秦岭地区煌斑岩特征及其与金矿成矿关系   总被引：1，自引：1，他引：0  

涂怀奎 《黄金地质》1999,5(4):37-42

秦岭地区广泛分布有煌斑岩,其主要赋存于古生界志留系与濯舅系的粉砂质板岩中,大部分含金较高。经不同成矿区煌斑岩与金矿关系的对比研究,认为其具有相似性,并与金成矿关系密切。对煌斑岩出露区的找矿标志以及本区的找矿方向作了分析。  相似文献   

Correlation of mineralogical and textural characteristics with engineering properties of selected granitic rocks from Turkey   总被引：3，自引：0，他引：3  

A. Tu rul  I. H. Zarif 《Engineering Geology》1999,51(4):506-317

Granitic rocks show a variety of engineering properties that may affect quarrying operations, tunneling, mining, slope stability and the use of rock as a construction material. The physical and mechanical properties are a function of the mineralogical and textural characteristics of the rock. The purpose of this study is to apply correlation analysis to investigate the relationships between petrographical and engineering properties of granitic rocks. A variety of granitic rock samples from different parts of Turkey were subjected to petrographic studies. The same samples were then tested to determine specific gravity, dry and saturated unit weight, water absorption, effective and total porosity, sonic velocity, Schmidt hardness, point load strength index, uniaxial compressive strength, tensile strength and modulus of elasticity. The relationships between these properties and the petrographical characteristics are described by simple regression analyses. The study revealed that the influence of the textural characteristics on the engineering properties appears to be more important than the mineralogy. It also determined that the types of contacts, grain (mineral) shape and size significantly influence the engineering properties of the granitic rocks.  相似文献   

Research on limestone decay in a polluting environment, I˙stanbul-Turkey     

A. Tuğrul  H.Ì. Zarif 《Environmental Geology》1999,38(2):149-158

 I˙stanbul, the capital of the east Roman, Byzantine and Ottoman Empires embraces two continents, one arm reaching out to Asia, the other to Europe. It is therefore, a rich city in terms of monuments and historical cites. Shell limestones of Upper Miocene age are used as building stone in the majority of the monuments in I˙stanbul because of their attractiveness, availability and workability. The durability characteristics of the limestones are examined, and those factors that are responsible for atmospheric weathering are discussed, in a humid and marine environment with important problems of urban pollution, specifically due to traffic. In the present study weathering of the building stones were first examined in situ by macroscopic observations. The weathering that developed as a result of environmental effects since this limestone was first used in historical monuments has been affected 0.1–1.5 cm deep from the surface. The weathered facing stone of Şehzade Mehmed Mosque in I˙stanbul is undergoing a program of progressive replacement. During this study, samples were taken from this monument where the shell limestone was used. The stone surface was principally examined by means of Scanning Electron Microscopy (SEM). Petrographical and mineralogical analyses were made by using optical microscopy and X-ray diffraction method. The physico-chemical properties of these rocks control their weathering behaviour and reactivity. Major and trace element analyses and the effect of deterioration on the physical properties of the limestones (unit weight, porosity and water absorption) have also been investigated. Studies on the samples implies that weathering on the stone surface caused important variations on the physical characteristics of the rock. Received: 11 February 1998 · Accepted: 18 August 1998  相似文献   

老君山成矿区变质成因夕卡岩的地质地球化学特征   总被引：16，自引：1，他引：15  

曾志刚  李朝阳  刘玉平  涂光炽 《矿物学报》1999,19(1):48-55

老君山成矿区广泛分布的夕卡岩是主要含矿岩层。通过对夕卡岩地质特征岩石化学特征、稀土结球化学特征和成岩年龄的分析研究,证明了夕卡岩是区域变质作用的产物。  相似文献   

广西1999年度气候特点及其影响评价     

周玲萍  黄雪松  涂方旭 《气象研究与应用》2000,21(1):33-38

分析广西1999年度（1998年12月至1999年11月）的气候状况,其特点为：各地年平均气温17.3～23.8℃,比常年偏高0.5～1.3℃;有49个县市（占56%）气温异常偏高,有25个县市（占29%）气温显著偏高;全区年平均气温21.2℃,比常年偏高0.8℃,与1998年并列为广西自1959年以来第2暖年。年降水量为928～2399mm,与常年相比,桂北正常到偏多3成,桂南正常到偏少2成。年日照时数1060～2362h,大部地区比常年偏少50～300h。主要气候事件及其影响以大范围长时间冬春连旱最为突出,其次是汛期局部暴雨洪涝。1999年度气温异常偏高,降水接近常年,日照稍少,冬春连旱严重,对农业生产的影响利弊同存,属正常偏好年景。  相似文献   

QBO的变化特征及其与广西气候变化的关系     

李耀先  涂方旭  李秀存  覃峥嵘 《气象》2000,26(12):29-30

利用平流层月矢量平均纬向风资料,分析了平流层风场的准两年振荡（ＱＢＯ）的演变特征,找出ＱＢＯ与广西气候变化的一些关系。  相似文献   

近百年北半球陆面降水资料的插补及初步分析   总被引：6，自引：2，他引：4  

李庆祥  屠其璞 《南京气象学院学报》2000,23(4):528-535

采用ＥＯＦｓ展开方法插补延长了一个北半球陆面月降水资料,并讨论了该资料插补工作的合理性。利用该资料初步分析了近百年北半球陆面降水的基本特点。  相似文献   

秦岭地区蚀变煌斑岩型金矿的发现及金的预富集研究   总被引：7，自引：1，他引：6  

涂怀奎 《地质论评》2000,46(5):543-548

秦岭地区煌斑岩广泛分布,大部分蚀变煌斑岩型金矿发现于微成盆地南侧。本文对煌斑岩金的预集提出了认识,深入研究蚀变煌斑岩型金矿中金的预富集和成矿特征有望扩大在秦岭地区的找金前景。  相似文献   

南沙群岛海区晚第四纪深海碳酸盐沉积作用   总被引：5，自引：1，他引：5  

吴时国  涂霞 《海洋地质与第四纪地质》1996,16(3):67-80

根据５个柱样分析，讨论了冰期一间冰期碳酸盐沉积作用变化，南沙海区碳酸盐旋回在３５００ｍ以浅表现为大西洋旋回，源于冰期陆源碎屑物质的稀释作用，相反，在３５００ｍ以下出现太平洋碳酸钙旋回，文中根据浮游有孔虫的溶解指数和种属数量讨论了冰期－间冰期溶解作用变化。  相似文献   

Assimilation of sea surface temperature in the Northwest Pacific Ocean and its marginal seas using the ensemble Kalman filter   总被引：2，自引：0，他引：2  

Gwang-Ho Seo  Byoung-Ju Choi  Yang-Ki Cho  Young Ho Kim  Sangil Kim 《Ocean Science Journal》2010,45(4):225-242

Satellite-borne sea surface temperature (SST) data were assimilated with the ensemble Kalman filter (EnKF) in a Northwest Pacific Ocean circulation model to examine the effect of data assimilation. The model domain included the northwestern part of the Pacific Ocean and its marginal seas, such as the Yellow Sea and East/Japan Sea. The performance of the data assimilation was evaluated by comparing the simulated ocean state with that observed. Spatially averaged root-mean-squared errors in the SST and sea surface height (SSH) decreased by 0.44 °C and 4 cm, respectively, by the assimilation. The results of the numerical experiments substantiated the effectiveness of the SST assimilation via the EnKF for all marginal seas, as well as the Kuroshio region. The benefit of the data assimilation depended on the characteristics of each marginal sea. The variation of the SST in the East/Japan Sea and the Kuroshio extension (KE) region were improved 34% and those in the Yellow Sea 12.5%. The variation of the SSH was improved approximately 36% in the KE region. This large improvement was achieved in the deep-water regions because assimilation of SST data corrected the separation point of the western boundary currents, such as the Kuroshio and the East Korea Warm Current, and the associated horizontal surface currents. The SST assimilation via the EnKF also improved the subsurface temperature profiles. The effectiveness of SST assimilation was seasonally dependent, with the improvement being relatively larger in winter than in summer, which was related to the seasonal variation of the vertical mixing and stratification in the ocean surface layer.  相似文献