| 福建省上杭-大田地区中生代成岩成矿作用与构造环境演化 |
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| 引用本文： | 毛建仁,许乃政,胡青,邢光福,杨祝良.福建省上杭-大田地区中生代成岩成矿作用与构造环境演化[J].岩石学报,2004,20(2):285-296. |
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| 作者姓名： | 毛建仁 许乃政 胡青 邢光福 杨祝良 |
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| 作者单位： | 南京地质矿产研究所,南京,210016 |
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| 基金项目： | 原地矿部项目(编号:地科专96-02)，中国地质调查局基础地质调查项目(编号:19991020110003)资助. |
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| 摘 要： | 本文所研究的四个中生代花岗岩体具不同的同位素年代:汤泉岩体为183～158Ma,紫金山岩体为157-145Ma。才溪岩体为133Ma,四方岩体为108～105Ma,汤泉和紫金山岩体分别属于早中生代中、晚侏罗世,才溪和四方岩体时代为晚中生代早白垩世。汤泉和四方岩体为A/CNK<1.0的准铝质花岗岩类,因富Ba、Sr,贫HREE、Y、Yb而具埃达克岩地球化学特征,是最具铜矿成矿潜力的含矿母岩;紫金山花岗岩体为A/CNK>1.1的强过铝花岗岩,并富K、Rb、Th、Y、HREE,贫Sr、Ba、Ti,具地壳泥质岩石熔融的特征。才溪岩体为A/CNK1.0～1.1的弱过铝花岗岩,其元素地球化学特征介于四方岩体和紫金山岩体之间。富Na2O的汤泉岩体是地幔起源的基性岩浆底侵作用,促使加厚的元古代下地壳基性岩石部分熔融所形成,是铜、铁多金属矿床成矿系列的主要含矿母岩;富K2O的四方岩体是地幔起源的富钾基性岩浆与中下地壳物质部分熔融形成的花岗质混合岩浆,使岩浆中的K2O含量增高,并从地幔中获取大量铜及其它金属和硫,而成为斑岩型铜金多金属矿床成矿系列的主要含矿母岩。研究区自早-中侏罗世(180Ma)以来已有岩石圈伸展的岩石学记录。紫金山强过铝花岗岩是这种伸展机制延续的结果。随时间推移,岩石圈伸展减薄作用和底侵作用增强,地幔组分在花岗质岩浆的形成过程中贡献
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| 关 键 词： | 花岗岩类 中生代 成矿作用 构造环境 闽西南地区 |
| 文章编号： | 1000-0569/2004/020(02)-0285-96 |
| 修稿时间： | 9/9/2003 12:00:00 AM |
The Mesozoic rock-forming and ore-forming processes and tectonic environment evolution in Shanghang-Datian region, Fujian |
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| MAO JianRen,XU NaiZheng,HU Qing,XING GuangFu and YANG ZhuLiang Najing Institute of Geology and Mineral Resources,Chinese Academy of Geological Sciences,Nanjing,China.The Mesozoic rock-forming and ore-forming processes and tectonic environment evolution in Shanghang-Datian region, Fujian[J].Acta Petrologica Sinica,2004,20(2):285-296. |
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| Authors: | MAO JianRen XU NaiZheng HU Qing XING GuangFu and YANG ZhuLiang Najing Institute of Geology and Mineral Resources Chinese Academy of Geological Sciences Nanjing China |
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| Abstract: | There are various isotopic ages for four granitic plutons in the studied area, which respectively are as fo llows: Tangquan pluton 185 ~158Ma; Zijinshan pluton 157 ~145Ma; Caixi pluton 133Ma; Sifang pluton 108 ~ 105. Tangquan and Zijinshan plutons are belonged to respectively Early-Middle-Jurassic and Late-Jurassic in Early-Mesozoic, and Caixi and Sifang plutons belong to Early-Cretaceous in Late-Mesozoic. Both Tangquan and Sifang plutons, which are the metaluminous granites with A/CNK < 1. 0, are regarded to possess the geochemical characteristics of adakite rich in Sr, Ba and poor in HREE, Y, Yb, as the most potential host rocks of ore-bearing for the copper deposit. Zijinshan pluton is regarded as peraluminous granites with A/CNK > 1. 1 , and possesses the geochemical feature of crust-derived mud materials by partial melting with enrichment in K, Rb, Th, Y, HREE and depletion in Sr, Ba, Ti. Caixi pluton is weak-peraluminous granites with A/CNK = 1. 0 ~ 1. 1, and its geochemical feature lies between the Zijinshan pluton and Sifang pluton. Tangquan pluton with higher Na2O content, which was formed by partial melts of the thickened lower-crust derived basic rock during Proterozoic, resulting from the underplating of mantle-derived basic magma, is the major host rocks of the metallogenic series of copper, iron and multiple metals deposits. Sifang pluton with higher K2O content, which was mixed between middle-lower crust-derived by granite magmas partial melting and mantle derived basic magma with high K, resulted in increase of K2O content in the melt and obtaining of a large amount of copper, other metals and sulphur from mantle, is the major host rocks of the metallogenic series of the porphyry copper, gold and multiple metal deposits. There have been the petrological records of lithosphere extension since Early-Middle-Jurassic (180Ma) in the region, and formation of Zijinshan peraluminous granites is resulted from the extension mechanism. With the time past, the lithosphere extension-thinning and underplating is increased gradually, meanwhile the contribution of mantle to granite formation is increased gradually. |
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| Keywords: | Granites Mesozoic Ore-forming processes Tectonic environment Southwestern Fujian |
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