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1.
It has been inferred and proved by the remote sensing equations under rational hypotheses in atmospheric physics that there is a linear correlation between the ground reflective brightness Wij and the total reflective brightness Rij received in different bands with a remote sensor. Nine models delineating the ground-space correlation between the ground spectra and the optimal bands of images of the typical gold deposits have been established based on the ground-space correlativity and field measurements of the ground spectra of the typical gold deposits in the Ailaoshan area. According to the 9 correlation models, TM images were inverted into ground-space correlation images that are related to the typical gold deposits within the area and then recognized by a computer. Research on the ground . spectra and TM data in the Ailaoshan area shows that the correlation analysis of the ground spectra and TM data of gold deposits can be effectively applied to the prediction of gold deposits, location of prospecti  相似文献   

2.
A lot of new gold deposits have been found on the eastern margin of the Qinghai-Tibet Plateau during the past two decades. Among them, three main types of gold deposits have been recognized, including quartz-vein-type, shearzone-type and porphyry-type. The former two types of gold deposits are mainly hosted within metamorphic rocks, while the latter is related to Cenozoic magmatism. Although all of these gold deposits are believed to have been formed during the uplift process of the Qinghai-Tibet Plateau in the Cenozoic era (Wang et al., 2002b), precise isotopic age constraints have still been lacking until quite recently. This paper presents new ^40Ar/^39Ar data of some gold deposits on the eastern margin of the Qinghai-Tibet Plateau, which indicate that gold mineralization in the region occurred in response to the episodic stages of the orogenies. Recently obtained ^40Ar/^39Ar data on quartz and feldspars from several gold deposits, such as the Sandiao deposit, the Baijintaizi deposit, the Pusagang deposits, provide new constraints on gold mineralization on the eastern margin of the Qinghai-Tibet Plateau. Geochronological studies of gold deposits along the Daduhe River indicate that there are three stages of gold mineralization. The early two stages occurred as early as 65.1 Ma in the Shuibaiyang deposit and 58.95 Ma in the Ruoji deposit, while the latter stage occurred as late as 25.35 Ma in Baijintaizi and 24.70 Ma in Sandiao. Isotopic dating of three plagioclases from the Beiya deposit, Zhifanggou deposit and Luobodi deposit and a K-feldspar from the Jinchangqing deposit in Yunnan Province indicates that these deposits were formed at two stages. The Zhifanggou and Jinchangqing deposits have early stage records as old as 58.82 Ma in Zhifanggou and 55.49 Ma in Jinchangqing, but all of the above four deposits in Yunnan have late stage records of 23.18 Ma in Jinchangqing, 24.54 Ma in Zhifanggou, 24.60 Ma in Luobodi and 24.56 Ma in Hongnitang. The above results suggest that the gold deposits on the eastern margin of the Qinghai-Tibet Plateau were formed concentratedly at two main episodes, i.e. the end of the Paleocene (about 58 Ma) and the boundary between the Paleogene and the Neogene (about 25 Ma). The later episode appears to be looks like more important and was coupled with the Sichuan movement, which was extensively activated at that period. The beginning of the Cenozoic Era (about 65 Ma) might be another episode of gold mineralization, but only one deposit (Shuibaiyang) in this study has been proved to have been be formed at this stage and might be earlier than the initial collision between the Indian Plate and the Eurasia Plate. In view of geology, the above three episodes of gold mineralization are associated with three events of tectonicmagmatism and/or fluid events. Even though the gold deposits (for example, the Shuibaiyang deposit, Ruoji deposit and Pusagang deposit) were formed at different episodes, all of them are genetically related to tectonic movements in largescale shear zones. It looks like theat tectonic events (including large-scale strike-slip) between Paleogene and Neogene had a wide influence upon gold mineralization, with new deposits formed and old deposits enriched or superimposed to be a higher grade by new stage of mineralization. The above data suggest that gold deposits were not only concentrated in some areas, but also formed mainly at different boundaries of geological times, indicating that there existed some peak stages of gold mineralization (metallogenic episodes), and that the gold deposits were formed mainly by episodic mineralization.  相似文献   

3.
The west sector of the northern Qilian Mountains is well-known for the Jingtieshan-type iron deposits. A new breakthrough has been made in prospecting for gold and copper in recent years. In this paper, the distribution characteristics of ore deposits in the study area are discussed from the viewpoint of tectonic evolution. It is suggested that there are 9 stages of mineralization from the Palaeoproterozoic to Indosinian. Four minerogenetic series and two minerogenetic subseries of ore deposits are recognized. Iron mineralization occurred in several stages, while most of the metals were accumulated in large amounts in the Caledonian. The enrichment and mineralization of gold is related to large-scale shear-strike-slip faults and the ascent and unloading of deep-seated fluids.  相似文献   

4.
As a typical Palaeozoic island arc system, the eastern Tianshan area, Xinjiang, is different from eastern China but similar to the Meso-Cenozoic island arc metallogenic provinces along the coast of the Pacific Ocean in metallogenic environment, geology and geochemistry. Three types of gold deposits, ductile shear zone-hosted gold deposits (Kanggur ), magmatic hydrothermal gold deposits (Jinwozi) and volcanic- or subvolcanic-hosted gold deposits (Xitan and Mazhuangshan), have been identified in this area. Regionally, gold deposits are structurally controlled by the Kanggur Tag ductile shear zone, Shaquanzi fault, Hongliuhe fault and Yamansu fault. Generally, gold mineralization occurs in the transition zones from volcanic rocks to sedimentary rocks. The horizon bearing well-developed jasper is an important indicator for gold mineralization. Each of the three types of gold deposits has its distinctive metallogenic background and geological-geochemical characteristics.  相似文献   

5.
In this paper an intergrated geological and geochemical comparison is made of Carlintype and Carlin-like-type gold depostis in the region of South Qinling with their associated hydrothermal sedimentary lead-zinc pdposits,the Carlin-type deposits in the Yunnan-Guizhou-Guangxi gold triangle,China,the Carlin gold deposits,Carlin,western United States,and the Muruntau-type gold deposits in Uzbekistan.The comparative study indicates that the formation of these deposits has an intimate coupling relation with the mechanism of the tectonic movement of modern plates.Therefore,these deposits belong to those that were formed in the orogenic stage. They have the following similar characteristics:they are all sediment-hosted.occur in a tectonic environment of extensional rifting nature and show the characteristics of syngenetically modified mineralization.On the other hand,they alsso have noticeable differences:they are different in respect to their tectonic settings.association and structure of orogenic belts and complexity and strength of the modified mineralization.The regional tectonic evolution and extensive mineralization in orogenic belts are different expressions of the same continental dynamic process.  相似文献   

6.
The Zhangjiakou-Xuanhua area is a mineral resource-concentrated area for gold-silver polymetallic ore deposits. The temporal and spatial distribution and origin of mineral resources have been argued for a long time. Based on the comprehensive studies of geochronology and sulfur, lead, oxygen, carbon and noble gas isotopes, it is considered that the temporal and spatial distribution of mineral resources in this area is obviously controlled by the Zhangjiakou-Xuanhua mantle branch structure, as is reflected by the occurrence of gold deposits in the inner parts and of Ag-Pb-Zn polymetallic ore deposits in the outer parts. The mineralization took place mainly during the Yanshanian period. Ore-forming materials came largely from the deep interior of the Earth, and hydrothermal fluids were derived predominantly from Yanshanian magmatism.  相似文献   

7.
The depth is important for ore finding in Jiaodong gold deposit. However, many geologis tsare still discussing how to confirm the depth for the tectonic and metallogenesis formation. The authors of this paper propose a new method—the correction of metallogenic depth via its structure to calculate the depth. This method, based on the crust rock in a solid stress state, emphasizes the elastic pattern rather than the static-fluid pattern. In addition, this method is more appropriate to the actual situation in the crust than the method of weight/special weight. The authors of this paper illustrating, with the Jiaodong gold deposit as an example, the metallogenic depth correction via structure conclude that the depth of the most deposits, lower than 4-6 km, is often 2.5 kin. Therefore, the authors suggest that there exists a second enrichment belt and that ore resources are more potential at the belt of Jiaodong area. These results have been demonstrated by years of exploration.  相似文献   

8.
In the light of field investigation, microscopic study, X-ray phase analysis and mineral infrared spectral analysis, it is considered that laumontitization is of extensive occurrence in the Axi gold orefield. The development of laumontitization and its relationship to mineralization show that the laumontitization appeared mainly at the top of and in the periphery of orebodies, and occurred at the edge of the epithermal system or at the late stage of epithermal system evolution. Therefore, laumontitization can be used as an exploration indicator of epithermal gold deposits. The fluids responsible for laumontitization in the Axi gold orefield are similar to those producing hot spring-type gold deposits or those from modem geothermal fields. Epithermal mineralization of the Axi gold deposit was dated at Carboniferous, indicating that the West Tianshan of China is a region favorable to epithermal-type gold mineralization and preservation. Hence the West Tianshan of China is a target area for exploring epithermal gold deposits.  相似文献   

9.
Based on detailed geologic study,the important role of structuring in the formation of gold deposits in the area is discussed with special reference to structural evolution,Syngenetic faulting contemporaneous with tectonic-volcanic events is thought to be responsible for providing the ore-forming material at depth.The lithofacies formed by highly alternating deposition of terrestrial and carbonate detritus is chemically characterized by the assemblage of Au-Sb-As,constituteing a favorable source bed for the activation and enrichment of gold.This gold source bed has undergone four major stages of structural deformation,accompanied by multi-staged alteration and mineralization.  相似文献   

10.
The Daiyunshan-Shiniushan volcanic depression in Fujian Province is situated in a volcanic belt of the southeast coastal area in China along the west Pacific Ocean. A new breakthrough has been made in the exploration of gold and silver ore deposits in recent years. The minerogenic series of the Daiyunshan-Shiniushan volcanic depression is discussed in this paper based on the analysis of major metallogenic types and factors. According to the study of enormous ore deposits and occurrences in the study area, two minerogenic series have been recognized: 1. Late Jurassic Au-Ag-Pb-Zn minerogenic series related to intermediate-acid, acid volcanic formations; 2. nonmetallic minerogenic series (pyrophyllite, alunite pearlite, andalusite, zeolite, corundum and so on) related to intermediate and acid volcanic formations. The division and study of the minerogenic series have revealed metallogenic and time-space distribution characteristics of the ore deposits in the volcanic belt of the southeast coastal area in Ch  相似文献   

11.
黑龙江多宝山-呼玛地区金矿分类及成矿地质背景研究   总被引:1,自引:0,他引:1  
黑龙江省西北部的多宝山-呼玛地区发育大小型金矿(点)16处,主要集中分布在北东向和北西向构造形成的菱环形构造带内.元古宇和下古生界地层单元为金成矿提供物质来源,古生代以来3阶段强烈岩浆热事件为金矿成矿提供了热源、流体和就位空间.根据金矿床赋矿岩石类型、成矿流体等特征和区域构造演化过程,将本地区金矿划分为3个类型:①与火山岩有关的浅成低温热液型金矿,赋矿围岩为早白垩世火山岩,成矿流体源于大气降水;②受压扭性构造控制的低温热液金矿,对围岩无选择,成矿流体具有变质流体和大气降水混合特征,低盐度,少CO2;③夕卡岩型、斑岩型伴生金矿床,具有成矿温度高、盐度高、流体包裹体富含CO2的特点.第一类与第二类为同期异相,形成环境为造山后陆内裂谷-伸展环境;第三类形成于与古太平洋板块的斜向俯冲作用和北部鄂霍次克洋闭合有关的挤压造山环境.  相似文献   

12.
青海双朋西-斜长支沟地区金矿成矿地质条件及成矿规律   总被引:9,自引:0,他引:9  
张涛 《西北地质》2007,40(3):62-67
双朋西—斜长支沟地区是青海东部较为重要的贵金属和有色金属成矿区。在已探明的金矿床中,有矽卡岩型、破碎蚀变岩型、石英脉型三类。金的成矿作用受构造-岩浆控制,在不同的岩性组合中分布着不同类型的金矿。矽卡岩型和石英脉型金矿赋存于二叠系中,破碎蚀变岩型金矿赋存于三叠系中。  相似文献   

13.
粤西是我国华南的主要金、银矿床集中医,医内金矿床与银(金)多金属矿床具有相间排列的分布规律,即从南到北分为以下5个矿带:廉江地区银(金)多金属矿带、高州-信宜金矿带、罗宁-云浮银(金)多金属矿带、德庆-清远金矿带、连山地区银(金)多金属矿带。本文从区域地层、岩浆岩及成矿作用等方面对粤西金、银矿床区域分布规律进行了探讨,认为影响金、银矿床分布的主要因素是不同区域地层、岩浆岩Au、Ag含量的差异及金矿床与银(金)多金属矿床成矿作用的差异。  相似文献   

14.
周鑫 《地质与勘探》2024,60(2):425-432
柬埔寨王国磅通省三丹县地区的整体地质工作程度较低,对该地区已有金矿床(点)成矿地质条件的研究对于该区域金矿勘查具有重要意义。本文详细阐述了三丹县金矿床(化)的成矿地质要素,并与IRGS型金矿进行了对比研究,认为陆缘弧和弧后克拉通盆地接触部位的大地构造背景和钙碱性区域岩浆岩条件,为区内金矿化提供了有利的区域地质条件,这与典型IRGS型金矿床具有相似的构造背景。调查区内的金矿体(矿化)常发育在侵入岩及其边缘地带,在空间分布上金矿化与侵入岩关系密切,且围岩常具石英-碳酸盐-绢云母化围岩蚀变组合,金矿石以网脉状和角砾状类型为主,这符合IRGS型金矿的矿化特征。初步认为区域内金矿化与侵入岩关系密切,属于IRGS型金矿。  相似文献   

15.
豫西地区是国家重点金多金属成矿区带,成矿地质条件优越,区内金及多金属矿类型多样。通过对研究区地质特征及成矿地质条件的分析,得出区内金及多金属矿矿床形成受多重因素控制,包括地层、构造以及岩浆岩因素,并且在这些因素中,构造控矿占主导。在此基础上,将研究区内金矿矿床类型分为构造蚀变岩型金矿床、构造破碎带型金矿床、斑岩型金矿床以及爆破角砾岩筒型金矿床4种类型,并对每一种类型选取1个典型的矿床进行具体讲述。依据对研究区成矿地质特征以及5种构造控矿类型的叙述,论述了拆离-变质核杂岩构造对金矿成矿的构造控矿作用和构造控矿规律,并根据该区金矿矿床成矿规律,提出选取找矿靶区的8项依据,最后优选出7处找矿有利靶区。  相似文献   

16.
非造山带型金矿--胶东型金矿的陆内成矿作用   总被引:42,自引:2,他引:40  
综合了全球有关金矿床的资料 ,Goldfarb和Groves等发表了著名的造山带金矿的论述 ,提出了与造山带有关的金矿在全球范围和从中太古代到整个显生宙的地质时期有广泛的分布和周期性。该类金矿的特点是与变形和变质的中地壳岩块共生 ,特别是在空间上与相应的地壳构造一致。金矿出现在造山带的不同构造部位 ,与不同的金属共生或伴生成矿。胶东作为一个重要的金矿矿集区 ,以不到中国领土面积的 0 .2 % ,而金矿产量占全国的 1 /4。国内一些地质学家也将胶东型金矿划归为造山带型金矿。最近的研究表明 ,胶东矿集区的东界与华北克拉通的东界吻合 ,金矿以华北克拉通变质岩及其有关的侵入岩为控矿围岩。主成矿期成矿时代为 (1 2 0± 1 0 )Ma ,约在不到 1 0Ma的短时限内。成矿物质具有多元性 ,既来自于控矿围岩———花岗片麻岩和变质岩 ,又来自于幔源的岩浆岩 ,特别是与中基性脉岩、偏碱的钙碱性花岗岩的侵入关系密切。除胶东金矿集区之外 ,华北克拉通的边缘和内部普遍含有金矿 ,而且金矿的物质来源、成矿方式、矿产类型、成矿围岩和成矿年龄都是一致的。这种大规模、短时限、高强度的成矿 ,被中国地质学家所重视并称为中生代成矿大爆发或金属异常巨量堆积。深部结构和成分的研究表明 ,华北东部的岩石圈在中生代急  相似文献   

17.
华北克拉通北缘及邻区印支期岩浆活动与钼和金成矿作用   总被引:4,自引:0,他引:4  
对华北克拉通北缘及邻区19处钼矿床和5处金矿床的产出环境、形成时代和成矿机理及其与印支期侵入岩的关系进行了讨论。尽管各个矿床所处的地理位置不同,但是它们大都在前寒武纪或早古生代地层中产出,并且与印支期侵入岩具有密切的时空分布关系。印支期钼矿床的形成作用可以从早三叠世一直持续到晚三叠世,大规模成矿作用高峰期为230~220 Ma。相比之下,金矿床的形成时间明显早于钼矿床,同位素年龄数据集中分布在245~239 Ma。研究结果表明,自早三叠世开始,华北克拉通北缘及邻区曾发生过多期大规模伸展构造作用,并且形成若干条近东西向展布的裂陷带。张裂构造作用所诱发的富碱性岩浆作用及相关流体活动为钼或金矿床的形成提供了动力和物质来源,因此,印支期侵入岩发育区是寻找隐伏钼或金矿床的有利地区。  相似文献   

18.
铜陵矿集区深部找矿工作的一些思考   总被引:1,自引:0,他引:1  
铜陵矿集区深部结构特征为该区大规模成岩成矿作用奠定了良好的基础,浅表已发现的矿床只是矿集区成矿系统的一部分。除此之外,深部还应有多个可以找寻的矿床(矿体)的富集空间。与成矿相关的花岗岩研究表明,铜陵矿集区可能存在与宁芜火山盆地同期的成岩成矿作用,是铜陵矿集区找矿的新方向。铜陵矿集区奥陶系灰岩中铜金矿化作用的初步研究表明,除传统矿床类型外,前泥盆纪地层中的成矿作用应该在今后的找矿工作中得到关注。覆盖区成矿预测初步研究表明,铜陵矿集区向斜核部及褶皱倾伏端等地段具有与已知典型矿床相似的成矿条件。铜陵矿集区的进一步找矿工作应该在上述地段运用矿田构造系统分析、深部地球物理探测和工程验证等方法逐步展开。  相似文献   

19.
施炜  刘建民  王润生 《地球学报》2007,28(3):291-298
内蒙古东部喀喇沁旗地区位于燕山造山带东段的成矿带之上,金矿资源丰富.本文运用遥感技术,结合野外调查,对这一地区金矿围岩矿化异常信息进行了提取和分析.研究表明,本区现有矿床分布与明显受区域构造控制,区内金矿床围岩蚀变以硅化和含铁矿物为主,粘土矿物蚀变较少.区内主要发育3个成矿带,即南北各存在一个近E-W向的成矿带,喀喇沁旗东南发育一个NE-SW向的成矿带,且明显受断裂控制.成矿有利区主要位于本区东南部,且在本区南部NE-SW向断裂和近EW向断裂交汇地带围岩蚀变信息较强,可能为富矿部位.研究表明围岩蚀变遥感异  相似文献   

20.
甘肃省合作市早子沟金矿床构造应力场分析   总被引:2,自引:0,他引:2  
甘肃省合作市早子沟金矿床是西秦岭地区近年来发现的规模达到百吨级别的矿床。该矿床金矿体受构造控制作用明显,因此开展控矿构造研究,可为矿区勘查找矿工作提供指导。本文主要是在野外实地对控矿断裂构造详细观测分析的基础上,利用构造解析法、节理分析法、共轭剪节理法和断层擦痕分析法,通过吴氏网投图分析,确定了早子沟金矿床多期次构造活动的主应力方向,并根据叠加和切割关系以及成岩成矿时代的确定,推断了应力作用的期次和时代。根据分析结果,将早子沟金矿的构造应力场划分为3期5个阶段:成矿前的基底变形、区域变形和岩浆侵位阶段,早期和晚期成矿阶段,以及成矿期后阶段,矿体局部被错断。结合成矿作用特征,进一步分析了不同阶段断裂活动与成矿关系,认为构造应力场演化与成矿作用具有一致性,并指出了NE向主断裂与旁侧分支断裂的复合部位以及NE向断裂与NW向断裂的交会部位是矿区深部寻找富大矿体的有利空间。  相似文献   

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