广西大厂矿田深部成矿预测及成矿机制研究
A study of deep metallogenic prediction and metallogenic mechanism of the Dachang deposit in Guangxi
通讯作者: 景建恩(1973-),男,博士,副教授,主要从事电磁法数据处理与正反演的教学与研究工作。Email:jje2008@cugb.edu.cn
责任编辑: 沈效群
收稿日期: 2020-08-11 修回日期: 2020-10-5 网络出版日期: 2021-04-20
基金资助: |
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Received: 2020-08-11 Revised: 2020-10-5 Online: 2021-04-20
作者简介 About authors
刘成功(1992-),男,研究生,主要研究方向为电磁法数据处理与正反演。
大厂矿田作为大型锡多金属矿之一,成矿演化过程复杂,隐伏矿产资源繁多。为了研究大厂矿田笼箱盖岩体外围隐伏矿床的分布位置和成矿机制,对覆盖大厂矿田的音频大地电磁数据进行精细的处理,得到了地下3 km以内的二维电性结构模型。根据电性资料结果,推断了隐伏花岗岩和矿体的位置。花岗岩呈高阻特征,埋深约1.5 km,沿断裂构造成脊状隆起;低阻矿体位于花岗岩顶部中泥盆统地层中,推测矿体发育自底部花岗岩体,表明花岗岩具有明显的控矿作用。根据大厂矿田近铜远锡的分带特点和地表元素异常,以找到矽卡岩型锌铜矿体和锑钨矿床的可能性最大。研究表明,晚白垩世时期,中、下地壳(及少量上地幔)岩浆热液沿NW向基底断裂上涌到地壳浅层泥盆系地层,后经结晶分异与围岩产生成矿作用。
关键词:
As one of the large tin-polymetallic deposits in the world, the Dachang deposit has complicated metallogenic mechanism and rich hidden mineral resources. In order to detect the distribution and study mineralization mechanism of the concealed deposits around the cage and cover rock in the Dachang ore district, the authors finely processed the audio magnetoelectromagnetic data covering the Dachang ore district, and obtained a two-dimensional electrical structure model within the depth of 3 km. According to the results of resistivity model, the location of concealed granite and orebody was determined. Granite is characterized by high resistance and is buried at a depth of about 1.5 km, with the formation of ridge uplift along the fault structure. The low-resistivity orebody is located in the middle Devonian strata at the top of granite, so it is inferred that the orebody was developed from the granite at the bottom, which indicates that granite has an obvious ore-controlling effect. According to the zonal characteristics of copper in the near place and tin in the distant place as well as anomalies of metallic elements in the Dachang ore district, it is most possible to find skarn type Zn-Cu deposits and Sb-W deposits. The research shows that, in the late Cretaceous period, the magmatic hydrothermal fluids of the middle and lower crust together with a small amount of upper mantle rose to the shallow Devonian strata of the crust along the basement fault in the NW direction, and then formed mineralization with surrounding rocks through crystallization differentiation.
Keywords:
本文引用格式
刘成功, 景建恩, 金胜, 魏文博.
LIU Cheng-Gong, JING Jian-En, JIN Sheng, WEI Wen-Bo.
0 引言
广西大厂矿田是世界知名的锡(Sn)多金属矿田之一,成矿条件优越,已探明大、中型矿床数十个,产有丰富的锡、锌、银、锑、铜、汞、钨等多种矿产资源。大厂矿田浅部至中深部已发现有长坡—铜坑矿床、巴力矿床、瓦窑山矿床、大福楼矿床、灰乐矿床、亢马矿床等高温岩浆热液型锡矿床,以及黑水沟—大树脚锌铜矿、拉么矿床等接触交代型锌铜矿床和茶山锑钨矿产[4,5,6]。经过几十年的开采,现有可开采资源储备严重不足,迫切需要增加矿山的资源储量,以延长矿山的开采寿命。目前,大厂矿田西矿带除黑水沟—长坡矿区,其他大部分已知矿床的勘查深度不超过600 m,已知矿床周边和深部成矿条件好,限于前人的勘查技术,留下了大量“空白区”[7]。NW、NE向断裂构造附近,隐伏岩体接触带及其附近的找矿远景良好;沿响水湾至茶山一线都有寻找钨锑和锌铜矿的前景[8,9]。
1 地质环境
华南是我国 Sn、W、Sb及其他有色金属矿产资源最为丰富的地区,广西大厂矿田位于华南加里东褶皱系和扬子地台交接部位,具体位于江南古陆西南缘、右江盆地北东侧、NW 向丹池褶断带中段[12,13](图1)。受丹池断裂带的控制,区内出露中泥盆统生物礁灰岩、粉砂岩和页岩,上泥盆统灰岩和硅质页岩,石炭系至二叠系页岩、粉砂岩和石灰岩,夹杂少量的二叠系灰岩和砂岩(图2)。主要赋矿地层为泥盆系纳标组(D2n)、罗富组(D2l)、榴江组(D3l)、五指山组(D3w),同车江组(D3t)中矿化较弱[14]。矿田内的主要构造为NNW向的复式褶皱,NW向丹池背斜和丹池断裂带组成了区内构造格架,NE、SN及EW向构造叠加其上[15,16]。
图1
图2
在NW、NE两组断裂的交汇部位,岩浆活动极其发育,以燕山中—晚期中酸性浅成岩为主。区内产出的岩石类型有花岗岩、花岗斑岩、闪长玢岩等。岩浆岩主要出露于大厂矿田中部的龙箱盖一带,地表分布面积较小,仅0.5 km2,经钻孔资料和重、磁的研究结果发现,地表出露的小岩体下部存在一个巨大的隐伏岩株,并延伸到了西矿带的巴里、铜坑、长坡矿区深部[17,18,19]。根据SHRIMP 锆石U-Pb方法确定,笼箱盖花岗岩中黑云母花岗岩的年代为93±1 Ma,斑岩花岗岩的年代为91±1 Ma,花岗斑岩的年代为91±1 Ma,闪长斑岩的年代为91±1 Ma,均属于燕山期热事件的产物[20,21]。拉么矽卡岩铜锌矿床(图2)[16]位于上泥盆统灰岩与花岗岩体的接触带;铜坑—长坡、巴厘、龙头山、大福楼、灰乐、亢马多锡金属矿沿花岗岩的东西边缘分布。花岗岩中主要成矿元素Sn、Cu、Sb、W、Ag的含量一般高于其他花岗岩平均值的数倍或数十倍,因此,花岗岩分布区域是寻找矿体的有利靶区[22]。
2 AMT数据处理
为了研究大厂田深部隐伏矿体的分布特征,在大厂矿田中段布设了1条音频大地电磁测深(AMT)剖面(见图2),测线全长约6 000 m,方位NE20°,横跨笼箱盖断裂和笼箱盖背斜构造。野外数据采集使用加拿大凤凰公司MTU-5A型大地电磁测深仪,数据采集过程中采用张量测量方式布极,每个测点测量2个磁场分量(Bx,By)和2个相互正交的水平电场分量(Ex,Ey)。大地电磁测深点采集过程中使用GPS同步观测,采集时间均在4~5 h。对采集的原始时间序列数据进行快速傅立叶变换,将时间域信号转变为频率域数据,再通过Robust估计、远参考、功率谱挑选等技术处理,获得了高质量的阻抗数据。图3给出了A04测点和A10测点的视电阻率和相位曲线。
图3
图3
部分测点的视电阻率和相位
Fig.3
Apparent resistivity and phase diagram of some measuring points
阻抗二维偏离度也是描述地下介质构造维度的重要指标,根据维性分析结果,剖面二维偏离度基本都小于0.3,呈现二维构造特征。同时,研究表明,大厂矿田矿脉严格受到呈二维NW向控矿构造的制约,本文采用的AMT 测线是垂直于构造走向布设的,因此,对测线AMT数据进行二维反演建模是合理可行的。采用G-B阻抗张量分解技术[23]进行电性主轴分析,存在60°和150°两个优势主轴方向(图4),由于本区主要为NW向断裂构造,由此确定电性主轴方向为NE150°,据此将阻抗数据旋转到电性主轴方向。为克服三维畸变的影响,实践中多采用TM或 TE+TM联合模式进行大地电磁数据二维反演[24]。本文应用非线性共轭梯度(NLCG)算法[25]对AMT数据选取TE+TM模式的数据参与反演。对于AMT剖面TE+TM数据反演参数设置为:TE模式视电阻率误差为20%,相位误差为10%,TM模式视电阻率误差为10%,相位误差为5%,采用L曲线法[26]确定正则化因子为5(图5),迭代168次后,获得大厂矿区中部二维电阻率模型(图6)。
图4
图4
电性主轴分频统计结果
Fig.4
Strike analysis results for the specific corresponding frequency band
图5
图5
不同正则化因子反演得到的模型粗糙度与拟合差曲线
Fig.5
Model roughness and fitting difference curve of inversion by different regularization factors
图6
3 电性结构分析
矿区岩矿石标本电阻率测试数据统计结果:矿石0.5~35 Ω·m,尾矿砂40 Ω·m左右,炭质层和围岩(灰岩、硅质岩、大理岩等)电阻率约100~1 000 Ω·m,围岩与矿体存在明显的电性差异[27]。电性结果显示,沿剖面自西向东存在3个不连续的高导体(C1、C2、C3)和2个不连续高阻块体(R1、R2),高导和高阻区域形态分明。高阻异常体R1呈锥形隆起(图6中虚线所示部位),其深部电阻率可能高达2 000 Ω·m以上,与两侧围岩存在明显的电性差异。根据大厂矿田1∶20万和1∶5万重力研究发现,笼箱盖岩体顶部沿丹池断裂、铜坑—灰乐横断裂、大厂断裂均呈脊状隆起[17,19];此外,根据大厂矿田岩石物性测试和钻探资料,花岗岩呈高阻特征[7],由此推断高阻异常体R1可能为隐伏的笼箱盖花岗岩体,其顶板埋深约1 500 m。高阻体R2形态呈不规则块状,埋深西浅东深,电阻率值在1 000 Ω·m以上;地层以中泥盆统生物礁灰岩为主,推测高阻体R2主要是致密的生物礁灰岩。
大厂矿田隐伏矿体为多金属矿体,呈低阻(高导)特征,因此,高导体是寻找隐伏矿床的重点区域。结合地质构造和岩石的物性特征,对高导体的成因进行了讨论。高导体C1位于丹池背斜残留的石炭系灰岩地层,因地层剥蚀严重,灰岩裂隙和节理极为发育,推断低阻体C1可能是破碎的石炭系灰岩风化带。高导体C2出露于上泥盆统灰岩和硅质页岩地层中,紧邻笼箱盖断裂,异常中心位于地表,推断高导体C2可能是由于上泥盆沉积层遭到破坏形成的局部破碎带。高导体C3埋深较大,位于拉么Zn-Cu矿床和茶山Sn-W矿床之间,与深部脊状隆起的花岗岩相互伴生,推测其可能是深部隐伏矿床。
4 讨论
4.1 隐伏矿床的讨论
整个矿田内矿体同属于一个岩浆活动成矿系统,各类矽卡岩型矿床围绕岩笼箱盖花岗岩体中心呈环状分布,矽卡岩系统位于碳酸盐岩中,横向和垂直都与花岗岩相接触[28,29]。花岗岩体向外依次为锌铜矿床(局部叠加有晚期的钨锑矿化)、锡多金属矿床、铅锌银矿床和汞锑矿床,各环之间有着明显的叠加和渐变现象。据统计,一般矽卡岩型锌铜矿距离花岗岩体约0~200 m,锌矿体约200~600 m,锑钨矿约500~2 000 m,锡石硫化物型矿床约600~2 000 m,铅锌银矿约800~3 000 m[30]。接触交代型锌铜矿床,位于大厂矿田笼箱盖隐伏岩浆房的顶部及其周边,这类矿床成矿作用主要集中出现在岩浆房高位突出的顶界面凹凸部位及其内外接触带范围。根据本文所获得的电阻率模型,高导体C3位于大厂矿田笼箱盖隐伏岩浆房的顶部,距离笼箱盖花岗岩体约500 m,具有接触交代型锌铜矿床的构造特征(接触交代型锌铜矿床,位于大厂矿田笼箱盖隐伏岩浆房的顶部及其周边,这类矿床成矿作用主要集中在岩浆房高位突出的顶界面凹凸部位及其内外接触带范围)。此外,根据大厂矿田地表岩石地球化学Sn、Zn、Sb、Cu元素异常平面示意图,笼箱盖—茶山区地表Sb、W、Zn、Cu矿化强烈,反映了深部可能存在隐伏Zn-Cu和Sb-W矿床[7];大厂矿田ΔT高精度磁测化极上延500 m垂向二导异常图显示,异常总体围绕隐伏花岗岩体呈环状分布,反映矿液活动可能来源于隐伏花岗岩体或受到岩浆的驱动[18]。基于以上研究,推测隐伏矿体C3可能为矽卡岩型锌铜矿床,后期叠加锑钨矿床。
4.2 成矿物质——流体来源和高阻隐伏岩浆侵入体
4.3 控矿因素
区域性的大构造控制了成矿带、矿田、矿床的形成与分布,而矿区范围内的小构造则控制了矿体的形态、产状。NW向的深大断裂在区域地质挤压、拉张作用下,往往成为混合成矿流体运移的通道;而NE、SN和EW3组次级断裂构造控制了矿体的形态和结构。背斜轴部易产生轴向断裂构造和虚脱空间,是矿液充填的有利场所。大厂矿田的容矿构造主要为层间滑脱破碎带、细(网)脉状裂隙构造、NE向大脉状裂隙构造及岩浆侵入接触带构造,层间滑脱破碎带是大厂矿田最主要的控矿构造类型。流体包裹体特征和 He、Ar、S 同位素组成共同表明,铜坑—长坡矿床脉状及层状矿体具有相同的成矿物质来源和相同的成因,成矿作用与燕山期构造、岩浆热事件有关[34]。
4.4 成矿机制
根据南丹地区1∶20万区域重力及航磁资料,结合广西地区1∶100万区域重力、地震测深资料综合推断,NW向断层可能达到下部地壳,甚至上地幔[16,19,22]。电性结果表明紫云—垭都断裂带中、下地壳及上地幔高导体主要是岩石圈物质局部熔融,幔源岩浆底侵地壳产生的热量使上覆成熟地壳发生部分熔融[35]。上地幔物质的局部熔融产生大量的热使上覆地壳发生部分熔融,断裂构造为中、下地壳(及少量上地幔物质)的岩浆热液和深部地幔热源向上运移提供了通道[35,36]。基于3He/4He比值高和富CO2流体的存在, 认为在铜坑—长坡矿床成矿过程中有少量深部地幔流体的参与,另外,高的R/Ra比表明了矿液中存在地幔物质的贡献[21]。根据对稀土元素含量和S、Pb等元素的同位素分析,也得出了类似的结论[37,38,39,40,41]。
根据成矿模式的综合描述,得到研究区电性约束下的大厂锡多金属矿理想化成矿模式图(图7)。晚白垩世时期,华南西部地区软流圈上涌并诱发岩石圈地幔部分熔融,幔源岩浆底侵地壳产生足够的热使上覆成熟地壳发生部分熔融。燕山运动期间本区深部的岩浆活动强烈,中、下地壳(及少量上地幔物质)的岩浆热液和深部地幔岩浆沿上涌到浅层泥盆系地层。岩浆作用推动原有的成矿流体和岩浆流体带来的成矿物质在SN向断裂和NE向构造带等构造附近的减压地带成矿,形成部分层状矿体和大部分的脉状矿体,同时有中性—酸性岩浆侵入[7]。泥盆纪至白垩纪形成了一个完整的成矿时空格架:泥盆纪时期,区域性控矿断裂形成;印支—燕山期,强烈的挤压褶皱作用和拉张形成层间裂隙和次级断裂等容矿构造;晚白垩世时期,中酸性岩浆侵入(深、浅源流体混合),后经成矿流体分异,在中上泥盆统地层富集成矿。
图7
图7
大厂矿田成矿模式(据广西二一五地质队资料修编)
Fig.7
Metallogenic model diagram of Dachang deposit(modified by data of the 215 geological team,Guangxi province)
5 结论
1)根据先前重力和大地电磁测深的结果,NW向断裂构造为切穿莫霍面的深大断裂,断裂构造为中、下地壳(及少量上地幔物质)的岩浆热液和深部地幔热源向上运移提供了通道。
2)利用大厂矿田AMT剖面反演结果初步圈定了隐伏花岗岩和隐伏矿体的位置;花岗岩成脊状隆起,推测矿体发育自底部花岗岩体,表明花岗岩具有明显的控矿作用。推测晚白垩世时期,深部成矿流体和岩浆热液沿断裂上涌到浅层泥盆系地层中,经结晶分异作用形成笼箱盖花岗岩体和隐伏矿体。
致谢
在野外数据采集与资料收集中,得到了广西大厂矿田苏亚汝总工的大力支持,在此表示感谢。
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金属矿产资源的深部找矿、勘探与成矿的深层动力过程
[J].世界上任何一个国家或地区,在科学与技术的进步,社会与经济的发展进程中,无一例外的必须以大量的,各种类型的金属矿产资源为后盾.当今我国正处在快速工业化和经济腾飞的前夜,国内矿产资源供给不足,且紧缺,故对外的依存度日益增大.为此,在多元化共享世界资源的同时,必须以本土资源为本,并迅速建立起安全、可靠与稳定供给的重要金属矿产战略后备基地.本文基于金属矿产资源形成和聚集的深部介质和构造环境,深层过程和动力学响应的新认识,并分析和讨论了国内、外已发现的深部金属矿床实例.据此提出:必须迅速强化进行地壳内部第二深度空间(500~2000 m)高精度地球物理找矿、勘探和深入研究深部物质与能量的交换与矿产资源形成的深层动力过程.
Deep disscover ore,exploration and exploitation for metal mineral resocrces and its deep dynamical process of formation
[J].The advance of science and tecndogy, develop of society and economy for any countris and areas in the word must be the backing for great quantity and all kinds metal mineral resources. China is just the eve for rapid industrializiation and economic prance, but internal supply havent't enogh and very deficency at the present time, so result in makes increas unceaslu of the dependent degrce on aborad. Therefore use word's mineral resources by many way at the same time, determined to have a foothold in national resources and rapid to building the strategic reserve base of matal mineral resurces for safety, reliable and stable supply. In view the new understand; for deep medium and structural environnment、deep process and dynamic response for formation and acomulation of metal minearal resoreces, we are analysed and discused a few fact examples for deep metalliferous deposit of China and abroad. According to these suggest; ① must be rapid strengthen develop discover ore、exploration of metal mineral resources in second deep space (depth: 500 m to 2000 m) by geophysical method and tecnology of high precision, ② go deep into study the substance and energy exchangs in depths and its deep dynamic process of formation of metal mineral recorces.
长江中下游成矿带及典型矿集区深部结构探Sino-Probe-03年度进展综述
[J].
Probing on deep structure of middle and lower reaches of the Yangtze metallogenic belt and typical ore concentration area:a review of annual progress of Sino-Probe-03
[J].
大厂锡石——硫化物多金属矿带地质特征及成矿系列
[J].
Geological characteristics of the Dachang cassiterite sulphide deposits and metallogenetic series
[J].
广西大厂锡多金属矿田地质特征、矿床模式与成矿预测
[D].
The geological characteristics, genesis and metallogenic prediction of Dachang tin-polymetallic ore field,Guangxi
[D].
大厂矿田长坡矿床深部区叠瓦状构造控矿特征及找矿前景分析
[J].
Control of mineralization of imbricate structure and prospecting perspective in deep part in the Changpo deposit of Dachang ore filed
[J].
大厂矿田硫同位素特征及找矿预测
[J].
Sulfur isotope characteristics and prospecting prediction of Dachang tin-polymetallic ore field
[J].
Three-dimensional inversion of magnetotelluric data for mineral exploration:An example from the McArthur River uranium deposit,Saskatchewan,Canada
[J].
DOI:10.1016/j.jappgeo.2008.02.002
URL
[本文引用: 1]
AbstractShallow exploration targets are becoming scarce, meaning interest is turning towards deeper targets. The magnetotelluric method has the necessary depth capability, unlike many of the controlled-source electromagnetic prospecting techniques traditionally used. The geological setting of ore deposits is usually complex, requiring three-dimensional Earth models for their representation. An example of the applicability of three-dimensional inversion of magnetotelluric data to mineral exploration is presented here. Inversions of an audio-magnetotelluric data-set from the McArthur River uranium mine in the Athabasca Basin were carried out. A sub-set comprising data from eleven frequencies distributed over almost three decades was inverted. The form of the data used in the inversion was impedance. All four elements of the tensor were included. No decompositions of the data were done, nor rotation to a preferred strike direction, nor correction for static shifts. The inversions were successful: the observations were adequately reproduced and the main features in the conductivity model corresponded to known geological features. These included the graphitic basement fault along which the McArthur River uranium deposit is located.]]>
九瑞矿集区三维电性结构研究及找矿意义
[J].
Three-dimensional electrical structures and significance for mineral exploration in the Jiujiang-Ruichang District
[J].
广西丹池矿带锡多金属矿床地质地球化学特征及成矿作用
[J].
Geological and geochemical characteristics and mineralization of the tin-polymetallic deposit in the Danchi ore belt, Guangxi
[J].
丹池晚古生代盆地的沉积和构造演化
[J].丹池盆地属右江裂谷带靠近江南古陆南缘的次级裂陷盆地,其中的沉积可分为五个相区,十三种相类型。研究认为丹池盆地的形成、沉积作用、相和相序的分布均明显受到同沉积期断裂活动的影响。构造演化从泥盆纪初开始即有北西向丹池断裂的张裂作用,此种张裂与其派生的北北东向走滑断裂的复合作用,到二叠纪时,演变为北西向断裂的走滑活动,丹池盆地最初由半地堑式发展为地堑式盆地,到二叠纪成为—走滑盆地。
Sedimentary and tectonic evolution of the late Paleozoic danchi basin
[J].
大厂锡多金属矿床热液喷气沉积成因的证据——含矿建造及热液沉积岩
[J].
Evidence for exhalative origin for rocks and ores of the Dachang tin polymetallic field: the ore-bearing formation and hydrothermal exhalative sedimentary rocks
[J].
广西丹池地区锡多金属成矿带控矿因素及成矿预测
[J].
Ore-controlling factors and metallogenic prediction of tin polymetallic metallogenic belt in Danchi, Guangxi
[J].
广西丹池成矿带构造特征及其控矿作用
[J].
Structural characteristics and ore-controlling effect of the Danchi metallogenic belt, in Guangxi Province
[J].
广西大厂隐伏岩体重力反演及其地质意义
[J].
The gravity inversion and its geological significance for the hidden granite body in Dachang,Guangxi
[J].
大厂矿田地面磁测资料综合处理研究报告
[R].
Research report on comprehensive processing of surface magnetic survey data in Dachang ore field
[R].
应用重磁资料研究广西芒场——大厂成矿带的地质构造及隐伏岩体预测
[D].
Application of gravity and magnetic data to study the geological structure and hidden rock mass prediction of the Mangchang-Dachang metallogenic belt in Guangxi
[D].
广西大厂锡矿田侵入岩SHRIMP锫石U-Pb年龄及其意义
[J].应用高精度SHRIMP锆石U-Pb方法对广西大厂锡矿田不同类型中―酸性侵入岩进行了系统的定年研究,获得龙箱盖含斑黑云母花岗岩的成岩年龄为93±1Ma,斑状花岗岩91±1Ma,石英闪长玢岩脉(西岩墙)91±1Ma,花岗斑岩脉(东岩墙)91±1Ma,四者在测试误差范围内基本一致,微量元素特征及稀土配分模式相近,为同期不同阶段岩浆活动的产物。区内成岩与锡多金属成矿的时代相一致,均形成于板内伸展剪切的构造环境,应同属燕山晚期构造―热事件的产物。
SHRIMP zircon U-Pb dating of the intrusive rocks in the Dachang tin-polymetallic ore field, Guangxi and their geological significance
[J].
The origin of the tongkeng-changpo tin deposit, Dachang metal district,Guangxi,China:clues from fluid inclusions and He istope systematics
[J].DOI:10.1007/s00126-007-0127-5 URL [本文引用: 2]
南盘江—右江成矿带广西境域深部找矿潜力分析
[J].
Analysis of deep prospecting potential in Guangxi region of Nanpanjiang-Youjiang metallogenic belt
[J].
Decomposition of magnetotelluric impedance tensors in the presence of local three-dimensionalgalvanic distortion
[J].DOI:10.1029/JB094iB02p01913 URL [本文引用: 1]
大地电磁资料精细处理和二维反演解释技术研究(二)——反演数据极化模式选择
[J].
DOI:10.3969/j.issn.0001-5733.2010.11.018
URL
[本文引用: 1]
针对大地电磁二维反演中TE、TM极化模式的选择问题,设计了多个二维、三维模型进行了正演计算,从数据对比和反演结果对比两方面入手,分析研究了三维模型和二维模型响应数据的差异、反演中极化模式的选择、以及三维模型数据的二维反演近似等问题.研究结果表明:在三维模型条件下,利用二维模型进行反演时,TE模式对模型的二维的近似程度要求远高于TM模式;当三维结构影响较明显时,利用TM模式数据进行二维反演比利用TE模式或利用TE+TM模式联合反演都更合理,反演结果中的虚假结构明显减少;对于TM模式,相位受三维畸变影响较小,视电阻率较大,所以二维反演中可适当加大相位的权;对于实测数据的二维反演,应优先考虑采用TM模式数据进行二维反演,其次是TM+TE模式,一般不要单独采用TE模式.
Refined techniques for data processing and two-dimensional inversion in magnetotelluricⅡ:Which data polarization mode should be used in 2D inversion
[J].
Nonlinear conjugate gradients algorithm for 2D magnetotelluric inversion
[J].DOI:10.1190/1.1444893 URL [本文引用: 1]
Analysis of discrete ill-posed problems by means of the L-curve
[J].DOI:10.1137/1034115 URL [本文引用: 1]
大厂锡多金属矿区深边部找矿中的TEM异常特征
[J].
Abnormal characteristic of TEM response for prospecting depth and margin area of Tin-polymetallic deposit in Dachang
[J].
An oxygen, hydrogen, sulfur, and carbon isotope study of carbonate-replacement skarn tin deposits of the Dachang tin field, China
[J].
Fluid inclusion studies of zoning in the Dachang tin-polymetallic ore field,People's Republic of China
[J].
广西大厂矿田矿床分布规律与找矿方向
[J].
Distributing rules of deposits and prospecting direction in Dachang mining area,Guangxi
[J].
广西芒场锡多金属矿田稳定同位素组成对矿床成因探讨
[J].
Discussion on the stable isotopic composition and genesis of Mengchang Tin-polymetallicore field ore deposit in Guangxi
[J].
广西大厂长坡锡矿床地质及成因
[J].
Geology and genesis of changpo tin deposit, Dachang, Guangxi
[J].
广西大厂矿田泥盆系地层地球化学及其成矿指示
[J].
Geochemical characteristics and mineralization indication of Devonian strata in Dachang ore field, Guangxi
[J].
广西大厂锡多金属矿田亢马矿床地质特征及成矿时代
[J].亢马矿床是广西大厂锡多金属矿田东矿带中一个研究程度较低的中型锡多金属矿床。矿床特征研究表明,区内的锡多金属矿化主要呈脉状产出,明显受构造控制,成矿作用以充填-交代为主,后生成矿作用特征明显。成矿作用可分为3个阶段,各阶段的完全均一温度分别为30 0~35 0℃、2 10~2 80℃、14 5~175℃。石英流体包裹体Rb- Sr测年获得等时线年龄为94 .1±2 .7Ma(2σ) ,表明成矿时代属燕山晚期,成矿流体的87Sr/ 86 Sr初始值为0 .710 15 ,与大厂矿田中部龙箱盖黑云母花岗岩87Sr/ 86 Sr的初始值0 .7110接近。成矿年龄与成矿流体的87Sr/ 86 Sr初始值均表明亢马锡多金属矿的成矿作用与区内的龙箱盖岩体具有一定的成生联系。
Geological characteristics and ore-forming time of the kangma deposit in the Dachang tin-polymetallic ore field, Guangxi
[J].
南盘江盆地壳幔电性结构研究
[D].
Studying on the electrical structure of the crust In the Nanpanjiang basin
[D].
Genesis of tin-dominant polymetallic deposits in the Dachang district, South China:Insights from cassiterite U-Pb ages and trace element compositions
[J].DOI:10.1016/j.oregeorev.2018.03.023 URL [本文引用: 1]
广西铜坑锡多金属矿黄铁矿的Re-0s同位素组成及成矿物质来源示踪
[J].
Re-Os isotope composition and source of ore-forming material of pyrite in Tongkeng Tin-pollmetallic
[J].
广西大厂石榴石REE含量及Sm-Nd同位素定年
[J].
REE geochemistry and Sm—Nd isotope age of garnet from the Dachang,Guangxi
[J].
Chemical and Rb-Sr,Sm-Nd isotopic systematics of tourmaline from the Dachang Sn-polymetallic ore deposit, Guangxi Province,P.R.China
[J].DOI:10.1016/S0009-2541(98)00200-9 URL [本文引用: 1]
Dating of the Dachang superlarge tin-polymetallic deposit in Guangxi and its implication for the genesis of the No.100 orebody
[J].
Lead isotope composition and constraints on origin of Dafulou ore deposit,Guangxi,China
[J].DOI:10.1016/S1003-6326(13)62659-X URL [本文引用: 1]
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