Migration and internal architecture of marine dunes in the eastern English Channel over 14 and 56 year intervals: the influence of tides and decennial storms     

Y. Ferret  S. Le Bot  B. Tessier  T. Garlan  R. Lafite 《地球表面变化过程与地形》2010,35(12):1480-1493

Submarine dune dynamics are controlled by tidal currents and wind forces. According to the relative influence of these forces and the nature of dune sediment, different bedform behaviors can be observed. The footprint of the different hydrodynamic agents is recorded into the internal architecture of dunes. This paper is concerned with bedforms that compose the thick sediment wedge located in the eastern English Channel, off the Bay of Somme. This sedimentary archive constitutes an interesting feature to achieve a better understanding of seabed sediment dynamics and its timeline building stages. The dynamics of large submarine dunes, which are organized in fields, are studied thanks to bathymetric and seismic data over the periods 1937–1993 and 1993–2007. Dune morphology presents low lee and stoss side slopes (on average 8° and 3°, respectively) and dune migration rate is not very high. Dune movements are in the direction of residual tidal currents, i.e. toward the east, with mean migration rates around 0·8 to 5 ± 0·25 m yr^?1 and up to 6·6 ± 0·7 m yr^?1, respectively, at multi‐decennial and decennial time scales. The dune internal architecture is complex with superimposed eastward prograding units, displaying locally opposite progradation. Second‐order discontinuities (dip of 0·5°–4° perpendicular to dune crests) constitute dune master bedding. By counting the number of second‐order reflectors between 1937–1993 and 1993–2007, the formation periodicity of these bounding surfaces is estimated to range from 4 to 18 years. These time intervals coincide with the long‐term tidal cyclicities and also with the inter‐annual to decennial variability of storm activity in northern Europe. Two theories were made to interpret the dune internal structures: the second‐order surfaces are interpreted either as the depositional surfaces corresponding to the marks of weak energy periods (weak tidal and storm action), or as erosive surfaces due to an opposite direction of dune migration provoked temporarily by exceptional storms from the northeast. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Ground penetrating radar for facies architecture and high-resolution stratigraphy: Examples from the Mesoproterozoic in the Chapada Diamantina Basin,Brazil     

《Marine and Petroleum Geology》2017

Ground Penetrating Radar (GPR) surveys were conducted on Mesoproterozoic eolian, fluvial, deltaic, estuarine, and shallow marine successions in the Chapada Diamantina Basin. The subsurface continuation of facies and facies architecture exposed on road cuts was imaged using the GPR signal of a 400-MHz antenna penetrating 8 m in depth, even with mudstone intervals. Reflection patterns in the GPR profiles that were compared with photo mosaics of outcrops and supporting data from vertical sections and gamma ray logs, reveal sedimentary, stratigraphic, and structural features, such as sedimentary structures, the external geometry of architectural elements, stratigraphic surfaces, folds and tension gashes. The patterns most likely reflect the response from low-weathered, non-porous muscovite-illite-rich mudstone and quartzarenite sandstone in which authigenic and detrital illite and sericite are prevalent clay minerals.Measured vertical sections and radar stratigraphy indicate high-frequency cyclic successions of estuarine and shoreface intervals are present at the base of the Tombador Formation. The shoreface intervals are composed of heterolithic strata and offshore tidal bars deposits. The heterolithic shoreface strata exhibit tabular geometry that can be easily identified throughout the outcrop and in the subsurface. Such intervals represent the end of high-frequency transgressive cycles, and hence they are potential candidates for including the maximum flooding surfaces and for defining genetic sequences. Therefore, GPR proved to be an independent method for studying facies architecture and the establishment of a high-resolution stratigraphic framework even in the Precambrian.  相似文献   

The study of deep water submarine reservoir in Bangle Bay Basin     

Wei Xiao  Liping Liu  Xuewei Liu 《Marine Georesources & Geotechnology》2017,35(8):1086-1098

Although the huge potential of the Bangle Bay Basin has been proven by a series of discoveries, recent drilling and other studies still have not demonstrated the mechanism of hydrocarbon accumulations in Bangle Bay Basin because of the low exploration degree and less geological data available. So, it is difficult to identify and predict the distribution patterns of the main gas reservoir by now. Based on a review of previous work and the latest exploration activities in the study area, the depositional environment and reservoir distribution had been discussed, and thereby assess the location of reservoir–seal couplets for the purposes of stratigraphic traps identification and prospect evaluation within the study area. This paper has also discussed the sequence stratigraphic framework, depositional environment, and facies features by using the biostratigraphic, geochemical analyses and wireline, image logs data. Various broad depositional environments and depositional subsettings have been identified or updated, meanwhile some new environment modeling had been proposed. In this article, reservoir geology study had been conducted after regional depositional feature analysis. Reservoir architecture had been summarized as mouthbars, submarine canyon fill, submarine channels, and levees. Most prospective reservoir intervals identified within the study area are in the Lower Pliocene, Upper Pliocene, and Lower Pleistocene formations.  相似文献   

基础地理信息跨尺度联动更新规则体系研究   总被引：4，自引：3，他引：1  

杜晓  刘建军  杨眉  刘剑炜  赵文豪  李瞾 《测绘通报》2017,(3):104-107

系统介绍了基础地理信息跨尺度联动更新关键技术相关的规则体系,通过图层映射、几何对应、图面综合、要素取舍、关系协调等多套规则的有机结合,实现了变化更新信息的准确提取;同时开展了基于增量的要素编辑与自动化标注的约束性规则研究,并以1：1万DLG数据联动更新1：5万DLG数据为例,进行了跨尺度基础地理信息联动更新试验。  相似文献   

从储层构型到“地震构型相”——一种河流相高精度概念模型的表征方法   总被引：2，自引：0，他引：2  

胡光义  范廷恩  陈飞  井涌泉  王晖  宋来明 《地质学报》2017,91(2):465-478

碎屑岩油气储层构型是指不同级次储层构成单元的形态、规模、方向及其叠置关系。由Miall(1985)运用于河流相储层表征。碎屑岩油气储层构型是储层非均质性的直观表现,直接影响到油气藏开发效果,如何进行精细构型表征是关系到能否正确量化开发指标、或者能否正确描述剩余油分布进而有效减少低效井比例的关键因素。针对渤海明化镇组河流相沉积储层厚度低于地震分辨率的先天不足,对各种构型在地震数据约束下可分辨尺度上进行分类,形成3种构型7类样式的分类体系:垂叠型、侧叠型和孤立型3种砂体构型,垂叠型、密接触侧叠型、疏散接触侧叠型、离散接触侧叠型、下切侵蚀河道孤立型、决口扇孤立型、孤立河道7类样式。研究了每类构型的地震响应特征,阐述了地震属性描述图版,概括了"地震构型相"将构型类型与地震响应有机结合,构建了基于地震构型相的高精度概念模型表征方法。鉴于目前地质建模和数模技术前提下无法对各类储层构型很好地网格化,建立"等效意义"的概念模型开启了一种很好的技术途径。  相似文献   

荒漠植物枝系构型影响因素分析   总被引：13，自引：2，他引：11  

何明珠  张景光  王辉 《中国沙漠》2006,26(4):625-630

荒漠植物的枝系构型的影响因素包括各级分枝角度、各级分枝长度、枝径比、逐步分枝率和总体分枝率、树冠分维数、分枝分维数和计盒维数等17个指标。采用主成分分析（PCA）方法对50种典型荒漠植物的17个构型指标进行分析,结果表明：第一主成分的贡献率十分高,达到77.0％,其中2级分枝长度和3级分枝长度是影响枝系构件的主要因素;第二主成分的贡献率只有11.3％,主要综合了3级分枝角度、2级分枝角度和1级分枝角度三个因素。对枝系构型因素进行PCA排序可将其划分为三类：第一类包括各级分枝长度;第二类包括逐步分枝率和分形维数;第三类包括各级分枝角度和枝径比等。通过第一和第二主成分分析体现了荒漠植物的两种不同的生态适应机制,即在分枝长度上和分形维数上,趋于增加和减小两种趋势,但在分枝角度方面,都有趋于增大的趋向。  相似文献   

The correlation and sequence architecture of the Ormskirk Sandstone Formation in the Triassic Sherwood Sandstone Group of the East Irish Sea Basin,NW England     

N. S. Meadows 《Geological Journal》2006,41(1):93-122

The existing stratigraphic nomenclature applied to the Early and Middle Triassic Sherwood Sandstone Group in NW England has resulted from more than 150 years of geological investigation, but is characterized by a lithostratigraphic system that is insufficiently flexible to allow for variations in lithology and sedimentary facies within a continental depositional system. A revised well correlation based on the detrital mineralogical and chemical composition of the Ormskirk Sandstone Formation in four offshore wells, that is then extended to provide near‐basin‐wide well correlations using a regional shale marker, confirms previously suggested but unproven diachroneity at the top of the Sherwood Sandstone Group. It also reveals the presence of incised valleys filled by stacked amalgamated fluvial channel sandstones and cut into previously deposited aeolian and sandflat sequences as well as older fluvial channel sandstones. The combination of well correlations indicates that the valleys were incised by a fluvial system flowing NW from the Cheshire Basin into the East Irish Sea Basin and then west towards the Peel and Kish Bank basins. The stratal geometry of the upper part of the Sherwood Sandstone Group is suggested to conform to models of climatically mediated alternations of fluvial degradation and aggradation in response to changes in the relationship between sediment flux and stream discharge. This model is supported in the Sherwood Sandstone Group by climatically driven variations in the non‐channelized facies which record upward wetting and drying cycles that can be locally tied to fluvial incision surfaces, and suggest a hierarchy of at least three levels of climatic cyclicity recorded within the sedimentary succession. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

一种新的移动空间信息服务系统的体系结构   总被引：6，自引：0，他引：6  

李琦  史文勇  林宇 《地理与地理信息科学》2003,19(4):45-48

该文结合移动通信技术和空间信息科学的发展趋势,介绍了面向公众的移动空间信息服务系统的主要组成部分和相关技术。基于移动空间信息服务系统关键技术难点的分析,提出一种开放式、易扩展、功能可重用的移动空间信息服务平台的体系结构。  相似文献   

BOOK REVIEWS     

《The Professional geographer》1984,36(4):498-530

Book reviewed is the article: Small-State Security in the Balkans . Aurel Braun. South American Development: A Geographical Introduction . Rosemary D. F. Bromley and Ray Bromley. Interregional Migration, National Policy and Social Justice . Gordon L. Clark. Marketing Architectural and Engineering Services . Weld Coxe. A Geography of the Third World . J. P. Dickenson, C. G. Clarke, W. T. S. Gould, R. M. Prothero, D. J. Siddle, C. T. Smith, E. M. Thomas-Hope, and A. G. Hodgkiss. Wildlife and Man in Texas: Environmental Change and Conservation . Robin W. Doughty. At the Sea's Edge . William T. Fox. Englewood Cliffs Geography and Ecology . I. P. Gerasimov. Urbanization in Contemporary Latin America. Critical Approaches to the Analysis of Urban Issues . Alan Gilbert in association with Jorge E. Hardoy and Ronaldo Ramírez, eds. The Coming of the Transactional City . Jean Gottmann. College Park Visions of City and Country: Prints and Photographs of Nineteenth-Century France . Bonnie L. Grad and Timothy A. Riggs. Worcester Soviet Geography Today: Physical Geography . N. A. Gvozdetskiy, ed. Adaptive Responses of Native Amazonians . Raymond B. Hames and William T. Vickers, eds. Urban and Regional Industrial Research: The Changing UK Data Base . Michael Healey, ed. Cuando se Acaban los Montes . Stanley Heckadon Moreno. A Panama Forest and Shore: Natural History and Amerindian Culture in Bocas del Toro . Burton L. Gordon. Pacific Grove Mozambique: From Colonialism to Revolution, 1900–1982 . Allen Isaacman and Barbara Isaacman. Soviet Natural Resources in the World Economy . Robert G. Jensen, Theodore Shabad, and Arthur W. Wright, eds. The Changing Geography of the United Kingdom . R. J. Johnston and J. C. Doornkamp, eds. Pluralism and Political Geography—People, Territory and State . Nurit Kliot and Stanley Waterman, eds. Landmarks Preservation and the Property Tax . David Listokin. Irrigation Horticulture in Highland Guatemala: The Tablón System of Panajachel . Kent Mathewson. Her Space, Her Place: A Geography of Women . Mary Ellen Mazey and David R. Lee. Man, A Geomorphological Agent . Dov Nir. Dordrecht The Book of America: Inside the 50 States Today . Neal R. Peirce and Jerry Hagstrom. Rivers . Geoffrey E. Petts. Proceedings, United States/Australia Workshop on Design and Implementation of Computer-Based Geographic Information Systems . Donna Peuquet and John O'Callaghan, eds. Outdoor Recreational and Resource Management . John Pigram. Remaking the City: Social Science Perspectives on Urban Design . John S. Pipkin, Mark La Gory and Judith R. Blau, eds. The Crust of Our Earth: An Armchair Traveler's Guide to the New Geology . Chet Raymo. Englewood Cliffs Concepts and Themes in the Regional Geography of Canada J. Lewis Robinson. Vancouver Secondary Cities in Developing Countries: Policies for Diffusing Urbanization . Dennis A. Rondinelli. Beverly Hills Legal Foundations of Environmental Planning , Vol 1. J. G. Rose. Can We Delay a Greenhouse Warming? Stephen Seidel and Dale Keyes. Mobilizing Human Resources in the Arab World . R. Paul Shaw. Prairie Mosaic: An Ethnic Atlas of Rural North Dakota . William C. Sherman. The Future of Conflict in the 1980s . William J. Taylor, Jr. and Steven A. Maaranen, eds. The Visual Display of Quantitative Information . Edward R. Tufte. U.S. 40 Today: Thirty Years of landscape Change in America . Thomas R. Vale and Geraldine R. Vale. Madison Silent Violence: Food, Famine and Peasantry in Northern Nigeria . Michael Watts. Readings in Historic Preservation: Why? What? How? Norman Williams Jr., Edmund Kellogg and Frank Gilbert, eds.  相似文献   

Effective solutions to a global 3D visual system in networking environments   总被引：2，自引：0，他引：2  

ZHANG Liqiang    ZHANG Yan  YANG Chongjun  LIU Suhong  REN Yingchao  RUI Xiaoping & LIU Donglin . State Key Laboratory of Remote Sensing Sciences  School of Geography  Remote Sensing  Beijing Normal University  Beijing  China  . State Key Laboratory of Remote Sensing Sciences  Institute of Remote Sensing Applications  Chinese Academy of Sciences  Beijing  China  . Institute of Geographical Sciences  Natural Resources Research  Chinese Academy of Sciences  Beijing  China   《中国科学D辑(英文版)》2005,48(11):2032-2039

Today, with the proposal of digital earth, digital city and digital community, and rapid advances in informa-tion technologies and collection of spatial data, to a great degree, the traditional 2D GIS is promoted to Web and 3D GIS, which greatly challenges the capaci-ties of the system in transmitting and handling massive datasets. A great number of 3D GIS prototype systems have been developed and applied in such areas as mine resource management, digital cities. However, appli-cation sys…  相似文献