發(fā)布時間：2018-06-03 20:35

  本文選題：鋯石U-Pb定年 + Hf同位素��； 參考：《合肥工業(yè)大學(xué)》2015年碩士論文

【摘要】：天井山金礦處于江南造山帶的東段,安徽皖南地區(qū),發(fā)育于皖浙贛斷裂帶的次級斷裂：璜茅-三陽-屯溪韌性剪切帶中。天井山金礦周圍的巖漿活動主要集中于晉寧期和燕山期,晉寧期的花崗巖為靈山巖體,約占天井山礦區(qū)面積的三分之二,產(chǎn)于礦區(qū)的南東側(cè)。燕山期的花崗斑巖大多沿井譚組和靈山巖體的斷層侵入,呈巖枝、巖脈產(chǎn)出,其中青山-長陔巖帶在區(qū)域構(gòu)造地質(zhì)背景上與天井山成礦密切相關(guān)。天井山金礦產(chǎn)于靈山巖體與圍巖接觸帶中,呈脈狀,透鏡狀分布,以石英脈型和蝕變巖型礦石為主。礦石礦物以自然金、硫化物為主,蝕變類型主要有硅化、綠泥石化、絹云母化,石英脈的流體包裹體溫度在286～380℃,鹽度在3.0%～6.12%NaCleq之間,屬于典型的巖漿熱液性金礦特征。H-O同位素落在巖漿水范圍,天井山金礦為巖漿熱液型金礦。青山-長陔巖帶為Ⅰ型花崗巖,具有弱過鋁質(zhì)的高鉀鈣堿性系列,其中青山巖體(QS001-1)年齡為150.3±1.7 Ma,長陔巖體(14QC001-1)年齡為140.3±2.6 Ma,長陔巖體(14QC002-5)年齡為141.0±2.4 Ma,古祝巖體(14QC004-1)年齡為141.0±3.0 Ma,石門鄉(xiāng)(早山)巖體(14QC005-2)年齡為140.6±2.2 Ma,大嶺腳巖體(14QC006-1)為141.0±2.0 Ma,形成于燕山期晚侏羅世-早白堊世。該系列巖漿巖輕稀土元素相對富集,重稀土元素相對平坦的右傾型分配模式,鋯石Hf同位素指示青山-長陔巖帶巖漿巖具有殼�；烊鄣奶攸c。青山-長陔巖帶巖漿巖經(jīng)歷了角閃石、磷灰石、榍石和長英質(zhì)等礦物的分離結(jié)晶,其巖漿巖源區(qū)與皖南地區(qū)出露的新元古代和中元古代基底關(guān)系密切,早期巖漿產(chǎn)生的構(gòu)造背景屬于大陸島弧環(huán)境,而晚期處于拉張的構(gòu)造背景,構(gòu)造背景的轉(zhuǎn)換為古太平巖板塊向歐亞板塊俯沖所致。
[Abstract]:The Tianjingshan gold deposit is located in the eastern section of the Jiangnan orogenic belt and in the south of Anhui province, and developed in the secondary fault zone of the Anhui, Zhejiang and Jiangxi fault zones: Huangmao-Sanyang-Tunxi ductile shear zone. The magmatic activities around the Tianjingshan gold deposit are mainly concentrated in Jinning and Yanshanian periods. The granite in Jinning period is Lingshan rock body, accounting for about 2/3 of the area of Tianjingshan mining area, and occurs in the east and south of the mining area. Most of Yanshanian granitic porphyry intruded along the fault of Jingtan formation and Lingshan rock body, which appeared as branches and veins, among which the Qingshan-Changyan belt was closely related to the mineralization of Tianjingshan in the regional tectonic geological setting. The Tianjingshan gold deposit is in the contact zone between Lingshan rock mass and surrounding rock. It is vein-like and lenticular, mainly of quartz vein type and altered rock type ore. The ore minerals are mainly natural gold and sulfides, and the alteration types are mainly silicification, greenstone, sericite, fluid inclusion temperature of quartz veins at 2866 ~ 380 鈩，

本文編號：1974093