地球学报
地毬學報
지구학보
ACTA GEOSCIENTIA SINICA
2013年
4期
437-446
,共10页
于波%裴荣富%邱小平%陈景河%黎敦朋%张文慧%刘文元
于波%裴榮富%邱小平%陳景河%黎敦朋%張文慧%劉文元
우파%배영부%구소평%진경하%려돈붕%장문혜%류문원
紫金山矿田%岩浆岩演化%同位素年代学%中生代
紫金山礦田%巖漿巖縯化%同位素年代學%中生代
자금산광전%암장암연화%동위소년대학%중생대
Zijinshan orefield%magmatic evolution%isotopic geochronology%Mesozoic
福建紫金山矿田中生代岩浆活动分为晚侏罗世和早白垩世二幕,第一幕为晚侏罗世(154~149 Ma)挤压环境下的岩浆活动,表现为壳源S型花岗岩紫金山复式岩体与才溪岩体的侵位,复式岩体具有154 Ma、150 Ma及149 Ma三次脉动;才溪岩体侵位时代约150 Ma。第二幕发生于早白垩世(125~93 Ma)构造拉张、地幔上涌的环境,岩浆活动共4期,形成一套 I 型花岗岩及共源异相的火山岩、次火山岩,为成矿提供了物源和热源。其中第1期为早白垩世火山喷发与岩浆超浅层就位,形成石帽山群下段的英安岩及紫金山次火山岩(125~118 Ma);第2期表现为石帽山群下段安山岩喷发与四方岩体的侵位以及英安玢岩的形成(109~103 Ma);第3期表现为石帽山群下段英安岩的喷发和罗卜岭—紫金山似斑状花岗闪长(斑)岩的侵位以及龙江亭、二庙沟附近的石英闪长玢岩的形成(103~100 Ma);第4期表现为晚期罗卜岭斑岩的侵位、石帽山群上段流纹岩的喷发和大岩里花岗斑岩岩脉、金铜矿的石英斑岩脉等成矿后期无矿脉岩的形成(100~93 Ma)。晚侏罗世、早白垩世两个岩浆系统各自形成共源岩浆异地异相分异演化的格局。
福建紫金山礦田中生代巖漿活動分為晚侏囉世和早白堊世二幕,第一幕為晚侏囉世(154~149 Ma)擠壓環境下的巖漿活動,錶現為殼源S型花崗巖紫金山複式巖體與纔溪巖體的侵位,複式巖體具有154 Ma、150 Ma及149 Ma三次脈動;纔溪巖體侵位時代約150 Ma。第二幕髮生于早白堊世(125~93 Ma)構造拉張、地幔上湧的環境,巖漿活動共4期,形成一套 I 型花崗巖及共源異相的火山巖、次火山巖,為成礦提供瞭物源和熱源。其中第1期為早白堊世火山噴髮與巖漿超淺層就位,形成石帽山群下段的英安巖及紫金山次火山巖(125~118 Ma);第2期錶現為石帽山群下段安山巖噴髮與四方巖體的侵位以及英安玢巖的形成(109~103 Ma);第3期錶現為石帽山群下段英安巖的噴髮和囉蔔嶺—紫金山似斑狀花崗閃長(斑)巖的侵位以及龍江亭、二廟溝附近的石英閃長玢巖的形成(103~100 Ma);第4期錶現為晚期囉蔔嶺斑巖的侵位、石帽山群上段流紋巖的噴髮和大巖裏花崗斑巖巖脈、金銅礦的石英斑巖脈等成礦後期無礦脈巖的形成(100~93 Ma)。晚侏囉世、早白堊世兩箇巖漿繫統各自形成共源巖漿異地異相分異縯化的格跼。
복건자금산광전중생대암장활동분위만주라세화조백성세이막,제일막위만주라세(154~149 Ma)제압배경하적암장활동,표현위각원S형화강암자금산복식암체여재계암체적침위,복식암체구유154 Ma、150 Ma급149 Ma삼차맥동;재계암체침위시대약150 Ma。제이막발생우조백성세(125~93 Ma)구조랍장、지만상용적배경,암장활동공4기,형성일투 I 형화강암급공원이상적화산암、차화산암,위성광제공료물원화열원。기중제1기위조백성세화산분발여암장초천층취위,형성석모산군하단적영안암급자금산차화산암(125~118 Ma);제2기표현위석모산군하단안산암분발여사방암체적침위이급영안분암적형성(109~103 Ma);제3기표현위석모산군하단영안암적분발화라복령—자금산사반상화강섬장(반)암적침위이급룡강정、이묘구부근적석영섬장분암적형성(103~100 Ma);제4기표현위만기라복령반암적침위、석모산군상단류문암적분발화대암리화강반암암맥、금동광적석영반암맥등성광후기무광맥암적형성(100~93 Ma)。만주라세、조백성세량개암장계통각자형성공원암장이지이상분이연화적격국。
The Mesozoic magmatic activities of the Zijinshan orefield included Late Jurassic and Early Cretaceous Episodes. The first episode of magmatic activity occurred in Late Jurassic(154~149 Ma)in a compression environment, characterized by the intrusion of Zijinshan composite granite body and Caixi pluton of S-type granite. The Zijinshan composite granite body has 3 pulsations, which occurred in 154 Ma, 150 Ma and 149 Ma. Caixi pluton intrusion occurred around 150 Ma. The magmatic activity of the second episode was composed of four stages during 125~93 Ma in Early Cretaceous in a tension and mantle upwelling environment, forming a series of I-type granites and their cogenetic heterophase volcanic rocks and subvolcanic rocks and providing metallogenic material and heat. The volcanic eruption and super-hypabyssal magmatic intrusion of the first stage finds expression in the formation of dacite of the Lower Member in Shimaoshan Group and the Zijinshan subvolcanic rocks (125~118 Ma). The volcanic eruption and intrusion of the second stage are characterized by the andesite eruption of Shimaoshan Group and Sifang pluton intrusion as well as the formation of dacite porphyrite(109~103 Ma). The volcanic eruption and intrusion of the third stage are characterized by the dacite eruption as well as the porphyraceous granodioritic porphyry intrusion in Luoboling-Zijinshan together with the formation of quartz dioritic porphyrite near Longjiangting and Ermiaogou(103~100 Ma). The volcanic eruption and intrusion of the fourth stage are characterized by the intrusion of Luoboling prophyry, the eruption of rhyolite in the upper member of Shimaoshan Group and the intrusion of barren vein rocks after the ore-forming period (e.g., Dayanli granite porphyry dykes, quartz porphyry dykes in Zijinshan gold-copper ore deposit)(100~93 Ma). The Late Jurassic and the Early Cretaceous co-magmas respectively differentiated and evolved into varied facies in different areas.