【摘要】：中國阿爾泰廣泛發(fā)育的花崗質巖石已獲得大量研究,但是其東南緣研究薄弱,制約了對整個阿爾泰造山帶構造巖漿演化的認識。本文新獲得阿爾泰東南緣四個花崗質巖體(昆格依特、庫吉爾特、布鐵烏及卡拉特玉別)鋯石U-Pb年齡,分別為382±4Ma、381±4Ma、385±5Ma和363±6Ma。巖石學、地球化學特征等顯示這些花崗質巖石具有高鉀鈣堿性、準鋁質—弱過鋁質的I型特點,全巖εNd(t)值為-2.42~-0.53,Nd模式年齡tDM為1.6~1.3Ga;鋯石εHf(t)值為-3.44~+13.26,絕大多數(shù)為正值,鋯石Hf二階段模式年齡tDM-2為2.5~0.6Ga,表明源區(qū)物質組成復雜,有較多的新生幔源物質參與花崗質巖石的形成,并含有古老地殼成分。綜合已有年齡分析顯示,中國阿爾泰花崗質巖石的形成時代可分為480~440Ma(峰期460Ma)、420~390Ma(峰期400Ma)、390~370Ma(峰期380Ma)、370~360Ma(峰期365Ma)、360~350Ma。處于巖漿發(fā)育峰期的早泥盆世(420~390Ma)多為準鋁-過鋁質的鈣堿性系列;中晚泥盆世(390~360Ma)多為準鋁—弱過鋁質的高鉀鈣堿性系列;370~360Ma為高鉀鈣堿性系列。該地區(qū)363Ma的高鉀鈣堿性花崗質巖石的確定,為進一步厘定整個阿爾泰泥盆紀花崗質巖漿由鈣堿性(480~390Ma),到高鉀鈣堿性(390~360Ma),再到354Ma的布爾根堿性花崗巖的演變特點提供了新的證據(jù),進一步揭示阿爾泰造山帶該時期由俯沖增生演變到碰撞及后碰撞的演化過程。
[Abstract]:The extensive development of granitic rocks in Altai, China, has been extensively studied, but the study on the southeastern margin of the granitic rocks is weak, which restricts the understanding of tectonic magma evolution in the Altai orogenic belt. The zircon U-Pb ages of four granitic rocks (Kungoit, Kugill, Butiu and Karat jade) in the southeastern margin of Altai are 382 鹵4 Ma, 381 鹵4 Ma, 385 鹵5Ma and 363 鹵6 Ma, respectively. The petrological and geochemical characteristics of these granitic rocks indicate that these granitic rocks have the characteristics of high potassium calc-alkaline, quasi-aluminite-weak peraluminous type I. the whole rock 蔚 Nd (t) values are -2.42 ~ 0.53 ND model age tDM is 1.6 ~ 1.3Ga.The zircon 蔚 Hf (t) values are -3.44 ~ 13.26, mostly positive. The zircon Hf two-stage model age (tDM-2) is 2.5? 0. 6Ga, which indicates that the source region has a complex material composition, more new mantle source materials are involved in the formation of granitic rocks, and there are ancient crustal elements. The comprehensive age analysis shows that the age of formation of Altai granitic rocks in China can be divided into 480~440Ma (peak 460Ma) 420D 390Ma (peak-stage 400Ma) 370Ma (peak 380Ma) 370-360Ma (peak 365Ma) 360N350Ma.The age analysis shows that the age of Altai granitic rocks in China can be divided into 480~440Ma (peak 460Ma) 420D 390Ma (peak 400Ma) 370Ma (peak 380Ma). The early Devonian (420~390Ma) at the peak of magma development is mostly quasi-aluminum-peraluminous calc-alkaline series, and the 390~360Ma high-potassium calc-alkaline series of high-potassium calc-alkaline series at 370,360 Ma is a high-potassium calc-alkaline series. The determination of high-potassium calc-alkaline granitic rocks in 363Ma provides new evidence for the further determination of the evolution characteristics of the whole Altai Devonian granitic magma from calc-alkaline (480~390Ma) to high-potassium calc-alkaline (390~360Ma), and then to 354Ma's Burgen alkaline granite. It is further revealed that the Altai orogenic belt evolved from subduction to collision and post-collision in this period.
【作者單位】： 中國地質科學院地質研究所;中國地質大學(北京);新疆地礦局第八地質大隊;
【基金】：NSFC-新疆聯(lián)合基金重點支持項目(U1403291) 中國地質調查局項目(編號:12120113094000、1212010811033、12120113096500、1212010611803)聯(lián)合資助
【分類號】：P597.3;P588.1

【相似文獻】

相關期刊論文 前10條

1 夏祖春,徐學義,夏林圻,李向民,馬中平,王立社;天山石炭-二疊紀后碰撞花崗質巖石地球化學研究[J];西北地質;2005年01期

2 王守信;;甘肅省花崗質巖石的成因探討[J];西北地質;1985年05期

3 Shunso Ishihara;Atsuyuki Mizuno;靳娟娟;;日本九州島西南沿海甑海丘花崗質礫石的年齡[J];世界地質;1988年01期

4 凌賢長;撫順東部地區(qū)紫蘇花崗質巖石特征及成因[J];吉林地質;1995年02期

5 施性明 ,趙元進 ,趙希o，

本文編號：2217601