%0 Journal Article
%T 鄂尔多斯盆地西南缘崆峒山砾岩碎屑锆石U-Pb
%A 师晓林
%A 陈
%A 刚
%A 杨
%A 甫
%A 张文龙
%A 徐小刚
%A 刘
%A 腾
%A 康
%A 昱
%A 高
%A 磊
%J 高校地质学报
%D 2015
%X ：鄂尔多斯盆地西南缘平凉崆峒山砾岩的地层时代和沉积物源环境一直存在争议。本文选取崆峒山主峰南、北两侧的 崆峒山组和三桥组碎屑岩样品，采用LA-ICP-MS锆石U-Pb年代学分析方法，探讨崆峒山砾岩的物质来源及其地质构造意 义。结果表明，上三叠统崆峒山组碎屑锆石U-Pb年龄主要包含438~778Ma(n=16)、827~1269Ma(n=40)、1354~1706Ma(n= 16)、1826~2080Ma(n=15)和2410~2809Ma(n=17)，相应的峰值年龄为540Ma、995Ma、1660Ma、1930Ma和2480Ma；下 白垩统三桥组碎屑锆石U-Pb年龄主要分布在281~413Ma(n=6)、445~643Ma(n=12)、712~1386Ma(n=45)、1563~1808Ma (n=14)、1888～2039Ma(n=10)和2150～2633Ma(n=23)六个年龄区间，相应的峰值年龄为335Ma、488Ma、980Ma、1676Ma、 1805Ma、1970Ma和2488Ma。锆石U-Pb年龄谱对比分析认为，崆峒山组和三桥组的沉积物源分别主要来自于祁连山东 段-北秦岭西段的前志留纪和前二叠纪岩石地层单元，少量来自（华北）鄂尔多斯古陆的沉积岩和变质基底岩系。崆峒山 组砾岩的沉积物源以北秦岭西段的秦岭群、宽坪群、大草滩群和加里东期岩浆岩贡献相对较大，且主要受控于印支期秦祁碰撞造山带的构造作用；三桥组砾岩的沉积物源则以祁连山东段的马衔山群、葫芦河群和祁连-北秦岭地区加里东中晚 期岩浆岩等为主，且主要受控于（华北）鄂尔多斯地块西南缘燕山中期的秦-祁陆内造山作用。</br>:Kongtongshanconglomeratedeposits,generallycomposedofKongtongshanFormationandSanqiaoFormation,distributein thePingliangareaofthesouthwesternOrdosBasin.ThestratigraphicageandprovenanceoftheKongtongshanconglomeratehavebeen controversialforalongtime.By usingtheLA-ICP-MSzirconU-Pbisotopegeochronologicmethod,twosamplesofclasticrockswere collectedfromKongtongshanFormationandSanqiaoFormationinthesouthandnorthsidesofKongtongshanpeakstodiscussthesourceandtectonicsignificanceofKongtongshanconglomerate.TheresultsshowthatthedetritalzirconagesoftheUpperTriassic KongtongshanFormationmainlyinclude438~778Ma(n=16),827~1269Ma(n=40),1354~1706Ma(n=16),1826~2080Ma(n=15) and2410~2809Ma(n=17),andthecorrespondingpeakagesare540Ma,995Ma,1660Ma,1930Maand2480Ma.Thedetritalzircon agesoftheLowerCretaceousSanqiaoFormationmainlyinclude281~413Ma(n=6),445~643Ma(n=12),712~1386Ma(n=45),1563~ 1808Ma(n=14),1888~2039Maand(n=10)and2150~2633Ma(n=23),andthecorrespondingpeakagesare335Ma,488Ma,980Ma, 1676Ma,1805Ma,1970Maand2488Ma.ThecomparativeanalysesofzirconU-PbagesshowthatthemainsourcesofKongtongshan Formation and Sanqiao Formation come from the sedimentary rocks, igneous rocks and metamorphic rocks of Pre-Silurian and Pre-PermianfromtheeasternpartofQilianMountainandthewesternpartofNorthQinlingMountainrespectively.Andthereisafew sourcesofthesedimentaryrocksandmetamorphicbasementrocksintheNorthChina(Ordos)oldland.Furthermore,theKongtongshan Formation Conglomerate is composed by the main sources of Qinling Group, Kuanping Group, Dacaotan Group and Caledonian magmaticrocksinthewesternpartoftheNorthQinlingMountain,anditiscontrolledbytheIndosiniantectonismoftheQinlingand QiliancollisionalOrogenicBelts.TheSanqiaoFormationConglomerateiscomposedbythemainsourcesofMaxianshanGroup,Huluhe Group and Caledonian magmatic rocks in the eastern part of Qilian Mountain, and it is controlled by the Qinling and Qilian
%K 鄂尔多斯盆地&lt
%K /br&gt
%K 崆峒山砾岩
%U http://geology.nju.edu.cn/CN/abstract/abstract9739.shtml