新疆地质
新疆地質
신강지질
XINJIANG GEOLOGY
2013年
3期
167-172
,共6页
褚方%赵同阳%张建东%朱志新%唐智%闫晓兰
褚方%趙同暘%張建東%硃誌新%唐智%閆曉蘭
저방%조동양%장건동%주지신%당지%염효란
沙尔布拉克%蛇绿岩%锆石U-Pb SHRIMP测年%构造环境
沙爾佈拉剋%蛇綠巖%鋯石U-Pb SHRIMP測年%構造環境
사이포랍극%사록암%고석U-Pb SHRIMP측년%구조배경
Sherbulake%Ophiolite%Zircon SHRIMP U-Pb dating%Tectonic settings
介绍了沙尔布拉克蛇绿岩物质组成、岩石地球化学特征及形成时代,并探讨其就位机制。该蛇绿岩套包括蛇绿岩残片、上覆岩系、外来岩块3部分,其中镁铁质火山岩具亏损高场强元素和富集大离子亲石元素特征,稀土元素球粒陨石标准化曲线总体平坦,分馏程度较弱,说明岩浆地幔源区可能卷入岛弧火山岩和洋中脊玄武岩成份,获得玄武岩中锆石SHRIMP U-Pb年龄为(322±9)Ma,认为沙尔布拉克蛇绿岩与库尔提蛇绿岩形成环境较相似,均形成于弧后盆地。就位过程应包括俯冲过程中的侵位、碰撞过程的侵位、地壳缩短期的侵位和阿尔泰南缘二叠纪地壳伸展减薄阶段的改造等。
介紹瞭沙爾佈拉剋蛇綠巖物質組成、巖石地毬化學特徵及形成時代,併探討其就位機製。該蛇綠巖套包括蛇綠巖殘片、上覆巖繫、外來巖塊3部分,其中鎂鐵質火山巖具虧損高場彊元素和富集大離子親石元素特徵,稀土元素毬粒隕石標準化麯線總體平坦,分餾程度較弱,說明巖漿地幔源區可能捲入島弧火山巖和洋中脊玄武巖成份,穫得玄武巖中鋯石SHRIMP U-Pb年齡為(322±9)Ma,認為沙爾佈拉剋蛇綠巖與庫爾提蛇綠巖形成環境較相似,均形成于弧後盆地。就位過程應包括俯遲過程中的侵位、踫撞過程的侵位、地殼縮短期的侵位和阿爾泰南緣二疊紀地殼伸展減薄階段的改造等。
개소료사이포랍극사록암물질조성、암석지구화학특정급형성시대,병탐토기취위궤제。해사록암투포괄사록암잔편、상복암계、외래암괴3부분,기중미철질화산암구우손고장강원소화부집대리자친석원소특정,희토원소구립운석표준화곡선총체평탄,분류정도교약,설명암장지만원구가능권입도호화산암화양중척현무암성빈,획득현무암중고석SHRIMP U-Pb년령위(322±9)Ma,인위사이포랍극사록암여고이제사록암형성배경교상사,균형성우호후분지。취위과정응포괄부충과정중적침위、팽당과정적침위、지각축단기적침위화아이태남연이첩기지각신전감박계단적개조등。
The article mainly introduces the material composition, geochemical characteristics, geochronology and Em-placement mechanism of Sherbulake ophiolite. The ophiolite includes ophiolite fragment, overlying rocks and exotic block, the mafic volcano rock with loss of high field elements and enrichment of large ion lithophile elements, chondrite normalized REE curves generally flat, fractionation of the weaker, indicate the magma of mantle source region may be involved in island-arc volcano rock and mid-ocean ridge basalt composition, and get the basalt SHRIMP zircon U-Pb age of (322±9) Ma. Therefore, we think that the formation environment of Sherbulake and Kuerti ophiolite are relatively sim-ilar, formed in the back arc basin. Emplacement process should be included four stages, emplacement during subduction, emplacement of collision process, emplacement of crustal shortening and transformation of the crustal extension of south-ern crustal margin of the Altai basin.