CAJ | 학술논문

出露于新疆塔里木南缘铁克里克地区西段的都维吐卫花岗岩体,侵入赫罗斯坦岩群(Pt1 H )黑云二长片麻岩中,与库浪那古岩群(Pt2 K )和大同西岩体呈断层接触,东部多被博查特塔格组(Jxbc )不整合覆盖。通过地球化学分析,显示岩体具高 Si、高 Al、高 K,贫 Na、低 Ga、低 P、低 Ti 和贫 Mg 的特征,铝饱和指数(A/CNK)为1.38~1.43,CIPW 标准刚玉分子大于1%,属高钾钙碱性过铝质花岗岩。在稀土元素方面显示,轻稀土元素(LREE)富集、重稀土元素(HREE)亏损,轻重稀土元素分馏明显,Eu 出现中等负异常(δEu=0.59~0.82)；在微量元素方面,明显富集大离子亲石元素 Rb、Ba、Th 和 K,亏损高场强元素 Nb、Ta、Ti。岩体 LA ICP MS 锆石 U Pb 同位素定年获得年龄为(1909±47)Ma,属于古元古代花岗岩。综合分析认为该岩体是造山晚期同碰撞环境下形成的,与加厚地壳引起的地壳重熔有关,推断西昆仑造山带强烈的陆内造山活动应在古元古代已经开始了；结合赫罗斯坦岩群(Pt1 H )中角闪斜长片麻岩中锆石年龄记录,推断2000~1800Ma塔里木陆块存在 Columbia 超大陆聚合事件。
출로우신강탑리목남연철극리극지구서단적도유토위화강암체,침입혁라사탄암군(Pt1 H )흑운이장편마암중,여고랑나고암군(Pt2 K )화대동서암체정단층접촉,동부다피박사특탑격조(Jxbc )불정합복개。통과지구화학분석,현시암체구고 Si、고 Al、고 K,빈 Na、저 Ga、저 P、저 Ti 화빈 Mg 적특정,려포화지수(A/CNK)위1.38~1.43,CIPW 표준강옥분자대우1%,속고갑개감성과려질화강암。재희토원소방면현시,경희토원소(LREE)부집、중희토원소(HREE)우손,경중희토원소분류명현,Eu 출현중등부이상(δEu=0.59~0.82)；재미량원소방면,명현부집대리자친석원소 Rb、Ba、Th 화 K,우손고장강원소 Nb、Ta、Ti。암체 LA ICP MS 고석 U Pb 동위소정년획득년령위(1909±47)Ma,속우고원고대화강암。종합분석인위해암체시조산만기동팽당배경하형성적,여가후지각인기적지각중용유관,추단서곤륜조산대강렬적륙내조산활동응재고원고대이경개시료；결합혁라사탄암군(Pt1 H )중각섬사장편마암중고석년령기록,추단2000~1800Ma탑리목륙괴존재 Columbia 초대륙취합사건。
The Duweituwei granite exposed in western Tiekelike area of the southern Tarim Basin of Xinjiang intrudes into biotite monzo-gneiss of Heluositan terrain (Pt1 H ),and contacts by fault withthe Kulangnagu (Pt2 K )terrain and west Datong granite.Besides,the east of the granite is unconformably covered by Bochatetage group (Jxbc ).Geochemical analysis shows that the gran-ite has high SiO2 ,Al2 O3 ,K2 O content but relatively low CaO,P2 O5 ,TiO2 and MgO content. The ratios of A/CNK vary from 1.37 to 1.43,and CIPWcorundum molecule is larger than 1%, suggesting its type of high-K calc-alkaline peraluminous syn-collision granite.The chondrite-nor-malized REE patterns show that the granite is rich in LREE but depleted in HREE,with high fractionations between LREE and HREE and moderate negative Eu anomalies (δEu is 0.59 to 0.82).In addition,the granite is relatively rich in such LILEs as Rb,Ba,Th and K,but poor in such HFSES as Nb,Ta and Ti in the primitive mantle-normalized trace elements patterns.Zircon LA-ICP-MS dating yielded the age of (1 909±47)Ma,implying that the magmatic crystallization epoch of the granite is late Paleoproterozoic.Comprehensive analysis suggests that the rock mass is formed in the late orogenic collision environment relevant to the formation of thickened crust induced crustal remelting.It is therefore speculated that the strong intracontinental orogenic ac-tivityin western Kunlun orogenic belt should have begun in the Paleoproterozoic.Combined with the zircon record of hornblende plagioclase gneiss in Heluositan rock group (Pt1 H ),it is inferred that the Columbia supercontinent events occurred in the Tarim block during 2 000 to 1 800Ma.