| 张宣金矿密集区基底及成矿作用年代学研究进展 |
| 点此下载全文 |
| 引用本文：李怀坤,陆松年,李惠民,杨春亮.1999.张宣金矿密集区基底及成矿作用年代学研究进展[J].地球学报,20(2):169-176. |
| DOI： |
| 摘要点击次数: 2398 |
| 全文下载次数: 2326 |
|
|
| 中文摘要:张宣地区是华北地台北缘著名的金矿密集区之一，分布着规模不等的金矿床（点）百余处。区内前寒武纪基底呈双层结构模式：其下层结构是由厘定后的桑干杂岩组成，主体是太古宙晚期－元古宙初期的深成花岗质片麻岩，含规模不等和时代更老的各类表壳岩包体；上层结构是时代上可能和邻区集宁岩群相当的艾家沟岩组孔兹岩系。和基底有关的金矿主要与下层结构关系密切。Ａｕ丰度１０倍于地壳克拉克值的初始地壳，是该区形成金矿密集区的物质基础。精确的单颗粒锆石Ｕ－Ｐｂ年代学研究表明，区内重要金矿床小营盘金矿在吕梁运动期１８００Ｍａ左右的退变质作用过程中有一期重要矿化作用；而著名的东坪金矿则形成于其赋矿围岩石英二长岩就位之后约６０Ｍａ的３５０Ｍａ的海西早期。 |
| 中文关键词:基底及成矿作用 年代学 张宣金矿密集区 |
| |
| Advancement on the Geochronology of the Precambrian Basement and Mineralization in the Zhangxuan Gold-concentrated Region |
|
|
| Abstract:The Zhangxuan Area, in which over one hundred gold de posits/gold mineralized places have been discovered, is one of the famous gold-deposit-concentrated regions on the northern margin of the North China platform. The Precambrian basement in this district shows the feature of two-layer pattern . The lower layer is composed of the Sanggan Complex, which mainly consists of v arious gneisses, the products of metamorphism and deformation of the 2351 Ma g ranitoids. The upper one is the Aijiagou khondalite series, which is roughly com parable with the adjacent Jining khondalite in age. The gold deposits, associat ed with the Precambrian basement, are closely related to the lower layer. The in itial crust (directly-mantle-derived crust) with tentime-Clark-value of gold ab undance is the basis of forming gold-deposit-concentrated region in this area. U-Pb ages of single zircons indicate that there was a significant gold mineraliz ation period during the 1800 Ma retrometamorphism process in the Luliang movem ent at the Xiaoyingpan Gold Deposit and that the well-known Dongping Gold Deposit was formed at 350 Ma during the early stage of the Hercynian movement, about 60 Ma younger than the emplacement age of the direct country rock, the quartz-monzonite (the main part of the Shuiquangou alkaline rocks), which was formed at 410 Ma. |
| keywords:geochronology Precambrian basement gold deposits Zhangxuan area |
| 查看全文 查看/发表评论 下载PDF阅读器 |
|
|
|
|
|
