胶东半岛发现元古宙蛇绿岩套          下载免费PDF全文

王仁民 《地震地质》1994,16(3):216-216

胶东半岛发现元古宙蛇绿岩套王仁民（北京大学地质学系，北京１００８７１）近年来在原胶东群内部，新发现一条ＮＮＥ走向的蛇绿岩套。层序基本齐全，出露宽约１５ｋｍ，从北海岸到南海岸延长在１００ｋｍ以上，大约在东经１２２°附近将胶东半岛分割为东西两半。蛇绿岩套  相似文献   

黄土高原小流域特性指标与产沙统计模式   总被引：27，自引：0，他引：27  

尹目康  陈钦峦 《地理学报》1989,44(1):32-46

本文从黄土高原实际情况出发，在广泛的野外考察基础上，收集了面积在0．193--329km2的58个小流域(包括21个变量)的系列数据。通过分析筛选，建立了流域地表综台特性指标：  相似文献   

Quantification of recent movement potentials in Schleswig-Holstein (Germany) by GIS-based calculation of correlation coefficients     

Rouwen Lehné  Frank Sirocko 《International Journal of Earth Sciences》2005,94(5-6):1094-1102

In order to investigate connections between deep tectonic and halokinetic structures and the development of recent topography, GIS-based calculation of correlation coefficients was carried out between different stratigraphic horizons of the deep Northwest German Basin (NGB) according to the “Geotektonischer Atlas von NW-Deutschland” and surface topography of Schleswig-Holstein. The results show seven areas of high correlation that are traceable from the Base Zechstein up to the recent surface topography. Five areas with high correlation are connected to NNE–SSW trending salt structures within the Glückstadt Trough, i.e. the area of the salt domes Oldensworth, Tellingstedt, Eisendorf and, to the north of Hamburg, the area of the salt domes Elmshorn and Sievershütten. Two areas, however, with NW–SE trending high correlation are located in the northwest (restricted to the Westschleswig Block) and the northeast (south of Fehmarn) outside the Glückstadt Trough. These NW–SE trending correlation areas are not related to known salt structures and/or faults but match the general orientation of faults in the NGB.  相似文献   

Correlation of the Kimmeridgian succession of the Normandy coast,northern France with that of the Dorset-type area,southern England     

Ramues Gallois 《Comptes Rendus Geoscience》2005,337(3):347-355

The Kimmeridgian Stage is represented in the cliffs of the Dorset-type area and those in Normandy by richly fossiliferous marine mudstones and limestones. Taken together, these coastal exposures provide the only complete composite outcrop through this part of the Jurassic in the Sub-boreal Faunal Province. Detailed correlations between the two successions are presented here: these enable the Normandy-coast sections to be more accurately placed than previously within in their regional chronostratigraphical context. The Normandy succession is more completely exposed than that in Dorset, and is situated midway between Dorset and the Sub-Tethyan succession of the Berry region. It therefore offers a better prospect than any English section for inter-province correlation at this stratigraphical level. To cite this article: R. Gallois, C. R. Geoscience 337 (2005).  相似文献   

Spatial association between residential radon concentration and bedrock types in New Hampshire     

Xun Shi  David J. Hoftiezer  Eric J. Duell  Tracy L. Onega 《Environmental Geology》2006,51(1):65-71

Using a large database of residential short-term radon measurements in New Hampshire, this study evaluated the ability of expert-assigned bedrock radon potential for predicting residential radon concentration. First, each bedrock type was assigned a radon potential level by a geologist familiar with the local geology. Then, using residential radon measurements, a continuous surface of radon concentration was generated through a kriging process. The mean residential radon concentration within the spatial extent of each bedrock type was then calculated based on that surface. The Spearman Rank Correlation Coefficient was calculated between the two ranks of the bedrock types, one based on the expert-assigned potential level and the other based on the mean residential concentration. A strong correlation between the rank correlation and the area of the bedrock type was found. When only the 15 largest bedrock types were used, the Spearman Correlation Coefficient reached 0.6. Geological knowledge is concluded to be useful in predicting and mapping residential radon concentration, but the prediction should be interpreted with caution, especially for areas in which the underlying bedrocks are highly localized.  相似文献   

Assessment of rock geomechanical quality by quantitative rock fabric coefficients: Limitations and possible source of misinterpretations     

Richard P&#x;ikryl 《Engineering Geology》2006,87(3-4):149-162

Rock microfabrics were quantified by image measurement system (petrographic image analysis) of thin sections. Along with common measured parameters (grain area and size, length of major and minor axes and their orientation), some quantitative parameters (aspect ratio, grain boundary smoothness) and fabric coefficients (micropetrographic quality index (K), “texture” coefficient (TC), indexes of interlocking (t) and grain size homogeneity (g)) were determined. The reliability of these parameters for the evaluation of geomechanical properties was tested on the set of granitic rocks showing pronounced variability in rock mechanical properties. None of the tested rock fabric coefficients or parameters proved a close correlation to rock mechanical properties except grain size. Based on experimental findings, the grain size is, along with porosity, the controlling factor of rock mechanical properties of genetically and mineralogically similar rocks. Obliteration of the real effects of rock fabric parameters on the mechanical properties of rocks by application of complex fabric coefficients disables their practical use in petrography applied to geomechanics.  相似文献   

中国-老挝古近纪钾盐矿对比   总被引：6，自引：0，他引：6  

张建林 《云南地质》2006,25(3):309-314

云南江城勐野井钾盐矿的探明，填补了我国无固体钾盐矿的史例。时代属古近系古新统（E1），与老挝万象钾镁盐矿属同时代、同构造带。勐野井钾盐矿赋存在勐野井组上部（E1me^3），属氯化钾（KCl）类；老挝万象钾镁盐矿属光卤石类，地层为古新统塔贡组下部（E1tg^1）。  相似文献   

Stratigraphy and ammonite fauna of the upper Shemshak Formation (Toarcian–Aalenian) at Tazareh, eastern Alborz, Iran   总被引：1，自引：0，他引：1  

K. Seyed-Emami  F.T. Fürsich  M. Wilmsen  F. Cecca  M.R. Majidifard  G. Schairer  A. Shekarifard 《Journal of Asian Earth Sciences》2006,28(4-6):259-275

With a thickness of 3900 m, the Tazareh section is one of the thickest developments of the Shemshak Formation in the Alborz range. It overlies with sharp and disconformable contact the limestones and dolomites of the Lower–Middle Triassic Elikah Formation and is topped, again with a disconformable contact, by the marls and limestones of the Middle Jurassic Dalichai Formation. The nearly exclusively siliciclastic succession represents a range of environments, from fluvial channels, flood plains, swamps and lake systems to storm-dominated shelf, and a comparatively deep marine and partly dysoxic basin. The segment of the section between 2300 and 3500 m is exclusively marine and contains a moderately diverse ammonite fauna, ranging from the Middle Toarcian to the Upper Aalenian. The ammonite fauna comprises 21 taxa, among them the new genus Shahrudites with two new species, Shahrudites asseretoi and S. stoecklini from the Middle Aalenian Bradfordensis Zone. The other ammonites from the Shemshak Formation at Tazareh (as elsewhere in North and Central Iran) are exclusively Tethyan in character and closely related to faunas from western and central Europe. An ammonite-based correlation of Toarcian–Aalenian successions of the eastern Alborz with time-equivalent strata of the Lut Block, part of the Central-East Iranian Microcontinent (ca. 500 km to the south), suggests a strong influence of synsedimentary tectonics during the deposition of the upper Shemshak Formation.  相似文献   

Performance of Multi Model Canonical Correlation Analysis (MMCCA) for prediction of Indian summer monsoon rainfall using GCMs output     

Ankita Singh  Nachiketa Acharya  Uma Charan Mohanty  Gopbandhu Mishra 《Comptes Rendus Geoscience》2013,345(2):62-72

The emerging advances in the field of dynamical prediction of monsoon using state-of-the-art General Circulation Models (GCMs) have led to the development of various multi model ensemble techniques (MMEs). In the present study, the concept of Canonical Correlation Analysis is used for making MME (referred as Multi Model Canonical Correlation Analysis or MMCCA) for the prediction of Indian summer monsoon rainfall (ISMR) during June-July-August-September (JJAS). This method has been employed on the rainfall outputs of six different GCMs for the period 1982 to 2008. The prediction skill of ISMR by MMCCA is compared with the simple composite method (SCM) (i.e. arithmetic mean of all GCMs), which is taken as a benchmark. After a rigorous analysis through different skill metrics such as correlation coefficient and index of agreement, the superiority of MMCCA over SCM is illustrated. Performance of both models is also evaluated during six typical monsoon years and the results indicate the potential of MMCCA over SCM in capturing the spatial pattern during extreme years.  相似文献   

Hydrodynamic characteristics of a typical karst spring system based on time series analysis in northern China     

《China Geology》2021,4(3):433-445

In order to study the hydrodynamic characteristics of the karst aquifers in northern China, time series analyses (correlation and spectral analysis in addition with hydrograph recession analysis) are applied on Baotu Spring and Heihu Spring in Jinan karst spring system, a typical karst spring system in northern China. Results show that the auto-correlation coefficient of spring water level reaches the value of 0.2 after 123 days and 117 days for Baotu Spring and Heihu Spring, respectively. The regulation time obtained from the simple spectral density function in the same period is 187 days and 175 days for Baotu Spring and Heihu Spring. The auto-correlation coefficient of spring water level reaches the value of 0.2 in 34–82 days, and regulation time ranges among 40–59 days for every single hydrological year. The delay time between precipitation and spring water level obtained from cross correlation function is around 56 days for the period of 2012–2019, and varies among 30–79 days for every single hydrological year. In addition, the spectral bands in cross amplitude functions and gain functions are small with 0.02, and the values in the coherence functions are small. All these behaviors illustrate that Jinan karst spring system has a strong memory effect, large storage capacity, noticeable regulation effect, and time series analysis is a useful tool for studying the hydrodynamic characteristics of karst spring system in northern China.© 2021 China Geology Editorial Office.  相似文献