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目前,国内众多矿山急需一些投资小、见效快的勘探方法,以解决燃眉之急。将电法勘探中的激发极化法应用于矿山坑道,利用坑道有限的空间区域,开展就矿找矿,是较为理想的选择。实际测量中采用穿、沿脉结合的测量方法,寻找坑道附近的隐伏矿体或评价已知矿体的规模等,为矿山扩大储量服务。近年来,前人在坑道激电的应用方面做了不少工作,也积累了不少好的经验。笔者在吸收前人工作经验的基础上,在陕西某金矿和内蒙某金矿应用坑道激电寻找深部隐伏矿,为矿山解决接替资源问题,取得了良好的效果。同时,指出了开展坑道激电深部找矿时需要注意的几个问题,包括空间的制约、噪声的影响、电磁波的干扰以及矿体分布的全方位等,希望能给以后的工作者起到一定的借鉴意义。 相似文献
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ICP-AES 法测定地质样品中微量锆、 铪的研究 总被引:2,自引:0,他引:2
摘 要 在2%酒石酸介质中用阳离子交换树脂吸附干扰元素以 ICP-AES 法分别在
343∙823nm 和264∙141nm 直接测定地质样品中的微量锆和铪。锆的检出限为0∙5×10
-6 铪
为0∙4×10
-6 。此方法简单、快速应用于地球化学标准样品中锆和铪的分析取得了满意
的结果。 相似文献
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By analyzing the deep seismic sounding profiles across the Longmen Shan,this paper focuses on the study of the relationship between the upper crust structure of the Longmen Shan area and the Wenchuan earthquake.The Longmen Shan thrust belt marks not only the topographical change,but also the lateral velocity variation between the eastern Tibetan Plateau and the Sichuan Basin.A lowvelocity layer has consistently been found in the crust beneath the eastern edge of the Tibetan Plateau, and ends beneath the ... 相似文献
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Deep Background of Wenchuan Earthquake and the Upper Crust Structure beneath the Longmen Shan and Adjacent Areas 总被引:5,自引:0,他引:5
LI Qiusheng GAO Rui WANG Haiyan ZHANG Jisheng LU Zhanwu LI Pengwu GUAN Ye HE Rizheng 《《地质学报》英文版》2009,83(4):733-739
Abstract: By analyzing the deep seismic sounding profiles across the Longmen Shan, this paper focuses on the study of the relationship between the upper crust structure of the Longmen Shan area and the Wenchuan earthquake. The Longmen Shan thrust belt marks not only the topographical change, but also the lateral velocity variation between the eastern Tibetan Plateau and the Sichuan Basin. A low-velocity layer has consistently been found in the crust beneath the eastern edge of the Tibetan Plateau, and ends beneath the western Sichuan Basin. The low-velocity layer at a depth of ~20 km beneath the eastern edge of the Tibetan Plateau has been considered as the deep condition for favoring energy accumulation that formed the great Wenchuan earthquake. 相似文献
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V.B. Kaplun 《Russian Geology and Geophysics》2018,59(4):419-431
The paper describes the results of magnetotelluric sounding (MTS) carried out in the Zeya block of the Stanovoi megablock, in the area of its junction with the Aldan Shield. The border between them runs along the Stanovoi fault. Based on the results of interpretation of MTS curves and the gravity, magnetic, and geological data, geological/geophysical sections have been constructed to a depth of 7 km along two ~ 20 km long profiles running across the Stanovoi fault. About 1 km thick and approximately 2 km long conductivity zone has been distinguished beneath the Okonon plateau of Quaternary basalts with electrical resistivity of < 100 Ohmm. This anomaly is associated with ore mineralization in Early Proterozoic gabbro intrusion. A 3D density modeling was performed. High-density bodies of NW strike dip to the northeast to a depth of 25 km in the area of the Okonon basalt plateau.?Corresponding author. 相似文献
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内蒙古东部区深部构造特征和大地构造问题浅议 总被引:6,自引:0,他引:6
内蒙古东部区为镜像异常区 ,莫霍面隆坳与现代地貌特征呈镜像关系。松辽前寒武古陆块 (含开鲁坳陷 ) ,是大中型移置体 ;大兴安岭是松辽地体与蒙古板块 (兴安古生代褶皱系 )挤压碰撞活动的产物 ;大兴安岭以东是中生代构造区 ,希洛克—石勒喀—鄂霍茨克中生代缝合带 ,是西伯利亚和华北地台东段拼合位置。 相似文献
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XIONG Xiaosong WANG Guan LI Qiusheng LU Zhanwu GAO Rui FENG Shaoying WU Guowei 《《地质学报》英文版》2022,96(6):1932-1944
The Chuan-Dian Block (CDB) is located in the southeastern margin of the Tibetan Plateau, with a complex geological structure and active regional faults. The present tectonic condition with strong crustal deformation is closely related to the ongoing collision of the India and Eurasia plates since 65 Ma. The study of the crustal structure of this area is key to revealing the evolution and deep geodynamics of the lateral collision zone of the Tibetan Plateau. Deep seismic sounding is the most efficient method with which to unravel the velocity structure of the whole crust. Since the 1980s, 19 deep seismic sounding profiles have been captured within the CDB area. In this study, we systematically integrate the research results of the 19 profiles in this area, then image the 3D crustal velocity, by sampling with a 5 km spacing and 2D/3D Kriging interpolation. The results show the following. (1) The Moho depth in the study area deepens from 30 km in the south to 66 km in the north, whereas there is no apparent variation from west to east. The Pn wave velocity is higher in stable tectonic units, such as 7.95 km/s in the Lanping-Simao block and 7.94 km/s in the western margin of the Yangtze block, than in active or mobile tectonic units, such as 7.81 km/s in the Baoshan block, 7.72 km/s in the Tengchong block and 7.82 km/s in the Zhongdian block. (2) The crustal nature of the Tengchong block, the northern Lanping-Simao block and the Zhongdian block reflects a type of orogenic belt, having relatively strong tectonic activities, whereas the crustal nature of the central Lanping-Simao block and the western margin of the Yangtze block represents a type of platform. The different features of the upper-middle crust velocity, Moho depth and Pn wave velocity to both sides of the Red River fault zone and the Xianshuihe fault zone, reflect that they are clearly ultra-crustal. (3) Based on the distribution of the low velocity zones in the crust, the crustal material of the Tibetan Plateau is flowing in a NW–SE direction to the north of 26°N and to the west of 101°E, then diverting to flowing eastwards to the east of 101°E. 相似文献
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TECTONIC EVOLUTION OF THE WESTERN KUNLUN AND KARAKORAM MOUNTAINS—SOME NEW OBSERVATIONS FROM A MULTI-DISCIPLINARY GEOSCIENTIFIC TRANSECT (MGT) IN NW TIBET 相似文献
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The method of complex demodulation has been used here to compute the amplitude and phase of a signal present in a geomagnetic
series using, Banks’ method. It is found that the results are quite accurate when four or more continuous cycles of the signal
of interest are present. The same limitations have also been observed when band-pass filters are used to isolate a signal.
The information on phase is always correct. It is concluded that complex demodulation will give correct results for periodic
variations like 11-year, 27-day, Sq or pulsations; but will give small values of amplitude for signals like sudden impulses
or bays. The latter is not a limitation in conductivity studies where ratios likeZ/H, Z/D orH/D are mostly used in calculations. It has been shown that even with the records of one magnetic storm the cause of anomalies
can be accurately identified which otherwise would need a large number of events. 相似文献
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中国大陆科学钻探场址区的地壳速度结构特征 总被引:4,自引:0,他引:4
为了深入研究大别—苏鲁超高压变质带的深部结构及空间展布特征, 进一步揭示该超高压变质形成的动力学过程, 在中国大陆科学钻探场址区进行了广角反射/折射地震测深调查.根据广角反射/折射地震测深的资料研究, 建立了中国大陆科学钻探场址区的地壳纵波速度结构.从纵向上来看, 研究区域的地壳结构可划分为上、中、下3层: 上地壳的速度小于6.2 0km/s, 厚10余km; 中地壳的速度为6.4 0km/s, 厚亦为10km左右; 下地壳的速度为6.6 0km/s.地壳厚度为31km左右, 且其地壳的平均速度为6.30km/s.上地壳中的速度倒转指示了超高压变质体在地壳内部的空间分布, 且超高压变质体在大陆科学钻探场址及其附近的下部呈现为一隆起形态. 相似文献
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东昆仑大地震的深部构造背景 总被引:5,自引:1,他引:5
本文以深地震测深剖面资料揭示的地壳结构形态为切入点 ,探讨东昆仑 8.1级大地震的深部构造背景。沱沱河—小柴旦长 5 0 0km的剖面范围内发现两处大的莫霍面错断 ,分别位于东昆仑 柴达木结合带之下和金沙江断裂之下。青藏高原北部的地壳厚度 6 1~ 75km :莫霍面具有一致南倾 ,逐步加深的产状及弱反射性特征 ;下地壳明显增厚 ,但速度未见明显降低 ;上地壳发育逆冲、走滑断裂 ;地壳中部存在低速层。北邻的柴达木盆地地壳相对刚性 ,厚 5 2± 2km。东昆仑及邻区的壳幔结构有利于强地震孕育。在印度板块向北推挤和柴达木地块的向南插入的区域挤压应力场中 ,青藏高原北部较弱的下地壳缩短增厚 ,变形过程中的蠕滑引起地壳浅部的应力放大。但NE向主压应力的作用不是大地震形成的唯一要素 ,与青藏高原北部各地体侧向运动有关。侧向运动速率和幅度的差异使应力在各地体的边界断裂积累并使其复活。而低速层对形成孕育大地震需要的“立交桥式”的局部应力环境是必不可少的条件。 相似文献
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In 1967 a major earthquake in the Koyna region attracted attention to the hitherto considered stable Indian shield. The region is covered by a thick pile of Deccan lava flows and characterized by several hidden tectonic features and complex geophysical signatures. Although deep seismic sounding studies have provided vital information regarding the crustal structure of the Koyna region, much remains unknown. The two available DSS profiles in the region have been combined along the trend of Bouguer gravity anomalies. Unified 2-D density modelling of the Koyna crust/mantle suggests a ca. 3 km thick and 40 km wide high velocity/high density anomalous layer at the base of the crust along the coastline. The thickness of this anomalous layer decreases gradually towards the east and ahead of the Koyna gravity low the layer ceases to be visible. Based on the seismic and gravity data interpretation in the geodynamical/rheological boundary conditions the anomalous layer is attributed to igneous crustal accretion at the base of the crust. It is suggested that the underplated layer is the imprint of the magmatism caused by the deep mantle plume when the northward migrating Indian plate passed over the Reunion hotspot. 相似文献