共查询到20条相似文献，搜索用时 15 毫秒
1.
《Quaternary Science Reviews》2007,26(22-24):2996-3016
River terraces are well established as an important source of Lower and Middle Palaeolithic artefacts in Europe, large collections having been assembled there during the years of manual gravel extraction. Now that many terrace sequences can be reliably dated and correlated with the oceanic record, potentially useful patterns can be recognized in the distribution of artefacts. The earliest appearance of artefacts in terrace staircases, marking the arrival of the first tool-making hominins in the region in question, is the first of several archaeological markers within fluvial sequences. The Lower to Middle Palaeolithic transition, with the appearance of Levallois, is another. Others may be more regional in significance: the occurrences of Clactonian (Mode 1) industry, twisted ovate handaxes and bout coupé handaxes, for example. IGCP Project no. 449 instigated the compilation of fluvial records from all over the ‘old world’. Comparison between British and Central European sequences confirms the established view that there is a demarcation between handaxe making in the west and flake/core industries in the east. Other centres of activity reported here have been in the Middle East (Syria), South Africa and India. Data from such areas will be key in deciphering the story of the earlier ‘out-of-Africa’ migration, that by pre-Homo sapiens people. There is clear evidence for diachroneity between the first appearances of different industries, in keeping with the well-established idea of northward migration. 相似文献
2.
《Quaternary Science Reviews》2007,26(22-24):2970-2995
Vertebrate and invertebrate faunal biostratigraphy is a well-tested method for establishing relative chronologies for fluviatile sequences that has proved useful in many parts of the world. The robust bones and teeth of large mammals are commonly found in fluviatile deposits, whereas small vertebrates can be readily recovered through systematic sieving of calcareous sediments, as can molluscs, the other major faunal group that has been used for biostratigraphical analysis of fluvial sequences. Because of their rapid and quantifiable rates of evolution, extinction, body mass change and dispersal during the Late Cenozoic, mammals are especially useful for ordering the fragmentary terrestrial sequence of interglacials and glacials, and proposing correlation with the global marine climatostratigraphic record. Other groups (e.g. reptiles and amphibians, ostracods) are as yet only in the initial stages of development as a dating tool, whereas some (e.g. fish, birds) still require substantial development in order to fully explore their utility. As part of IGCP 449, vertebrate and molluscan assemblages have made important contributions to datasets from a number of areas, notably northern France, central Germany, the Czech Republic and the Ukraine. Further south, mammalian assemblages have proved useful in separating discrete periods of climatic change in Iberia and Syria. At greater distances from the core area of fluvial biostratigraphical archives, significant contributions have come from South America (Uruguay River), South Africa (Vaal) and Australia (Riverine Plain and Lake Eyre drainage basin). 相似文献
3.
WolfgangEder MargaretePatzak 《《幕》》2004,27(2):150-151
Although many countries, especially from the developing world, share the most exciting geological features, geological structures and natural resources, research activities at various institutions are undertaken in isolation. The IGCP is unique as an international Programme that brings together several thousands of scientists from different disciplines, to stimulate dialogue and facilitate communication among 相似文献
4.
1990年至今,笔者带领的国土资源部岩溶动力学重点实验室研究群体连续成功申请与实施了与岩溶有关的IGCP299、IGCP379、IGCP448和IGCP513四个国际地质对比计划项目,为国际岩溶学术界同行提供了一起学习、工作机会,进而共同解决岩溶形成、碳循环、岩溶生态、水资源等领域的资源与环境问题。[第一段] 相似文献
5.
作指出了1973年至今世界上50余项地球化学填图计划中普遍存在的缺陷大都涉及分析问题。1988－1992年实施的国际地质对比计划IGCP259项目旨在使全世界地球化学填图方法标准化。在此项目中对分析问题提出了若干规定，主要是要求今后的填图计划应统一分析71种元素，痕量及超痕量元素的检出限必须低于相应的地壳丰度值及采用中国的GSD和加拿大的STSD标样系列，以使全球数据可以对比，在其后开始延续至今的全球地球化学填图计划IGCP360，旨在用极低密度采样早日覆盖全球大陆，讨论了正在实行的两种极低密度采样方案，并提出通过极低密度采集地极少量样品示范性实现IGCP259项目对分析要求的具体建议。 相似文献
6.
岩溶IGCP国际合作30年与岩溶关键带研究展望 总被引：2，自引：1，他引：1
全球岩溶类型多样,对环境变化敏感,资源与环境问题突出,是地球关键带监测与研究的重点,IGCP661项目的执行为岩溶区关键带类型划分与监测对比研究提供了契机和国际合作平台。近30年岩溶IGCP执行始终强调岩溶系统与人类活动环境的相互作用,其轨迹实际上与地球系统科学到地球关键带理念是一脉相承的。IGCP299提出了岩溶形态组合概念,揭示各种岩溶形态与其形成环境之间的因果关系。岩溶动力系统(IGCP379), 岩溶生态系统(IGCP448)概念的提出有助于我们更好地理解岩溶系统的整体功能,及系统内水、生物地球化学过程、人类活动的相互作用,进而形成了一整套岩溶动力学研究方法体系。开辟了岩溶记录与全球变化、碳循环与应对气候变化、石漠化形成演变与生态修复等研究新领域,并取得了丰硕的研究成果,有力地推动了现代岩溶学的发展。 相似文献
7.
More than 40 national and regional geochemical mapping projects in the world carried out from 1973 to 1988 do not conform to common standards. In particular they have many analytical deficiencies. In the period 1988 to 1992, the International Geochemical Mapping project （Project 259 of UNESCO＇s IGCP Program） prepared recommendations designed to standardize geochemical mapping methods. The analytical requirements are an essential component of the overall recommendations. They included the following： 71 elements should be analyzed in future mapping projects; the detection limits of trace and ultratrace elements must be lower than the corresponding crustal abundances; and the Chinese GSD and Canadian STSD standard sample series should be used for the correlation of global data. A proposal was also made to collect 5000 composite samples, at very low sampling densities to cover the whole Earth＇s land surface. In 1997 an IUGS Working Group on Global Geochemical Baselines was formed to continue the work which began with IGCP 259. From 1997 up to now, new progress has been made especially in China and FOREGS countries under the aegis of this working group, including the study of suitable sampling media, development of a multi-element analytical system, new proficiency test for selection of competent laboratories and role of wide-spaced mapping in mineral exploration. One of the major problems awaiting solution has been the inability of many laboratories to meet the IGCP recommendations to generate high quality geochemical maps. Fortunately several laboratories in China and Europe have demonstrated an ability to meet the requirements and they will be well placed to render technical assistance to other countries. 相似文献
8.
“白垩纪大洋红层——海洋/气候响应”研究进展综述 总被引：2，自引：0，他引：2
“白垩纪大洋红层”是中国学者提出并开拓的白垩纪研究新方向。在其所领导的两个国际地质对比计划项目(IGCP463/494)的推动下,“白垩纪大洋红层”所蕴含的古海洋与古气候意义,正引起越来越多的学者的重视。特别是近几年召开的学术会议对“白垩纪大洋红层”研究起到了很好的推动作用: (1)在2002 年度IGCP463 项目启动会议上,对“白垩纪大洋红层”的研究现状进行了初步的交流,制订了项目研究的总体目标和未来五年工作计划,并考察了亚平宁—阿尔卑斯—喀尔巴阡沿线的大洋红层;(2)2003 年度的IGCP463 工作会议和IGCP494 启动会议,不仅积累了大洋红层研究的资料,而且将白垩纪大洋红层研究推进到白垩纪中期;(3)2004 年度两个项目的工作会议,以及通过在第32 届国际地质大会特别讨论会的工作,进一步推进了大洋红层的研究,并将“白垩纪大洋红层”研究介绍给广大的国际地球科学界;(4)在欧洲地球科学联盟2005 年会上,“白垩纪大洋红层”研究体现出了多学科共同参与的可喜现象。回首近几年来的研究历程可以发现,“白垩纪大洋红层”研究已实现了如下转变:(1)从区域性研究到全球对比综合研究的变化;(2)从由中国科学家单独研究变为多个国家的科学家申请到项目和经费共同研究;(3)从举办IGCP项目学术年会快速向国际大会或 相似文献
9.
从端点走向连续:河流沉积模式研究进展述评 总被引：10，自引：7，他引：3
从河道类型的划分、河床演变与河型转换、河道沉积与河流砂体的建筑结构要素、河漫滩沉积、季节性河流与分支河流体系、河流沉积相模式、河流沉积学研究技术与方法等方面对国内外河流沉积模式的研究进展进行了综述,认为近十年来河流沉积学的理论和方法都发生了重要的变化。地貌学家、沉积学家和工程师认识到河道形态是连续可变的,而不是只有4~40多个端点类型。河床的演变受河床比降、流量变幅、河岸沉积物粒度构成、气候、植被以及构造沉降速率等多方面的影响。垂向剖面分析法难以对古河流类型做出正确的判断,运用建筑结构要素分析法重建河道内大型底形的地貌形态是河型判别和河流相模式重建的正确方法。河漫滩是河流沉积事件记录最为齐全的部位,对河漫滩、天然堤和泛滥平原沉积层序的研究能够揭示更多古河流沉积过程以及古环境、古气候和古生物方面的信息。对季节性河流、受季风强烈影响地区的河流、以及不同气候带河流所发育的独特沉积构造和建筑结构要素的研究不断增加。分支河流体系的概念得到越来越多的应用,但也得到不少质疑。我国学者应当注重对现代河流地貌形态和沉积过程的观察,把河床演变学的定量方法与沉积学的观点、理论和资料相结合,利用露头、三维地震资料和探地雷达技术建立河流砂体内部建筑结构信息数据库,加强对古河流河漫滩和泛滥平原的沉积过程、特征及其控制因素的研究,加强对不同构造和气候条件下河流沉积的差异性研究,不断发展河流沉积学研究技术,加强河流沉积学实验室建设和研究队伍建设,加强国际交流与合作,使我国河流沉积学为国家经济社会发展提供更加有力和有效的支撑,为推动国际河流沉积学发展做出中国人自己的贡献。 相似文献
10.
全球变化中的地球化学基线值研究及中国的研究现状 总被引：1，自引：0，他引：1
介绍了“全球地球化学制图”(IGM)项目及其在中国的进展情况。展望了我国地球化学基线值研究工作方向及研究重点。 相似文献
11.
微亮晶(臼齿)碳酸盐岩:21世纪全球地学研究的新热点 总被引：25，自引：2，他引：25
国际地质对比计划委员会批准启动了 IGCP44 7-元古代臼齿碳酸盐岩和地球演化项目 ( 2 0 0 1～ 2 0 0 5 )〔1〕。本文简要地回顾了臼齿碳酸盐岩的研究历史和最新进展。臼齿碳酸盐岩是一种具有类似大象臼齿的肠状褶皱构造的岩石 ,具有特殊的时限范围 (中 -新元古代 )。试图解释其成因和可能用于古大陆地层对比是本项目研究的重要课题 ,其重要意义还在于它们是解决前寒武纪生物学和地球化学事件的关键。臼齿碳酸盐岩的发育和衰退关系到地球生命起源和海洋碳酸盐岩沉积地球化学的突变。 87Sr/86 Sr年龄同位素测定证明 ,微亮晶 (臼齿 )碳酸盐消失的时限很可能为75 0 Ma。另外 ,中 -新元古代碳酸盐岩地层具有重要的生烃潜力。 相似文献
12.
中国河流沉积学研究20年 总被引：19，自引：4，他引：15
从河型及其分类研究、现代河流沉积调查、河流沉积相与相模式研究、河流相地层的层序地层学研究、河流沉积砂体建筑结构精细解剖、河流沉积模拟研究等六个方面回顾了自《沉积学报》创刊以来20年中国河流沉积学研究的主要进展,指出我国的河流沉积学取得了许多富有特色的研究成果,主要表现在网状河概念的引入与普及、建筑结构要素分析法的推广、界面层次的划分和及其概念的扩张、岩石相类型和岩石相组合概念的应用、河流砂体露头调查的方法与技术、沉积构造的沉积动力学解释、层序地层学在河流沉积研究中的应用、河流沉积过程的模拟实验、河流相储层的建模技术等方面。但是20年来,中国河流沉积学研究并没有出现国际公认的理论首创,应当加强河流沉积学的研究组织,吸收地理地貌和水利学的研究成果,结合社会经济建设需要不断扩大河流沉积学的研究领域,积极进行国际学术交流,使我国的河流沉积学研究走在国际河流沉积学研究的前列。 相似文献
13.
国际地球化学填图样品分析方法和数据对比 总被引：2，自引：0，他引：2
以中国和世界发达国家或地区(欧洲、北美、澳大利亚与日本)过去10年内完成的或目前正在开展的全球性或国家性地球化学填图项目为例,总结了国际地球化学样品分析技术的新进展,并以中国实验室与欧洲实验室的分析数据的对比结果,剖析国际地球化学填图样品分析技术面临的挑战。研究表明:分析组成地壳所有元素的构想已被越来越多国家性、全球性地球化学填图项目所采纳;中国是世界上唯一具有填图样品76元素分析能力的国家;高水平的分析实验室(欧洲与中国)取得的数据大部分可以实现对比,但仍有10余个元素的分析数据存在明显偏差。实现所有分析元素数据的全球可对比,应是今后国际地球化学填图样品分析技术的主要发展方向。 相似文献
14.
The Ganga Plain is one of the most densely populated regions of the world due to its fertile soil and availability of water. The rivers of this plain are the lifeline for millions of people of this vast alluvial plain. All rivers of this plain are characterized by narrow channel confined within wide valley. Continuously increasing pressure of population on this plain has led to the intensification of settlement even into the valley of the river. This unplanned expansion has enhanced the damage due to flooding during high-discharge period and lateral erosion during low-discharge period. Flooding and lateral erosion are identified as fluvial hazards in the Ghaghara River area. Extensive studies have been carried out on flooding, but not much attention has been paid to the phenomenon of lateral erosion. However, it has been observed that lateral erosion is an independent fluvial hazard that operates during low-discharge period. Low degree of compaction due to the presence of sandy and silty facies in the river valley deposits, mass movement, palaeocurrent pattern, and fractures initiates and enhances the lateral erosion. The present paper deals with the fluvial hazards in the Ghaghara River area. 相似文献
15.
《Sedimentology》2018,65(2):597-619
Fluvial channel‐belt clustering has recently been documented using quantitative metrics for systems dominated by autogenic controls. It has long been recognized that allogenic forcing (tectonic and eustatic controls) can lead to confinement of fluvial systems, resulting in clustering of channel belts. To date, no study has quantitatively documented the differences in channel‐belt clustering, compensational stacking of channel belts and interchannel‐belt connectivity in unconfined and confined systems. This study quantitatively compares world‐class outcrops of an unconfined fluvial system (Palaeocene lower Wasatch Formation) with outcrops of a confined fluvial system (Cretaceous Dakota Sandstone). Two new methods have been developed to quantitatively document channel‐belt clustering and intrachannel‐belt connectivity. These new methods, and other previously developed methods, are used to document an increase in channel‐belt clustering and intrachannel‐belt connectivity downdip in both systems. Additionally, it was found that channel belts within the unconfined system stack more compensationally than those in the confined system. These new methods and empirical relationships can be used for predicting intrachannel‐belt connectivity, and accurately modelling unconfined and confined fluvial systems in the subsurface. 相似文献
16.
通过地表实地踏勘和浅层探槽解释，结合卫星照片解译，参考第四纪和历史地理研究结果，对准噶尔盆地西北缘黄羊泉扇的沉积特征及其第四纪以来的演变进行了分析.黄羊泉扇是一个发育在内陆干旱地区、以河流沉积为主的河流扇，扇体平面上呈上细下粗的“葫芦型”，可以划分为上扇、中扇和扇缘3个相带，沉积物具有由上扇向扇缘变细的趋势.扇上沉积动力以河流为主，缺乏泥石流沉积，但扇面活动水道不发育，大多数河道为偶尔才有径流通过的暂时性河道，风对扇表面的沉积物有明显的改造作用.黄羊泉扇扇缘发育4种不同的终止方式，一部分进入艾里克湖，一部分终止在沼泽地带，一部分在小型湖泊边缘消失，一部分受地形阻挡终止，与经典冲积扇和扇三角洲都不完全相同.结合前人历史地理研究成果认为第四纪以来黄羊泉扇所在的古玛纳斯湖出现过6次高湖平面，在30 ka以前，黄羊泉扇体一直处于古玛纳斯湖包围中，形成黄羊泉扇三角洲.直到30~10 ka期间才由于湖泊水位下降，扇体逐步出露形成河流扇.研究建立了黄羊泉扇随着湖平面升降从河流扇三角洲不断演化为河流扇的沉积模式，表明黄羊泉扇目前正处于河流扇三角洲沉积体系向河流扇沉积体系演变的过渡阶段. 相似文献
17.
全球岩溶生态系统对比:科学目标和执行计划 总被引：88，自引：4，他引：88
由我国提出的新的国际地质对比计划“全球岩溶生态系统对比”（IGCP 448）已于2000年初由IGCP科学委员会批准，在2000－2004的5年中执行。该项目的科学目标是：对比全球不同气候条件下的宏观岩溶生态系统，揭示其形成机理；对比不同地质条件下微观岩溶生态系统，揭示其对物种选择的影响，为岩溶地区石漠化治理，重建良性生态系统探索新思路，从地理，地质角度对比地下岩溶生态系统；研究岩溶生态系统与人类活动的相互作用。5年中除40余个参与国将作好本国岩溶生态系统研究作为全球对比的基础外，还将重点联合考察罗马尼亚，巴西，中国，西班牙，法国，美国，俄罗斯，澳大利亚等国的典型岩溶区，并作深入对比研究，IGCP448的核心科学问题是岩溶生态系统的运行规律，对如何利用我国地域优势和组织该多边国际合作计划的有利条件，进一步做好我国岩溶生态系统研究提出了若干建议。 相似文献
18.
河流沉积对于气候和海平面变化响应的讨论 总被引：2，自引：0，他引：2
河流沉积地层是古代陆相沉积和大陆边缘沉积的重要组成部分。河流沉积与气候和海平面升降之间的关系虽然研究较多，但是众多的研究集中于河流沉积与相对海平面之间的变化，而研究河流沉积与气候的关系则集中于对近100Ma年以来的河流沉积，而对古代河沉积与气候之间的变化关系研究较少。本文拟对河流沉积与海平面变化和气候变化的响应进行一些讨论。 相似文献
19.
Jonathan P. Allen Christopher R. Fielding Martin R. Gibling Michael C. Rygel 《Sedimentology》2014,61(5):1332-1381
Tectonics and climate are the major extrinsic upstream controls on both the external and internal architectures of fluvial channels. While the role of tectonics has been well‐documented, the role of climate has received less attention. Because both tectonics and climate can produce similar stratigraphic architectures, the ability to recognize and differentiate these has major ramifications for the interpretation of fluvial stratigraphy. The Pennsylvanian to Permian succession of the Maritimes Basin complex on Cape Breton Island is ca 5 km thick, and is composed of predominantly non‐marine strata deposited within a series of depocentres characterized by different subsidence regimes. Basins in the west are transtensional depocentres characterized by episodic fault movement. In contrast, basins in the east were formed during prolonged periods of passive thermal subsidence. The stratigraphy is composed of four second‐order sequences (A to D), each 5 to 10 Myr in duration. These sequences are composed of amalgamated fluvial channel deposits that fine upwards into extensive mud‐dominated floodplain deposits with isolated fluvial channel bodies. A spectrum of fluvial styles is recorded within the study area including perennial, perennial/intermittent and ephemeral. Four stratigraphic intervals (E1 to E4) are recognized in which the deposits of strongly seasonal perennial/intermittent fluvial deposits are predominant. These intervals, 2 to 6 Myr in duration, are correlated across the study area between basins with differing tectonic regimes and do not correlate with a particular position in second‐order sequences. This suggests that climate exerted the dominant influence on the formation of these intervals and can be differentiated from tectonic imprints. While the tectonic regime of a particular basin exerted a fundamental control on the external architecture, a coherent record of climate change is recognized in the internal architecture of fluvial units. This study demonstrates that tectonic and climatic controls can be recognized and differentiated in vertical successions by evaluating the changes in fluvial architecture. 相似文献
20.
《Sedimentology》2018,65(1):96-122
This paper characterizes the detailed sedimentology of a fluvial sandbody on Mars for the first time and interprets its depositional processes and palaeoenvironmental setting. Despite numerous orbital observations of fluvial landforms on the surface of Mars, ground‐based characterization of the sedimentology of such fluvial deposits has not previously been possible. Results from the NASA Mars Science Laboratory Curiosity rover provide an opportunity to reconstruct at fine scale the sedimentary architecture and palaeomorphology of a fluvial environment on Mars. This work describes the grain size, texture and sedimentary facies of the Shaler outcrop, reconstructs the bedding architecture, and analyses cross‐stratification to determine palaeocurrents. On the basis of bedset geometry and inclination, grain‐size distribution and bedform migration direction, this study concludes that the Shaler outcrop probably records the accretion of a fluvial barform. The majority of the outcrop consists of large‐scale trough cross‐bedding of coarse sand and granules. Palaeocurrent analyses and bedform reconstruction indicate that the beds were deposited by bedforms that migrated towards the north‐east, across the surface of a bar that migrated south‐east. Stacked cosets of dune cross‐bedding suggest aggradation of multiple bedforms, which provides evidence for short periods of sustained flow during Shaler deposition. However, local evidence for aeolian reworking and the presence of potential desiccation cracks within the outcrop suggest that fluvial deposition may have been intermittent. The uppermost strata at Shaler are distinct in terms of texture and chemistry and are inferred to record deposition from a different sediment dispersal system with a contrasting provenance. The outcrop as a whole is a testament to the availability of liquid water on the surface of Mars in its early history. 相似文献