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三江平原沼泽发育与晚更新世末期以来古地理环境演变的研究 总被引：6，自引：2，他引：6
本文根据沼泽剖面的 ~(14)C测年、孢粉分析、粘土矿物X-衍射分析、植物残体鉴定和沉积物化学元素资料,研究了晚更新世末期以来三江平原沼泽发育与古地理环境演变。结果表明,沼泽发生及其发展与古地理环境演变有极其密切的关系。可分为四个时期:晚更新世末期沼泽孕育期,早全新世沼泽萌芽发育期,中全新世沼泽旺盛发育期,晚全新世沼泽继续扩大发育期。距今11000年左右应为本区晚更新世与全新世的分界。腐泥层底是全新统的下界。同江县勤得利农场十九队、抚远县创业队沼泽剖面可作为本区全新世的标准剖面。泥炭积累速率为晚全新世>早全新世>中全新世。 相似文献
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中国北方全新世泥炭形成的初步研究(英文) 总被引：5，自引：0，他引：5
周昆叔 《海洋地质与第四纪地质》1985,(4)
本文指的中国北方主要是包括华北和东北地区.该区泥炭分布较多,其中东北区多于华北区.据初步调查,东北区分布有裸露泥炭沼泽200多万公顷,埋藏泥炭约3万公顷,泥炭总储量约150多亿吨;华北区有裸露泥炭沼泽0.5万公顷,大部为埋藏泥炭,泥炭总储量约3亿多立方米.本区裸露与埋藏泥炭分布界线,大致是从辽宁省东南的岫岩以东起,经本溪、抚顺、西丰、伊通、双阳、榆树、巴彦、绥化、海伦、依安、富峪至科尔沁右旗,此线东北基本上为裸露泥炭沼泽分布区,而此线西南,主要为埋藏泥炭分布区,此线附近呈过渡状态.孢粉分析反映本区蕴藏泥炭的全新世地层古气候有三个演变过程,即从早期较冷较干,或较冷较湿,变得温暖潮湿,随后气温又变得偏凉偏干.古气候的演变导致沉积环境的变更,致使沉积相有三次较大的演变旋回,这在华北平原和沿海平原表现得尤为突出.在华北平原,全新世早期以河湖相为主,中期湖沼相普遍发育,晚期以冲积和洪积为主;在沿海平原某些地段,全新世早期为海陆过渡相,中期为海相,晚期又为海陆过渡相.北京和辽南一些地点泥炭自早全新世就开始沉积,东北平原中南部的泥炭多在中全新世形成,但都多在距今两千年左右被砂粘土或黄土状物质等埋藏.长白山、小兴安岭有的泥炭自中全新世沉积,但不少自晚全新世才开始沉积,均延 相似文献
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我国沿海地区的埋藏泥炭及其形成的古地理 总被引：2，自引：0，他引：2
我国东部沿海地区,位于北纬18°12′—42°间欧亚大陆的东岸,面向太平洋,受海洋影响,是泥炭比较丰富的地区。本区的泥炭大多是全新世12000年来形成的,如今多数已被泥砂掩埋,属于埋藏泥炭。 本区毗邻海洋,泥炭的生成与分布同海洋有关。由于海洋性气候降水较多,湿度较大,对发育沼泽、堆积泥炭是较有利的。但我们认为本区泥炭比较丰富的主要原因,是由于海洋水体对陆地水的水力影响。而它们在空间与时间上的分布特征,则是海面在全新世有过较大幅度的升降,引起沿海地区海进、海退造成的。 本区埋藏泥炭的上覆盖层不厚,一般1—2米,容易开采。可制做各种腐植酸肥料,促进农业生产发展。此外,泥炭对研究第四纪具有十分重要的地位。因此,研究本区泥炭有着重要的经济意义与理论意义。 相似文献
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莱州湾东岸的地貌发育 总被引：3，自引：1，他引：3
在地球发展史的最新一页——全新世里,最大的地质事件不过于全球性的最后一次冰期已进入结束阶段,海平面上升到达目前的高度、海侵达到最盛时期。根据渤海海底钻探揭示,在最后一次海侵到达这里之前,它是一个内陆洼地,发育了淡水沼泽泥炭沉积层。渤海海侵在距今八千年左右发生,海水自渤海海峡进入。在渤海中部、3—5米厚的海相砂质软泥直接覆盖在陆相洼地和沼泽相之上。海侵引起了海岸线的巨大变迁,发育了一系列新的侵蚀和堆积地貌。 相似文献
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全新世时期的海岸层序产生了沼泽和由一系列淤泥和泥炭控制的泥滩，一般仅在横向狭窄体(如潮沟充填物，海岸砂坝)中含有砂和砾石。在全新世时间尺度上，最新的沉积是不易被压缩的，但是淤泥(特别是含有合适比例植被成分的)，当然还有泥炭，它们的自压实程度则可能被忽视。自压实盐沼地貌形态动力学、海平面研究、全新世地层和考古学、以及海岸管理方面都很有意义。 相似文献
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论中全新世的一次海面下落 总被引：1，自引：0，他引：1
多年来,学术界一直认为中全新世时期为冰后期(全新世)气候最温暖时期,特称之为“适宜期”或者“高温期”(Optimum,altithermal,hypsithermal);与此同时,还认为在“高温期”曾出现过中全新世“高海面”,在一些大洋岛屿沿岸地带形成了一级阶地,被称为“戴利阶地”(Daly levels)或“戴利岸线”。关于“戴利阶地”,在60年代后期及70年代,经一些学者研究表明,有的地方它与局部的构造上升有关,在另一些地方它可能是更早时期(如上次间冰期)高海面的产物。但关于是否存在比今海面还要高几米的中全新世高海面问题,至今还有不同的看法。有 相似文献
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根据 2个典型沼泽剖面的1 4 C测年、孢粉分析、粘土矿物X衍射分析、泥炭植物残体鉴定获得的信息 ,综合对比分析和相互印证 ,探讨了全新世以来小兴安岭东部沼泽发育过程与古地理环境演变过程。小兴安岭东部全新世气候变化、植被演替和森林沼泽形成与发育均相应可划分为 6个时期 ,气候变化为 :寒冷较湿 ( 90 0 0— 830 0aB .P .)→温和略湿 ( 830 0— 680 0aB .P .)→温暖湿润 ( 680 0— 30 5 0aB .P .)→温凉较湿 ( 30 5 0— 2 35 0aB .P .)→冷凉湿润 ( 2 35 0— 0aB .P .)→温凉湿润 (现代 ) ;植被演替为 :针叶林→阔叶林或针阔混交林→以栎、榆、胡桃为主阔叶林→以桦为主阔叶林或以松为主的针阔混交林→以松为主的针阔混交林→针阔混交林和次生林 ;沼泽形成和发育为 :富营养沼泽孕育期→富营养沼泽萌发期→富营养沼泽旺盛、中营养沼泽孕育期→富营养沼泽扩大、中营养沼泽形成期→富营养和中营养沼泽继续扩大、贫营养沼泽形成期→沼泽退化期。最早形成始于 ( 70 95± 90 )aB .P .。贫营养、中营养和富营养沼泽最早发育时间分别为 1 60 0aB .P .、40 0 0aB .P .和 70 95aB .P . 相似文献
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太湖的形成和演变过程 总被引：21，自引：0，他引：21
洪雪晴 《海洋地质与第四纪地质》1991,(4)
本文从沉积学、地层学、地貌学、考古学和历史地理学角度,综合分析了太湖的成因和演变。认为地壳沉降与海面上升是构成江南碟形洼地的内外动力,为太湖的形成奠定了基础。全新世海侵最盛时,太湖海湾水深潮急、泻湖、滨海沼泽围绕海湾分布。随南部湾口沙嘴封堵,海湾趋于消失,陆地扩大,遗址增多。3700a来,海面回升,湖面逐渐扩展,形成现代太湖。 相似文献
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Edward J. Anthony 《Marine Geology》1989,90(4):297-309
The coast of northern Sierra Leone, between the Scarcies and Mellacoree estuaries, forms a prograding muddy Holocene plain comprising two separate, as yet undated, clusters of sand cheniers. The general coastal morpho-stratigraphy and available data on regional climatic and sealevel history suggest that alternations between muddy progradation and chenier cluster formation have been controlled by a probable conjunction of several factors, including the local geomorphic framework, a climatically induced change in mud supply, and relative sealevel oscillations since the middle Holocene. The inner chenier cluster was apparently elaborated under conditions of efficient wave action over a deep, largely unfilled Mellacoree estuary and at a time of reduced mud availability. It peters out seaward, probably in response to several factors, including an increase in mud supply from the upland, a negative sealevel pulse resulting in higher rates of mud export from accreted inner tidal flats, increased muddy sedimentation over a shallower nearshore zone, and attenuated wave action as a result of energy capture by accreted estuarine shoals. The outer cluster, which partly fringes the coast, was formed in a mayor embayment representing the terminus of longshore sand drift. It is suggested that its formation may have been favoured by a higher sealevel resulting in efficient winnowing of sands from subtidal muds, a greater propensity for accretion of tidal flats landwards and, consequently, a lower mud supply to the foreshore.
Although the timing of muddy progradation and chenier formation has not been determined, the foregoing interpretation suggests a complex sequence of events, reflecting as much the influence of local morphodynamic factors as external factors. 相似文献
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西冈位于盐城市西部,是全新世海侵时代的产物,也是盐城市境内成陆最早的陆地。本文通过对全新世以来海面变化、西冈的地貌形态、沉积特征、形成条件等方面的研究,探讨全新世海侵对西冈古砂堤形成的影响以及苏中地区海岸的演变规律。 相似文献
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《Marine Geology》2006,225(1-4):63-84
This paper examines the role of peat compaction as a driving mechanism behind the widespread inundation of a late Holocene coastal wetland in southeast England, UK. Detailed stratigraphic and dating evidence (lithology, grain size, foraminifera, pollen and radiocarbon dates) from a sample site in Romney Marsh documents the gradual inundation of a coastal wetland after 1263–1085 cal. yr BP (c. 700–850 AD) and the establishment of a saltmarsh. Shortly thereafter there was a rapid increase in water depth that was associated with the deposition of nearly 4 m of laminated intertidal mudflat and tidal channel sediments, prior to site reclamation from the sea by AD 1460. Grain-size data and statistical analysis of sand and mud laminae thicknesses suggest the laminated sediments accumulated rapidly (c. 0.2 m per year) as heterolithic tidal rhythmites. Rapid compaction of the thick peat bed that underlies the study site provided the accommodation space for their deposition. This process began with the gradual tidal inundation of the site, but accelerated following the widening of a breach in a coastal barrier in the 13th century. Compaction lowered the peat surface by at least 3 m and was associated with widespread landscape change. The study demonstrates the powerful influence that compaction had on the evolution of the late Holocene landscape at this site and, we believe, at many other coastal lowlands in northwest Europe. This process is likely to have been a key driving mechanism behind rapid late Holocene coastal change, far exceeding the longer-term effects of either eustatic change or crustal uplift/subsidence. 相似文献
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Sea ingressions have happened twice in the Bohai Gulf since the Holocene. In the Mid-Holo-cene (about 6000 yrs BP) the sea reached the farthest inland and flooded the area about 4 meters ASL. Later, the seawater retrograded gradually and formed a coastal plain. It was once again submerged about 2000 BP, resulting in the submergence of large-scale cultural remains at about 2.5-3 m ASL from the Warring States to the Western Han Dynasty by marine accumulations, or the overlap of peat and clay layers of continental facies by the coastal dunes about 3000 BP. 相似文献
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莱州湾东部滨海水域第四纪沉积及古地理特征 总被引：5，自引：0，他引：5
本文通过对６个钻孔和４６１ｋｍ浅层地震剖机测量获得的测年、微古、孢粉、藻类、古地磁以及岩持征和地震反射界面等资料的综合分析，将本区第四系划分为中更新统、上更新统和全新统，对各时期的沉积进行了较详细的阐述，并对不同时期的沉积相特征和古地理环境的变化进行了初步地揭示。 相似文献
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High-resolution Reconstruction of a Holocene Coastal Sequence (NW Germany) Using Inorganic Geochemical Data and Diatom Inventories 总被引：1，自引：0，他引：1
O. Dellwig F. Watermann H. -J. Brumsack G. Gerdes 《Estuarine, Coastal and Shelf Science》1999,48(6):617
Holocene deposits of the NW German coastal plain consist of many different lithological facies, for example tidal flats, brackish water sediments and peat beds. The effects of the Holocene sea-level rise on palaeoenvironmental conditions of this coastal sequence were studied by inorganic geochemical methods in conjunction with diatom analyses. Three hundred samples from two parallel sediment cores which cover the entire NW German Holocene were taken at high resolution and were examined for major and minor elements and bulk parameters. Selected samples were analysed for redox-sensitive trace elements and REE distribution, reactive iron and bulk sediment34S/32S-ratios. Chemical parameters, for example Si/Al and Ca/Sr-ratios and total organic carbon (TOC) contents correlate with depositional factors such as wave-energy and lithofacies changes, which allow a detailed reconstruction of the palaeoenvironment. Diatom analyses reveal information about changes between marine, brackish and limnic conditions and serve to reconstruct palaeosalinity. Early diagenetic effects are evident in the TOC-rich intervals. Most peat layers are affected by sulphate reduction and resulting pyrite formation as well as by enrichments in redox-sensitive trace elements. The highest enrichments are seen for As, Mo, Re and U, indicating a distinct seawater influence. S-isotope ratios of peat samples are compatible with pyrite formation under both open- and closed-system conditions, depending on exposition to seawater. The inorganic geochemical and diatom data suggest limnic conditions at the base of the sequence and repeated changes towards marine conditions within the overlying clastic units. On the other hand, data obtained from the clastic units yield evidence of a recurrent succession from open to restricted marine, brackish-lagoonal, and finally fen environments. Clastic sediments overlying peat layers, correlate with the increase of marine-derived geochemical signatures and pelagic diatoms attest transgressive overlaps. The analyses suggest that major controls on the palaeoenvironments were (i) climate-related oscillations of the coast line and (ii) the morphology of the coastal region allowing marine incursions even into distal semi-terrestrial lowlands. 相似文献
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全新世泥炭古气候记录研究进展 总被引：9，自引：2，他引：9
以年代标尺和古气候代用指标的建立为线索，总结了国内外近年来对全新世泥炭沉积古气候记录研究取得的最新进展，展望了未来泥炭古环境记录研究的前景，指出在建立可靠年代标尺和可靠环境代用指标过程中存在的一些急需解决的问题，如年代标尺与环境代用指标序列的协调问题，提出在泥炭剖面年代标尺建立过程中有必要分析环境代用指标，选取合适的组分进行测年。最后，作者指出用泥炭沉积进行全新世大气环境示踪研究具有较好的前景和重要的意义。 相似文献
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海南岛红树林泥炭的海侵成因研究及其意义 总被引：6，自引：0，他引：6
本文在海南岛全新世红树林泥炭及其含沉积特特征，形成环境详细研究的基础上，对比会南晚更新世以来的海平面变化，综合分析得出：红树林泥炭形成于泥炭坪相；晚更新世晚期－全新世的快速海侵为含炭沉积的形成提供了古地理背景；红树林泥炭发育于４０００ａ以来的海平面波动上升时期；泥炭坪的发育主要取决于海平面的上升速度和植物有机质的堆积速度。海南岛全新世海侵成碳的研究为华北晚古生代含煤建筑的解释提供了比较沉积学的论据 相似文献
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