剪切带中矿化与非矿化地段流体——岩石相互作用差异性研究  

DISCRIMINATION STUDY ON FLUID/ROCK INTERACTION WITHIN METALLOGENIC AND NON-METALLOGENIC SECTIONS IN SHEAR ZONE

作　　者：魏俊浩[1] 张德会[1] 王思源[1] 刘伟[1] 

机构地区：[1]中国地质大学,武汉430074

出　　处：《地质科学》1999年第4期473-484,共12页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：国土资源部矿产资源定量预测与勘查评价开放实验室资助;国家自然科学基金资助

摘　　要：以河南西峡石板沟金矿为例 ,选择了一条控矿剪切带 ,对其中成矿地段的近矿蚀变岩和非成矿地段糜棱岩进行了系统的采样 ,探讨了二者在流体 -岩石反应及岩石质量平衡之间的差异性。研究表明 ,剪切带中矿化地段蚀变岩其岩石体积总是扩容的 ,非矿化地段糜棱岩在变形过程中体积是损失的。矿化地段蚀变岩活性元素 ( K、Na、Si)总体呈被带入趋势 ,非矿化地段糜棱岩活性元素总体呈迁出趋势 ,糜棱岩的流体岩石率 ( Nu 为 93.68— 468.40 )远大于蚀变岩的流体岩石率 ( N cs( ) 为 36.1 1 - 2 1 6.67) ,剪切带中常量元素与微量元素富集与损失是渗透性流体带入、带出 ,岩石的体积损失与扩容综合作用的结果。The differentiations of local chemical,fluidic,mechanical and themal processes in a shear zone result in metallogenic differentiation in local section.In this paper,based on the general geological setting of Shibangou gold deposit in Xixia,Henan,the petrological and petrochemical samples of altered rocks from metallogenic and mylonites from non metallogenic sections in a shear zone have been collected systematically.The discriminations of fluid/rock interaction and petrological mass balance between altered rocks near orebody and mylonites in the shear zone have been discussed.The research results show that the petrological volume of altered rocks in metallogenic section from shear zone is almost always dilatant,while mylonite volume in non metallogenic section is almost always losing.Major elements in altered rocks from metallogenic section and inmylonites from non metallogenic section are always enriched and lost,respectively.The fluid/rock ratio of mylonites( N u=93.68-468.40) are larger than that of altered rocks( N C s (Ⅳ) =36.11-216.67).The enrichment and loss of major and trace elements from alfered rocks and mylonites in shear zone are the result of synthetic process through flowing in and out of percolating fluids and loss and dilatancy of rock volume.

关 键 词：剪切带 蚀变岩 糜棱岩 流体/岩石率 矿化 金矿床 

分 类 号：P618.510.5[天文地球—矿床学] P588.332[天文地球—地质学]