CAJ | 학술논문

博格达三个山地区基性岩墙地球化学研究显示，该岩墙属亚碱性系列，为岩浆高度演化产物，轻稀土富集，不相容元素Ba，La，K相对富集，高场强元素Nb，Th，Yb相对亏损，Ti亏损不明显，Nb/Ta（平均14.1）、Zr/Hf（平均35.99）比值与原始地幔Nb/Ta（17.8）、Zr/Hf（37）比值相似，(Th/Nb)N的值大于1，Nb/La比值小于1，表明该岩墙的岩浆源自地幔，且在侵位过程中受到地壳物质的混染。本区基性岩墙的LA-ICP-MS锆石U-Pb加权平均年龄为（322.1±6.5）Ma，表明是博格达造山带岩石圈拉张减薄时的产物，反映晚石炭世早期博格达造山带处于岩石圈拉张的构造环境与动力学背景。
박격체삼개산지구기성암장지구화학연구현시，해암장속아감성계렬，위암장고도연화산물，경희토부집，불상용원소Ba，La，K상대부집，고장강원소Nb，Th，Yb상대우손，Ti우손불명현，Nb/Ta（평균14.1）、Zr/Hf（평균35.99）비치여원시지만Nb/Ta（17.8）、Zr/Hf（37）비치상사，(Th/Nb)N적치대우1，Nb/La비치소우1，표명해암장적암장원자지만，차재침위과정중수도지각물질적혼염。본구기성암장적LA-ICP-MS고석U-Pb가권평균년령위（322.1±6.5）Ma，표명시박격체조산대암석권랍장감박시적산물，반영만석탄세조기박격체조산대처우암석권랍장적구조배경여동역학배경。
Researching geochemistry of mafic dyke in Sangeshan Bogda shows that it is the product of highly evolved of magma and belongs to sub-alkaline series.The mafic dyke is rich in LREE,comparatively rich in incompatible ele-ments(Ba,La,K),high field strength elements(Nb,Th,Yb) comparatively depleted,and slightly deplete Ti.Alike Nb/Ta(av-erage is 14.1)、Zr/Hf(average is 35.99)of mafic dyke with Nb/Ta(17.8)、Zr/Hf(37)of primitive mantle,all (Th/Nb)N are above 1,Nb/La are all below 1,it indicates that magma of this mafic dyke were derived from mantle and experienced crustal contaminations in the emplacement process.The zircon SHRIMP U-Pb age of the mafic dyke is (322.1±6.5 ) Ma, it indicates that it was generated in lithospheric plate of Bogda expanding and thinning setting,It shows the Bogda orogen was in the tectonic environment and geodynamic setting of lithospheric expand thinning during the early Carboniferous.