北京周口店岩体地球化学特征及物源分析  

Geochemical characteristics and genesis of Zhoukoudian complex

作　　者：张丽芬[1] 曾夏生 张树明[3] 

机构地区：[1]中国地震局地震研究所,湖北武汉430071 [2]湖北中南勘察基础工程有限公司,湖北武汉430081 [3]东华理工学院

出　　处：《岩石矿物学杂志》2006年第6期480-486,共7页Acta Petrologica et Mineralogica

基　　金：国家自然科学基金重点资助项目(40133020)

摘　　要：通过对周口店岩体地球化学特征和构造环境及其与埃达克岩对比的分析,发现该岩体具有C型埃达克岩的地球化学特征。143Nd/144Nd87Sr/86Sr图解发现该岩体的锶、钕同位素投影点均落在EMⅠ型富集地幔区域内,表明其物质来源与EMⅠ型富集地幔有关。而εNd(t)ISr图解中,其投影点正好落在汉诺坝二辉麻粒岩包体范围内(汉诺坝二辉麻粒岩包体是幔源基性岩浆在晚古生代—中生代底侵到下地壳底部构成的年轻下地壳的一部分)。由此推测认为,周口店岩体是中生代新增生的华北克拉通下地壳的部分熔融的产物。Based on geochemical characteristics and tectonic setting of intrusive rocks in Zhoukoudian complex and a comparison with adakites, the authors have revealed that these intrusive rocks are similar to adakites in petrological and geochemical characteristics. ^143Nd/^144Nd-^87Sr/^86Sr diagram shows that the projections are in the EM I -rich mantle region, suggesting that their material sources are related to EM I irich mantle. Besides, εNd（ t ）- ISr figure proves that the projections are within granulites and pyroxenite xenoliths in Hannuoba basalts. Further research indicates that Zhoukoudian complex was formed by partial melting of young lower crust in the North China craton in Mesozoic.

关 键 词：埃达克岩 地球化学 成因 周口店岩体 

分 类 号：P588.12[天文地球—岩石学] P581[天文地球—地质学]