火山热液型铅锌矿床岩石地球化学特征及预测指标   总被引：2，自引：1，他引：1  

刘崇民  马生明  胡树起  王之峰  汤丽玲  李冰 《物探与化探》2008,32(2):154-158

火山热液型铅锌矿床赋矿围岩、后期脉岩和蚀变岩石中成矿元素铅锌银含量高,矿体元素组合复杂,原生异常发育,并存在着原生分带现象。矿体前缘元素为I、Hg、As、Sb、B、Ba;近矿指示元素是Pb、Zn、Ag、Au、Cd、Mn、Cu;尾部或矿下指示元素为Cu、Mo、W、Sn。根据矿床指示元素的分布规律和原生晕的分带性,研制了判别矿床剥蚀程度和评价异常的地球化学指标,建立了该类矿床的地球化学找矿预测标志。  相似文献   

一个新的沉积变质型钛矿床的成矿模式及找矿方法     

王君恒  潘竹平  郭雷  张宏萄  孟贵祥  刘光海 《物探与化探》2008,32(3):233-240

内蒙古羊蹄子山沉积变质型钛矿床是一个新的钛矿床类型。通过对地质、地球物理前提条件的研究和找矿方法试验,认为高精度磁法是找沉积变质型钛矿床的基本方法,重力为有效的找矿方法。在矿区北带磨石山以金红石为主的富钛矿体上有600 μGal的重力异常,无磁异常;南带的羊蹄子山钛铁矿体上重力异常为500 μGal,有60 nT的弱磁异常。  相似文献   

商城县汤家坪钼矿地球化学特征及找矿远景     

杨泽强 《物探与化探》2008,32(6)

矿区地质、地球化学特征研究入手,总结了综合找矿标志,指出了进一步找矿方向。研究表明该矿床成矿组分单一,异常元素组合主要为Mo、Bi、Ag,次为W、Sn、Zn、Cu、Pb,仅有钼能形成较大规模的异常;矿床元素水平分带序列为(Mo-Bi-Ag)-(W-Sn)-(Pb-Zn-Cu),垂向分带序列为(Mo-Ag-Pb-Zn)-Cu-(Bi-W-Sn),并以w(Mo)/[w(Bi)×100]≥65,[w(Pb)×w(Zn)/w(W)×w(Sn)]≥25为判别标志,来预测深部盲矿体的存在。  相似文献   

Direct shear tests on Mexico City clay with reference to friction pile behaviour     

E. Ovando-Shelley 《Geotechnical and Geological Engineering》1995,13(1):1-16

Summary This paper presents results of static and cyclic direct shear tests performed on undisturbed and remoulded samples of Mexico City clays, including results of soil-on-interface tests. Experiments show that the static adhesion coefficient depends on the soils' liquidity index and that it diminishes due to the effect of repeated dynamic loads. Dynamic overstrength effects were not apparent, as has been observed when testing this clay in other apparatus. Interface strength in remoulded clays is initially less than half the strength of interfaces with undisturbed materials but it increases with time. At least in the materials tested in this research, it did not equal the strength of interfaces with undisturbed materials. Correction factors derived from experimental data can be used to modify the adhesion coefficient to account for dynamic and remoulding effects.  相似文献   

老湾金矿床地球物理特征及找矿标志   总被引：4，自引：2，他引：4  

马长源  简新玲 《物探与化探》2003,27(2):83-87,100

老湾金矿是我国近年来探明的重要的大型构造蚀变岩型金矿床.金矿体(或矿脉群)、控矿构造、岩浆岩、赋矿地层、近矿热液蚀变带以及周围地质体之间存在某种物性差异,因而有明显的地球物理异常特征,构成了金矿床重要的地球物理找矿标志.作者试图在矿床地球物理特征研究的基础上,总结地球物理找矿标志,确定找矿勘查物探方法组合流程,以期配合、指导正在进行中的桐柏-大别山北坡金银成矿带的普查找矿工作.  相似文献   

Copper-Polymetal Metallogenic Series and Prospecting Perspective of Eastern Section of Gangdise   总被引：1，自引：0，他引：1  

ZhengYouye XueYingxi GaoShunbao 《中国地质大学学报(英文版)》2003,14(4):349-355

Geological, geophysical, geochemical and remote sensing comprehensive studies show that big ore-prospecting potentiality is contained in the eastern section of the Gangdise Mountains, Tibet.There are various mineralization types with dominant types of porphyry and exhalation. According to their relations with tectonic evolution, they are divided into four kinds of metallogenic series as follows:magnmtic type (Cr, Pt, Cu, Ni) and exhalation type (Cu, Pb, Zn, Ag) ore deposit series related to Neo-Tethys oceanic crust subduction action (125-96 Ma); epithermai type (Au, Ag, Pb, Zn, Sb), altered fractured rock type (Cu, Mo) and skarn rock type (Cu) ore deposit series related to arc-continental collision; porphyry type (Cu, Mo), cryptoexplosion breccia type (Cu, Au, Pb, Zn), shear zone type (Au, Ag, Sb) and skarn rock type (Cu, Fe) ore deposit series with relation to post-orogenic extensional strike-slip. From subductive complex to the north, zoning appears to be crystallization differentiation type (segregation type)-shear zone type (altered rock type)-skarn rock type, epithermai type-porphyry type-porphyry type and exhalation type-exhalation type-hydrothermai filling-replacement type.The ore deposit is characterized by multi-places from the same source, parity and multi-stage, hypabyssal rock from the deep source and poly genetic compound as a whole.  相似文献   

基于直射辐射遥感图象的地物双向反射特性研究(英文)     

李先华  李琦  喻歌农  兰立波  杨武年  池天河  黄雪樵 《遥感学报》1997,(Z1)

该文讨论了一种在ＧＩＳ支持下利用直射辐射遥感图象研究地物双向反射特性的原理和方法。其主要依据是象元地面的坡度和坡向的不同，同时改变了象元地面与太阳之间、象元地面与卫星传感器之间的相对位置，并且造成了同类象元太阳直射辐射遥感分量的差异。而正是这种差异体现了该类地物双向反射特性。在ＧＩＳ的支持下利用卫星直射辐射遥感数字图象，研究卫片象元同类地物的这种差异的规律以及它们与对应坡面上的太阳位置、卫星位置的关系，便可进行该类地物的双向反射特性研究。  相似文献   

综合气体地球化学测量     

尹冰川 《物探与化探》1997,21(4):241-246

本文在综合大量资料的基础上,总结了气体地球化学的发展历史,对有关综合气体测量在发展过程中出现的一些术语,阐述了一点浅见,介绍了综合气体测量的采样方法、理论依据,提出了综合气体测量的发展方向。  相似文献   

Laboratory and Numerical Studies of the Convective Boundary Layer Capped by a Strong Inversion     

Yuji Ohya  Takanori Uchida 《Boundary-Layer Meteorology》2004,112(2):223-240

The convective boundary layer (CBL) with a wide range of stability is simulated experimentally using a thermally stratified wind tunnel, and numerically by direct numerical simulation (DNS). The turbulence structures and flow characteristics of various CBL flows, capped by a strong temperature inversion and affected by surface shear, are investigated. The various vertical profiles of turbulence statistics similar to those from the observed CBL in the field are successfully simulated in both the wind-tunnel experiment and in DNS. The comparison of the wind-tunnel data and DNS results with those of atmospheric observations and water-tank studies shows the crucial dependence of the turbulence statistics in the upper part of the layer on the strength of the inversion layer, as well as the modification of the CBL turbulence regime by the surface shear.  相似文献   

Influence of the total atmospheric optical depth and cloud cover on solar irradiance components     

K. O. Ogunjobi  Y. J. Kim  Z. He   《Atmospheric Research》2004,70(3-4):209-227

Broadband solar irradiance data obtained in the spectral range 400–940 nm at Kwangju, South Korea from 1999–2000 have been analyzed to investigate the effects of cloud cover and atmospheric optical depth on solar radiation components. Results from measurements indicate that the percentage of direct and diffuse horizontal components of solar irradiance depend largely on total optical depth (TOD) and cloud cover. During summer and spring, the percentages of diffuse solar irradiance relative to the global irradiance were 5.0% and 4.9% as compared to 2.2% and 3.0% during winter and autumn. The diffuse solar irradiance is higher than the direct in spring and summer by 24.2%, and 40.6%, respectively, which may largely be attributed to the attenuation (scattering) of radiation by heavy dust pollution and large cloud amount. In cloud-free conditions with cloud cover ≤2/10, the fraction of the direct and diffuse components were 66.0% and 34.0%, respectively, with a mean daily global irradiance value of 7.92±2.91 MJ m⁻² day⁻¹. However, under cloudy conditions (with cloud cover ≥8/10), the diffuse and direct fractions were 97.9% and 2.2% of the global component, respectively. The annual mean TOD under cloudless conditions (cloud cover≤2/10) yields 0.74±0.33 and increased to as much as 3.15±0.67 under cloudy conditions with cloud amount ≥8/10. An empirical formula is derived for estimating the diffuse and direct components of horizontal solar irradiance by considering the total atmospheric optical depth (TOD). Results from statistical models are shown for the estimation of solar irradiance components as a function of TOD with sufficient accuracy as indicated by low standard error for each solar zenith angle (SZA).  相似文献