shale, and mudstone are delineated within this formation. Based on the grain size, sedimentary structures, water depth and genesis of individual facies, facies are grouped into three types of facies associations like (i) coarse-grained conglomerate facies association in relation to tractive current deposits of alluvial fan set up at the base of litho-succession (FAC), (ii) medium to fine-grained sandstone-siltstone-mudstone facies association or facies association in relation to strong tide (FAT) characterizing the middle part of litho-succession, (iii) very fine-grained sandstone-siltstone-mudstone facies association in relation to less frequent weak tide or heterolithic facies association (FAHL) characterizing upper part of litho-succession and shallow marine facies association (FASM) composing the uppermost litho-succession. Presence of gluconite indicates that the depositional environment was shallow to deep marine. The dominant paleoflow direction during the deposition of Dupi Tila Formation was toward southeast to southwestern direction. The rivers were of braided type at the piedmont alluvial depositional set up at the lower part, which later changed to estuarine-tidal flat type environmental set up in the middle part to upper part and paleo-environment was shallow marine in the uppermost part. 相似文献
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珠江口盆地珠一坳陷珠海组三角洲沉积特征 总被引：3，自引：0，他引：3
利用珠江口盆地珠一坳陷珠海组取心井、测井及地震资料,探讨了珠海组三角洲沉积的岩石相、沉积微相、沉积亚相特征及发育分布规律,分析了其岩电响应特征,进而建立岩电响应模式,并通过研究区井-震对比,建立了珠海组三角洲沉积的地震响应模型. 相似文献
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酒西盆地下白垩统下沟组重力流水下扇沉积 总被引：6，自引：1，他引：6
重力流水下扇由四种岩相组成:1.砾岩相,属水下碎屑流沉积;2.砾质泥岩相,是多成因的;3.砂岩相,系高密度浊流沉积;4.粉砂岩泥岩相,为低密度浊流和正常湖泊沉积。细分为十五种亚相。岩相的空间配置关系表明水下扇是由突变性洪水事件(和水下滑坡)-水下碎屑流-高密度浊流-低密度浊流的重力流系列形成。本文对重力流沉积从层序结构、沉积体形态、岩相变化和构造控制诸方面进行了探讨。 相似文献
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DONALD J. P. SWIFT PETER M. HUDELSON ROBERT L. BRENNER PETER THOMPSON 《Sedimentology》1987,34(3):423-457
The Upper Cretaceous (Campanian) Kenilworth Member of the Blackhawk Formation (Mesaverde Group) is part of a series of strand plain sandstones that intertongue with and overstep the shelfal shales of the western interior basin of North America. Analysis of this section at a combination of small (sedimentological) and large (stratigraphical) scales reveals the dynamics of progradation of a shelf-slope sequence into a subsiding foreland basin. Four major lithofacies are present in the upper Mancos and Kenilworth beds of the Book Cliffs. A lag sandstone and channel-fill shale lithofacies constitutes the thin, basal, transgressive sequence, which rests on a marine erosion surface. It was deposited in an outer shelf environment. Shale, interbedded sandstone and shale, and amalgamated sandstone lithofacies were deposited over the transgressive lag sandstone lithofacies as a wave-dominated delta and its flanking strand plains prograded seaward. Analysis of grain size and primary structures in Kenilworth beds indicates that there are four basic strata types which combine to build the observed lithofacies. The fine- to very fine-grained graded strata of the interbedded facies are tempestites, deposited out of suspension by alongshelf storm flows (geostrophic flows). There is no need to call on cross-shelf turbidity currents (density underflows) to explain their presence. Very fine- to fine-grained hummocky strata are likewise suspension deposits created by waning storm flows, but were deposited under conditions of more intense wave agitation on the middle shoreface. Cross-strata sets in this region are bed-load deposits that accumulated on the upper shore-face, in the surf zone. Lag strata are multi-event, bed-load deposits that are the product of prolonged storm winnowing. They occur on transgressive surfaces. While the graded beds are tempestites in the strict sense, all four classes of strata are storm deposits. The distribution of strata types and their palaeocurrent orientations suggests a model of the Kenilworth transport system driven by downwelling coastal storm flows, and probably by a northeasterly alongshore pressure gradient. The stratification patterns shift systematically from upper shoreface to lower shoreface and inner shelf lithofacies partly because of a reduction in fluid power expenditure with increasing water depth, but also because of progressive sorting, which resulted in a decrease in grain size in the sediment load delivered to successive downstream environments. The Kenilworth Member and an isolated outlier, the Hatch Mesa lentil, constitute a delta-prodelta shelf depositional system. Their rhythmically bedded, lenticular, sandstone and shale successions are a prodelta shelf facies, and may be prodelta plume deposits. Major Upper Cretaceous sandstone tongues in the Book Cliffs are underlain by erosional surfaces like that beneath the Blackhawk Formation, which extend for many tens of kilometres into the Mancos shale. These surfaces are the boundaries of Upper Cretaceous depositional sequences. The sequences are large-scale genetic stratigraphic units. They result from the arranging of facies into depositional systems; the depositional systems are in turn stacked in repeating arrays, which constitute the depositional sequences. The anatomy of these foreland basin sequences differs 相似文献
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基于野外地质露头观察、岩心描述、薄片鉴定和地球化学等分析测试资料的综合分析,对鄂尔多斯盆地及周缘地区上二叠统石千峰组沉积岩石类型、沉积构造、沉积相类型及沉积体系空间展布等方面开展研究。结果表明,石千峰组主要发育冲积平原、三角洲平原、三角洲前缘、浅湖和南部海陆过渡的潟湖、沙坝等沉积环境,石千峰期,古气候干燥炎热,沉积古地形相对平缓,物源供给充足,形成了一套紫红色、棕红色泥岩和浅灰色中粗粒长石岩屑砂岩、岩屑长石砂岩、长石砂岩为主的地层。盆地北部三角洲规模大,以辫状河道发育沉积特征为主,砂体厚度大、横向分布稳定,而盆地南部三角洲规模相对较小。石千峰期,海水可能多次入侵盆地南部麟游-韩城-乡宁一带,发育海相夹层和沙坝沉积,一定程度上影响了南部的沉积环境和砂体展布。 相似文献