滇西北普朗斑岩铜矿床成矿时代及其意义   总被引：24，自引：0，他引：24  

曾普胜侯增谦  李丽辉屈文俊王海平  李文昌蒙义峰　杨竹森 《地质通报》2004,23(11):1127-1131

普朗斑岩铜矿在中国斑岩铜矿床中有其特殊性,无论对中甸岛弧带的基础地质还是矿产资源评价预测的研究,都具有重要意义。然而,该斑岩铜矿床无确切的年代学数据。通过作辉钼矿Re-Os年龄和单矿物K-Ar年龄测定,首次确定了普朗斑岩铜矿床内具有钾硅酸盐化的黑云石英二长斑岩成矿作用的活动时间为(235.4±2.4)Ma～(221.5±2.0)Ma,石英-辉钼矿阶段的辉钼矿Re-Os年龄大致为(213±3.8)Ma,两者十分相近。表明普朗斑岩铜矿床的成矿作用是在印支期完成的。主矿体钾长石K-Ar年龄显示热液活动持续到(182.5±1.8)Ma左右,说明与斑岩铜矿有关的热液系统寿命可达40Ma之久。这种长寿命的热液系统是高品位大规模的斑岩铜矿形成的必要条件之一。  相似文献   

三江地区义敦岛弧造山带演化和成矿系统   总被引：80，自引：12，他引：80       下载免费PDF全文

侯增谦杨岳清  曲晓明黄典豪吕庆田  王海平余金杰 唐绍华 《地质学报》2004,78(1):109-120

义敦岛弧是喜马拉雅巨型造山带中的一个复合造山带,它经历了印支期洋壳俯冲造山、燕山湖弧-陆碰撞和喜马拉雅期陆内走滑作用诸演化历史。可能由于洋壳板片俯冲角度不同,义敦晚三叠世古岛弧带(206～237 Ma)南北两段具有不同的发育历史,北段昌台弧以发育孤间裂谷为特色,具张性弧特征,发育扩张环境流体聚敛成矿系统,形成VMS型Zn-Pb-Cu矿床和浅成低温热液型Ag-Au-Hg矿床;南段中甸弧不发育弧后盆地,但广泛发育钙碱性弧火山岩-玢岩-斑岩杂岩系和挤压环境岩浆-流体成矿系统,形成斑岩型-夕卡岩型铜多金属矿床。在三叠纪-侏罗纪之交的弧-陆碰撞作用中,早期大陆板片俯冲形成同碰撞花岗岩带(约200 Ma),晚期造山后伸展作用,形成A型花岗岩带(75～138 Ma),伴随扬子大陆板片俯冲而发生的强烈剪切和推覆,在甘孜-理塘蛇绿混杂带发育挤压剪切环境流体聚敛成矿系统,形成剪切带型金矿。伴随造山后伸展和A型花岗岩侵位,发育伸张环境岩浆-流体聚敛成矿系统,主要形成夕卡岩型锡矿和构造破碎带热浪脉型银多金属矿床。印度-亚洲大陆碰撞在义敦造山带主要表现为陆内走滑作用,并控制碱性花岗岩和花岗斑岩的发育(50～30 Ma),伴随斑岩型金矿的形成。  相似文献   

Underplating in the middle-lower Yangtze Valley and model of geodynamic evolution:Constraints from geophysical data   总被引：3，自引：0，他引：3  

Lü Qingtian  HOU Zengqian  YANG Zhusen & SHI Danian Institute of Mineral Resources  Chinese Academy of Geological Sciences  Beijing  China 《中国科学D辑(英文版)》2005,48(7)

~~Underplating in the middle-lower Yangtze Valley and model of geodynamic evolution:Constraints from geophysical data1)East China petroleum Administration,1988(unpublished data). 1)Measurements of regional rock densities and magnetic parameters of Anhui Province(research report),Annul Geological and Mineral Bureau,1987(unpublished). 1)In this paper South China Block(SCB)includes the Yangtze block and Cathaysian block.In the Neoproterozoic the Yangtze block had been sutured to th…  相似文献   

试论幔柱构造与成矿系统——以三江特提斯成矿域为例   总被引：30，自引：4，他引：26  

侯增谦  李红阳 《矿床地质》1998,17(2):97-113

以三江特提斯成矿域为例,简述了幔柱构造特征,提出了“幔柱构造成矿体系”新观点。研究表明,热幔柱发育演化,导致大陆岩石圈向大洋岩石圈构造体制转化,伴随大陆活化、减薄、去根、张裂、解体和成洋诸事件;冷幔柱形成演变,导致大洋岩石圈向大陆岩石圈构造体制转变,并引发俯冲造山→碰撞造山→陆内造山过程。在幔柱构造制约下,一系列形成于不同构造背景、产出不同地质环境、具有不同成矿体制、不同序次组合和不同成矿类型的矿床成矿系列组合和矿床成矿谱系,共同构成统一的成矿体系。热幔柱成矿体系包括热幔柱热点和热幔柱－扩张脊２大次级成矿系统,冷幔柱成矿体系包括冷幔柱－俯冲造山、冷幔柱－碰撞造山和冷幔柱－陆内造山３大次级成矿系统。最后,按成矿体系,成矿系列和矿床三级体制对三江特提斯成矿域主要矿床形成条件和成矿规律进行了全新分析。  相似文献   

古代与现代海底黑矿型块状硫化物矿床矿石地球化学比较研究   总被引：33，自引：1，他引：33  

侯增谦 《地球化学》1996,25(3):228-241

选择西南太平洋冲绳海槽现代海底烟囱硫化物矿床、日本小坂矿山上向黑矿（第三纪）和中国西南呷村黑矿型矿床（三叠纪）进行了矿石地球化学比较研究。黑矿型矿床矿石吨位－品位模式与其他火山成因块状硫化物（ＶＭＳ）矿床类似，矿田（２０－５０ｋｍ＾２）矿石吨位与单个喷气－沉积型（Ｓｅｄｅｘ）矿床相当，金属总量４－６Ｍｔ，为矿田范围内热液流体搬运的最大金属量。与洋脊环境ＶＭＳ矿床相比，岛弧裂谷环境产出的黑矿型矿床相  相似文献   

雅鲁藏布江北岸基性-超基性岩带的成因   总被引：2，自引：0，他引：2  

高永丰侯增谦  魏瑞华蔡剑辉  孟祥金黄卫 《地质通报》2003,22(10):789-797

沿雅鲁藏布江北岸大竹卡-谢通门一带，即冈底斯弧岩浆岩带南缘出露了一条超基性一基性岩带，岩带的分布与雅鲁藏布江北岸的强航磁异常带相吻合。岩带主要由零星孤立出露的规模较小的近圆形辉长岩岩体、岩瘤或岩滴组成，在日喀则县曲尼出露了超镁铁堆晶岩、辉长岩和玄武岩连续剖面。它们呈一系列自北而南逆冲推覆的构造岩片，经历了明显不同于弧花岗岩基的形成过程。通过野外地质考察和系统的岩石学研究，认为曲尼基性-超基性岩带是在岛弧-弧后系统形成的蛇绿混杂岩，是新特提斯大洋岩石圈在俯冲消亡过程中的残片。  相似文献   

滇西北中甸斑岩及斑岩铜矿   总被引：59，自引：7，他引：59       下载免费PDF全文

曾普胜  莫宣学  喻学惠  侯增谦  徐启东  王海平  李红  杨朝志 《矿床地质》2003,22(4):393-400

在较为详细的野外地质观测和精确的同位素测年的基础上 ,结合前人资料 ,将中甸地区的印支期岛弧斑岩体分为东、西两个斑岩带 ,东斑岩带形成于 2 1 8～ 2 0 3Ma ;西斑岩带形成于 2 4 2 .92～ 2 37.5Ma。喜马拉雅期(5 3.0 2Ma)斑岩叠加于早期的斑岩体之上 ,与斑岩铜矿化关系密切。中甸地区岛弧带内东、西两个斑岩带的斑岩型铜矿找矿远景极大 ,尤以东斑岩带前景最佳 ,普朗斑岩铜矿床远景规模在大型以上。中甸斑岩铜矿将成为我国又一重要的斑岩铜 (多金属 )矿产地  相似文献   

Geochemical and Nd, Sr Isotopic Study of the Post-Orogenic Granites in the Yidun Arc Belt of Northern Sanjiang Region, Southwestern China   总被引：7，自引：0，他引：7  

Xiaoming QU  Zengqian HOU  Shugui ZHOU 《Resource Geology》2002,52(2):163-172

Abstract: In the arc (basin)–back area of the Yidun arc belt in the north segment of the Sanjiang tectonic zone, southwestern China, there occurs a post‐orogenic granite belt extending for more than 300 km in NNW direction. It strides across two different tectonic units of the arc (basin)–back area and the subduction area, and is accompanied by extensive Ag‐Sn polymetal–lic mineralizations. More than ten granite bodies have very similar geochemical characteristics: high SiO₂ (73.8–76.3 wt%) and K₂O+Na₂O (7.16‐8.41 %), and low Al₂O₃ (11.9–13.6 %), CaO (0.46‐1.54 %) and MgO (0.16‐0.61 %), as well as high enrichment of Nb, Ta, Ga and Y, and strong depletion of Sr and Eu. Most of these features are peculiar to A‐type granite. Rb‐Sr and ⁴⁰Ar/³⁹Ar isotopic dating results indicate that the formation ages of the granites decrease from 103.7 Ma of the north end to 75.2 Ma near the south end, and that the magmatism became younger from north to south. The tectonic environment analysis clearly reveals that they were formed in post‐orogenic within–plate extension settings. The magma genesis was controlled by a united crustal extension regime after the arc‐continent collision. The granites have low _Nd values ranging from –4.96 to –8.40, whereas the _Sr values vary greatly ranging from –31.7 to 296, reflecting that the source composition transited from mantle – differentiated igneous rocks in the north to basement – dominated metamorphosed sedimentary rocks in the south. Under high temperature and water‐absent conditions, the anatexes of the crustal rocks made a great amount of plagioclase separated from melts and left in magma sources. Through this mechanism, the post‐orogenic granites took geo‐chemical characteristics such as low Al₂O₃ and CaO, and strong depletion of Sr and Eu.  相似文献   

安徽新桥块状硫化物矿床地球化学特征   总被引：6，自引：0，他引：6  

李红阳  李英杰  侯增谦  杨竹森  蒙义峰  曾普胜  徐文艺 《地质科学》2005,40(3):337-345

新桥块状硫化物矿床发育双层结构,地球化学特征也呈现出明显的“二元性”和垂向变化。下部网脉状蚀变矿化岩石SiO₂、Al₂O₃、K₂O和Na₂O等含量较高,上部层状块状矿石和含矿岩石Fe₂O₃、FeO、CaO、MgO及SiO₂等明显富集。稀土含量相对较低,上部层状块状矿层平均值为10.73×10^-6,下部通道相蚀变矿化岩石平均值为126.1×10^-6。重晶石δ³⁴S值为+16.2‰,硬石膏δ³⁴S值为+11.2‰,黄铁矿δ³⁴S值为+1.5‰～+4.7‰。含矿硅质岩δ¹⁸O为+12.0‰～+13.9‰,下部通道相含黄铁矿石英脉δ¹⁸O值为+13.3‰～+18.6‰。自下部网脉状矿化到上部层状块状矿层,从粗晶细晶到变胶状胶状黄铁矿,δ³⁴S、δ¹⁸O和δ30Si值逐渐降低,²⁰⁶Pb/²⁰⁴Pb、²⁰⁷Pb/²⁰⁴Pb和²⁰⁸Pb/²⁰⁴Pb平均值逐渐增高。  相似文献   

Regional fractures and denudation of gold ore deposits in Gangdise block,Tibet: Evidence of Ag/Au values     

Li  Shengrong  Deng  Jun  Hou  Zengqian  Xiao  Run  Yuan  Wanming  Feng  Xiaoliang  Zhao  Zhidan  Shen  Junfeng  Zhou  Su 《中国科学:地球科学(英文版)》2001,44(1):121-127

Mapping with Ag/Au ratios of mineralized rocks and ores as a parameter reveals that the deep fractures in the Gangdise block control the distribution of the high value regions which may represent the shallow zones of strongly mineralized areas. The variance gradient regions with large Ag/Au ratio may represent the boundaries between strongly mineralized areas and weakly mineralized areas. In the middle part of the Gangdise block, gold and silver mineralization centers mainly distribute along the NW extending Coqen-Xigaze region, NE extending Yangbajain region and E-W extending Lhasa-Gongbogyamda region. The gold and silver mineralized rocks and ores may have been slightly denuded in the west of the middle Gangdise block, and the denudation in the east, however, may be stronger. The primary gold and silver prospect in the west may be better than in the east.

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