中国矿业
中國礦業
중국광업
CHINA MINING MAGAZINE
2014年
5期
82-89
,共8页
锆石U-Pb年龄%晚三叠世%高钾钙碱性系列%后造山花岗岩%伊尔施
鋯石U-Pb年齡%晚三疊世%高鉀鈣堿性繫列%後造山花崗巖%伊爾施
고석U-Pb년령%만삼첩세%고갑개감성계렬%후조산화강암%이이시
Zircon U-Pb ages%late triassic%high-K calc-alkaline series%post-orogenic granite%Yi’ ershi
伊尔施花岗岩位于大兴安岭中段，出露面积约260km2，由中细粒二长花岗岩、中粗粒斑状正长花岗岩和中粗粒正长花岗岩三期侵入体构成。岩体侵入于石炭-二叠系地层，被晚侏罗世火山岩不整合所覆。锆石LA-ICP-MS U-Pb年龄为（226．3±1．4） Ma ，表明为晚三叠世花岗岩。花岗岩具有高硅、富碱、低钙的特征，属于弱过铝质岩石。稀土元素总量较高，轻稀土相对富集，重稀土相对亏损，Eu负异常明显。强不相容元素富集，亏损Ba、S r、P和T i。总体属于高钾钙碱性系列向碱性系列过渡的花岗岩，具有后造山花岗岩类（POG ）的特征，形成于挤压造山向拉张体制转变阶段的构造环境，暗示该区受西伯利亚板块和华北板块碰撞造山作用的影响持续到三叠纪。
伊爾施花崗巖位于大興安嶺中段，齣露麵積約260km2，由中細粒二長花崗巖、中粗粒斑狀正長花崗巖和中粗粒正長花崗巖三期侵入體構成。巖體侵入于石炭-二疊繫地層，被晚侏囉世火山巖不整閤所覆。鋯石LA-ICP-MS U-Pb年齡為（226．3±1．4） Ma ，錶明為晚三疊世花崗巖。花崗巖具有高硅、富堿、低鈣的特徵，屬于弱過鋁質巖石。稀土元素總量較高，輕稀土相對富集，重稀土相對虧損，Eu負異常明顯。彊不相容元素富集，虧損Ba、S r、P和T i。總體屬于高鉀鈣堿性繫列嚮堿性繫列過渡的花崗巖，具有後造山花崗巖類（POG ）的特徵，形成于擠壓造山嚮拉張體製轉變階段的構造環境，暗示該區受西伯利亞闆塊和華北闆塊踫撞造山作用的影響持續到三疊紀。
이이시화강암위우대흥안령중단，출로면적약260km2，유중세립이장화강암、중조립반상정장화강암화중조립정장화강암삼기침입체구성。암체침입우석탄-이첩계지층，피만주라세화산암불정합소복。고석LA-ICP-MS U-Pb년령위（226．3±1．4） Ma ，표명위만삼첩세화강암。화강암구유고규、부감、저개적특정，속우약과려질암석。희토원소총량교고，경희토상대부집，중희토상대우손，Eu부이상명현。강불상용원소부집，우손Ba、S r、P화T i。총체속우고갑개감성계렬향감성계렬과도적화강암，구유후조산화강암류（POG ）적특정，형성우제압조산향랍장체제전변계단적구조배경，암시해구수서백리아판괴화화북판괴팽당조산작용적영향지속도삼첩기。
Yi’ershi granite located in the middle of Daxing ’anling area ,about 260 km2 .It consists of three phase intrusions , the middle-fine grained adamellite ,coarse-grained grained porphyritic orthoclase granite and coarse-grained orthoclase granite ,respectively .Pluton intruded into the Carboniferous-Permian strata ,and the Late Jurassic volcanic rocks are unconformably overlying them .Zircon LA-ICP-MS U-Pb dating ages of the pluton is (226 .3 ± 1 .4) Ma ,indicates that the Late Triassic granite .The granitoid has the characteristics of high silica ,alkali-rich ,low calcium ,belongs to the weakly peraluminous rocks .Total REE abundance is variable ,rich of HREE ,and the fractionation of LREE is more than that of HREE relatively ,and by obivious Eu anomalies .Strong incompatible elements are enrichment ,lack of Ba ,Sr ,P and Ti .Overall belong to the transition series from high-K series to calc-alkaline series granite ,shows the characteristics of typical post-orogenic granite (POG ) .It mainly formed in the transition phase from the extrusion orogenic to extensional regime tectonic environment , which suggesting the collision orogeny between Siberian Plate and North China Plate affected by continued to Triassic in the region .
