• 首页|本刊简介|在线投稿|过刊浏览|高级检索|专家风采|学习园地|期刊论坛|联系我们
广东龙口南昆山铝质A型花岗岩的成因
Origin of Nankunshan aluminous A-type granite, Longkou County, Guangdong Province
  
中文关键词:铝质A型花岗岩 广东 南昆山 成因
英文关键词:aluminous A_type granite,Guangdong Province,Nankunshan,genesis
基金项目:国家自然科学基金资助项目 ( 40 132 0 10,4 0 0 730 0 9,4 0 0 2 52 0 9)
刘昌实  陈小明  王汝成  胡欢
南京大学地球科学系内生金属矿床成矿作用国家重点实验室 江苏南京210093 (刘昌实,陈小明,王汝成)
,南京大学地球科学系内生金属矿床成矿作用国家重点实验室 江苏南京210093(胡欢)
摘要点击次数: 2471
全文下载次数: 1462
中文摘要:
      南昆山花岗岩出露面积约 2 0 0km2 ,为一等轴状岩体。具中粒等粒结构 ,由黑鳞云母、钠长石、条纹长石和石英组成。弱过铝质 ,MgO和CaO含量极低 ,亚碱质 ,碱度率和NK/A值偏高 ;富F贫Cl,具较高F/Cl值 ;具较高的锆石饱和 (液相线 )温度 (81 0~ 847℃ ) ,与澳大利亚A型花岗岩的平均值 (839℃ )基本相当。在微量元素特征上 ,具有高的 1 0 4 Ga/Al值和 (Zr+Nb +Ce +Y)元素组合值 ,分别高于A型花岗岩下限值的 2 .6和 350× 1 0 - 6 。在同位素组成特征上 ,具有较高的εNd(t)值 (- 1 .54~ - 2 .87)和较低的δ1 8O值 (7.9‰~ 9.8‰ )。按幔 -壳混合模型计算 ,其源区地幔组分约占 63 %~ 69%。上述特征表明 ,南昆山花岗岩与国内外典型铝质A型花岗岩 (如苏州花岗岩和澳大利亚Lachlan褶皱带A型花岗岩 )很相似。这一发现对阐明南岭东段燕山晚期地壳伸展构造的发育具有重要意义
英文摘要:
      Nankunshan aluminousA_type granite occurs in Longkou County of Guangdong Province, with a outcrop area of about 200 km2. With medium-grained texture, the granite is composed of protolithionite, albite plagioclase, perthite and quartz. The rock usually is weakly peralumious and subalkaline with high alkali ratio rangeand NK/A values. The granite contains markedly low MgO and CaO and extremely high (FeO+Fe2O3) with ahigh FeO*/(FeO*+MgO) ratio. Nankunshan granite is evidently rich in F and poor in Cl, having a high F/Clratio range. Based on its high Zr contents, the calculated zircon saturation temperatures of the rock are relativelyhigh (810~847℃), consistent with those of A_type granites in Australia (839℃,on average). In terms oftrace element data, the granite has high 104Ga/Al and (Zr+Nb+Ce+Y) values. These values are higher than the low_limited values of 2.6 and 350(×10-6) for aluminous A_type granites in Lachlan Fold Belt of Australiarespectively. The rock has higher total REE contents and strongly Eu negative anomalies, showing a sea_gullshaped REE partition patterns on its chondrite_normalized diagrams, and Rb, U, Th, Nb, Ta, Zr, Hf, Sm el-ements show evidently positive anomalies on the primitive mantle_normalized trace element spider diagrams. Thegranite possesses relatively highεNd(t) values (-1.54~-2.87) and lowδ18O Values (7.9‰~9.8‰), indi-cating that its source rocks are located in the interaction belts between the mantle and the crust. Mantle compo-nent accounts for about 63%~69% in its total source materials, as calculated by the mixing model of the mantl and the crust end members on the basis of the isotopic data. These features are obviously similar to those of alu-minous A_type granites elsewhere in the world. The discovery is important for study on the extensional structureof late Yanshanian crust in eastern part of Nanling Mountain.
刘昌实,陈小明,王汝成,胡欢,2003,广东龙口南昆山铝质A型花岗岩的成因[J].岩石矿物学杂志,22(1):1~10.
查看全文  查看/发表评论  下载PDF阅读器
关闭
您是本站第 5828863位访问者  京ICP备05032737号-8
版权所有:《岩石矿物学杂志》编辑部
主管:中国科学技术协会 主办:中国地质学会岩石学专业委员会 中国地质学会矿物学专业委员会 中国地质科学院地质研究所
技术支持:北京勤云科技发展有限公司

京公网安备 11010202007772号