摘要
崎峰茶－得田沟金矿田位于华北地块东北部，是华北地块北缘巨型ＥＷ向金矿带的组成部分。本文研究了该矿田各类岩石的稀土元素特征。通过与含金石英脉和金属硫化物的对比分析，探讨了它们与成矿的关系。结果显示，金属硫化物、含金石英脉及蚀变岩石的稀土元素特征很相似，它们与矿田内的燕山期正长斑岩脉和花岗岩（脉）具有很大相似性，从而确定了它们之间的成因联系，为找矿预测提供了依据。
The Qifengcha Detiangou gold field in Huairou county,Beijing,is one of those that constitute the huge E W trending gold mineralization belt at the north margin of the North China Block and is located in the southwestern flank of the Miyun Huairou uplift.The orefield is composed of the Qifengcha and the Detiangou gold deposits,and a group of discrete gold occurrences and Au mineralized spots.The gold bodies and Au mineralized bodies are mainly in veins or in lenses and are controlled mainly by faults,fractures and ductile shear zones,associated with hydrothermal alterations such as silicification,chloritization,sericitization,pyritization and carbornatization.They mainly occur as native gold,and tellurides (calaverite and petzite),or as very fine grains and colloids within the crystal lattice of pyrite,pyrrhotite,chalcopyrite,galena and sphalerite.Quartz vein type and rock alteration type are two types of gold mineralization in this orefield,indicating a hydrothermal mineralization process. In this paper,REE composition of sulfides,gold bearing quartz veins,altered rocks,Mesozoic intrusive rocks and Archean metamorphic rocks in and around the orefield is studied.The main results are as follows: (1)Fractionation of light and heavy REE of relatively earlier and larger acid or alkali acid magmatic bodies is usually higher than that of the later and smaller veins. (2)The fact that the ΣCe/ΣY,La/Sm,(La/Sm) N,Gd/Yb,(Gd/Yb) N,La/Yb,(La/Yb) N and Sm/Nd ratios of sulfides are higher than those of Au bearing quartz veins,indicates a higher light REE and higher LREE/HREE fractionation in sulfides than in quartz veins. (3)The syenite porphyry veins and syenite in this orefield are products of magmatism of the same source,with the former evolved from the latter at a late stage.REE geochemistry of syenite porphyry veins,such as ΣREE,ΣCe/ΣY,La/Sm,(La/Sm) N and Sm/Nd is more similar to that of the Au bearing veins compared with the syenite masses. (4)Acid intrusive rocks especially the beschtauite and granite porphyry veins
出处
《地质力学学报》
CSCD
1998年第2期30-38,共9页
Journal of Geomechanics
基金
地质矿产部定向科研基金
关键词
地球化学
金矿田
稀土族
北京
REE,geochemistry,gold field,Qifengcha Detiangou,Huairou,Beijing
