CAJ | 학술논문

白土滩花岗质杂岩体主要由黑云二长花岗岩、正长花岗岩和花岗闪长岩构成。通过锆石LA-ICP-MS U-Pb法测得黑云二长花岗岩和正长花岗岩的年龄分别为（291±2）Ma和（277±3）Ma。岩石地球化学研究表明，与黑云二长花岗岩相比，花岗闪长岩中硅、碱较低，而铝较高；高∑REE和∑LREE，低铕负异常；富 Cr,Zn,Sr,Zr,Ba和Hf，贫Rb,Ta和Th，Nb/Ta和Zr/Hf均升高，DI,Rb/Sr下降，从花岗闪长岩到黑云二长花岗岩表现出连续分异演化的趋势。结合区域地质特征认为，白土滩花岗质杂岩体为高钾钙碱性I型花岗岩，其源区物质是含水的、碱性和高钾钙碱性的安山岩和玄武质安山岩，形成于南天山东段碰撞造山的碰撞-后碰撞阶段。
백토탄화강질잡암체주요유흑운이장화강암、정장화강암화화강섬장암구성。통과고석LA-ICP-MS U-Pb법측득흑운이장화강암화정장화강암적년령분별위（291±2）Ma화（277±3）Ma。암석지구화학연구표명，여흑운이장화강암상비，화강섬장암중규、감교저，이려교고；고∑REE화∑LREE，저유부이상；부 Cr,Zn,Sr,Zr,Ba화Hf，빈Rb,Ta화Th，Nb/Ta화Zr/Hf균승고，DI,Rb/Sr하강，종화강섬장암도흑운이장화강암표현출련속분이연화적추세。결합구역지질특정인위，백토탄화강질잡암체위고갑개감성I형화강암，기원구물질시함수적、감성화고갑개감성적안산암화현무질안산암，형성우남천산동단팽당조산적팽당-후팽당계단。
The Baitutan granitic complex is mainly composed of monzogranites,orthoclase granites and granodiorites. Zircon LA-ICP-MS U-Pb dating gave ages of (291±2) Ma and (277±3) Ma for the monzogranite and orthoclase granite. Geochemically,in comparison with the monzogranite, the granodiorite is lower in Si,alkai,DI,Eu,Rb,Ta,Th and Rb/Sr,but higher in ∑REE,∑LREE,Nb/Ta and Zr/Hf, and richer in Cr, Zn, Sr, Zr, Ba and Hf. A continuous differentiation ternd is exhibited from granodiorite to monzogranite. Based on geological setting and geochemical characteristics, it is showed that Baitutan granitic complex is high-K calc-alkaline 1 I-type granites, the source material is aqueous, alkaline and high-K calc-alkaline andesite and basaltic andesite. It is produced in a trsnsitional tectonic setting from continental collision tectonic environment of orogenic epoch to post-collisonal.