Geochemical evidence of aeolian deposits in European soils     

Andreas J. Scheib  Manfred Birke  Enrico Dinelli  GEMAS Project Team 《Boreas: An International Journal of Quaternary Research》2014,43(1):175-192

Hafnium (Hf) and zirconium (Zr) concentrations measured in over 4100 agricultural soil samples from Europe were assessed with the focus on their relationship to the distribution of aeolian deposits, such as loess and coversands. Comparison of extractable (aqua regia; ICP‐MS) and total (XRFS) concentrations shows that only 1.0 to 1.7% of the total Hf and Zr is chemically extractable because of the resistant nature of their host minerals. Resistate minerals, such as zircon, are commonly found in the predominantly silty fraction of loess deposits. In this study a statistical analysis of total Hf and Zr soil data from areas with and without loess was carried out to derive threshold values of 10 mg kg^?1 (Hf) and 318 mg kg^?1 (Zr). These values were subsequently applied across the project area in an attempt to indicate the presence of aeolian deposits. The spatial distribution of above‐threshold concentrations suggests a more extensive and coherent loess belt across central and eastern Europe, providing additional evidence of loess across Brittany, Aquitaine and near the Vosges mountains in France as well as in the basins of central and northern Spain. Above‐threshold concentrations were also detected in loess regardless of its thickness, emphasising the importance of the abundance of zircon in the upper part of the soil profile rather than the actual thickness of the deposit. Soil data however, failed to indicate various loess facies within most of the Pannonian Basin, suggesting that this approach only works where deposits contain a sufficient amount of zircon. This may also explain why the extensive coversands across northern Germany and Poland were largely undetected. This study demonstrates that continental‐scale soil geochemical data can help identify and map the distribution of zircon‐rich loess and coversand, and subsequently enhance and improve current knowledge of the extent of these deposits.  相似文献   

The multiple chronological techniques applied to the Lake Suigetsu SG06 sediment core,central Japan     

Richard A. Staff  Takeshi Nakagawa  Gordon Schlolaut  Michael H. Marshall  Achim Brauer  Henry F. Lamb  Christopher Bronk Ramsey  Charlotte L. Bryant  Fiona Brock  Hiroyuki Kitagawa  Johannes van der Plicht  Rebecca L. Payne  Victoria C. Smith  Darren F. Mark  Alison Macleod  Simon P. E. Blockley  Jean‐Luc Schwenninger  Pavel E. Tarasov  Tsuyoshi Haraguchi  Katsuya Gotanda  Hitoshi Yonenobu  Yusuke Yokoyama  Suigetsu Project Members 《Boreas: An International Journal of Quaternary Research》2013,42(2):259-266

The varved sediment of Lake Suigetsu (central Japan) provides a valuable opportunity to obtain high‐resolution, multi‐proxy palaeoenvironmental data across the last glacial/interglacial cycle. In order to maximize the potential of this archive, a well‐constrained chronology is required. This paper outlines the multiple geochronological techniques being applied – namely varve counting, radiocarbon dating, tephrochronology (including argon–argon dating) and optically stimulated luminescence (OSL) – and the approaches by which these techniques are being integrated to form a single, coherent, robust chronology. Importantly, we also describe here the linkage of the floating Lake Suigetsu (SG06) varve chronology and the absolute (IntCal09 tree‐ring) time scale, as derived using radiocarbon data from the uppermost (non‐varved) portion of the core. This tie‐point, defined as a distinct (flood) marker horizon in SG06 (event layer B‐07–08 at 1397.4 cm composite depth), is thus derived to be 11 255 to 11 222 IntCal09 cal. years BP (68.2% probability range).  相似文献   

A new European testate amoebae transfer function for palaeohydrological reconstruction on ombrotrophic peatlands     

Dan J. Charman  Antony Blundell  ACCROTELM Members 《第四纪科学杂志》2007,22(3):209-221

Proxy climate data can be obtained from reconstructions of hydrological changes on ombrotrophic (rain‐fed) peatlands using biological indicators, such as testate amoebae. Reconstructions are based on transfer functions, relating modern assemblage composition to water table and moisture content, applied to fossil sequences. Existing transfer functions in Europe and elsewhere are limited geographically and there are often problems with missing or poor analogues. This paper presents a new palaeohydrological transfer function based on sampling raised mires from across Europe. Relationships between assemblages and hydrological variables are described using ordination analyses. Transfer functions are developed for depth to water table (n = 119) and moisture content (n = 132) with root mean squared errors (RMSEP) of 5.6 cm and 2.7% respectively. Both transfer functions have an r² of 0.71, based on ‘leave one out’ cross‐validation. Comparisons with an existing transfer function for Britain show that the European transfer function performs well in inferring measured water tables in Britain but that the British data cannot be used to infer water tables for other European sites with confidence. Several of the key missing and poor analogue taxa problems encountered in previous transfer functions are solved. The new transfer function will be an important tool in developing peat‐based palaeoclimatic reconstructions for European sites. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Simulation and evaluation of satellite scanner stereo images     

Vijay K. Agarwal  R. Ramani  R. M. Patel  Meoss Project 《Journal of the Indian Society of Remote Sensing》1987,15(1):55-65

During 1986–1996, several satellite missions on Stereoscopy are planned. This paper sumarises an attempt in evaluating these stereoscopic images for cartographic purposes. For the purpose, we have taken into account a proposed Indian experiment on satellite stereoscopy, which will be based on push-broom type scanning and a ground resolution of 70m×70m. *** DIRECT SUPPORT *** A04KF003 00004  相似文献   

CMAQ—ASM模式业务化     

陈贤 《中国气象科学研究院年报》2006,(1):29-30

CMAQ成功移植到了国家气象中心业务系统神威和IBM巨型机上，为实现全国及区域空气质量预报准业务化系统提供重要的技术保障。另外，针对模式中污染源不确定性因素引起预报偏差的技术难题，发展了空气质量预报模式的动力-统计模型（CMAQ-MOS）与源同化新技术，其效果明显优于国外原CMAQ模式。  相似文献   

首都北京及周边地区大气、水、土环境污染机理及调控原理     

""城市环境项目办公室 《中国气象科学研究院年报》2003,(1):15-18

2003年“首都北京及周边地区大气、水、土环境污染机理及调控原理”项目主要工作进展：  相似文献   

林业技术开发试验示范区管理模式、运行机制及政策     

福建省南平市林业技术开发试验示范区 《湿地科学与管理》2000,(1):36-40

<正> 南平林业技术开发试验示范区是在1990年5月南平市政府(原地区行署)与中国林科院签订了长期友好合作,共建技术开发试验区协议的基础上,于1992年8月林业部正式批准成立的。 南平林业技术开发试验示范区的范围为南平市所辖10个县(市、区)行政区域,总面积26031平方公里(263.18万公顷),总人口300万人。山地面积217.28万公顷,有林地  相似文献   

论江西省大气成分观测与服务系统建设     

江西省大气成分观测与服务系统研究项目组 《气象与减灾研究》2005,28(3):9-16

在介绍国内外大气成分观测与研究进展的基础上，对建设江西省大气成分观测与服务系统的必要性和可行性进行了科学的分析，并从系统建设的原则、目标、内容、技术路线、监测方案，以及系统研究的主要内容和提供的产品等方面，对拟建的江西省大气成分观测与服务系统进行了全面的阐述。研究结果认为，随着江西经济建设的快速发展，建设江西省大气成分观测与服务系统，有利于了解和掌握江西大气物质成分分布特征及变化情况；有利于提高江西天气气候预报预测准确率，提升江西气象公共服务的能力和水平；可为预防大气化学灾害和控制区域大气环境质量，提供科学的决策依据，具有显著的社会、经济效益和生态效益。  相似文献   

A NUMERICAL MODEL FOR SEDIMENTATION IN FENHE RESERVOIR AND THE ADJOINING REACHES     

GUAN Yiexiang  RONG Fengtao  WANG Jingxin  YIN Lisheng  WANG Hongtu Project Engineer  Hydraulic Research Institute  Shanxi Province  China  Vice Chief Engineer  Senior Engineer  Water Resources 《国际泥沙研究》1991,(1)

In this paper, a numerical model for sedimentation in Fenhe Reservoir and the adjoining reaches has been presented on the basis of the theory of non-equilibrium sediment transport. The model is calibrated by using a part of the sediment data collected for Fenhe Reservoir and checked by simulating the remaining data. Moreover, the method of optimization in nonlinear programming has been applied to determine the basic parameters of the model applying a concept of fuzzy mathematics to formulate the objective functions. The computed amounts of reservoir deposition and channel deformation arc found to be substantially in agreement with the values observed.  相似文献   

三叠纪嘉陵江期华蓥山同沉积断层的沉积、储层响应   总被引：1，自引：0，他引：1  

刘宏  孙振  李卓沛  李凌  聂勇  吴家杰  周小刚  谭秀成 《地层学杂志》2010,(3)

对于断裂带在地质历史时期活动特点的认识,因多期次、不同活动性质的叠加改造而难以确定。以四川盆地南部嘉陵江组为例,通过三叠纪嘉陵江期华蓥山断裂带两侧的沉积、储层的研究发现沉积、储层响应与断面倾向南东、东侧下降的观点矛盾。主要表现为:在非浅滩化的嘉三期,紧邻断裂带西北侧的下降盘地层异常增厚;浅滩化的嘉一晚期—嘉二1期,东南侧的泸州古隆起地区颗粒岩累计厚度较西北侧增厚;另外,断层东南侧的颗粒岩发育早期岩溶型储层,而在西北侧这类储层欠发育。结果表明在三叠纪嘉陵江期华蓥山断裂带的断面倾向北西,为西侧下降的同沉积正断层。  相似文献