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1.
白洋淀流域特殊地貌--撞击成因与相关问题的探讨 总被引：2，自引：0，他引：2
(1)白洋淀流域特殊地貌和撞击成因：近年来使用GIS方法在河北平原地区做历史地貌研究时,在白洋淀流域区发现一种特殊的地貌现象,暂称之为“碟形洼地”(图1)。这种奇特的地貌在1926年出版的顺直地形图上显示清楚,使用这种早期的地形图,可以较好地分析原始地貌的特征。结合部分航空照片研究,并利用数字高程模拟的方法(DEM)综 相似文献
2.
喀斯特地区流域地貌与岩性的统计关系探讨——以贵州省为例 总被引：12，自引：3，他引：9
岩石是地貌演化发育的物质基础,不同的岩性分布区常常发育特定的地貌形态。本文统计分析了喀斯特地区22 个中小流域的地貌类型和岩石的出露关系,从量上揭示了流域地貌与岩性的关联规律。分析结果表明:在碳酸盐岩出露的地区常发育着峰丛洼地;在碳酸盐岩夹碎屑岩出露地区易于形成峰丛谷地;在非碳酸盐岩出露地区发育形成非喀斯特地貌;而在峰林谷地和非喀斯特地貌分布区常有松散岩出露。 相似文献
3.
新疆开都河流域主要地貌形态特征研究 总被引：1，自引：0，他引：1
自然环境组成要素中没有一个要素与地貌形态无相互影响,人类的任何一个生产活动也与地貌形态具有密切联系.以新疆开都河流域地貌形态为研究对象,探讨流域尺度地貌形态类型、不同地貌形态的空间变异特征.在开都河流域实地考察、制图分析、对地貌形态分类和测定不同地貌类型的面积和相对高度、各地貌类型相互影响的数据基础上,采用地貌类型学和地统计学的方法,对研究区的地貌形态进行了制图分类及其特征变异分析,并采用GIS定位测定方法,做出开都河流域的地貌类型空间数字地图.结果表明:开都河流域地貌形态复杂多样,虽然开都河流域是以天山山脉中段南麓的山间盆地——焉耆盆地为中心,但是在流域中陆地上的地貌类型均有分布.该流域是典型的封闭性盆地地貌为主,多种地貌形态并存而交叉分布;该流域由三个盆地地貌单元组成,表现出山间盆地地貌类型的环状分布特点. 相似文献
4.
利用DGY孔沉积物的岩性、粒度及孢粉分析资料,探讨了太湖平原碟形洼地沉积物记录的8000年以来植被演化、气候波动,流域地貌环境的演变及其对海平面波动的响应。孢粉记录表明:本区距今8000~5000年木本植被由以落叶阔叶乔木和针叶乔木为主变为落叶阔叶乔木和常绿阔叶乔木为主,气候由温和略干转为暖热湿润;距今5000~4000年森林退缩,气候温和偏干;距今4000年左右出现低温事件;距今4000~3,000年木本植被以常绿阔叶乔木为主,气候温暖湿润;距今3000年以来木本植被主要为常绿阔叶乔木、落叶阔叶乔木和针叶乔木,气候总体温暖湿润,有波动变凉干趋势。岩性、粒度及孢粉记录综合显示本区距今8000~5000年发育潟湖相泥质粉砂,反映流域环境开放、与海连通;距今5000~4000年发育淡水沼泽,未受海水作用,反映水域缩小、流域环境封闭;距今4000~3000年水域扩大,并出现海水倒灌,反映内低外高的碟形洼地已经形成;距今3000年以来,发育湖沼平原,发生数次海水倒灌,反映碟形洼地地貌的进一步发育。 相似文献
5.
太湖平原碟形洼地沉积物记录的距今8 000年以来植被、气候与地貌演变 总被引：1，自引：1，他引：0
利用DGY孔沉积物的岩性、粒度及孢粉分析资料,探讨了太湖平原碟形洼地沉积物记录的8 000年以来植被演化、气候波动,流域地貌环境的演变及其对海平面波动的响应。孢粉记录表明：本区距今8 000～5 000年木本植被由以落叶阔叶乔木和针叶乔木为主变为落叶阔叶乔木和常绿阔叶乔木为主,气候由温和略干转为暖热湿润;距今5 000～4 000年森林退缩,气候温和偏干;距今4 000年左右出现低温事件;距今4000～3000年木本植被以常绿阔叶乔木为主,气候温暖湿润;距今3 000年以来木本植被主要为常绿阔叶乔木、落叶阔叶乔木和针叶乔木,气候总体温暖湿润,有波动变凉干趋势。岩性、粒度及孢粉记录综合显示本区距今8 000～5 000年发育潟湖相泥质粉砂,反映流域环境开放、与海连通;距今5 000～4 000年发育淡水沼泽,未受海水作用,反映水域缩小、流域环境封闭;距今4 000～3 000年水域扩大,并出现海水倒灌,反映内低外高的碟形洼地已经形成;距今3 000年以来,发育湖沼平原,发生数次海水倒灌,反映碟形洼地地貌的进一步发育。 相似文献
6.
金沙江乌东德水电站岸坡槽谷堆积体成因分析 总被引：1，自引：0，他引：1
在西南地区江河流域,岸坡上常常发育有一系列的凹槽负地形,这些地形呈上宽下窄形态,也就是上部表现出U形洼地,稍显开阔,紧接其下部谷地变窄一直连到江河沟谷边。这样的地貌形态其上部洼地发育的高程一般在1 500~2000m。在以往的地质灾害调查中,这种现象常常被认为是滑坡堆积地貌。本文以金沙江乌东德水电站岸坡槽谷堆积体为主要研究对象,从堆积体地貌、物质结构特征以及对比分析了其成因。最后提出该岸坡槽谷堆积体的成因与冰雪作用有关,而不是简单的滑坡堆积地貌。 相似文献
7.
喀斯特流域水文地貌系统及其识别方法初探 总被引：6，自引：0，他引：6
本文运用系统论的思想,把陆地水文学和地貌学相结合,首先阐述了喀斯特流域与水文地貌系统的内涵和关系;然后对喀斯特流域水文地貌系统识别方法进行了探讨,提出了流域形态径流强度系数和导数高程积分曲线;最后以水文与形态之间的映射关系来探讨识别喀斯特峰丛洼地系统中的地下水系结构。 相似文献
8.
为研究流域地貌形态特征的量化指标,提出基于高程分布概率的多重分形计算模型,结合大理河岔巴沟流域和大堡岔流域DEM数据进行多重分形计算,对流域地貌形态特征多重分形谱的表征意义进行了探讨。结果表明:流域地貌形态特征多重分形谱可以更加敏感、更加全面地对流域地貌形态的总体特征进行描述;多重分形谱的顶点对应简单分形的容量维,多重分形谱的宽度可以定量表征流域表面的起伏程度,多重分形谱的端点维数的差别可以间接地反映流域峰谷数目的比例;流域地貌形态特征多重分形谱能够分层次地刻画流域内部的精细结构,从而更加突出地表现异常局部地貌变化特征;流域地貌形态特征多重分形谱的无标度区间的合理范围,应该确定为DEM像元尺度到流域最大高程值的1.5倍左右最为合适。 相似文献
9.
论中国岩溶峰丛洼地的形成 总被引：4，自引：0，他引：4
中国的岩溶峰丛洼地，作为世界岩溶的典型模式，主要分布于秦岭以南的湿热岩溶区，这种岩溶峰丛洼地以高度有序的民深洼地配置呈多边形为主要的地貌结构特征，古老坚硬的水平地层，质纯层厚的块状灰岩，相对隆升的地块和弱的外源水作用是峰洼地发育的基本条件。高温多雨，湿热同期的季风气候使峰丛洼地系统远离平衡态，并在系统自身地形结构的影响下产生了不同地貌部位的差异溶蚀作用，因此，我国特殊的气候是其奇特的峰丛洼地形成的 相似文献
10.
乐业-凤山世界地质公园岩溶地貌景观特征与价值分析 总被引：1，自引：1，他引：0
乐业-凤山世界地质公园发育在“孤岛”状的碳酸盐岩区上,以高峰丛深洼地、大洞穴、大峡谷、天坑群、天窗群、天生桥、地下河为特色,景观类型丰富、系统完整、珍稀典型,观赏价值与科研价值极高。公园内不同地貌景观由于成因差异而各具特色,经定性与定量评价:天坑群、天窗群是世界级品牌景观,为公园五级地貌景观;天生桥、峡谷是公园重要景观,为公园四级地貌景观;峰丛洼地、峰丛谷地、坡立谷、洞穴景观是公园地貌景观的重要组成部分,为公园三级地貌景观;穿洞、岩溶泉、地下河景观是公园地貌景观的重要补充,为二级地貌景观;落水洞、竖井是公园点缀地貌景观,为公园一级地貌景观。 相似文献
11.
Emily Keeble David I. Whiteside Michael J. Benton 《Proceedings of the Geologists' Association. Geologists' Association》2018,129(2):99-119
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco. 相似文献
12.
Gilles Serge Odin 《Comptes Rendus Geoscience》2002,334(6):409-414
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414. 相似文献
13.
The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts 总被引：4，自引：0，他引：4
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species. 相似文献
14.
Emmanuel Skourtsos Daniel Vachard Alexandra Zambetakis-Lekkas Rossana Martini Louisette Zaninetti 《Comptes Rendus Geoscience》2002,334(12):925-931
Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931. 相似文献
15.
正20141596 Liu Yunhuan(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China);Shao Tiequan Early Cambrian Quadrapyrgites Fossils of Xixiang Boita in Southern Shaanxi Province(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,35(3),2013,p.39-43,3 illus.,20 refs.) 相似文献
16.
正20141719 Chen Zhijun(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China);Chen Jianguo Automated Batch Mapping Solution for Serial Maps:A Case Study of Exploration Geochemistry Maps(Journal of Geology,ISSN1674-3636,CN32-1796/P,37(3),2013,p.456-464,2 illus.,2 tables,10 refs.) 相似文献
17.
正20140962 Chen Fenning(Xi’an Institute of Geology and Mineral Resources,Xi’an710054,China);Chen Ruiming Late Miocene-Early Pleistocene Ostracoda Fauna of Gyirong Basin,Southern Tibet(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,87(6),2013,p.872-886,6illus.,56refs.) 相似文献
18.
正1.IGNEOUS PETROLOGY20142008Cai Jinhui(Wuhan Center,China Geological Survey,Wuhan 430205,China);Liu Wei Zircon U-Pb Geochronology and Mineralization Significance of Granodiorites from Fuzichong Pb-Zn Deposit,Guangxi,South China(Geology and Mineral Resources of South China,ISSN1007-3701,CN42-1417/P,29(4),2013,p.271-281,7illus., 相似文献
19.
正20141205Cheng Weiming(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China);Xia Yao Regional Hazard Assessment of Disaster Environment for Debris Flows:Taking Jundu Mountain,Beijing as an 相似文献
20.
正20141266Fan Chaoyan(Guangdong Provincial Key Laboratory of Mineral Resources and Geological Processes,Guangzhou 510275,China);Wang Zhenghai On Error Analysis and Correction Method of Measured Strata Section with Wire Projection Method(Journal of 相似文献