Integrated studies for characterization of lineaments used to locate groundwater potential zones in a hard rock region of Karnataka, India

An integrated study was carried out to investigate the subsurface geological conditions in a hard rock environment, with the aim of identifying zones with groundwater resource potential. The study, in Bairasagara watershed, Karnataka, India, considered geomorphology, water level, resistivity imaging, self potential, total magnetic field and susceptibility. The signatures due to lineaments have been clearly identified and their role in groundwater movement has been documented. Synthetic simulation methods were used to model the electrical response of the lineament using finite differential modeling scheme. The inverted image of the field data is compared with the synthetic image and iteration were performed on the initial model until a best match was obtained resulting on the generation of the calibrated resistivity image of the subsurface. Resistivity imaging revealed that the dykes are weathered/fractured to a depth of 6–8 m and are compact at deeper levels, and that they behave as barriers to groundwater movement, yet facilitate a good groundwater potential zone on the upgradient side. The results of magnetic surveys were utilized in differentiating granites and dolerite dykes with an insignificant resistivity contrast. Geomorphological expression alone cannot reveal the groundwater potential associated with a lineament. However, characterizing the nature of the feature at depth with integrated geophysical methods provides essential information for assessing that potential.The online version of the original article can be found at     

电磁波CT成像技术在防水工程场地勘查中的应用

电磁波CT成像技术是基于地下介质的物性差异，利用各种波源透视探测目的体及地质现象的一种地球物理方法，文章介绍了电磁波CT成像技术的原理和工作方法、某防水工程场地电磁波CT成像勘查实例及应用效果。     

陆-陆碰撞造山环境下含铜斑岩岩石成因——以藏东玉龙斑岩铜矿带为例

大型斑岩铜矿不仅可以形成于陆缘弧和岛弧构造环境,而且还可以形成于陆-陆碰撞造山环境.然而,对陆-陆碰撞造山环境下含矿斑岩的成因仍存在很大的争论.本文以藏东玉龙斑岩铜矿带为例,从岩相学、元素地球化学以及Sr-Nd-Pb-Hf同位素地球化学等方面较系统地研究了含矿斑岩岩石成因.结果表明,含矿斑岩属于钾玄质岩石,同时具有埃达克岩某些地球化学特征.岩石是由至少100km深处的二辉橄榄质岩石圈地幔中交代成因的金云母-石榴石单斜辉石岩脉发生低程度部分熔融而形成的.印度-亚洲大陆碰撞形成了金沙江区域性走滑断裂系统,并导致软流圈地幔上涌,最终诱发交代岩石圈地幔的部分熔融而形成含矿斑岩.它对于进一步认识陆-陆碰撞造山环境下含矿斑岩的起源以及斑岩型铜矿的成因具有较为重要的意义.     

成像光谱遥感技术及其在地质中的应用

成像光谱遥感技术作为20世纪80年代初发展起来的新型遥感技术,代表了遥感定量化的发展方向。概述了当前成像光谱遥感技术的发展和应用现状,探讨了成像光谱数据的特点及其处理技术方法,并介绍了其在地质领域的应用。     

Oblique photogrammetry with visible and thermal images of active lava flows

Digital images from hand-held cameras are increasingly being acquired for scientific purposes, particularly where non-contact measurement is required. However, they frequently consist of oblique views with significant camera-to-object depth variations and occlusions that complicate quantitative analyses. Here, we report the use of oblique photogrammetric techniques to determine ground-based thermal camera orientations (position and pointing direction), and to generate scene information for lava flows at Mount Etna, Sicily. Multiple images from a consumer grade digital SLR camera are used to construct a topographic model and reference associated ground-based thermal imagery. We present data collected during the 2004–2005 eruption and use the derived surface model to apply viewing distance corrections (to account for atmospheric attenuation) to the thermal images on a pixel-by-pixel basis. For viewing distances of ~100 to 400 m, the corrections result in systematic changes in emissive power of up to ±3% with respect to values calculated assuming a uniform average viewing distance across an image.     

Si- and alkali-rich melt inclusions in minerals of mantle peridotites from eastern China: Implication for lithospheric evolution

CO2 fluid inclusions in mantle minerals are an im-portant source for us to get the information of mantle fluids. Fluid inclusions are mainly composed of CO2, with minor CO, H2O, CH4, N2, H2S, SO2, F, etc., which were demonstrated by lots of Raman spec-trometer analyses in recent years. In contrast, there are very few researches on CO2-bearing melt inclusions since it is more difficult to do so. The available studies have found that the primary CO2-bearing melt inclu-sions are basaltic …     

Numerical simulation of three-dimensional saltwater–freshwater fingering instabilities observed in a porous medium

We consider saltwater–freshwater fingering instabilities in a saturated porous medium. In the first part, we present three-dimensional results obtained from a laboratory experiment using non-invasive imaging. In the second part, we define a set of model problems in which the performed laboratory experiments can be ranged in. Due to its highly non-linear behavior and inevitable modeling errors, a detailed numerical reproduction of the physical concentration measurements cannot be expected. Nevertheless, four criteria have been identified, two quantitative and two qualitative, which facilitate a substantiated comparison of the physical experiment and the numerical simulation. With respect to these criteria a high degree of similarity could be observed. The use of these features allows a deeper understanding of the physical processes and the influence of the initial conditions.     

无人机载线阵摆扫CCD影像几何校正

充分利用无人机载GPS/INS组合导航系统提供的导航遥测数据,首先分析线阵CCD传感器摆扫成像的基础原理和成像特点,并建立严格的成像模型;然后提出线阵摆扫CCD影像严格几何校正的详细算法和流程;最后进行多组实验证实成像模型和几何校正算法的正确性和准确性。实验结果证实采用文中的成像模型和几何校正流程,可获得正确、高精度地理编码的线阵摆扫CCD正射影像。