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1.
The Western foreland basin in Taiwan originated through the oblique collision between the Luzon volcanic arc and the Asian passive margin. Crustal flexure adjacent to the growing orogenic load created a subsiding foreland basin. The sedimentary record reveals progressively changing sedimentary environments influenced by the orogen approaching from the East. Based on sedimentary facies distribution at five key stratigraphic horizons, paleogeographic maps were constructed. The maps highlight the complicated basin-wide dynamics of sediment dispersal within an evolving foreland basin.The basin physiography changed very little from the middle Miocene (∼12.5 Ma) to the late Pliocene (∼3 Ma). The transition from a passive margin to foreland basin setting in the late Pliocene (∼3 Ma), during deposition of the mud-dominated Chinshui Shale, is dominantly marked by a deepening and widening of the main depositional basin. These finer grained Taiwan derived sediments clearly indicate increased subsidence, though water depths remain relatively shallow, and sedimentation associated with the approach of the growing orogen to the East.In the late Pleistocene as the shallow marine wedge ahead of the growing orogen propagated southward, the proximal parts of the basin evolved into a wedge-top setting introducing deformation and sedimentation in the distal basin. Despite high Pleistocene to modern erosion/sedimentation rates, shallow marine facies persist, as the basin remains open to the South and longitudinal transport is sufficient to prevent it from becoming overfilled or even fully terrestrial.Our paleoenvironmental and paleogeographical reconstructions constrain southward propagation rates in the range of 5–20 km/Myr from 2 Ma to 0.5 Ma, and 106–120 km/Myr between late Pleistocene and present (0.5–0 Ma). The initial rates are not synchronous with the migration of the sediment depocenters highlighting the complexity of sediment distribution and accumulation in evolving foreland basins. 相似文献
2.
Gao Tianjun Bureau of Geology Mineral Resources of Fujian Province Fuzhou Fujianand Huang Hui Geoscience Institute of Fujian Province Fuzhou Fujian Jiang Minxi 《《地质学报》英文版》1995,69(1):1-13
The Taiwan Strait is a part of the continental-margin rift of eastern China, which can tectonically be divided into the Taiwan Strait basin, southwestern Taiwan basin and Penhu-Beigang uplift. The basins are structurally semi-graban down-faulted ones in character. The Cretaceous-Cenozoic sedimentary strata in the basins have a maximum thickness of over 10,000 m. The formation and development of the Taiwan Strait rift were not only affected by both the East China Sea basin and South China Sea basin but also closely related to the Central Range collision orogen of Taiwan. In the Cenozoic, the Taiwan Strait area experienced, under the influence of a multiple of tectonic mechanisms, three stages of evolution: poly-centre downfault-ing, down warping-faulting and foreland basin formation. The depositional centres of the basins migrated from west to east during the Tertiary, resulting in the thinning of the Palaeogene strata from west to east but that of the Neogene in the reverse direction. All this determine 相似文献
3.
Sébastien Castelltort Stefan Nagel Frédéric Mouthereau Andrew Tien-Shun Lin Andreas Wetzel Boris Kaus Sean Willett Shao-Ping Chiang Wei-Yi Chiu 《Journal of Asian Earth Sciences》2011,40(1):52-71
This work presents sedimentological observations and interpretations on three detailed sections of the Pliocene Yutengping/Ailiaochiao formations, deposited in the early stages of collision in Taiwan. Seven facies associations record paleoenvironments of deposition ranging from nearshore to lower offshore with a strong influence of tidal reworking, even in shelfal sub-tidal environments, and a pro-delta setting characterized by mass-flows. The association of shallow facies of the upper offshore to lower shoreface with pro-delta turbidite facies sourced in the orogen to the east suggests a peculiar setting in which turbidite deposition occurred below wave base but on the shelf, in water depths of probably less than 100 m. This adds to the examples of “shallow turbidites” increasingly commonly found in foreland basins and challenges the classical view of a “deep” early underfilled foreland basin. Time series analysis on tidal rhythmites allow us to identify a yearly signal in the form of periodic changes of sand-supply, energy and bioturbation that suggests a marked seasonality possibly affecting precipitation and sediment delivery as well as temperature. The Taiwan foreland basin may also present a potentially high-resolution record in shallow sediments of the early installation of monsoonal circulation patterns in east Asia. We confirm partly the paleogeography during the early stages of collision in Taiwan: the Chinese margin displayed a pronounced non-cylindrical geometry with a large basement promontory to the west in place of the modern Taiwan mountain range. Collision in Taiwan may have happened at once along the whole length of the modern mountain range, instead of progressively from north to south as classically considered. 相似文献
4.
Amir Kalifi Philippe Sorrel Philippe-Hervé Leloup Vincenzo Spina Bastien Huet Albert Galy Jean-Loup Rubino Bernard Pittet 《Sedimentology》2020,67(5):2455-2501
A comprehensive sedimentological study was undertaken in the Miocene of the subalpine massifs and southern Jura (France) with the aim to constrain the evolution of process changes in third-order sequences of peripheral foreland basins during the overfilled phase (i.e. sediment supply higher than accommodation space). Fieldwork analyses based on 35 sedimentological sections allowed the identification of four depositional models: wave dominated, mixed wave-tide, river to tide and river dominated. The sections were dated using chemostratigraphy (i.e. marine strontium isotopic ratios), revealing three-third-order sequences between the Upper Aquitanian and the Langhian. Chronostratigraphical and sedimentological results document prominent and recurrent changes in depositional models along third-order sequences: (i) in the earliest stage of the transgression, mixed-energy coastal environments influenced by the local coastal morphology prevailed (in palaeo-highs or incised valleys); (ii) during the course of the transgression, Gilbert delta deposits suggest a prominent steepening linked to a tectonic uplift in the proximal depozone (between the tectonically active frontal part of the orogenic wedge and the proximal foredeep). Instead, in the distal depozone (between the proximal foredeep and the proximal border of the flexural uplifted forebulge), deposits were characterized either by wave-dominated or mixed wave-tide environments and are likely eustatically-driven; (iii) during the maximum flooding stage, water depth remained shallow below the storm-weather wave base; and (iv) during the regression, the proximal depozone is characterized by the progradation of gravel-rich fan deltas. In the distal depozone, mixed wave-tide systems preceded the development of river to tidal depositional environments. These results were integrated and compared with facies models from other basin analogues worldwide. A model tackling the evolution of process changes within third-order sequences (of the overfilled phase) of foreland basins is proposed, thereby improving sequence stratigraphic predictions in foreland basins. 相似文献
5.
Andrew D. La Croix Jianhua He Valeria Bianchi Jiahao Wang Sebastian Gonzalez Jim R. Undershultz 《Sedimentology》2020,67(1):457-485
Interpretations of palaeodepositional environments are important for reconstructing Earth history. Only a few maps showing the Jurassic depositional environments in eastern Australia currently exist. Consequently, a detailed understanding of the setting of Australia in Gondwana is lacking. Core, wireline logs, two-dimensional and three-dimensional seismic from the Precipice Sandstone and Evergreen Formation in the Surat Basin have been used to construct maps showing the evolution of depositional environments through the Early Jurassic. The results indicate the succession consists of three third-order sequences (Sequence 1 to Sequence 3) that were controlled by eustatic sea level. The lowstand systems tract in Sequence 1 comprises braidplain deposits, confined to a fairway that parallels the basin centre. The strata were initially deposited in two sub-basins, with rivers flowing in different orientations in each sub-basin. The transgressive systems tract of Sequence 1 to lowstand systems tract of Sequence 3 is dominated by fluvio–deltaic systems infilling a single merged basin centre. Finally, the transgressive and highstand systems tracts of Sequence 3 show nearshore environments depositing sediment into a shallow marine basin. In the youngest part of this interval, ironstone shoals are the most conspicuous facies, the thickness and number of which increase towards the north and east. This study interprets a corridor to the open ocean through the Clarence–Moreton Basin, or the Carpentaria and Papuan basins, evidence of which has been eroded. These results challenge a commonly held view that eastern Australia was not influenced by eustasy, and propose a more dynamic palaeogeographic setting comprising a mixture of fluvial, deltaic and shallow marine sedimentary environments. This work can be used to unravel the stratigraphic relationships between Mesozoic eastern Australian basins, or in other basins globally as an analogue for understanding the complex interplay of paralic depositional systems in data poor areas. 相似文献
6.
Abraham Zelilidis 《Geological Journal》2003,38(1):31-46
The sediment distribution in three narrow, linear basins, two modern and one ancient, in Greece and Italy, was studied and related to changes in basin configuration. The basins are the Plio‐Quaternary Patras–Corinth graben, the Pliocene–Quaternary Reggio–Scilla graben and the middle Tertiary Mesohellenic piggy‐back basin. These basins were formed at different times and under different geodynamic conditions, but in each case, the tectonic evolution produced a narrow area in the basin where the water depth decreased dramatically, forming a strait with a sill. This strait divided the basin into major and minor sub‐basins, and the strait has a similar impact on sedimentary environments in all three basins, even though different depositional environments were formed along the initial basin axis. Predictions for the development of depositional environments in the two modern basins, especially in their straits, are based on the studied ancient basin. In the straits, powerful tidal flows will transport finer sediments to sub‐basins and trapezoidal‐type fan‐deltas will gradually fill up and choke the strait through time. In sub‐basins, according to basin depth, either deltaic (in the shallow minor sub‐basin) or turbiditic (in the deep major sub‐basin) deposits may accumulate. Moreover, an extensive shelf is likely to develop between the strait and major sub‐basin. This shelf will be cross‐cut by canyons and characterized by thin fine‐ to coarse‐grained deposits. These sediment models could be applied to analogous basin geometries around the world. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
7.
A stratigraphic motif observed in many foreland basins is the development of basinward tapering siliciclastic wedges characterized by various scales of depositional cycles. The Middle Devonian (Givetian) Mahantango Formation in the central Appalachian foreland basin is such an example. It consists of both small-and large-scale thickening- and coarsening-upward cycles; the small-scale cycles are typically less than 10 m thick whereas larger-scale cycles are generally a few tens of metres thick and commonly contain several of the smaller-scale cycles. Outcrop-based facies analyses indicate that the depositional cyclicity resulted from episodic progradation of a regionally straight, tide-dominated shoreline onto a storm-dominated, shallow marine shelf. The depositional model for this ancient shallow marine system consists of a vertical facies succession in which storm-dominated offshore marine mudstone and fine sandstone pass gradationally upward into storm-dominated nearshore marine shelf and shoreface sandstone overlain by, in proximal sections, tide-dominated shoreline sandstone, pebbly sandstone and mudstone. Transgressively reworked lag deposits cap most of the thickening- and coarsening- upward packets. In this model, coarse-grained rocks, rather than implying basinward shifts of facies, are a consanguineous part of the stacked shoaling cycles. Lateral facies relationships show that the dominance of storm- vs. tide-generated sedimentary features is simply a function of palaeogeographical position within the basin; proximal sections contain tidally influenced sedimentary features whereas more distal sections only display evidence for storm-influenced deposition. These results suggest caution when inferring palaeoceanographic conditions from sedimentological datasets that do not contain preserved examples of palaeoshorelines. 相似文献
8.
秦岭造山带以商丹断裂带为界分为南秦岭和北秦岭。南秦岭在早古生代是扬子板块的被动大陆边缘,在志留纪末曾因垂向隆升变为古陆。因其南缘长期处于地幔上涌的构造薄弱带,所以到泥盆纪首先从这里开始扩 张,并逐渐演化成有限洋盆,与扬子板块分离,成为独立的板块,内部也因拉张形成裂陷盆地与块断隆起相间的环境格局。其自南而北依次为安康古陆→旬阳-镇安盆地→小磨岭古陆→刘岭盆地。在盆地内堆积了从陆相到海相,从浅水到深水的各种沉积体系,组成向上变细和变深的充填序列。而在北侧,该板块仍在向华北板块下面俯冲。北秦岭南缘的弧前沉积体系记录了这种俯冲作用的演化。这种与早古生代十分不同的古地理格局标志秦岭造山带已进入了新的演化阶段。 相似文献
9.
Stratigraphic patterns and sequence development in tectonically active extensional basins remain poorly documented in comparison with passive‐margin settings. Rift basin fills are generally characterized by coarsening‐upward trends in response to the rapid creation of accommodation by extensional faulting, and the progressive filling of graben during more quiescent periods. The Early Permian Irwin River Coal Measures in the Northern Perth Basin (Western Australia) record a complex stratigraphic arrangement of conglomerate, sandstone, mudstone and coal, and have been attributed to delta plain depositional environments that developed in a cool–temperate climatic setting during syn‐rift activity. Sedimentary analysis of outcrop and core data from the fault‐bounded Irwin Terrace is used to distinguish nine facies associations reflecting deposition in braided rivers, fixed‐anastomosed channel belts, tide‐influenced coastal environments and storm‐affected distal bays. The broader depositional system is interpreted as a morphologically asymmetrical tide‐dominated embayment with a fluvial and wave influence. The stratigraphic architecture of the Irwin River Coal Measures was strongly influenced by the evolving rift basin margin. Fault reactivation of the major basin‐bounding Darling Fault in the early syn‐rift phase caused footwall uplift and the inception of transverse palaeo‐valleys occupied by braided fluvial systems. Fault block subsidence during the subsequent balanced, backstepping and drowning phases resulted in a dominantly retrogradational stacking pattern indicating progressive flooding of marginal‐marine areas and culminating in deposition of distal marine elements. In the active rift basin, it is proposed that preservation of a shallow‐marine syn‐rift sequence was promoted by the geomorphological confinement of the embayed system increasing tidal current acceleration and hampering transgressive ravinement. The proposed sequence model demonstrates that transgressive successions can develop in the early syn‐rift phase in response to footwall uplift and tectonic subsidence. The syn‐rift sequence recording the filling of an embayment on a rift basin margin may be applied in similar tectonic and/or depositional contexts worldwide. 相似文献
10.
裂陷盆地蕴含丰富的油气资源,盆地不同演化阶段发育独特的地层结构样式及其砂体成因类型,形成各具特色的油气藏系统。近年来湖盆初始裂陷层系不断获得油气勘探突破,使之成为石油工业界重要关注对象,其多级次断裂演化、组合关系、地貌特征及其与水系和沉积响应关系已成为当前地质学领域关注的热点科学问题。蒙古塔南凹陷下白垩统铜钵庙组良好记录了一套初始裂陷沉积序列,丰富的钻井及地震资料使之可作为理想的研究对象。综合利用地震、岩心及测录井资料,在构造—沉积学理论指导下重建了塔南凹陷初始裂陷构造—沉积演化及源—汇响应模式。研究表明,塔南凹陷初始裂陷第一阶段以新生的分割型小洼陷群为特征,与前裂陷阶段“高山深谷”地貌背景联控下形成短距离输送且数量众多的小型扇群;初始裂陷第二阶段伴随控洼断层长度的迅速增加发生软联结,形成连通且宽浅的盆地结构,发育多套低坡降构造转换带（面积大于50 km2）和西北侧缓坡带（延伸约28 km）供给型大套扇三角洲体系,长轴及陡坡方向水系运输距离较短。实例解析结合调研结果表明,先存水系和盆地地貌结构联合控制初始裂陷盆地源—汇系统,进而形成初始裂陷第一阶段盆地满盆富砂（沟通先存水系）或欠补偿（不沟通先存水系）,年轻短程水系主导的孤立小湖盆群则主要发育小规模近源碎屑沉积物;初始裂陷第二阶段源—汇系统则与该时期断裂体系联结方式有关:断裂晚期联结型湖盆主要发育以短程断崖或小型转换带水系为特征,而断裂早期联结型湖盆形成大型构造转换带水系及三角洲体系,其缓坡带长度亦快速增大,盆地整体具有“富砂”特征。本研究为其他裂陷盆地寻找大型优质砂体提供了科学理论依据。 相似文献
11.
Seyyedeh Halimeh Hashemi Azizi Payman Rezaee Mahdi Jafarzadeh Guido Meinhold Seyyed Reza Moussavi Harami Mehdi Masoodi 《Chemie der Erde / Geochemistry》2018,78(3):340-355
In Central Iran, the mixed siliciclastic?carbonate Nakhlak Group of Triassic age is commonly seen to have a Cimmerian affinity, although it shows considerable resemblances with the Triassic Aghdarband Group in far northeastern Iran, east of Kopeh-Dagh area, with Eurasian affinity. The Nakhlak Group is composed of the Alam (Late Olenekian?Anisian), Baqoroq (Late Anisian??Early Ladinian), and Ashin (Ladinian??Early Carnian) formations consisting mainly of volcanoclastic sandstone and shale and fossiliferous limestone. The Baqoroq Formation contains also metamorphic detritus. Sandstone petrofacies reflect the detrital evolution from active volcanism to growing orogen and again active volcanism. Textural and modal analyses of volcanic lithic fragments from the Alam Formation reflect the eruption style and magma composition of a felsic to intermediate syn-sedimentary arc activity. The detrital modes of the Baqoroq Formation sediments suggest a recycled orogenic source followed by arc activity in a remnant fore-arc basin. The sandstone samples from the Ashin Formation demonstrate a continuity of felsic to intermediate arc activity. Major and trace element concentrations of the Nakhlak Group clastic samples support sediment supply from first-cycle material and felsic magmatic arc input. The enrichment in LREE, the negative Eu anomalies, and the flat HREE patterns indicate origination from the old upper continental crust and young arc material. The chemical index of alteration (CIA ～51–70 for sandstone and 64–76 for shale samples) indicates medium degrees of chemical weathering at the source. Petrographical and geochemical evidence together with facies analysis constructed the following depositional conditions for the Nakhlak Group sediments: In the Olenekian, a fore-arc shallow to deep marine depositional basin developed that later was filled by recycled and arc-related detritus and changed into a continental basin in the Anisian. Ladinian extension let to a deepening of the basin. With respect to the similarities between the Nakhlak and Aghdarband (NE Iran) groups and unusual present-day position of the Nakhlak Group with no stratigraphic connection to the surrounding area, the development of first a fore-arc basin and later change into a back-arc depositional basin in close relation with the Aghdarband basin at the southern Eurasian active margin in the Triassic are here proposed. Understanding the basin development recorded in the Nakhlak Group provides constraints on the closure history of Palaeotethys and of the tectonic evolution of early Mesozoic basins at the southern Eurasian margin before the Cimmerian Orogeny. 相似文献
12.
Provenance record of late Maastrichtian–late Palaeocene Andean Mountain building in the Amazonian retroarc foreland basin (Madre de Dios basin,Peru) 
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下载免费PDF全文 Mélanie Louterbach Martin Roddaz Pierre‐Olivier Antoine Laurent Marivaux Sylvain Adnet Julien Bailleul Elton Dantas Roberto Ventura Santos Farid Chemale Jr Patrice Baby Caroline Sanchez Ysabel Calderon 《地学学报》2018,30(1):17-23
Biostratigraphic, sedimentological and provenance analyses suggest that a proto‐Andean Cordillera already existed in southern Peru by late Maastrichtian–late Palaeocene times. A 270‐m‐thick stratigraphic section shows changes in depositional environments from shallow marine (early Maastrichtian) to non‐marine (late Maastrichtian) then back to estuarine (late Palaeocene) conditions. An erosional surface separates lower Maastrichtian from upper Maastrichtian deposits. Above this surface, the late Maastrichtian unit exhibits moderately developed palaeosols and syn‐sedimentary normal faults. The sedimentary evolution is accompanied by a decrease in sedimentation rate and by changes in provenance. Shallow marine lower Maastrichtian deposits have a cratonic provenance as shown by their low εNd(0) values (?15 to ?16) and the presence of Precambrian inherited zircon grains. The upper Maastrichtian deposits have a mixed Andean and cratonic origin with εNd(0) values of ~12.6 and yield the first Cretaceous and Permo‐Triassic zircon grains. Estuarine to shallow marine upper Palaeocene deposits have an Andean dominant source as attested by higher εNd(0) values (?6 to ?10) and by the presence of Palaeozoic and Late Cretaceous zircon grains. The changes in depositional environments and sedimentation rates, as well as the shift in detrital provenance, are consistent with a late Maastrichtian–late Palaeocene period of Andean mountain building. In agreement with recently published studies, our data suggest that an Andean retroarc foreland basin was active by late Maastrichtian–late Palaeocene times. 相似文献
13.
秦岭造山带泥盆系热水沉积岩相应用研究及实例 总被引：9，自引：0，他引：9
构造-热水沉积岩相与盆地的古地理环境,热水沉积岩相与热水沉积成矿,热 (水 )流体岩相与构造背景、构造古地理,它们之间有密切地内在联系.应用热水沉积岩相、沉积相及沉积体系分析方法,对凤县铅硐山-双石铺三级构造热水成矿盆地进行研究. 相似文献
14.
Pindos foreland basin in west Peloponnesus (Tritea, Hrisovitsi and Finikounda sub‐basins) during Late Eocene to Early Oligocene was an underfilled foreland basin. The basin's geometry was affected by the presence of internal thrusting and transfer faults, causing changes in depth and width. Due to internal thrusting, the foreland basin changed through time from a uniform to non‐uniform configuration, whereas transfer faults have an intensive impact on depositional environments within the basin. Internal thrusting (Gavrovo, internal and middle Ionian thrusts) activated synchronously with the major Pindos Thrust, creating intrabasinal highs that influenced palaeocurrent directions. The transfer faults cross‐cut the intrabasinal highs and produced low relief areas that act as pathways for sediment distribution. The sediments are thicker and sandstone‐rich on the downthrown sides of the transfer faults. In these areas, sandstone reservoirs could be produced. Such tectonically active areas constitute promise for oil and gas reservoirs and traps. 相似文献
15.
A marked increase in manganese content from shallow to deep marine lithofacies can be observed within the carbonate fraction of the Middle Ordovician sequence in eastern Tennessee. The distribution of manganese is controlled by: (1) the original aragonite and calcite mineralogy of shallow and deep marine environments, respectively; (2) preferential substitution of manganese for calcium in the rhombohedral structure of calcite; (3) anoxic depositional and diagenetic environments; and (4) possibly, volcanism. 相似文献
16.
17.
Extensive deposition of marine evaporites occurred during the Early–Middle Eocene in the South‐eastern Pyrenean basin (north‐east Spain). This study integrates stratigraphic and geochemical analyses of subsurface data (oil wells, seismic profiles and gravity data) together with field surveys to characterize this sedimentation in the foredeep and adjacent platform. Four major evaporite units were identified. The oldest was the Serrat Evaporites unit, with a platform‐slope‐basin configuration. Thick salina and sabkha sulphates accumulated on the platform, whereas resedimented and gravity‐derived sulphates were deposited on the slope, and salt and sulphates were deposited in the deep basin. In the subsequent unit (Vallfogona evaporites), thin sulphates formed on the platform, whereas very thick siliciclastic turbidites accumulated in the foredeep. However, some clastic gypsum coming from the platform (gypsarenites and gypsum olistoliths) was intercalated in these turbidites. The following unit, the Beuda Gypsum Formation developed in a sulphate platform‐basin configuration, where the topography of the depositional surface had become smooth. The youngest unit, the Besalú Gypsum, formed in a shallow setting. This small unit provides the last evidence of marine influence in a residual basin. Sulphur and oxygen isotope compositions are consistent with a marine origin for all evaporites. However, δ34S and δ18O values also suggest that, except for the oldest unit (Serrat Evaporites), there was some sulphate recycling from the older into the younger units. The South‐eastern Pyrenean basin constitutes a fine example of a foreland basin that underwent multiepisodic evaporitic sedimentation. In the basin, depositional factors evolved with time under a structural control. Decreasing complexity is observed in the lithofacies, as well as in the depositional models, together with a diminishing thickness of the evaporite units. 相似文献
18.
若尔盖-松潘盆地中、上三叠统沉积剖面研究表明以陆相沉积为主,只在东北部青山峪有浅海相碳酸盐岩沉积。盆地北部出现河流、浅湖相沉积,中部以浅湖相沉积为主,局部出现深湖相沉积,南部主要为深湖相沉积。中、上三叠统地层的变形构造以冲褶席(duplex)构造为特点,表现出从北向南应变强度减弱。深部构造反映了盆地位于扬子板块大陆壳基底之上,叠覆在扬子板块北缘的前陆褶皱冲断带上。大地构造位置、沉积相与构造特点,共同说明若尔盖-松潘盆地是三叠纪碰撞造山作用时期扬子板块北部北缘的前陆盆地。 相似文献
19.
非海相沉积层序的成因和构型特征 总被引：4，自引：2，他引：4
根据东部盆地的地质、地球物理特征,初步对非海相层序地层学应用研究进行了总结.非海相沉积层序的形成要素,既有外旋回、又有自旋回,构造和气候因素很重要,强调了环境因素.沉积基准面在海上为海平面,在陆上为潜水面、湖平面、河流平衡剖面.相对基准面的周期性变化引起了可容纳空间的周期性变化,并由之形成了一系列旋回式的层序.大多数情况下内陆基准面的变化不受海平面变化的控制,在全球最大海泛期有某种联系.湖盆小而沉积速率高,形成层序的频率高于海相.以沾化凹陷为依据,提出了5种层序构型特征:冲积-河湖型,(半)盐湖-淡水湖泊过渡型,海流-深湖型,半深湖-缓坡型,河流-冲积平原型.在盆地主要发育期,断阶式坡折对沉积体系有明显的控制作用.除低水位扇外,低水位楔是构成隐蔽圈闭或复合圈闭的有利场所。 相似文献
20.
前陆盆地挠曲沉降和沉积过程3D模型研究 总被引：1，自引：0，他引：1
前陆盆地是在造山带负荷作用下岩石圈发生挠曲沉降而形成的,并且被主要从造山带搬运的沉积物所充填。为了更好地理解和认识前陆盆地的形成演化机制,特别是受控于周缘多个造山带活动所形成的前陆盆地的演化机制,本文通过建立前陆盆地挠曲沉降与沉积过程的3-D模型,模拟展示了造山带逆冲推覆作用、岩石圈挠曲沉降响应及在山盆体系中由于动力地形变化而导致的河流体系的发育变化及其产生的剥蚀和沉积过程。模型的建立和实验完整体现了逆冲推覆、弹性挠曲沉降和沉积物搬运这三者之间的耦合机制,为全面深入研究前陆盆地动力学提供了理论依据和方法。 相似文献