CAJ | 학술논문

内蒙古中部毫义哈达岩体位于华北板块北缘陆缘增生带,通过对该岩体进行系统的年代学与地球化学研究表明,毫义哈达岩体是由辉石闪长岩类构成.在对两个样品中的锆石进行LA-ICP-MS U-Pb定年,结果(加权平均年龄)均为266±2 Ma,表明岩体的形成时代为晚二叠世.对14个样品进行主量元素和微量元素分析,表明岩体属钙-碱性系列; Eu有一定程度的负异常,富集大离子亲石元素Rb、Sr及轻稀土,亏损高场强元素Nb、Ta,富Cu、Cr等过渡元素.岩体在地球化学上还具有岛弧火山岩的特征,推测其岩浆源区曾遭受过古亚洲洋板片流体交代.依据区域构造演化,推测毫义哈达岩体侵位于造山后伸展环境,成岩物质来源于上地幔并且发生了结晶分离作用.地球化学的特征以及在该岩体发现的铜钨矿化,预示着该地区将是一个有利的成矿远景区.
내몽고중부호의합체암체위우화북판괴북연륙연증생대,통과대해암체진행계통적년대학여지구화학연구표명,호의합체암체시유휘석섬장암류구성.재대량개양품중적고석진행LA-ICP-MS U-Pb정년,결과(가권평균년령)균위266±2 Ma,표명암체적형성시대위만이첩세.대14개양품진행주량원소화미량원소분석,표명암체속개-감성계렬; Eu유일정정도적부이상,부집대리자친석원소Rb、Sr급경희토,우손고장강원소Nb、Ta,부Cu、Cr등과도원소.암체재지구화학상환구유도호화산암적특정,추측기암장원구증조수과고아주양판편류체교대.의거구역구조연화,추측호의합체암체침위우조산후신전배경,성암물질래원우상지만병차발생료결정분리작용.지구화학적특정이급재해암체발현적동오광화,예시착해지구장시일개유리적성광원경구.
The Haoyihada intrusive body,which occurred in the continental margin accretion belt along the north margin of North China Plate in the middle region of Inner Mongolia,is composed the pyroxene diorite. With isotopic dating and geochemical research,the zircon LA-ICP-MS U-Pb dating of two samples yields an age of 266±2 Ma,failing into the range of late Permian Epoch. The geochemical characteristics of 14 samples are as follows,the pyroxene diorite shows low-SiO_2(47.87～56.17 wt%),high-Mg(3.65～6.79 wt%),also higher large-ion lithophile element of Rb,Sr and LREE,low high-field strength elements of Nb,Ta,high-Cu(35.97×10~(-6)～112.24×10~(-6)),REE patterns have negative Eu anomalies. It is suggested that the Haoyihada intrusive body should be among the calc-alkaline series,has the tectonic background of island-arc and its materials mainly derived from upper mantle and had fractional crystallization. The geochemical characteristics and the strong mineralization of Cu and W of Haoyihada intrusive body prefigured that the potential of ore prospecting and exploration is great in this area.