岩石学报
巖石學報
암석학보
ACTA PETROLOGICA SINICA
2009年
12期
3153-3164
,共12页
刘燊%胡瑞忠%冯彩霞%冯光英%于晓飞%李才%贾大成%齐有强%王涛
劉燊%鬍瑞忠%馮綵霞%馮光英%于曉飛%李纔%賈大成%齊有彊%王濤
류신%호서충%풍채하%풍광영%우효비%리재%가대성%제유강%왕도
埃达克岩%锆石U-Pb年龄%锆石Hf同位素%侏罗世
埃達剋巖%鋯石U-Pb年齡%鋯石Hf同位素%侏囉世
애체극암%고석U-Pb년령%고석Hf동위소%주라세
Adakites%Zircon U-Pb age%Zircon Hf isotopes%Jurassic
地球化学研究表明,大蒲柴河岩体具有典型的埃达克岩特征,来自加厚下地壳的部分熔融作用.本文采用激光等离子质谱对该岩体进行了U-Pb同位素定年,结果表明该岩体为晚侏罗世(165Ma)岩浆活动的产物.锆石的LA-MC-ICPMS Hf同位素研究结果显示,ε_(Hf)(165Ma)范围为-5.02～5.43,二阶段Hf模式年龄(t_(DM2))范围为965～1622Ma,暗示原始母岩浆为两种不同源区岩浆的混合.另外,Hf同位素研究表明,研究区在中-新元古代时(965～1304Ma)曾经历了一次重要的地壳增生事件.
地毬化學研究錶明,大蒲柴河巖體具有典型的埃達剋巖特徵,來自加厚下地殼的部分鎔融作用.本文採用激光等離子質譜對該巖體進行瞭U-Pb同位素定年,結果錶明該巖體為晚侏囉世(165Ma)巖漿活動的產物.鋯石的LA-MC-ICPMS Hf同位素研究結果顯示,ε_(Hf)(165Ma)範圍為-5.02～5.43,二階段Hf模式年齡(t_(DM2))範圍為965～1622Ma,暗示原始母巖漿為兩種不同源區巖漿的混閤.另外,Hf同位素研究錶明,研究區在中-新元古代時(965～1304Ma)曾經歷瞭一次重要的地殼增生事件.
지구화학연구표명,대포시하암체구유전형적애체극암특정,래자가후하지각적부분용융작용.본문채용격광등리자질보대해암체진행료U-Pb동위소정년,결과표명해암체위만주라세(165Ma)암장활동적산물.고석적LA-MC-ICPMS Hf동위소연구결과현시,ε_(Hf)(165Ma)범위위-5.02～5.43,이계단Hf모식년령(t_(DM2))범위위965～1622Ma,암시원시모암장위량충불동원구암장적혼합.령외,Hf동위소연구표명,연구구재중-신원고대시(965～1304Ma)증경력료일차중요적지각증생사건.
Based on geochemical evidence, the quartz diorites from Dapuchai, eastern Jilin Province, belong to typical adakites derived from partial melting of thickened lower crust. Zircon U-Pb dating by LA-ICPMS technique indicates that the studied plutons were emplaced during Late Jurassic with an age of 164.9 ± 0.8Ma. Zircon Hf analyses conducted by LA-MC-ICPMS show that these adakites have variational ε_(Hf) (165Ma)values from -5.02 to 5.43, and Hf model ages from 965Ma to 1622Ma, indicating that the primary magma of the adakites originated from mixing of two different magma, one from partial melting of pre-existing crustal source that was separated from a depleted mantle source during the Middle Proterozoic; While the other magma from asthenospheric mantle through underplating during 985 ～ 1304Ma, indicative of an important crustal growth beneath the studied area.
