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1.
Materials pertaining to Mesozoic granitoids in the Central Asian and Pacific Belts junction area and the adjacent platforms are summarized. Maps of the location of massifs, the extensiveness of granitoid magmatism, the manifestations of Mesozoic plumes, and the relief of the asthenosphere surface have been compiled. The locations of the major ore deposits are plotted on the maps. The distribution chart has been constructed for these deposits in the coordinates of the crust and lithosphere. The depth of the occurrence of the sources for large and superlarge gold, tin, polymetallic, molybdenum, tungsten, and uranium deposits has been estimated. Areas showing promise for the discovery of large deposits are defined.  相似文献   

2.
Abstract: The Bayankhongor region in central Mongolia consists of a Paleozoic subduction system including Precambrian microcontinents (Baidrag and Burd Gol zones), obducted ophiolites and accretionary sedimentary rocks (Bayankhongor and Dzag zones), and forearc sedimentary rocks (Khangay zone). Arc magmatism in the Bayankhongor region is characterized by dominance of Early Paleozoic ilmenite-series and Late Paleozoic magnetite-series granitoids. These granitoids accompany many hydrothermal deposits of such various types as porphyry, skarn and vein. K-Ar dating on four deposits in the region revealed that the South porphyry Cu-Au, Huh Bulgiin Hundii skarn Cu-Au, Han Uul shear zone-hosted Au and Taats Gol pegmatite W-Au deposits formed at 240±5 Ma, 252±5 Ma, 283±6 Ma and 329±7 Ma, respectively.
Thus the former three are related to the Permian to earliest Triassic magnetite-series granitoids, whereas the W-Au pegmatite at Taats Gol to the Early Carboniferous ilmenite-series granitoids. Porphyry and skarn Cu-Au mineralization occurred at latest Permian to earliest Triassic, when the Andean-type arc magmatism was immediately followed by the collision between the Baidrag and Tarbagatai microcontinents.  相似文献   

3.
Global manifestations of Early Paleozoic granite formation in the Central Asian Mobile Belt and some other orogenic areas worldwide are considered. The work is based on the author’s studies of Early Paleozoic granitoids from the Altai–Sayan and West Transbaikalian orogenic areas as well as abundant literature data on other world provinces. Special attention is paid to the scales of granitoid magmatism in the Early Paleozoic, its geodynamic settings, periods, and stages, compositional evolution over time, lateral variability in structures of different types, relationship with LIPs, and, correspondingly, connection with mantle plumes and superplumes..  相似文献   

4.
Based on the data base of 1285 mineral deposits of 22 commodities in 121 countries of 6 continents of the world, the authors use the linear trend analysis for their reserves to determine the cut-off limited order of reserves to select 36 exceptional superlarge (as peak mineral), 95 superlarge and 314 large deposits as new recognized intellect for their quantitative change. We have projected above 445 large-superlarge deposits on (1:5 M) global tectonic background map and divided 4 metallogenic domains, 21 metallogenic belts. Global metallogeny of large-superlarge deposits are: unity by endogenic, exogenic metamorphic and epigenetic in origin; speciality in different metallogenic domains and belts; preferentiality to ore-forming elements of Cu, Au, Fe, Ag, Cr, Mn, Zn, Pb, Sb, Hg, to continental margins or plate convergent belts, to Intra-continental tectono-magmatic complex belts and Large ductile shear zones; abnormality by the global oxyatmversion (excess oxygen atmospheric event) in Archean, redoxyatmversion (lack oxygen atmospheric event) in Proterozoic-Paleozoic, and tectonosphere thermal erosion (great amount of tectonic magmatic event) in Mesozoic-Cenozoic.  相似文献   

5.
There are good grounds to believe that the inherited development of ore bodies controls the most important regularities in the location of deposits, especially of large ones, and also explains quite clearly the relatively selective ore occurrence in different magmas. Giant silver deposits were identified among both Paleozoic bodies and their regenerated Late Mesozoic vein-disseminated analogues. Jointly they represent a unified polychronic ore formation range. The performed investigations of mineral composition and the isotopic Sm-Nd system of granitoids in the Dukat ore field and their gold- and silver-bearing melanocratic inclusions established the possible occurrence of the Paleozoic juvenile continental crust of the Siberian Craton in their composition and confirmed our complicated scheme of oregenesis at the Dukat silver giant. The occurrence of high-grade gold in the melanocratic mineral aggregates of granitoids in the Dukat ore field should be regarded as a feature of hypabyssal gold-bearing zones being of high commercial interest.  相似文献   

6.
By analogy with other metallogenic belts of the Circum-Pacific ring, the metallogenic belts in the Northeast of Russia are promising for discovery of large and superlarge porphyry-type Au-Cu-Mo deposits. The spatial distribution of these deposits is controlled by intrusive domes in Middle Paleozoic, Late Jurassic-Early Cretaceous, and Late Cretaceous volcanic belts. New data on formation conditions and sources of ore matter are presented in this paper with respect to the deposits of the Baim and Koni-P’yagina ore districts of the Oloi and Uda-Murgal metallogenic belts. Some aspects of a geological and genetic model of the porphyry copper ore-magmatic system are discussed.  相似文献   

7.
内蒙古赛乌素金矿成矿流体特征   总被引:2,自引:0,他引:2  
杨奎锋  刘爽  胡芳芳  范宏瑞 《岩石学报》2008,24(9):2079-2084
内蒙古赛乌素金矿是华北地台北缘金成矿带内的中低温热液型矿床。金的矿化类型是以石英脉型和蚀变岩型为主。矿体的形成与外围的晚古生代碱性花岗岩有着密切的成因联系,主要经历了四期流体成矿作用。成矿前期伴随花岗岩体的侵位及岩浆热液的活动,在早期近东西向的断层带内充填乳白色石英大脉,构成矿脉的主体,但无金成矿;初期成矿阶段富含CO2-CH4-H2O的流体活动,叠加在石英大脉之上,形成块状黄铁矿-浅色石英矿体;主期成矿阶段,混合了地表水的岩浆期后热液与围岩发生物质交换,形成富含CH4-H2O的流体和网脉状多金属硫化物-烟灰色石英矿体,主成矿期热液温度的降低及流体组成的变化是金沉淀成矿的主要原因;成矿后期形成的碳酸盐-石英脉体,基本无矿化。  相似文献   

8.
The paper presents a study of the gneissic granitoids of the Malkhan Complex and the intruisve granitoids of the Daur and Bichur complexes developed within the Khilok–Vitim fold belt of Central Transbaikalia. In the state geological map, these complexes have been attributed to the Early and Late Paleozoic. New 40Ar/39Ar geochronological data indicate that these rocks are Mesozoic rather than Paleozoic in age, which suggests the much broader manifestation of the Mesozoic granitoid complexes in this area. The studied Mesozoic granitoid massifs exhibit temporal and compositional zoning reflected in a westward decrease in age (from Early to Late Mesozoic) and increase in total alkalinity and potassium content at the appropriate trace-element characteristics. The obtained results of study of the Khilok–Vitim Belt are interpreted in the framework of the model of the formation of domal–cupola structures by the multiple activity of deep thermochemical plumes.  相似文献   

9.
大型,超大型矿床找寻与预测途径的探讨   总被引:1,自引:0,他引:1  
  相似文献   

10.
改造强度是形成中国绿岩带及变质细碎屑岩系中大型及超大型金矿床的关键条件。以超大型金矿床的形成作用作为讨论对象,并对一些特大型金矿床形成超大规模的前景进行了评估。该类矿床产在变质岩及晚期侵入体中,矿床经历了沉积、区域变质及成矿等多次形成作用,有的还经历了重熔岩浆作用阶段,但矿床最终为改造作用所形成。控制超大型矿床成矿的改造作用强度主要反映在被活化的矿源岩石规模大并有多种来源、成矿流体规模大且具较强氧化性、流体长期多次活动以及有稳定的热源等。决定改造强度的因素为多级构造组成的连网。玲珑超大型金矿床是改造强度巨大的产物,形成金山及河台等矿床的改造强度也很巨大,因此有发展成为超大规模的潜力。  相似文献   

11.
加强埃达克岩研究,开创中国Cu、Au等找矿工作的新局面   总被引:36,自引:27,他引:36  
埃达克岩与浅成低温热液Au-Ag及斑岩型Cu、Cu-Au矿床有密切的关系,环太平洋地区多数大型和世界级的斑岩铜矿均与埃达克岩有关。埃达克岩有利于成矿的关键因素与埃达克岩形成时角闪石转变为石榴石的脱水作用有关,而水能萃取出在地幔和基性岩中富集的金属元素。因此,埃达克岩集中分布的地区有利于铜、金等矿化的聚集。中国铜矿资源严重不足,解决这个紧迫问题的出路在寻找斑岩铜矿。全球铜矿主要分布在环太平洋地区,中国与环太平洋类似的地区不是中国东部,而是古亚洲洋造山带、东北吉黑东部和西藏冈底斯。从国家目标出发,建议实施铜、金等找矿工作的战略转移,把浅成低温热液和斑岩型Au、Cu、Ag等矿床找矿的重点放在古生代的古亚洲洋造山带、晚古生代-中生代的吉黑东部和中-新生代的冈底斯地区。古亚洲洋造山带首选阿尔泰西南缘-东准噶尔、东天山和内蒙古中部3个地区。埃达克岩可以作为找矿标志来使用,因此,在找矿思路上也应当有一个变化,即:先找埃达克岩,再找矿。  相似文献   

12.
南美洲大型-超大型金矿地质特征与成矿作用研究   总被引:1,自引:1,他引:0       下载免费PDF全文
金是南美洲仅次于铜的优势矿种,据美国地质调查局统计,2016年秘鲁金矿储量2800 t,巴西金矿储量2400 t,智利仅公布到2014年金矿储量3900 t。通过对南美安第斯成矿带和南美地台金矿地质背景分析,根据对31个大型-超大型金矿的综合研究,剖析斑岩型、浅成低温热液型、IOCG型、造山型等不同类型金矿床的时空分布、地质特征,梳理重要成矿区特征,摸清区域构造岩浆-成矿作用演化的关系,为以后在南美洲金矿的勘查开发提供科学依据。在安第斯成矿带,金成矿作用与太平洋板块向南美大陆板块的俯冲密切相关,大型-超大型金矿类型主要是以浅成低温热液型,以及与铜共生的斑岩型、IOCG型矿床为主,大规模金成矿作用集中在新生代,形成了众多世界著名的金矿床。南美地台成矿带位于亚马孙陆块边缘,受古元古代(2.5~1.8 Ga)Trans-Amazonian旋回影响,经历了反复俯冲造山运动,大型-超大型金矿以造山带型金矿为主,主要成矿期在太古宙—新元古代。南美的金资源相当丰富,未来具有巨大的勘查开发潜力。  相似文献   

13.
中国新疆及周边国家和地区是全球性中亚巨型成矿域的重要组成部分。黑色岩系矿床、斑岩矿床、块状硫化物矿床、陆相火山岩金矿床、与富碱性侵入岩有关矿床和砂岩铜矿等几种重要的典型矿床类型在该成矿域均已有不同程度的发现,特别是近几年来在该成矿域相继发现多个大型和超大型矿床的事实,说明中亚成矿域具有独特的成矿特点和巨大的找矿潜力。笔者通过分析研究中国新疆及周边国家和地区大型或超大型矿床的成矿规律和典型矿床特征,对新疆及相邻地区的大型或超大型矿床的找矿方向提出了见解。  相似文献   

14.
Abstract. Based on field investigation of large number of ore deposits including some latest discoveries and multidiscipline comprehensive research, we demonstrated the general features of metallic deposits and we suggest that Paleozoic archipelago-type collisional orogen at North Xinjiang, northwestern China show intimate similarity with the metallogenesis of Southeast Asia Cenozoic archipelago. We briefly described the characteristics of major porphyry-type, skarn-type Cu deposits and typical high-sulfidation type (HS-type) and low-sulfidation type (LS-type) epithermal Au deposits as well as some latest discoveries. Systematic isotopic age-dating on the Tuwu-Yandong superlarge porphyry Cu deposits revealed that they formed in Late Devonian to Early Carboniferous in an accretionary arc setting. The tectonic settings of epithermal Au deposits and its linkage with porphyry Cu deposits are further discussed. The formation condition for porphyry Cu deposits is more strict than epithermal Au deposits. The distribution width for porphyry Cu deposits in the orogenic belts is more limited than epithermal Au deposits. The discovery and prospecting progress of the Kalatage HS-type Cu-Au deposit were reported. The significance in further exploration was suggested.  相似文献   

15.
富湾超大型银矿床主要为脉状,产于下石炭统灰岩与长坑赋金硅质岩接触带及其下的破碎带中。银矿床矿化石英40Ar-39Ar年龄为(64.3±0.1) Ma。矿床铅同位素μ值(10.67~10.95)与赋矿地层的μ值(9.79~10.33)不同,而与粤西地区元古宇基底中矿床的μ值(10.62~10.66)相似。富湾超大型银矿床成矿物质主要来自元古宙变质基底,矿床形成与三水盆地晚白垩世到早第三纪强烈火山活动形成的有利成矿环境有关。有利于形成富湾超大型银矿床地质条件包括:(1)深大断裂构造交汇及盆地边缘同生断裂构造组成的连通网;(2)特殊岩性组合形成的聚矿-圈闭环境;(3)丰富成矿物质源区、多期矿化及成矿元素多次活化迁移;(4)多期次火山活动形成的循环地热系统。  相似文献   

16.
国外浅变质碎屑岩型金矿床的含矿岩系以含碳和黄铁矿,夹火山物质和热水沉积物,金含量高为特征.在含矿岩系的沉积、成岩过程中,局部可以形成贫金的含矿层,少数情况下以至于形成金矿体.含矿岩系的变质作用可能形成金矿化,或为后来的成矿作用造成有利的物理和化学环境.岩浆作用为成矿作用提供了部分成矿物质,或为改造成矿作用提供热源和动力.金矿床受构造控制,位于地热正异常区,金矿床的形成与热水沉积成矿作用、变质成矿作用、岩浆期后热液成矿作用和大气降水改造成矿作用等有关.超大型浅变质碎屑岩金矿床的形成过程持续时间长,具有多期多阶段的特点.改造成矿作用在超大型浅变质细碎屑岩型金矿床形成中起重要作用,中生代形成的超大型金矿床中,构造岩浆活化作用叠加十分重要.  相似文献   

17.
中亚造山带以晚古生代成矿为特色,但最近十几年来在新疆阿尔泰、东天山等发现越来越多的三叠纪矿床,包括3个超大型矿床。在古生代造山带中为什么三叠纪能够成矿和成大矿,不同类型矿产特征和分布规律是值得关注的重要科学问题。目前确定新疆中亚造山带19个三叠纪矿床主要为花岗伟晶岩型稀有金属矿床、斑岩型钼矿床和矽卡岩型钨矿床。花岗伟晶岩型稀有金属矿床分布于阿尔泰,斑岩型钼矿床、矽卡岩型钨矿床和钨(钼)矿床分布于东天山。19个矿床的成矿年龄变化于193~248 Ma,峰值为215 Ma。不同矿床类型成矿时代略有差别,形成时间相对较早的有矽卡岩型,其次是斑岩型,伟晶岩型形成时间跨度最大,多数形成于晚三叠世,少数延续到早侏罗世。东天山沙东-小白石头一带钨矿和阿尔泰稀有金属矿最具找矿潜力。  相似文献   

18.
巴彦洪格尔地区位于蒙古国中部 ,由古生代俯冲体系构成。该体系包括前寒纪微板块 (白得拉格和伯得高尔构造带 )、逆冲蛇绿岩带、加积型沉积岩 (巴彦洪格尔和得扎格构造带 )和弧前沉积岩 (可汗盖构造带 )。巴彦洪格尔地区岛弧岩浆作用主要以早古生代钛铁矿系列和晚古生代磁铁矿系列花岗岩类为特征。许多诸如斑岩型、矽卡岩型及脉岩型等各种类型的热液矿床与这些花岗岩类伴生。该区四大矿床的 K Ar同位素测年显示 :南方 Cu Au斑岩型矿床、呼布金洪迪矽卡岩型 Cu Au矿床、罕乌尔含金剪切带和塔磁高尔伟晶岩 W Au矿床的形成年龄值分别为 2 40± 5 Ma、2 5 2± 5 Ma、2 83± 6 Ma、32 9± 7Ma。由此可见 ,前三个地区的矿床与二叠纪—三叠纪初期磁铁矿系列花岗岩类具亲缘关系 ,而塔磁高尔W— Au伟晶岩则与早石炭世钛铁矿系列花岗岩类具亲缘关系。斑岩型和矽卡岩型 Cu— Au矿化作用发生在二叠纪末期—三叠纪初期 ,此时紧随着安第斯型岛弧岩浆作用 ,发生了白得拉格和塔巴嘎泰微板块的碰撞。  相似文献   

19.
We present results of a comparative study of Late Paleozoic granitoids of Eastern Kazakhstan and Western Transbaikalia composing the large Kalba-Narym and Angara-Vitim batholiths. We have established that despite the different geologic history of these regions, granitoid magmatism there proceeded nearly synchronously at the Carboniferous/Permian boundary (330–280 Ma) and was accompanied by mantle magmatism. The regularities of its evolution are considered in terms of the plume model and different stages of interaction of mantle plumes with the lithosphere. The major principles of plume-lithosphere interaction in accretion-collision fold belts have been formulated: (1) Plume-lithosphere interaction results in large-scale melting of sublithospheric mantle, lower lithosphere, and crustal substrates warmed by the preceding orogenic processes; (2) The processes last 30 to 50 Myr and produce large volumes of igneous rocks, mostly granitoids; (3) The sequence of formation of granitoid and basic igneous complexes and the metallogenic specialization can be different and depend on the lithosphere structure and preceding geologic history of the region.  相似文献   

20.
全球锑矿床成矿学基本特征及超大型锑矿床成矿背景初探   总被引:9,自引:0,他引:9  
本文对全球锑成矿的基本特征进行了初步研究并编制了全球锑成矿图。研究表明全球锑成矿的一般规律具以下特点:锑成矿与大陆型壳体的构造发展阶段及演化程度具显著相关性,全球锑矿床可划分为地槽型(或古地槽型)和地洼型两种基本大地构造类型;锑成矿在时、空分布上具有不均一性,成矿主要集中于大陆壳体较晚地质历史(中、新生代)的地槽区和地洼区;锑成矿是地洼区特征性成矿之一,往往在分异,演化程度较高的地洼区内形成锑成矿高峰;沿与深部上地幔关系密切的浅部碎裂岩断层带以中─低温热液交代或充填的方式富集是地洼型锑成矿的基本型式。最后文中对超大型锑成矿富集特殊性与非超大型锑工业富集的一般性进行了对比研究。  相似文献   

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