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211.
During the journey in Inner Mongolia, the geological results of which we have summarized in the preceding communication, we had the good fortune, F. Licent and I, of finding, in three different places (along the Choei Tong K'eou in the South of Ning Hia, along the Sjara Osso Gol in the southeastern corner of the Ordos, and near the village of You Fang T'eou in the South of Yu Lin), palaeolithic remains, in excellent stratigraphical and palaeontological conditions.  相似文献   
212.
DE WAARD  D. 《Journal of Petrology》1967,8(2):210-232
Elaborating on the theme of a previous paper (1965) and in responseto Buddington‘s criticism (1966) the present discussionis primarily concerned with the high-grade meta-morphic reactionsand regional-metamorphic zoning in the Adirondacks. The hypersthene isograd, delineated by the first appearanceof orthopyroxene as a product of Pw-T-controlted reactions involvinghornblende and biotite in quartz-buartz-bearing rocks. separatesthe almandite-amphibolite-facies terrane of the lowlands fromthe granulite-facies region of the highlands. In the almandite-amphibolite facies of the lowlands at leastone isograd, the orthoclase-garnet isograd, (Ruddington's lstgarnet isograd), can be recognized which is delineated by thePw-T-controlled appearance of these minerals at the expenseof muscovite and part of the biotite and quartz. The granulite-facies terrane of the highlands is characterizedby the predominance of assemblages of the hornblende-granulitefacies in which orthopyroxene cocxists with hydrous mineralssuch as biotite and hornblende in apparent equilibrium. In theAdlrondacks there is no sizeable, regional development of thepyroxene-granulite facies where hydrous minerals are virtuallyabsent. Within the hornblende-granulite-facies terrane two isogradscan be recognized. The garent-clinopyroxene isograd (Buddington's3rd garnet isograd) delineates the regional development of garnet,clinopyroxene, and quartz by P1-T-controlled reaction betweenorthopyroxene and plagioclase. The isograd defines in the easternAdirondack a region of the hornblende-clinopyroxene-almanditesubfacies of the honblende-granulite facies. In the westernAdirondacks, near the hypersthene isograd, a yet uncharted cordieriteisograd may define the areal extent of the biotite-cordierite-almanditesubfacies of the hornblende-granulite facies. The central portionof the Adirondacks, where cordierite is absent and garnet andclinopyroxene do not coexist except in silica-deficient rocks,is the region of the hornblende-orthopyroxene-plagioclase subfaciesof the hornblende-granulite facies.  相似文献   
213.
地中海位于非洲季风气候和欧洲温带气候的交界处,同时接受周边地区岩石性质和风化状况差异极大的碎屑物质,所以是研究地球表层水文循环的理想区域。前人的认识集中于撒哈拉风尘和尼罗河输入,往往忽视了其他的陆源碎屑沉积,尤其对不同水文气候条件下的潜在变化缺乏考虑。针对形成于全新世非洲湿润期的腐泥层S1页岩沉积,并结合采自岩心顶部的晚全新世/现代沉积物,文章从18个站位选取了30个样品开展碎屑组分的地球化学分析,通过在具有不同干湿环境背景的时间片段上开展盆地尺度的对比(约9.5~8.9 ka vs. 约1.7~0 ka),探讨全新世东地中海的陆源碎屑输入模式。Ti/Al、Zr/Al、Ca/Al、Y/Al都清晰显示了经向和纬向上的梯度变化,可用作撒哈拉风尘的可靠指标;这些碎屑元素之间的差异反映了北非风尘来源和传送路径的变化。这些风尘指标在南-北向上的一致变化指示了副热带高压与西风带的交互界限为36°N,该界限在全新世应稳定存在。与风尘相反,河流输入的指标值在早全新世时显著高于现代,并呈现不同的地理分布。K/Al具有西高东低、北高南低的分布特征,指示了地中海北部沿岸地区的河流输入。根据与Ti/Al、K/Al的差异,利用(Cr+Ni)/Al可较好地识别被增强的季风降雨所激活的北非古河流沉积。河流输入在早全新世时显著上升,但不同河流系统的影响范围差异很大,受制于源区水文气候、表层洋流搬运等因素。  相似文献   
214.
Two new fossil subgenera and two new fossil species of the genus Tipula Linnaeus, 1758, Tipula (Succinica) berendti subgen. and sp. n. and Tipula (Gedanica) adamowiczi subgen. and sp. n., are described from Baltic amber and compared with other species of Tipula known from the Eocene. The two new subgenera and species described herein are an excellent bridge between recent specimens and those preserved in sedimentary rocks, and thus enrich knowledge on the evolution of the family.  相似文献   
215.
In the series of analytical techniques for identification of chemical substances,infrared spectrometrypresents by far the highest information content.However,the information is most complicated too.Itconcerns a multitude of band positions,band intensities and band shapes,which,moreover,can bedisturbed by matrix and other effects.The high redundancy,however,allows conclusions to be made bya qualitative,subjective procedure.IR is often used to prove the equality between a sample and a reference material,e.g.in quality controlof a production process.In forensic control,the question to be answered is mostly not to prove equality,but whether or not the presence of a compound in a sample,e.g.a drug,can be proved.Moreover,testinghas to be performed according to objective rules.To fulfil these requirements,a new retrieval algorithm,the‘Adequate Peaks Search’,is presented.Itconcerns representing the reference spectra by sets of adequate peak positions and the sample spectrumby a set of all peak positions,whereafter the cross-sections of the sample set and the reference sets aredetermined.The concept‘adequate peak’is defined and criteria have been formulated to evaluate theresults into a positive(presence of the analyte is proved) or negative(presence is not proved)conclusion.The detection limit when the Adequate Peaks Search(APS)method was applied was four to seven timeslower than that attained by a number of experts.  相似文献   
216.
This paper deals with the effect of rainfall on the process of wind erosion of beach sands and presents results from both field and wind tunnel experiments. Although sediment transport by splash is of secondary importance on coastal dunes, splash–saltation processes can move sediments in conditions where no motion is predicted by aeolian processes. The effect of raindrop impact on the movement of soil particles by wind was measured on a sand beach plain using an acoustic sediment sampler. In general, an increase of particle movement by wind at the sensor heights was observed during rainfall. Rainfall also affected the wind erosion process during and after rain by changing the cohesive conditions of the surface. The influence of the surface moisture content on the initiation of wind erosion and on the vertical distribution of transported sand particles was studied in a wind tunnel. Moisture significantly increased threshold wind velocities for the initiation of sediment transport and modified vertical sediment profiles.  相似文献   
217.
218.
A new physically based hydrological and soil erosion model has been developed, which can be used for planning and conservation purposes: the LImburg Soil Erosion Model (LISEM). The LISEM model is one of the first examples of a physically based model that is completely incorporated in a raster Geographical Information System. This incorporation facilitates easy application in larger catchments, improves the user friendliness by avoiding conversion routines and allows remotely sensed data to be used. Processes incorporated in the model are rainfall, interception, surface storage in micro-depressions, infiltration and vertical movement of water in the soil, overland flow, channel flow, detachment by rainfall and throughfall, detachment by overland flow and transport capacity of the flow. Special attention has been given to the influence of tractor wheelings, small roads and surface sealing. Vertical movement of water in the soil is simulated using the Richard's equation. Optionally, the user can choose the Holtan or the Green–Ampt infiltration model. For the distribution flow routing, a four-point finite-difference solution of the kinematic wave is used together with Manning's equation.  相似文献   
219.
首次在中国发现的矿物   总被引:2,自引:0,他引:2  
本文主要内容是根据作者近期发表在英文杂志《岩石与矿物》上的同名文章译成的,它追述了在中国发现的新矿物种(类)的基本历史。列出了在中华人民共和国发现的99种矿物的名字及其发现地点和文献出处。本文修正了英语文献中的大量错误,从语言学角度介绍了矿物学在英文和中文交流之间存在的困难。作者为中文稿增加了一些新内容,更新了几处发现地的资料,还增加了一个新矿物:碲锌(铁)石(Zineospiroffite),它发表在英文稿付印之后。本文按化学组成和年代顺序对中国发现的新矿物进行了分析。所有列出的新矿物都是经过IMA-CNMMN批准的或者是“祖先级”(“grandfathered”)的矿物,只有一个是没有被批准的矿物。新矿物是按英文字母的顺序排列的。  相似文献   
220.
This paper demonstrates the utility of satellite remote sensing data in water management, and particularly, for flood monitoring and impact analysis. Satellite-derived data can provide timely geographical data from which water body extent in normal and flood regimes can be ascertained. Combined with exogenous and historical data, within a GIS, these can provide information useful for flood prevention decision making. The recent French Alsation, Camargue and Vaison la Romaine floods are taken to illustrate the utility of satellite remote sensing. © 1997 John Wiley & Sons, Ltd.  相似文献   
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