摘要
该文对小营盘金矿的两期主金矿脉一钾长石英脉和含金多金属硫化物石英脉进行了单颗粒锆石Ｕ－Ｐｂ同位素年龄测定，测得年龄值分别为１８２６±３１Ｍａ和１８００±１４Ｍａ，确定为吕梁运动时期在强烈区域退变质作用下的一次金的成矿作用。认为张宣地区至少存在两期金的成矿作用：１．古元古代与区域退变质作用有关的热液金矿成矿作用；２．海西一燕山期与重熔岩浆作用有关的热液金矿成矿作用。
Zhangiiakou-Xuanhua region is one of the major gold concentration area in NorthChina Platform, in which approximately one hundred gold deposits and ore occurrence aredistributed. Xiaoyingpan gold deceit is one of the superlarge gold deposits in this area.The main gold deceits formed in the definite stage Of evolution of the granite greenstone beltin this region and can be divided intO two types and three categories, that are primary andregenerated types and Xiaoyingpan, Inngping, Zhangquanzhuang categories.Xiaoyingpan gold deposit is the typical primary gold deposit, distributed within the granitegreenstone belt and controled by the low angle thrust nsppe, ductile--brittle shear zone. It formedin the Early Proterosoic Era(1800Ma±). But it is controversial problem about its metallogeneticePOCh for a long time. In order tO solve this problem, we have adopted the method of U-Pbisotopic age on single zircon. Two SamPles were got from the potach-feldspar quartz veins and thegold--bearing pci^tallic sulfidic quartz veins in the Xiaoyingpan gold dePOsit, we obtained twoage data at:1826±31Ma and 1800±14Ma separately. That indicate the Xiaoyingpan gold depositwas formed in 1800Ma±(Early Proterozoic), corresponding to the age of retrogressivemetarnorphism of greenschist factes in the stage of LUliang movement. We conclude that there aretwo stages of gold mineralization in Zhangiiakou-Xuanhua area namely: 1. gold mineralization inEarly Proterozoic Era. 2. gold rnineralization in the Hercynian or in the Hercynia-Yanshanianorogeny.
出处
《前寒武纪研究进展》
1997年第2期22-28,共7页
Progress in Precambrian Research
关键词
金矿床
成矿时代
锆石
铀
同位素年龄
铅
gold-bearing quartz vein, U-Ph isotopic age, retrogressive metamorphism,Lhliang movement
