首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 453 毫秒
1.
郭信 《地质与勘探》2020,56(5):985-1004
江西塔前-赋春成矿带近年发现了世界上最大的钨矿—朱溪钨铜矿。该矿床发育在富含钨铜元素的新元古代泥砂质岩基底之上,产在燕山期花岗岩与石炭纪-二叠纪灰岩接触带,阐明其覆盖区花岗岩与石炭纪-二叠纪灰岩的三维空间分布结构,是寻找该类矿床的关键问题。塔前-赋春成矿带控矿地层、花岗岩仅有微弱磁性,但是密度差异明显,这为本区开展重力工作提供了良好的前提。本文利用最新的1:5万重力调查成果,结合航磁建立了本区构造格架,使用重磁三维反演建模技术建立本区三维地质模型,取得了以下成果:(1)对区内控矿地层进行立体识别划分,推断了塔前-朱溪、双田-大游山和临港-乐河镇石炭-二叠系条带深部延展形态,推断红梅岭-排前村和刘家滩-珍珠山深部存在两条隐伏石炭-二叠系条带;(2)发现本区岩体具有环形重力低夹局部重力高的异常特征,结合磁法区分岩浆岩岩性,圈定了本区隐伏岩体;(3)根据朱溪钨铜多金属矿物化探异常特征,圈定了两类深部成矿有利靶区:一类位于地表出露石炭纪-二叠纪灰岩沿断裂延伸与隐伏岩体接触带;一类位于推断的隐伏石炭纪-二叠纪灰岩与隐伏岩体接触带。(4)塔前-赋春成矿带重力工作较少,通过分析本次重力调查成果,发现在地形复杂、具有明显密度差异的推覆构造发育地区开展1:5万重力调查可取得较好的勘查成果。重力调查工作成本低,工作周期短,在圈定的成矿有利靶区内开展大比例尺综合物化探异常查证和矿产调查工作,能有效提高矿产勘查效率;在地形、构造复杂地区推广应用1:5万重力调查并建立三维地质模型对开展深部找矿预测具有重要意义。  相似文献   

2.
内生磷矿(主要是岩浆岩型矿床)在世界磷矿资源中占据重要地位。世界三大内生磷矿中,最佳成矿模式为在古老地台边缘或地台活化带,受深大断裂控制的超基性 碱性 碳酸岩杂岩体型磷矿。我国已发现40多处碱性杂岩,主要分布在华北地台和塔里木地台,展望北方找磷前景乐观。对岩浆岩型磷矿的预测应按其成矿规律、杂岩体分布规律及矿床特征加以把握。  相似文献   

3.
陈小华 《江苏地质》2001,25(1):17-22
铜山铁(铜)矿床属接触交代-高温热液型矿床,主要受闪长夺和碳酸盐地层的接触带构造控制,成矿物质来源于岩浆岩,具有典型的地面磁异常、围岩蚀变和矿化分期分期带特征,分析了矿床西部的地层、构造、岩浆岩和磁异常特点,探讨了该区的找矿方向。  相似文献   

4.
东天山色尔特能东部大型铜镍矿成矿条件分析   总被引:2,自引:2,他引:0  
东天山是重要的铜镍金成矿带.先后发现了黄山铜镍矿、土屋斑岩铜矿、康古尔金矿等大型矿床;而东天山西段,仅发现小热泉子VMS型铜锌矿床.据综合资料推断,康古尔-黄山铜镍成矿带向西可延至色尔特能-彩华沟一带.色尔特能地区具有良好的铜镍金多金属成矿条件.色尔特能的东部蚀变现象普遍,铜矿化露头多,侵入杂岩体分异良好;岩石测量发现Ni、Cr、Cu、Co等组合异常;物探异常规模大,呈重力高、磁力高、极化率高、电阻率相对低的特征,即显示"三高一低"的铜镍硫化物型矿床的异常特征;认为有望找到大型铜镍硫化物矿床.  相似文献   

5.
辽宁省东部的翁泉沟硼矿是一个超大型硼矿床,B2O3矿物储量占全国总储量的1/4以上,利用1∶5万航磁、1∶20万区域化探和区域重力等资料,对翁泉沟硼矿周边地区硼矿资源潜力进行了分析研究,研究结果表明最新实测的1∶5万航磁异常与已知矿床(体)具有非常良好的对应关系。除已知矿床(体)的航磁异常外,在区域化探硼元素异常所指示的含硼岩系分布区还有一批航磁异常分布,而且这些航磁异常与剩余布格重力异常相互套合,说明这些异常是由强磁性、高密度地质体引起的。通过对航磁异常进行反演计算,结合研究区各类岩石物性资料,认为研究区硼矿找矿潜力巨大,具备发现新的大型以上硼矿床的条件。合理部署勘查工作,有望大幅提升该区硼矿资源量。开展硼矿找矿工作时要特别注意以往关注度不高的条痕状花岗岩出露区内航磁异常的硼矿找矿意义。  相似文献   

6.
黔东南重磁异常与金异常特征及找矿意义   总被引:1,自引:0,他引:1  
为了深入挖掘黔东南地区的找矿潜力,对黔东南地区区域重磁异常进行解释,研究东部地区的天锦黎金矿密集区及西部地区的金化探异常分布特征,发现金矿床(点)和金化探(元素、块体)异常的产出,同重、磁异常平面分布和推断的岩浆岩侵入体(基性岩类、酸性岩、构造蚀变岩)及区域性深大断裂构造(东西向、南北向)的分布,存在着空间、时间和成因上的联系,由此拓开了黔东南天锦黎金矿密集区及外围金矿地质找矿的新思路,不要只限于在相关地质层位里和北东向构造及伴生断裂(即“背斜加一刀”)交会处及其附近,来寻找变质碎屑岩中的脉型金矿。  相似文献   

7.
扬子准地台西南缘是我国重要的成矿区带。通过该区区域地球物理资料(包括重力测量、航空磁测、深反射地震和天然地震资料)的分析整理和编图,发现在扬子地台西南缘存在着一个菱形块体——川滇黔菱形地块,由四条(隐伏)深断裂带所围限。地球物理资料较为清楚地反映了菱形地块的构造格架。西侧重力异常梯度陡变,地壳厚度急剧变厚;内部存在由地幔隆起形成的重力高异常带,隆起带可能是菱形地块在元古宙时期裂解留下的遗迹;沿边界断裂地震活动剧烈而频繁。菱形块体的边界断裂及其内部的隆起带控制着本区的成矿作用,不同时期的矿产在菱形地块内有规律地分布。沿近南北向地幔隆起带分布有元古代沉积-喷流型Fe—Cu矿床,其两侧分布有与晚古生代峨眉山玄武岩有关的铜矿和密西西比型铅锌矿床;沿菱形块体边界分布有新生代与超壳深断裂有关的富碱斑岩型金(多金属)矿床,沿菱形地块内部的南北向深断裂(如小江深断裂)有剪切带型金矿床。不同类型的矿床有时相互叠加形成复合成因的矿床(如东川地区)。这表明,不同时期的构造背景控制着不同类型矿床,同时表明,扬子地台西南缘是一个不够稳定的地块(准地台或活化了的地台),菱形地块陡变的地球物理特征明显不同于其东侧稳定块体(缓变)。  相似文献   

8.
延边金苍-红光地区金矿成矿条件与成矿规律   总被引:1,自引:0,他引:1  
金苍-红光地区为延边东部东西向构造火山岩浆岩带中重要的金矿化集中区段。通过调查研究其中九三沟金矿床发现,矿区成矿岩浆岩条件为次火山岩相石英闪长(玢)岩,其中隐爆角砾岩(筒)及外围裂隙中赋存着金矿(化)体;次火山岩(体)受东西向断裂(带)与南北向断裂交汇部位的火山机构中心控制,成为该地区重要的成矿构造条件。成矿次火山岩体(石英闪长岩)在东西向断裂构造带上,自西向东在与南北向断裂交汇部位具有近等间距分布的规律,并与区域化探金异常空间吻合。  相似文献   

9.
彭聪  赵一鸣 《物探与化探》1998,22(3):175-182
长江中下游地区是我国重要的铁铜矿产基地。近十年来,我国所发现的含金夕卡岩矿床和铜伴生金夕卡岩矿床也主要产在长江中下游地区。作者借助12条大地电磁测深剖面、5条地震剖面、层析成像速度结构资料、重磁场等区域的和深部的地球物理资料进行综合对比研究,给出长江中下游及其邻区的三维深部构造格架及其与含金夕卡岩矿床和铜伴生金夕卡岩矿床的分布关系。作者认为,上地幔隆起带(岩石圈地幔减薄带)、上地幔异常区(相对低速区)、壳内高导层隆起带、深断裂(岩石圈剪切带)、地壳上地幔不均匀性块体的边缘、重力高反映的基底隆起区、跳跃磁场反映的岩浆岩带和构造交汇处等诸多因素的共同作用控制着含金夕卡岩矿床和铜伴生金夕卡岩矿床的分布。  相似文献   

10.
四川攀西地区氟碳铈矿型内生稀土矿床成矿模式   总被引:1,自引:0,他引:1  
四川攀西地区氟碳铈矿型内生稀土矿床成矿模式秦震(四川省地质矿产局)1大地杓造背景本类型矿床位于扬子地台西缘康滇地轴中段的西侧,为康滇地轴与甘孜地槽之间的台缘坳陷过渡地带。深部处于龙门山一锦屏山幔坡陡倾转折部位,系陆壳脆弱带。2控矿构造矿床分布乎格受求...  相似文献   

11.
In order to evaluate the quality of the land gravity data in the latest global gravity database V23, the authors chose the gravity data of eight blocks with a total area of 1 330 000 km2 to compare and analyze, and these blocks involved seven countries, including the United States, Peru, Ireland, South Africa, Kenya, Australia, and China. Based on the free-air gravity anomaly data of the latest global gravity database V23, the authors obtained the calculated Bouguer gravity anomaly using the gravity correction methods within the pure spherical coordinate system in these eight blocks. Then, the correlation coefficients between the measured Bouguer gravity anomaly and the calculated Bouguer gravity anomaly were calculated by the correlation analysis method in these eight blocks. Finally, through comprehensive analysis of the features of these correlation coefficients and differences between the measured Bouguer gravity anomaly and the calculated Bouguer gravity anomaly in these eight blocks, the quality of the gravity data of these eight blocks was evaluated in the latest global gravity database V23. The results showed that the latest global gravity database V23, released by Scripps Institution of Oceanography, integrated a large number of the ground or airborne gravity data measuring in an earlier era, and the newly surveyed ground or airborne gravity data may not be integrated into the database. The quality of land gravity data is relatively high in the areas with a large number of older ground or airborne gravity data, otherwise it is low in the zones with a lower gravity working degrees.  相似文献   

12.
多年来,不论重力勘探程度如何,在布格重力异常计算中都必须经过地形改正和中间层改正。本文通过分析在计算布格重力异常时地改和中间层改正对测点的重力补偿,提出了取消中间层改正以适应微重力勘探精细解释需要的地形校正方法。该方法建立在对实际地形(岩性)的正演基础上,可以根据施工地区的地质条件合理选择重力基准面进行可变密度地形校正。使用该方法可以比较好地消除地形起伏和不均匀岩性对测点产生的重力影响,从而得到比较可信的重力异常数据。  相似文献   

13.
In this study, Bouguer gravity and aeromagnetic data have been used to better understand the geology and mineral resources near the late Carboniferous-late Permian porphyry Cu-Mo polymetallic mineralization in the Chinese Eastern Tianshan belt, which is extensively covered by Gobi-desert. The reduced-to-pole (RTP) transformation of regional-scale aeromagnetic data shows that the porphyry Cu-Mo deposit is within a cluster of magnetic anomaly highs that overprint on a northeast trending magnetic gradient belt generally along the crustal-scale Kanguertag-Huangshan fault. The 10 km upward continuation transformation of both Bouguer gravity and aeromagnetic data indicates that the known porphyry Cu-Mo polymetallic deposits are located on the flanks of prominent gravity and magnetic anomaly highs. These anomalies are spatially correlated with the late Carboniferous-late Permian igneous rocks and in the Tuwu-Yandong mineralization district are centered over the granodiorite rocks genetically related to porphyry copper systems. In order to minimize interpretational ambiguities, a useful approach that is correlation analysis (CA) based on correlation coefficient (CC) given by gravity and magnetic data was employed to separate positively and negatively correlated anomalies features. The CA procedure is applied to 10 km upward continuation transformation of both Bouguer gravity and RTP transformed aeromagnetic data for mapping correlative magnetization and density contrast anomalies from deep sources, which may be associated with the porphyry Cu-Mo polymetallic mineralization. Five prominent CC positive anomalies have been found in the southern margin of Dananhu-Tousuquan arc. Those anomalies zones could be interpreted to reflect a late Carboniferous-late Permian magmatic belt that is favorable for additional discoveries of late Carboniferous to late Permian porphyry copper systems in north region of Eastern Tianshan.  相似文献   

14.
利用小波特性可以提取航空重力异常的重要信息,笔者采用小波分析方法建立三维地质体模型,讨论了小波模与地质体边界的对应关系。以我国某海域航空重力资料为例,利用小波模极大值识别了断裂信息,并与航空布格重力异常及其方向导数识别的断裂进行对比分析。结果表明,利用小波模不仅可以识别断裂构造,在航空布格异常和方向导数识别模糊的地区效果更为明显。  相似文献   

15.
基于地质异常单元金矿找矿有利地段圈定与评价   总被引:19,自引:1,他引:18  
赵鹏大  陈永清 《地球科学》1999,24(5):443-448
许多大型,超大型内生金属矿床通常位于壳昨杂的区域,如不同类型岩石圈板块的边界等,从而形成一些诸如环太平洋金属成矿带等全球规模的成矿域,对一些内生热液金属矿床就位的地质条件的统计分析表明:几乎所有被调查的主要工业矿床的矿田地质结构与其周围地区相比都是具有显著差异,而表现异常的特征。  相似文献   

16.
于双忠 《地质论评》1999,45(2):113-113
通过对典型活动断裂两盘重力场特征的对比与分析,发现具有大面积布各重力负异常(或相对我异常)的地块总是向赤道方向运动,而布格重力正异常(或相对正异常)的地块向极点方向运动,布格重力异常图反映了密度情况,正异常带为大密度地块,负异常带为小密度地块,从理论分析得知,地块的密度变化导致了受力条件的改变,致使地块失稳产生运动,岩浆活动是造成地块密度变化的重要因素。  相似文献   

17.
Gravity data were analyzed in conjunction with available geological data to determine the origin of observed gravity anomalies and their possible relationship to metallic ore deposits. The gravity data analysis included the construction of a Bouguer gravity anomaly, isostatic residual gravity anomaly and enhanced horizontal gravity gradient maps, and two and one-half dimensional gravity models. The isostatic residual gravity anomaly field could be broken down into five distinct regions based on anomaly amplitude, trend and wavelength. The analysis of these regions showed that both the Birimian and granitoid provinces consist mainly of a series of short wavelength gravity maxima and minima with a few large scale anomalies which suggests that the subsurface geology is more complicated than is currently known. Two gravity models roughly oriented north-south also implied this complicated subsurface geology and showed that most source bodies have depths up to 5 km. The known base metal deposits occur on the edge of small-scale gravity maxima within the Birimian province with the exceptions of the deposits within the Bouroum-Yalogo belt which occur next to a large amplitude gravity maximum related to an ultramafic complex.  相似文献   

18.
The present geophysical study deals with the ores and crustal demonstration of southeastern Hazara and its adjoining areas of Azad Jammu and Kashmir, Pakistan, on the basis of terrestrial gravity and magnetic data. Tectonically, the study area lies in the Lesser Himalayas as well as to an extent in the sub-Himalaya, more specifically in the western limb of Hazara Kashmir Syntaxis. In this study, 567 gravity and 508 magnetic stations have been measured with CG-5 gravimeter and proton precession magnetometer, respectively. The collected data have been processed by applying standard corrections and then different types of maps were prepared. The ores in the area have been delineated by the qualitative interpretation of residual Bouguer anomaly and reduction to pole total magnetic intensity maps, whereas regional structures are demarcated by the Bouguer anomaly and regional Bouguer anomaly maps. The positive contour closures on the residual Bouguer anomaly map indicate the iron ore and phosphate, whereas negative contour closures are the effects of low-density material which consists of gypsum and soapstone. The pole-reduced total intensity map also shows the negative and positive contour closures almost in the same localities and confirms the residual Bouguer anomaly map. The geological model computed on the basis of Bouguer anomaly demarcated a series of faults between different rock units in the study area. The Kashmir Boundary Thrust cuts the western limb of Hazara Kashmir Syntaxis near the apex in the north of Muzaffarabad and marks the boundary between Murree Formation and carbonates of Abbottabad Formation. The gravity model also suggests that the thickness of the crust increases towards the northeast.  相似文献   

19.
对河南省不同时期Mo矿的成矿地质背景和成矿特征进行了归纳,建立了主要类型Mo矿成矿模式,总结了成矿规律;进而通过综合信息数据处理,讨论了不同类型Mo矿预测要素的提取,建立了符合地质概念模型的斑岩-矽卡岩型Mo矿综合信息预测模型。研究表明:占绝对主要地位的早白垩世Mo矿受控于滨西太平洋构造域东秦岭-大别陆内岩浆弧,强烈的岩浆活动造成浅源浅成快速冷侵位的粗粒花岗岩大岩基与控制Mo矿的深源浅成热侵位细粒花岗岩-花岗斑岩-侵入角砾岩小岩体在同一剥蚀平面紧密共生,不仅存在“小岩体成大矿”的规律,而且存在大岩基边缘和旁侧成大矿的规律。相同特征的矿产因所处地质背景的不同而预测要素有所差异,但通常可以根据剩余重力低-ΔT化极正磁异常及其梯度模来拟合岩体与接触带,以Mo主成矿因子得分正异常和Pb-Zn-Ag主成矿因子得分负异常确定斑岩-矽卡岩型Mo(W)矿的成矿范围。通过CSAMT-SIP-裂隙地球化学联合剖面测量可有效预测隐伏矿体部位。  相似文献   

20.
Environmental managers and protection agencies try to assess the magnitudes of earthquakes in regions of seismic activity. For several decades they have used the seismic b-values and Bouguer anomalies for evaluating the crustal character and stress regimes. We have analyzed geostatistically data on both variables to map their spatial distributions in the southeast of the Zagros of Iran. We found a strong correlation between the distribution of the b-value and the Bouguer gravity anomaly in the region. The large Bouguer gravity anomaly values and small b-values all accord with there being a thinner crustal root and a larger concentration of stress in the center. The small to moderate Bouguer gravity anomaly values and intermediate to large b-values accord with the thicker crustal root and the smaller concentration of stress in the northeast. We conclude the southeast of the Zagros, consists of heterogeneous crust, such that accounts for its varied tectonics.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号