共查询到20条相似文献，搜索用时 62 毫秒
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清水泉一带位于新疆东准噶尔卡拉麦里成矿带西段,近年来,新发现铜矿床1处,铜矿点2处,金矿(化)脉6条,显示出良好的成矿潜力。在前人研究基础上,系统总结清水泉一带成矿地质背景,分析清水泉一带物化探和遥感异常特征。推断清水泉一带分布的主要地层与带内发现的金铜矿床赋矿地层一致;物探特征显示清水泉一带重力梯度值与深大断裂大体吻合;化探资料显示多处金铜矿的异常与带内金铜矿化带分布吻合;遥感资料异常提取结果与化探、构造特征在空间上的展布基本一致。在此基础上分析清水泉一带成矿地质特征,总结找矿模型,以期为资源潜力评价工作提供借鉴和参考。 相似文献
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邹平火山岩盆地是山东省重要的铜矿产地,深入认识其铜矿成矿规律,对于有序地推进战略性铜矿远景调查以及新的铜矿矿产地的发现有着重要意义。文章从区域地质背景分析着手,探讨了铜矿的赋存与青山群八亩地组、方格庄组火山岩地层,闪长岩、闪长玢岩、二长岩、辉长岩等岩体,以及放射状、环形断裂构造之间的空间关系。该区铜矿的赋存部位具有磁力低、电阻率低、激化率低,重力值高等物探异常的特征,空间上具有沿岩浆岩构造带展布、次火山岩内裂隙充填、空间等距、深部尖灭再现等特点。认为在王家庄岩体为中心的王家庄-大临池岩浆岩带,环形二长岩墙的内、外侧以及火山岩盆地深部收缩的＂颈部＂,具有较大的铜矿找矿潜力。大上口—夫村、大临池、于兹山—黄山、黄花山—西窝陀、老人峰—贺家庄地区位于火山岩盆地赋存铜矿的内部构造上,也具备铜矿成矿的地层、断裂构造、岩浆岩、物化探等异常条件,应是今后铜矿勘查工作的远景地区。 相似文献
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内蒙古五十家子—新城子地区位于滨太平洋成矿域兴蒙造山带铀-多金属成矿省,扎兰屯火山岩型铀成矿远景带南端,是我国北方热液型铀-多金属矿集区之一。区内中生代火山活动频繁且强烈,成矿地质条件优越,具有较好的找矿前景。根据富集储矿构造环境将研究区火山岩型铀矿划分为蚀变裂隙带和次火山岩2种类型,认为研究区铀成矿高峰期为晚侏罗世晚期—晚白垩世早期,相对集中在148.91～99.10 Ma之间,具时间跨度大、多期多阶段的特征;铀矿化异常主要沿西拉木伦河、黄岗粱—乌兰浩特断裂分布,多产于EW、NE向次级断裂和构造裂隙带内;富集于上侏罗统满克头鄂博组酸性熔岩、燕山晚期侵入岩内外接触带附近;主要受地层、断裂构造、火山机构、不同界面构造、次火山岩及热液蚀变复合控制。研究区铀矿找矿标志为火山盆地边缘靠近基底隆起带一侧发育酸性次火山岩部位,NE向控矿断裂带派生次级断裂交汇部位,花岗斑岩、流纹岩接触部位且硅化、赤铁矿化、紫黑色萤石化、水云母化蚀变叠加部位,物化探测量异常带耦合度较高的部位。初步建立研究区成矿模式,预测了曹家营子、王家大院、五间房、板山图4处重点铀矿勘查区。 相似文献
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《华南地质与矿产》2016,(3)
湖南省汝城县热水镇地热勘查区位于诸广山铀矿矿集区,区内震旦系—寒武系地层和诸广山岩体铀元素的背景值是克拉克值的4倍以上,鹿井、丰州等大型—特大型铀矿及矿点有数十个之多,呈NNE向分布。温泉与铀矿在空间分布上有一致性分布规律,诸广山岩体放射性矿物放热的累加,使之核心温度可达320℃,是异常高温的主要来源,是本区400 m以浅地热和4000 m以浅干热岩的主要热源,深部地核传导热与金属硫化物氧化放热是次要因素,中生代岩浆岩的岩浆余热对热异常贡献率较小。这是本区地热探井增温率呈非线性的"舌"状形态,而不是常规的与孔深呈线性耦合的原因。NE向遂川—热水断裂带与NW向常德—安仁断裂带在本区交汇,断裂带下切岩体深部基底,是主导热和铀矿控矿构造,次级张性断裂是热水和铀矿容矿构造,控制了非线性增温地热异常。花岗岩中(或外接触带)铀矿放射性元素放热和构造活动带中的金属硫化物氧化放热,形成了高地热增温率异常,具有干热岩和铀矿(或金属硫化物矿)找矿远景,建议树立综合找矿思维,运用地质及物化探综合手段,在开展干热岩资源勘查时,注意铀矿资源赋存条件与信息,对其持续探索,有可能达到"热—铀兼探"和"热—铀兼采"目的。 相似文献
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九龙嶂火山盆地位于南岭成矿带安远热隆的西部,面积120余km2,盆地基底为元古代变质岩,盖层为上侏罗统鸡笼嶂组火山岩系.在盆地边缘火山岩中分布3个铀矿点或矿化点.其中银坑山矿点受发育于流纹质熔结凝灰岩中的近SN向碎裂带控制.盆地基底岩石碱交代蚀变明显,火山期后浅成-超浅成侵入岩浆活动频繁,火山构造与区域线性构造交接复合并形成派生构造,使盆地具有良好的铀矿形成的源-运-聚条件.盆地南(东)部银坑山一带是找矿方向和勘查重点所在. 相似文献
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钦杭成矿带北东段火山岩型铀矿定向三等距分布规律及成矿预测 总被引：1，自引：0，他引：1
钦杭古板块结合带抚州—绍兴段及两侧地区火山岩型铀矿床密集分布,区域构造环境演化及铀成矿地质特征分析表明：它们是中生代相同构造背景下构造-火山岩浆活动的产物,可归属为钦杭成矿带北东段的组成部分。构造是区内火山岩型铀矿主要控矿地质因素,火山构造与断裂构造联合控矿特征明显,不仅表现为构造分级控矿规律,而且各级铀成矿单位均表现了铀矿定向三等距分布规律。依据矿产集中域定向三等距分布规律,开展了铀成矿预测,指出了值得进一步研究及勘查的工作区。 相似文献
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The mechanism of earthquake inoculation and the process of earthquake occurrence are very complicated. Additionally, earthquakes do not happen very often, and we lack enough cognition to the earth’s interior structure, activity regularity and other key elements. As a result, research progress about the theory of earthquake precursors has been greatly restricted. Ground gravity observation has become one of the main ways to study earthquake precursor information in many countries and regions. This paper briefly summarized the surface gravity observation technology and observation network in China: the surface gravity measurement instrument developed from Huygens physical pendulum in seventeenth Century to today’s high-precision absolute gravimeter, and its accuracy reached to ±1×10-8 m/s2. China has successively established the National Gravity Network, Digital Earthquake Observation Network of China,the Crustal Movement Observation Network of China Ⅰ and the Crustal Movement Observation Network of China, to provide a public platform for monitoring non tidal gravity change, seismic gravity and tectonic movement. The use of specific examples illustrated the role of gravity observation data in earthquake prediction. The gravity observation data of ground gravity can be used to capture the information of gravity change in the process of strong earthquake inoculation, and to provide an important basis for the long-term prediction of strong earthquakes. The temporal and spatial variation characteristics of the regional gravity field and its relation to strong earthquakes were analyzed: Before the earthquake whose magnitude is higher than MS 5, generally there will be a large amplitude and range of gravity anomaly zones. Strong earthquakes occur mainly in areas where the gravity field changes violently. The dynamic change images of gravity field can clearly reflect the precursory information of large earthquakes during the inoculation and occurrence. Finally, the existing problems of surface gravity technology in earthquake precursor observation were put forward and the use of gravity measurement data in earthquake prediction research was prospected. 相似文献
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A compilation of new and existing gravity data, as well as geophysical and geological data, is used to assess the cumulative effects of multiple rifting episodes on crustal and upper mantle density structures beneath the Uganda-Kenya-Ethiopia-Sudan border region. This compilation includes new gravity and geological data collected in 1990 in south-western Ethiopia. Variations in the trends and amplitudes of Bouguer gravity anomalies reveal three overlapping rift systems: Mesozoic, Paleogene and Miocene-Recent. Each of these rift systems is a number of 40–100 km long sedimentary basins, and each system is approximately 1000 km long. The Bouguer anomaly patterns indicate that the Ethiopian and East African plateaux and corresponding gravity anomalies are discrete tectonic features. Models of structural and gravity profiles of two basins (Omo and Chew Bahir basins) suggest that pre-Oligocene (Cretaceous?) strata underlie 3 km or more of Neogene-Recent strata within the northern Kenya rift, and that more than 2 km of Neogene-Recent strata underlie parts of the southern Main Ethiopian rift. The superposition of perhaps three rifting episodes in the Lake Turkana (Omo) region has led to 90% crustal thinning (β ≈ 2). 相似文献
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尼日尔三角洲深水勘探研究面临的挑战及其对策 总被引：1，自引：0，他引：1
面对深水勘探开发钻井和工程难度大、经济投资成本高的特点,针对深水区复杂油气藏,本文首先在深水研究区从深水重力构造形成机制和深水沉积储层研究入手,创新了深水研究区成藏规律认识。在深水重力构造研究方面,发现其由陆向海的演化模式,按演化和特征分成3种类型,建立深水沉积和重力控制下的构造模式;在深水沉积研究方面,以刻画深水沉积特征为基础,分析了海平面升降影响和重力流密度对深水沉积的控制作用,建立了两种深水沉积模式;然后通过研究重力构造、深水沉积与油气成藏三者的关系,确立了重力构造对深水油气成藏的主控作用,以及深水沉积储层与油气富集规律的关系,建立了深水油气成藏模式。在此基础上,提出了以断层为线索,落实构造,追踪油气,以沉积为单元,计算储量和资源量,进行深水高效勘探评价的新方法。并将上述思路应用到深水复杂油气藏勘探研究中,取得了较好的实际效果。 相似文献
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The seismic data incorporated in global Moho models are sparse and therefore the interpolation of global Moho depths on a local area may give unrealistic results, especially in regions without adequate seismic information. Gravity inversion is a useful tool that can be used to determine Moho depths in the mentioned regions. This paper describes an interactive way of local Moho depth determination using the gravity inversion method constrained with available seismic data. Before applying inversion algorithms, the Bouguer gravity data is filtered in various stages that reduce the potential bias usually expected in Moho depth determination using gravity methods with constant density contrast assumption. A test area with reliable seismic data is used to validate the results of Moho computation, and subsequently the same computation procedure is applied to the Sri Lankan region. The results of the test area are in better agreement with seismically determined Moho depths than those obtained by global Moho models. In the Sri Lankan region, Moho determination reveals a fairly uniform thin crust of average thickness around 20 km. The overall result suggests that our gravity inversion method is robust and may be suitable for local Moho determination in virgin regions, especially those without sufficient seismic data. 相似文献
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Influence of vertical ground motion on seismic-induced displacements of gravity structures 总被引：1，自引：0，他引：1
Andrzej Sawicki W&#x;odzimierz Chybicki Marek Kulczykowski 《Computers and Geotechnics》2007,34(6):485-497
A method enabling assessment of seismic-induced movements of gravity block is proposed. This method is based on dynamic analysis of the block subjected to both horizontal and vertical ground accelerations, and resultant forces acting on the block. There are two kinds of the motion. The first one is trivial, as it is a common motion of the block and subsoil. The second is a relative motion of the block with respect to subsoil, depending on combination of ground accelerations and the resultant of horizontal forces. Attention is focused on the influence of vertical ground motion on seismic-induced displacements of the structure. Experimental investigations performed in order to validate a numerical algorithm are described, and then experimental data are compared with numerical predictions. A good agreement is obtained. Then, the dynamics analysis of the block is presented for harmonic and pseudo-stochastic ground motions in order to illustrate the algorithm proposed. The results of computations show that, for some typical data and ground accelerations corresponding to strong earthquakes, large permanent displacements of the block take place, as observed in real conditions. 相似文献
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巴彦浩特盆地东缘中奥陶统混合型深水重力流沉积层序及其旋回 总被引：5，自引：1，他引：5
作者在巴彦浩特盆地东缘中奥陶统樱桃沟组中识别出一套巨厚的混合型深水重力流沉积岩,包括碳酸盐滑塌角砾岩?递变细砾岩?砂质砾岩?经典浊积岩?灰绿色泥页岩等岩相类型?作者认为碳酸盐滑塌角砾岩是近源海底断裂陡崖下形成的碎屑裙的产物,而陆源碎屑-浊积岩是基岩古风化壳剥蚀而形成的一系列碎屑流-浊流沉积物?对其纵向序列进行分析后作者认为,该套岩层总体上相当于一个Ⅱ级旋回,代表拗拉槽强烈沉陷阶段的产物,为次一级的地壳升降旋回,主要受古构造因素控制,而每一陆源与内源沉积物混合体则相当于一个Ⅲ级旋回,代表一个低级次的海平面升降旋回? 相似文献
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Ravi P. Srivastava Nimisha Vedanti O. P. Pandey V. P. Dimri 《Journal of the Geological Society of India》2009,73(5):715-723
Vindhyan Basin of Central India situated just north of SONATA rift zone, forms one of the major geotectonic segment of the
Indian subcontinent which is associated with complex thermo-tectonic history. Southern part of this basin is known to contain
favorable conditions for hydrocarbon entrapment. Keeping this in view, a detailed gravity survey network comprising 40 gravity
bases and 1500 data points in an area of about 110 × 100 km2 was planned in and around Jabera-Damoh region. Analysis of Bouguer and free air gravity anomaly maps, prepared using fractal
based gridding method, indicates presence of two sedimentary basins (Jabera and Damoh) faulted on either sides beside ridge
like features. However, well-known Jabera domal structure appeared to be a shallow feature only. Inversion of gravity data
further reveals presence of 5 to 6 km thick Vindhyan sediments in the Jabera basin which are underlain by Mahakoshal/Bijawar
group of rocks, resting directly over the lower crust, thereby indicating almost total absence of granitic crust from this
region. It appears that due to an underlying thermal anomaly, the entire region may have been subjected to sustained uplift,
deformation, erosion and consequent crustal extension during early to mid Proterozoics which brought high velocity mafic crust
to such shallow levels. 相似文献
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John MILSOM 《地球学报》2012,33(S1):41-42
Although many of its details have been criticised, the indenter model of India-Asia collision (Fig 1) is still widely accepted as providing a workable first-order explanation for the structural development of the eastern syntaxis and the initiation of the major NW-SE faults that segment the mainland of Southeast Asia. Arguments have largely concerned the extent to which the arrival of the continental crust of greater India has been accommodated by thickening beneath the Tibetan Plateau or by extrusion of blocks into Southeast Asia. Second-order structures relevant to such questions include elevated plateaus, metamorphic core complexes and the networks of rift basins with broadly N-S trends. In northern Thailand, one such rift network has been responsible for the development of a characteristic basin-and-range morphology. 相似文献
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本文利用航磁、重力异常及多种数据处理方法的对大黑山条垒北东段区哉构造进行了研究，以期为在该区寻找金、银矿床提供详实的区域构造等方面的信息。 相似文献
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Recent studies have demonstrated a plausible link between surface and near-surface tectonic features and the vertical projection of the Commerce geophysical lineament (CGL). The CGL is a 5- to 10-km-wide zone of basement magnetic and gravity anomalies traceable for more than 600 km, extending from Arkansas through southeast Missouri and southern Illinois and into Indiana. Twelve kilometers of high-resolution seismic reflection data, collected at four sites along a 175-km segment of the CGL projection, are interpreted to show varying amounts of deformation involving Tertiary and some Quaternary sediments. Some of the locally anomalous geomorphic features in the northern Mississippi embayment region (i.e., paleoliquefaction features, anomalous directional changes in stream channels, and areas of linear bluff escarpments) overlying the CGL can be correlated with specific faults and/or narrow zones of deformed (faulted and folded) strata that are imaged on high-resolution seismic reflection data. There is an observable change in near-surface deformation style and complexity progressing from the southwest to the northeast along the trace of the CGL. The seismic reflection data collaborate mapping evidence which suggests that this region has undergone a complex history of deformation, some of which is documented to be as young as Quaternary, during multiple episodes of reactivation under varying stress fields. This work, along with that of other studies presented in this volume, points to the existence of at least one major crustal feature outside the currently defined zone of seismic activity (New Madrid Seismic Zone) that should be considered as a significant potential source zone for seismogenic activity within the midcontinent region of the United States. 相似文献