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一概述磁法勘探在解释局部异常时,经常遇到选取正常场的问题.以往常用磁异常的中心剖面或主剖面求解正常场.但对平面上如何消除正常场影响,从而比较客观地突出局部异常特征的问题,一般考虑较少.在火山岩地区寻找铁矿,由于火山岩、次火山岩、深部矿体(有时还有深部的基底构造)往往都具有磁性,能产生各种干扰 相似文献
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利用区域地球物理资料研究天山和准噶尔地区的深部构造 总被引:3,自引:2,他引:3
当代地球科学的理论、方法和技术的发展以及电子计算机的应用,使地壳和上地幔的深部构造的研究成为现实。目前研究深部构造的方法很多,例如地震(天然和人工)、大地电磁等,但由于这些方法耗资巨大,研究范围受到限制。大面积地研究地壳深部构造仍然是利用重、磁资料,配合少量地壳测深以消除重、磁方法的多能性,提高解释的可靠性。 相似文献
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利用航磁资料研究区域构造时,可采用相关分析方法抑制实测异常中的干扰并对不同波长的信息进行分离,区分浅部和深部的信息。本文提供了工作的基本原理和具体方法,并以江苏地区为研究实例,说明该方法在提供磁性分层模式和磁异常解释剖面方面的效果。 相似文献
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准噶尔盆地南缘吐谷鲁背斜的构造解释与初步建模 总被引:4,自引:4,他引:0
通过对过吐谷鲁背斜地震剖面的构造解释,分析了吐谷鲁背斜深部构造的组合样式:深部断层在吐谷鲁处形成一构造三角带,导致对应的复合叠加褶皱的出现。在构造解释的基础上,利用地震主剖面与联络剖面的栅状图和地震主剖面的排列图,展示了组成吐谷鲁背斜的主要构造以及拟三维构造模型 相似文献
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关于冲断构造有两种对立的观点,一种观点认为大逆冲断层在深部变平缓,并与某些诉离面相接,向着逆冲的相反方向开拓类似阶梯式的路径,以达逆冲运动源地.另一种观点认为,逆冲断层向深部变陡,可以韧性应变的方式,消失于地壳的下部或地幔之中.第一种逆冲断层模式,通常称之为“薄皮式构造”或“外来构造”.第二种模式可以称之为“铅直运动构造”或“原地构造”,这种模式认为深部运动近于铅直,水平位移很少.图1是横过德国中部蒙希伯格地块的几个剖面,展示了这种模式对构造的不同解释.这 相似文献
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EH4电导率成像系统是一种混场源频率域电磁观测系统,其能穿透低阻覆盖层并清晰反映深部地质体空间展布特征,具有轻便高效、勘探深度大、分辨率高的特点。在对四川通安-小牛场地区控矿构造勘探中,利用EH4电导率成像系统剖面处理与解释结果,查明了区内隐伏构造及地层界线,证明EH4电导率成像系统在寻找隐伏构造与地质界线过程中的有效性。 相似文献
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多元地学数据信息处理及解译在西秦岭地区金矿找矿中的应用 总被引:1,自引:0,他引:1
多元地学数据信息处理及其在综合找矿中的应用,以其信息量大、多方位、立体化、快速高效等特点,近年来受到普遍重视。作者在秦岭成矿带甘肃段(西秦岭地区)约5万km2范围内,利用最新的地质、矿产、物化探、遥感等方面资料,开展金矿多元地学数据信息处理和综合分析解译,研究多元地学信息特征及其与金矿的关系和成矿地质环境,查明了深部构造和岩浆活动规律,建立三维空间的金矿找矿模型,寻找金成矿有利区。实践表明,该研究方法在金矿资源调查和分析研究区域地质构造方面有着显著的地质效果。 相似文献
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塔里木地台北缘内生磷矿预测及资源远景评价 总被引:5,自引:4,他引:1
塔里木地台北缘深断裂两侧有多处碱性杂岩体分布。通过对其长约2000km范围内地质资料的搜集,实地地质调查,遥感资料解译,航、地磁异常资料的分析与实测工作、重点评价区工程验证等一系列成果的综合分析与研究,发现260km铁磷矿化带,控矿岩体具有“串珠状等距性特征,铁磷矿体主要赋存在辉石岩和黑云母辉石岩中。”在三个调查区中划分出9个找矿远景区。尉犁-兴地调查区中发现多处偏碱性超基性杂岩体,其中三处远景区经深部验证均发现铁磷矿体。是寻找内生磷矿颇具找矿前景的地区。温宿-拜城调查区是寻找Nb-Ta—P矿前景的最佳地段。巴楚-阿图什调查区应是寻找碳酸盐型磷-稀土矿的有利地区。经研究提出:“古老地台边缘受深大断裂控制的偏碱性-超基性杂岩成矿,碱幔分异-碱性偏碱性不混熔岩浆成矿-熔离作用形成层状铁磷矿体的成岩成矿模式”。 相似文献
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煤矿采空区探测中的瞬变电磁干扰压制 总被引:1,自引:0,他引:1
煤田瞬变电磁探测常在人文干扰较强的煤矿周边进行工作,采集到的二次感应场信号大多噪声水平较高,难以开展处理解释工作.为消除野外数据中的电磁干扰,根据衰减曲线形态特征,利用曲线斜率的平均值及方差统计作为干扰判别机制,并参考邻近未受干扰的测点特性,可以快速简便地压制干扰,较好地恢复原始信号.使用该方法对理论数据与实测数据进行了处理解释,结果证明了方法的有效性.将该方法应用于煤矿采空区探测中,压制干扰后的曲线反演解释异常显示出与已知资料高度的一致性,得到了与实际相符的结果. 相似文献
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A. N. Hanchinal P. B. V. Subba Rao Nandini Nagarajan D. R. K. Rao B. P. Singh 《Journal of Earth System Science》1994,103(3):383-400
Magnetovariational studies have been carried out in Singhbhum and surrounding regions during 1987 and 1989. Three deep-seated
linear conductors have been identified. One of them is located to the north of Ranchi, Bokaro and Purulia extending in E-W
direction coinciding with high heat flow region and Gondwana sediments. The trend of anomaly at Ranchi and Purulia at longer
periods suggests a conductivity anomaly due to the mafic and ultramafic intrusions, considered to be responsible for the uplift
of Chhotanagpur plateau. The second conductor is associated with the basin margin fault that separates the Singhbhum craton
and Chhotanagpur plateau from the West Bengal basin. This conductive zone appears to extend further south and join the high
heat flow region of Attri-Tarabalo. This conductor could be isolated only after eliminating the coast effect from the observed
induction vectors. The third conductive zone follows the trend of Mahanadi valley located south of the Sukinda thrust. Conductive
anomaly associated with the Sukinda and Singhbhum thrust zones could not be resolved due to the interference from neighbouring
conductive structures. These two thrusts may not be very deep-seated structures. The Singhbhum granite batholith is found
to be highly resistive and seems to extend to greater depths. 相似文献
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O. A. Zaki S. H. AbdAlnabi S E. Abd El Wahab A. A. Ismail N. M. Soliman 《Arabian Journal of Geosciences》2017,10(14):310
This study presents analysis and interpretation of aeromagnetic data to construct subsurface structure maps and determine the depths to magnetic basement. Subsequent analysis steps are applied to the total magnetic intensity (TMI) data. These steps include Reduction to the Pole (RTP) map that was derived from the TMI map then subjected to spectral frequency analysis to isolate RTP map into high and low frequencies and determine pseudo-depth for each map from power spectrum in which there were two main average levels (interfaces) at depth 1.3 and 0.7 km for the deep-seated and near-surface magnetic structures, respectively. 3D Euler deconvolution technique is applied to calculate the depth to the magnetic contacts; the results show clustering of solutions, the shallow solutions are related to the outcrops less than 80 m from flight level, and the solutions which are related to sedimentary cover locations (Um al-Huweitat, Wasif, and Mohamed Rabah basins) are ranged between 200 and to more than 1100 m. Moreover, anomaly enhancement techniques such as tilt derivative (TD), horizontal tilt derivative (TDX), and source edge detect (SED) are applied to enhance shallow features, and determining structure element boundary for both shallow- and deep-seated anomalies and revealing possible faults such as 2D forward modeling are applied to selected profiles to adjust the interpreted structures and map the boundaries and basement relief of the three basins (Mohammed Rabah, Wasif, and Um al-Huweitat). The analysis shows that the study area is affected with network of dip–slip faults due to high shearing and compression stress which formed grabens and horsts at different depth levels in the study area. The trends of predominant faults related to deep-seated structures are NW–SE with depths ranged between 1 and 1.4 km and in regard to the shallow-seated structure, the predominant fault trends are NW–SE, NNW–SSE, and NNE–SSW with depths ranged between 0.3 and 0.8 km. 相似文献
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用综合方法研究中国东部深部构造 总被引:1,自引:0,他引:1
<正> 近年来在我国获得大量的地质、地球物理和地球化学等资料的基础上,特别是将地表地质构造的研究与深部地质构造和新构造运动的研究结合起来,更加深和丰富了对大地构造的认识。 1957年,地质部航测大队首次在我国东部发现了郯城—庐江深大断裂带。同时,大量的地球物理工作,为我国早期油田的勘探与开发提供了地质构造的依据。六十至七十年代,利用人工地震研究地壳和上地幔的结构,提出了部分地区的详细地壳模型和地壳厚度。在我国某些地区开始了古地磁学的研究。 相似文献
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《China Geology》2019,2(3):382-390
Ground gravity survey for regional structure unit delineation and oil and gas exploration in China is addressed in this paper with examples. Gravity survey scales, coverage, technical regulations and achievements at the national level are introduced, including data processing and anomaly interpretation techniques. Bouguer anomalies of terrestrial territories of China and classification of anomalous feature zones are also described; they are well correlated with lithotectonical boundaries, fault zones, and unexposed igneous plutons. Recent study results of petroliferous sedimentary basins are presented as well, including concealed boundaries and major structures of large basins. It is concluded that gravity survey is the most effective and economic method in unveiling unexposed and deep-seated structures, targeting and delineating oil and gas-bearing sedimentary basins, and locating main trap structures within prolific basins in early stage of exploration in China. Suggestions for improving exploration of both conventional and unconventional oil and gas reservoirs in China are also given in the paper. 相似文献
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在大地电磁测深法中,曲线类型的分析划分是资料解释流程中相当重要的一环。实测曲线类型不仅反映了测区地下地质构造的电性特征,更重要的是通过曲线类型的划分与分类,可定性地掌握测区地质构造单元的格局,制定相应的定量解释方法,有效地克服地质推断的多解性。本文在本文采用聚类分析的方法对MT曲线进行了分类,以求克服目前简单分类法,捕抓曲线特征中更深层的一些信息,并给出了应用实测。 相似文献