地质通报
地質通報
지질통보
GEOLOGICAL BULLETIN OF CHINA
2014年
5期
606-613
,共8页
塔里木%新元古代花岗岩%锆石U-Pb年龄%Hf同位素%构造意义
塔裏木%新元古代花崗巖%鋯石U-Pb年齡%Hf同位素%構造意義
탑리목%신원고대화강암%고석U-Pb년령%Hf동위소%구조의의
Tarim%Neoproterozoic granites%zircon U-Pb ages%Hf isotope%tectonic implications
报道了塔里木库鲁克塔格地区新元古代晚期花岗闪长岩和钾长花岗岩的锆石U-Pb年龄和Hf同位素组成。花岗闪长岩锆石U-Pb谐和年龄为630.1±1.3Ma,钾长花岗岩锆石U-Pb谐和年龄为630.6±1.3Ma。Hf同位素组成表明,这2种岩石主要来自古老(中)基性地壳的重熔,可能有部分地幔物质的加入。结合已有的研究表明,650~615Ma期间的岩浆活动代表了塔里木地块新元古代最晚期的岩浆活动,是Rodinia超大陆解体过程中的产物,与泛非造山事件无关。塔里木地块自新元古代中期到早寒武世,持续接受了被动大陆边缘沉积,表明在这一时期塔里木为冈瓦那大陆之外独立的大陆块体,或是位于冈瓦那大陆最边缘的稳定大陆块体。
報道瞭塔裏木庫魯剋塔格地區新元古代晚期花崗閃長巖和鉀長花崗巖的鋯石U-Pb年齡和Hf同位素組成。花崗閃長巖鋯石U-Pb諧和年齡為630.1±1.3Ma,鉀長花崗巖鋯石U-Pb諧和年齡為630.6±1.3Ma。Hf同位素組成錶明,這2種巖石主要來自古老(中)基性地殼的重鎔,可能有部分地幔物質的加入。結閤已有的研究錶明,650~615Ma期間的巖漿活動代錶瞭塔裏木地塊新元古代最晚期的巖漿活動,是Rodinia超大陸解體過程中的產物,與汎非造山事件無關。塔裏木地塊自新元古代中期到早寒武世,持續接受瞭被動大陸邊緣沉積,錶明在這一時期塔裏木為岡瓦那大陸之外獨立的大陸塊體,或是位于岡瓦那大陸最邊緣的穩定大陸塊體。
보도료탑리목고로극탑격지구신원고대만기화강섬장암화갑장화강암적고석U-Pb년령화Hf동위소조성。화강섬장암고석U-Pb해화년령위630.1±1.3Ma,갑장화강암고석U-Pb해화년령위630.6±1.3Ma。Hf동위소조성표명,저2충암석주요래자고로(중)기성지각적중용,가능유부분지만물질적가입。결합이유적연구표명,650~615Ma기간적암장활동대표료탑리목지괴신원고대최만기적암장활동,시Rodinia초대륙해체과정중적산물,여범비조산사건무관。탑리목지괴자신원고대중기도조한무세,지속접수료피동대륙변연침적,표명재저일시기탑리목위강와나대륙지외독립적대륙괴체,혹시위우강와나대륙최변연적은정대륙괴체。
Zircon U-Pb dating reveals that the K-feldspar granite and granodiorite in Quruqtagh on the northern margin of the Tarim block crystallized at 630.1 ± 1.3Ma and 630.6 ± 1.3Ma, respectively. Zircon Hf isotopes indicate that these granitic rocks were mainly derived from partial melting of old andestic-basic crust with possible involvement of basaltic magma from mantle sources. Based on a comprehensive analysis of the Neoproterozoic igneous activities in Tarim, the authors argue that the 650~615Ma igneous rocks in Quruqtagh were the latest phase of the Neoproterozoic igneous activities and genetically related to the breakup of the Rodin-ia suppercontinent, i.e., they had nothing to do with the Pan-Africa orogeny. From Neoproterozoic to Cambrian, sedimentary se-quences in Quruqtagh exhibited typical sedimentation features on a passive continental margin, which indicates that the Tarim block had never incorporated into the Gondwana Land.