• 首页
  • 学报简介
  • 编委会
  • 投稿指南
  • 订阅指南
  • 过刊浏览
  • 在线投稿
  • 联系我们
  • 网络预出版
  • English

本文将参加年度优秀论文评选,如果您觉得这篇文章很好,请投下您宝贵的一票,谢谢! 支持(4)   不支持(5)

福建政和铁山“印支期正长岩”是燕山期钾质交代岩的矿物学证据
投稿时间:2018-04-12  修订日期:2018-06-02  点此下载全文
引用本文:陈世忠,李亚楠,朱筱婷,隰弯弯,邢光福.2018.福建政和铁山“印支期正长岩”是燕山期钾质交代岩的矿物学证据[J].地质学报,92(9):1843-1858
摘要点击次数: 257
全文下载次数: 158
作者单位E-mail
陈世忠 中国地质调查局南京地质调查中心南京210016 nanjingcsz@qq.com 
李亚楠 中国地质调查局南京地质调查中心南京210016  
朱筱婷 中国地质调查局南京地质调查中心南京210016  
隰弯弯 中国地质调查局南京地质调查中心南京210016  
邢光福 中国地质调查局南京地质调查中心南京210016  
基金项目:中国科技部国家重点研发计划专题(课题编号: 2016YFC0600210)
中文摘要:福建政和铁山岩体以往被认为属于“正长岩”,是华南少见的印支期碱性侵入岩类。笔者等对铁山岩体西南部狮子岗岩体的研究表明,其岩性并非正常的侵入岩,而是由强烈的钾质流体交代作用形成的交代岩,交代岩中还保留了许多角砾状的原岩残留体,包括印支期花岗质岩体、早侏罗世梨山组砂砾岩及早白垩世南园组火山岩等,推断交代岩形成于白垩纪。交代岩中的钾长石可分为面型钾化蚀变、早期浅色钾化脉、晚期深色钾化脉和黑榴石辉石钾长岩等4种成因类型。第一类钾长石Or分子含量变化于77.9%~94.3%,Ab分子含量变化于5.2%~21.3%,An分子含量变化于0%~0.8%。第二类钾长石Or分子含量变化于81.5%~91.3%,Ab分子含量变化于8.2%~17.4%,An分子含量变化于0.5%~4.1%。第三类钾长石Or分子含量变化于91.8%~96.8%,Ab分子含量变化于3.2%~9.3%,An分子含量变化于0.1%~0.4%。第四类钾长石Or分子含量变化于85.2%~90.0%,Ab分子含量变化于10.8%~14.6%,An分子含量变化于0.2%~0.6%。钾交代可大致划分为早、晚两期。早期钾交代形成面型钾化蚀变和早期浅色钾化脉,钾长石有序度为0.71~0.80,结构参数为1.27~1.61,三斜度为0.23~0.29,T1(o)+T1(m) 为0.86~0.90;晚期钾交代形成晚期深色钾化脉和黑榴石钾长石岩,钾长石有序度为0.67~0.88,结构参数为1.10~1.91,三斜度为0.30~0.70,T1(o)+T1(m) 为0.84~0.93。早、晚两期钾长石都是微斜长石,多为高微斜长石,结晶温度为200~370℃之间。交代岩的岩石类型主要包括石英钾长石岩、辉石钾长石岩和黑榴石钾长石岩等。
中文关键词:结晶温度  钾长石成因类型  交代岩  铁山岩体  福建政和
 
Tiehshan Indo-China Syenite in Zhenghe of Fujian is Yanshanian Potassic Metasomatic Rock Based on Mineralogical Evidence
NameInstitution
CHEN ShizhongNanjing Center, China Geological Survey, Nanjing, 210016
LI YananNanjing Center, China Geological Survey, Nanjing, 210016
ZHU XiaotingNanjing Center, China Geological Survey, Nanjing, 210016
XI WanwanNanjing Center, China Geological Survey, Nanjing, 210016
XING GuangfuNanjing Center, China Geological Survey, Nanjing, 210016
Abstract:Tieshan complex in Zhenghe, Fujian province has long been regarded as syenite, which is Indosinian alkali intrusive rock uncommonly in South China. This study conducted an investigation for the Shizigang rocks in the south-western area of the Tieshan complex. The results show that their lithology is not common intrusive rock but a metasomatic rock due to strong potassic fluid. The metasomatic rock hosts some residues of protolith, including Indosinian grantic bodies, sandy conglomerate of Early Jurassic Lishan Formation, and volcanic rocks of Early Cretaceous Nanyuan Formation. Therefore, it can be inferred that the metasomatic rock formed in the Cretaceous. K-feldspar of the metasomatic rock occurs in four forms, surfacial potassic alteration, early light colour potassic veins, late dark potassic veins, and melanite pyroxene K-feldspar rock in origin. The first surfacial potassic alteration contains Or of 77.9%~94.3%, Ab of 5.2%~21.3% and An of 0%~0.8%. The second contains Or of 81.5%~91.3%, Ab of 8.2%~17.4%, and An of 0.5%~4.1%. The third contains Or of 91.8%~96.8%, Ab of 3.2%~9.3%, and An of 0.1%~0.4%. The last contains Or of 85.2%~90.0%, Ab of 10.8%~14.6%, and An of 0.2%~0.6%. Potassic metasom atism can be divided into early stage and late stage. X-ray powder diffraction and infrared spectrum analyses show that the early stage metasomatism formed the first two forms of K-feldspar with or dering degree of of 0.71~0.80, structural parameters of 1.27~1.61, triclinicities of 0.23~0.29, and T1(o)+T1(m) of 0.86~0.90; while the late formed the last two forms of K-feldspar with ordering degree of 0.67~0.88, structural parameters of 1.10~1.91, and triclinicities of 0.30~0.70, T1(o)+T1(m) of 0.84~0.93. The first two K-feldspars consist mainly of microclines, especially highly microclines, with crystallization temperatures varying from 200 to 370℃. The types of metasomatic rocks include quartz K-feldspar rock, pyroxene K-feldspar rock and dark garnet K-feldspar rock.
keywords:structure temperature  genesis of alkali feldspar  metasomatite  Tieshan syenite  Fujian Zhenghe
查看全文  查看/发表评论  下载PDF阅读器
您是第10122418位访问者  京ICP备05032737号-7  京公网 安备110102004559
版权所有:《地质学报》中文版
主管单位:中国科学技术协会 主办单位:中国地质学会
地  址: 北京市西城区百万庄大街26号 邮编:100037 电话:010-68312410,010-68999025 E-mail: dizhixuebao@163.com
本系统由北京勤云科技发展有限公司设计 

京公网安备 11010202007916号

WeChat