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1.
巴尔喀什成矿带晚古生代地壳增生与构造演化   总被引：6，自引：4，他引：2  
巴尔喀什成矿带是中亚成矿域重要的晚古生代斑岩铜钼成矿带。巴尔喀什成矿带晚古生代花岗岩类(石炭-二叠纪)主要为高钾钙碱性系列,晚期出现钾玄岩系列岩石,主要为I型花岗岩类;石炭纪处在同碰撞和火山弧环境,二叠纪为后碰撞环境。分析表明,博尔雷属于经典的岛弧花岗岩区,科翁腊德、阿克斗卡和萨亚克属于埃达克岩(Adakite)区。巴尔喀什成矿带内花岗岩类εNd(t)值为(-5.87～+5.94),εSr(t)值为(-17.16～+51.10)。以巴尔喀什中央断裂为界,成矿带东、西分带,断裂两侧具有不同的地壳生长历史:断裂以东的萨亚克和阿克斗卡地区εNd(t)值较高,具有亏损地幔组分特征,为古生代增生的新生陆壳;以西的科翁腊德和博尔雷εNd(t)值较低,主要是壳幔岩浆混合的结果,反映了古老基底的存在,主要为新元古代增生地壳。成矿带花岗岩类206Pb/204Pb、207Pb/204Pb和208Pb/204Pb比值范围分别为18.3346～20.9929、15.5213～15.7321和38.2874～40.0209,为造山带花岗岩类,具有与天山、阿尔泰和准噶尔花岗岩类的亲缘性。  相似文献   

2.
哈萨克斯坦阿克斗卡特大型斑岩型铜矿床产在中亚成矿域巴尔喀什成矿带阿克斗卡矿田。本文根据花岗岩类岩石的锆石U-Pb、40Ar/39Ar和裂变径迹(FT)热年代学研究,结合前人研究成果,给出了阿克斗卡斑岩铜矿床从深成岩浆活动、成矿作用、区域冷却到剥露作用的全过程。阿克斗卡矿床及附近花岗岩类锆石SHRIMPU-Pb定年结果,给出科尔达尔岩体早期英云闪长岩的结晶年龄为335.7±1.3Ma;主成矿期的含矿二长花岗斑岩结晶年龄为327.5±1.9Ma,反映了阿克斗卡矿床斑岩型铜成矿作用的年龄。花岗岩类角闪石、黑云母、钾长石40Ar/39Ar热年代学分别给出矿物冷却年龄为310.6Ma、271.5Ma和274.9Ma,进一步限定了深成斑岩型铜成矿作用的时代和区域冷却的历史。磷灰石FT测年数据揭示,受区域构造作用的影响,阿克斗卡铜矿田在晚白垩世(91～68.0Ma)发生地块的差异隆升和剥露作用。  相似文献   

3.
中亚成矿域巴尔喀什成矿带阿克斗卡矿田主要由阿克斗卡、艾达里和库兹尔基亚等矿床组成, 是发育在火山岛弧环境的典型斑岩型Cu-Mo-Au矿床群, 其中阿克斗卡为超大型斑岩铜矿。斑岩型铜成矿作用发生在晚古生代哈萨克马蹄形构造形成过程中, 成矿构造背景为乌拉尔-天山断裂系统的大型左行走滑作用和大陆地壳侧向增生过程, 具有典型的斑岩铜矿围岩蚀变和矿石矿物分带特征; 成矿作用受东西向、北东东向和北西西向断裂控制, 主要与早期碱性阶段的硅化蚀变有关, 酸性蚀变阶段发生了再矿化与富集成矿作用; 据含矿花岗闪长岩中锆石SHRIMP定年本文给出主要成矿时代为327.5 ± 1.9 Ma (早石炭世晚期), 成矿模式为"花岗闪长岩"型, 属于浅成斑岩铜矿成矿系统。   相似文献   

4.
巴尔喀什成矿带是世界著名的中亚成矿域斑岩型铜钼成矿带, 产出许多斑岩型铜钼矿床和一些石英脉-云英岩型钨钼矿床.对巴尔喀什成矿带西部的东科翁腊德、阿克沙套、扎涅特3个典型的石英脉-云英岩型钼钨矿床的成矿时代和剥露过程进行了地质热年代学研究.锆石SHRIMP U-Pb定年给出东科翁腊德、阿克沙套、扎涅特与成矿作用有关的花岗岩类岩浆作用的时代分别为293.6±2.7 Ma、306±1 Ma和304±4 Ma, 属海西晚期构造-岩浆活动的产物.花岗岩类40Ar/39Ar测年结果给出了与成矿有关岩体的冷却年龄, 其等时线年龄分别为292±3 Ma(阿克沙套黑云母)、288.8±3.6 Ma(阿克沙套钾长石)和278±5 Ma(东科翁腊德钾长石).磷灰石裂变径迹测年给出东科翁腊德、阿克沙套、扎涅特的年龄分别为92.1±5.7 Ma、92.2±5.0 Ma和80.3±4.9 Ma, 说明这3个矿床的剥露作用主要发生在晚白垩世.花岗岩类岩石U-Pb、40Ar/39Ar和裂变径迹热年代学研究, 揭示了巴尔喀什成矿带Mo-W矿床从深成岩浆侵入活动、成矿作用、区域冷却到剥露作用的全过程.   相似文献   

5.
巴尔喀什成矿带是世界著名的中亚成矿域斑岩型铜钼成矿带,产出许多斑岩型铜钼矿床和一些石英脉-云英岩型钨钼矿床。中亚成矿域可能是一个多核成矿系统,具有以走滑断裂为边界构成的断裂构造体系并受之控制。本文对巴尔喀什成矿带巴尔喀什—阿克沙套地区11件辉钼矿样品进行了Re-Os同位素分析,得到博尔雷大型斑岩型铜(钼)矿床和东科翁腊德、扎涅特、阿克沙套石英脉-云英岩型钨钼矿床的辉钼矿模式年龄(平均值)分别为315.9Ma、298.0Ma、295.0Ma和289.3Ma;其中,东科温腊德、阿克沙套和扎涅特等3个矿床的Re-Os等时线年龄为297.9-+30..949Ma,MSWD值为0.97。辉钼矿Re-Os年龄说明巴尔喀什成矿带Cu-Mo-W成矿作用发生在315.9～289.3Ma期间,Cu-Mo-W矿床的形成可分为两期:一期为斑岩型铜钼矿床,约形成于315.9Ma;另一期为石英脉-云英岩型钨钼矿床,约形成于297.9Ma。根据辉钼矿模式年龄和等时线年龄,推测该地区花岗斑岩和伟晶岩的形成时代与相应的矿床基本同时,均为晚石炭世,属海西期构造岩浆活动的产物。通过与我国境内西、东准噶尔和东天山斑岩铜矿带的对比表明,巴尔喀什成矿带铜钼成矿作用的年龄介于东天山土屋—延东斑岩铜矿与西准噶尔包古图斑岩铜矿之间。分析表明,中亚成矿域大规模斑岩型铜钼成矿作用集中在晚石炭世,属海西晚期构造-岩浆活动的产物。  相似文献   

6.
巴尔喀什成矿带是世界著名的中亚成矿域斑岩型铜钼成矿带, 产出许多大型-超大型斑岩型铜钼矿床和一些石英脉-云英岩型钨钼矿床。本文介绍了巴尔喀什成矿带博尔雷大型斑岩型铜(钼)矿床地质特征, 并对该矿床2件辉钼矿样品进行了铼-锇同位素分析, 得到博尔雷大型斑岩型铜(钼)矿床的辉钼矿模式年龄(平均值)为315.9 Ma, 说明了晚石炭世巴尔喀什成矿带斑岩型铜钼矿床的形成年龄, 属海西晚期构造-岩浆活动的产物。博尔雷斑岩铜矿成矿时代介于东天山与西准噶尔斑岩型铜矿床的成矿时代之间。   相似文献   

7.
哈萨克斯坦巴尔喀什湖南侧的奎干-玛依布拉克铜矿区位于巴尔喀什成矿带环巴尔喀什-准噶尔成矿省楚伊犁-北天山成矿亚省的西北部, 发育一系列中小型斑岩型铜矿床。本文概要介绍了奎干-玛依布拉克铜矿区矿床地质、围岩蚀变、成矿作用、矿石矿物组成与主要矿床特征, 并分析了铜矿床开发的前景。该铜矿区含矿岩石主要为花岗闪长斑岩, 成矿元素组合主要为Cu-Au-Mo, 具有与巴尔喀什湖北侧科翁腊德、阿克斗卡等超大型斑岩型铜矿床类似的地质特征, 说明了巴尔喀什成矿带斑岩型铜矿床的分布跨越了巴尔喀什湖, 在湖南侧也具有较好的斑岩铜矿成矿远景。   相似文献   

8.
<正>哈萨克斯坦巴尔喀什成矿带是中亚最重要的斑岩铜矿带之一,斑岩型铜矿床的数量和储量在中亚成矿域中居首位。区内发现规模不等的大小矿床近百处,其中超大型铜矿床2处(科翁腊德和阿克斗卡),大型铜矿床3处(博尔雷、萨亚克、科克赛),中型铜矿床10多处;除斑岩型外,还有热液型、矽卡岩型;既有Cu、Mo组合,也有Cu、Au组合及多金属组合。斑岩型矿床以  相似文献   

9.
哈萨克斯坦巴尔喀什成矿带是中亚成矿域重要的晚古生代斑岩铜钼和云英岩-石英脉型钨钼成矿带,是受走滑断裂边界控制的中亚多核成矿系统的核心之一。本文根据锆石SHRIMP U-Pb定年、40Ar/39Ar热年代学、磷灰石裂变径迹定年和热历史模拟,厘定了巴尔喀什成矿带西部地区晚古生代最晚期深成岩浆侵入事件。研究表明,原来被认为是属于三叠纪的后碰撞花岗岩类侵入岩体,给出锆石SHRIMP U-Pb年龄为289.7±2.3Ma,为早二叠世。结合前人研究,本文探讨了巴尔喀什成矿带西部从深成岩浆侵入、钨钼成矿作用、区域冷却到剥露作用热历史的全过程。晚古生代最晚期花岗岩类侵入体具有与钨钼矿床相同的晚中生代剥露作用年龄(92.4±5.9Ma)。  相似文献   

10.
查个勒铅锌矿床是西藏中冈底斯成矿带中段新发现的一个大型斑岩-矽卡岩型矿床,但其成岩成矿时代一直缺乏年代学约束。本文对该矿床含矿斑岩进行了LA-ICP-MS锆石U-Pb定年、辉钼矿Re-Os定年、主量和微量元素分析及Sr-Nd-Hf同位素组成研究,获得中冈底斯成矿带中段铜钼铅锌银矿化时代。含矿斑岩LA-ICP-MS锆石U-Pb年龄为64.6~62.9 Ma,代表岩浆的结晶年龄;辉钼矿Re-Os等时线年龄为(62.3±1.4)Ma,代表查个勒主成矿年龄,与其构造岩浆事件一致;结合区域林子宗群大规模火山活动(65~45 Ma)以及以亚贵拉铅锌矿床(68.6~ 65.0 Ma)为代表的成矿作用,表明在印度与欧亚大陆主碰撞过程中均可产生不同规模的成矿作用。查个勒含矿斑岩具富硅、富钾,贫钛、贫磷特征,铝饱和指数(A/CNK)为1.12 ~ 1.60,富集大离子亲石元素Rb、Th、U,亏损高场强元素Nb、Zr等,与冈底斯成熟大陆地壳物质相比具相对高的εNd(t)值(-6.64 ~ -5.79)和相对低的(87Sr/86Sr)i值(0.711 813~0.717 307),并具不均一的锆石εHf(t)值(-7.02~-1.27)以及古老的锆石Hf同位素地壳模式年龄(TCDM=1 093~1 419 Ma),属于过铝质S型花岗岩类。本文认为中冈底斯成矿带中段古新世岩浆活动和成矿作用,很可能与雅鲁藏布江洋盆闭合之后的印-亚大陆碰撞诱发幔源岩浆底侵导致的冈底斯地体古老地壳物质部分熔融有关,岩浆在上升过程中有不同程度的分离结晶。  相似文献   

11.
<正>The Central Asian metallogenic domain(CAMD) is a multi-core metallogenic system controlled by boundary strike-slip fault systems.The Balkhash metallogenic belt in Kazakhstan,in which occur many large and super-large porphyritic Cu—Mo deposits and some quartz vein- and greisen-type W—Mo deposits,is a well-known porphyritic Cu—Mo metallogenic belt in the CAMD.In this paper 11 molybdenite samples from the western segment of the Balkhash metallogenic belt are selected for Re—Os compositional analyses and Re—Os isotopic dating.Molybdenites from the Borly porphyry Cu deposit and the three quartz vein-greisen W—Mo deposits—East Kounrad.Akshatau and Zhanet—all have relatively high Re contents(2712—2772μg/g for Borly and 2.267—31.50μg/g for the other three W—Mo deposits),and lower common Os contents(0.670—2.696 ng/g for Borly and 0.0051—0.056 ng/g for the other three).The molybdenites from the Borly porphyry Cu—Mo deposit and the East Kounrad,Zhanet,and Akshatau quartz vein- and greisen-type W—Mo deposits give average model Re—Os ages of 315.9 Ma,298.0 Ma,295.0 Ma,and 289.3 Ma respectively.Meanwhile,molybdenites from the East Kounrad,Zhanet,and Akshatau W—Mo deposits give a Re—Os isochron age of 297.9 Ma,with an MSWD value of 0.97.Re-Os dating of the molybdenites indicates that Cu—W—Mo metallogenesis in the western Balkhash metallogenic belt occurred during Late Carboniferous to Early Permian(315.9—289.3 Ma),while the porphyry Cu—Mo deposits formed at—316 Ma,and the quartz vein-greisen W—Mo deposits formed at ~298 Ma.The Re—Os model and isochron ages thus suggest that Late Carboniferous porphyry granitoid and pegmatite magmatism took place during the late Hercynian movement.Compared to the Junggar-East Tianshan porphyry Cu metallogenic belt in northwestern China,the formation of the Cu—Mo metallogenesis in the Balkhash metallogenic belt occurred between that of the Tuwu-Yandong in East Tianshan and the Baogutu porphyry Cu deposits in West Junggar. Collectively,the large-scale Late Carboniferous porphyry Cu—Mo metallogenesis in the Central Asian metallogenic domain is related to Hercynian tectono-magmatic activities.  相似文献   

12.
《International Geology Review》2012,54(13):1660-1687
This study focuses on the geochronology and elemental and Nd isotopic geochemistry of the Baogutu Cu deposit and the newly discovered Suyunhe W-Mo deposit in the southern West Junggar ore belt (Xinjiang, China), as well as the geology of the newly discovered Hongyuan Mo deposit in the southern West Junggar ore belt and the Kounrad, Borly, and Aktogai Cu deposits and the East Kounrad, Zhanet, and Akshatau W-Mo deposits in the North Balkhash ore belt (Kazakhstan). The aim is to compare their petrogenesis, tectonic setting, and mineralization and to determine the relationship between the southern West Junggar and North Balkhash ore belts. Based on our newly acquired results, we propose that the Kounrad, Borly, Aktogai, and Baogutu deposits are typical porphyry Cu deposits associated with calc-alkaline magmas and formed in a Carboniferous (327–312 Ma) subduction-related setting. In contrast, the East Kounrad, Zhanet, Akshatau, Suyunhe, and Hongyuan deposits are quartz-vein greisen or greisen W-Mo or Mo deposits associated with alkaline magmas and formed in an early Permian (289–306 Ma) collision-related setting. Therefore, two geodynamic–metallogenic events can be distinguished in the southern West Junggar and North Balkhash ore belts: (1) Carboniferous subduction-related calc-alkaline magma – a porphyry Cu metallogenic event – and (2) early Permian collision-related alkaline magma – a greisen W-Mo metallogenic event. The North Balkhash ore belt is part of the Kazakhstan metallogenic zone, which can be extended eastward to the southern West Junggar in China.  相似文献   

13.
ABSTRACT

The Balkhash metallogenic belt (BMB) in Kazakhstan is a famous porphyry Cu–Mo metallogenic belt in the Central Asian Orogenic Belt (CAOB). The late Palaeozoic granitoids in the BMB are mainly high-K calc-alkaline and I-type granites, with shoshonite that formed during a late stage. Geochemical analyses and tectonic discrimination reveal a change in the tectonic environment from syn-collision and volcanic arcs during the Carboniferous to post-collision during the Permian. The late Palaeozoic granitoids from the Borly porphyry Cu deposit formed in a classical island-arc environment, and those from the Kounrad and Aktogai porphyry Cu deposits and the Sayak skarn Cu deposit are adakitic. The εNd(t) values for the late Palaeozoic granitoids are between ?5.87 and +5.94, and the εSr(t) values range from ?17.16 to +51.10. The continental crustal growth histories are different on either side of the Central Balkhash fault. On the eastern side, the εNd(t) values of the granitoids from the Aktogai and Sayak deposits are very high, which are characteristic of depleted mantle and suggest that crustal growth occurred during the late Palaeozoic. On the western side, the εNd(t) values of the granitoids from the Borly and Kounrad deposits are slightly low, which suggests the presence of a Neoproterozoic basement and the mixing of crust and mantle during magmatism. The granitoids have initial 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb values of 18.335–20.993, 15.521–15.732, and 38.287–40.021, respectively, which demonstrate an affinity between the late Palaeozoic magmatism in the BMB and that in the Tianshan, Altai, and Junggar orogens.  相似文献   

14.
综述了哈萨克斯坦巴尔喀什成矿带萨亚克大型铜矿田地质特征、矿田构造与成矿模式。萨亚克铜矿田是中亚成矿域巴尔喀什成矿带唯一的以矽卡岩型铜矿化为主的大型铜矿床,产在萨亚克地堑复向斜内。该矿田包括几个在空间上相对独立的矽卡岩型铜矿床、斑岩型铜钼网状脉矿床和一系列石英脉型矿脉,构成了斑岩型和矽卡岩型两个端元形成的成矿系列,但以矽卡岩型为主。矿床主要位于中石炭世灰岩与晚石炭世花岗岩类的接触带上,具有独特的矽卡岩型Cu-Au-Mo矿化组合,成矿时代为海西中晚期,根据本研究进行的锆石SHR I MP定年结果,主要与次要成矿期年龄分别为335±2Ma和308±10Ma。金属矿床主要赋存在地堑复向斜内局部发育的鞍状背斜顶部,部分富矿体的产出严格受断裂构造-岩浆活动的控制。闪长岩与铜矿化作用的关系最为密切,铜含量可高达1%以上;其次,花岗闪长岩与铜矿化的关系也较为密切,铜含量可达0.2%以上。萨亚克矽卡岩型铜矿田铜保有储量约为57.5万吨。  相似文献   

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