华北克拉通怀安县西洋河地区高压基性麻粒岩锆石U-Pb同位素年龄及地球化学特征  

Geochemical Characteristics and Zircon U-Pb Isotope Age of the High-pressure Basic Granulite in the Xiyanghe Area of the North China Craton

作　　者：侯红星 张蜀冀 胡新茁 张中跃 邵兴坤 HOU Hongxing;ZHANG Shuji;HU Xinzhuo;ZHANG Zhongyue;SHAO Xingkun(Langfang Natural Resources Comprehensive Survey Center,China Geological Survey,Langfang,065000,Hebei,China)

机构地区：[1]中国地质调查局廊坊自然资源综合调查中心,河北廊坊065000

出　　处：《西北地质》2022年第4期240-254,共15页Northwestern Geology

基　　金：中国地质调查局项目“西北沿边及特殊地区地质矿产调查”(DD20160079)资助。

摘　　要：华北中北部出露的高压麻粒岩对研究华北克拉通新太古代—古元古代构造演化具有重要意义。笔者通过对怀安县西洋河地区怀安杂岩中新发现的高压基性麻粒岩的地质、地球化学特征、变质作用及锆石U-Pb同位素年龄研究和讨论,确定研究区高压基性麻粒岩原岩为基性岩浆源(辉长岩或玄武岩),具有MORB型玄武岩地球化学特征,形成年龄早于2162 Ma;岩石主要经历了峰期高压麻粒岩相变质作用和后期退变质作用的改造;峰期平均变质年龄为1925 Ma,后期退变质年龄为1865 Ma;反映了新太古代-古元古代碰撞造山过程,为研究华北克拉通构造演化提供了新的证据。The high-pressure granulite exposed in the north-central part of north China is of great significance to the study of the Neo-Archaean-Palaeoproterozoic structural evolution of the north China craton.This thesis researched and discussed the geological,geochemical,metamorphic and U-Pb isotope ages of zircon in high pressure basic granulite,which newly discovered in the huaian complex in the xiyanghe area of huaian county.Though it,we concluded that the high pressure basic granulite was determined to be a basic magmatic source(gabbro or basalt),which has the geochemical characteristics of MORB type basalt,and its formation age was earlier than 2162 Ma.The rock has mainly undergone the geological transformation of high-pressure granulite facies metamorphism in the peak period and metamorphism in the later period,and with metamorphic ages of 1925 Ma and 1865 Ma respectively,which reflected the Neoarchean-Palaeoproterozoic collision orogenic process and provided new evidence for studying the structural evolution of the North China Craton.

关 键 词：华北克拉通 高压基性麻粒岩 同位素 地球化学 西洋河 

分 类 号：P597.3[天文地球—地球化学]