鲁西前寒武纪基性岩墙群  

The Precambrian Basic Dyke Swarms in the Western Shandong Province

作　　者：侯贵廷[1] 李江海[1] 金爱文[2] 钱祥麟[1] 

机构地区：[1]造山带与地壳演化教育部重点实验室 [2]山东科技大学地学院,泰安271019

出　　处：《地质学报》2005年第2期190-199,i003,共11页Acta Geologica Sinica

基　　金：国家自然科学基金项目 (编号 40 172 0 66;40 3 14 14 1)资助的成果

摘　　要：鲁西地区发育大规模的中元古代基性岩墙群,侵位于早前寒武纪结晶基底内,未变形未变质,以北北西向和近南北向为主,是鲁西前寒武纪最引人注目的一种伸展构造标志。鲁西基性岩墙群属于板内大陆裂谷拉斑玄武岩系列,与板内大陆裂谷活动密切相关,代表一种非造山岩浆活动。该岩墙群富集大离子亲石元素(L IL E) ,略亏损高场强元素(HFSE) ,比较富集Cr、Ni,明显亏损Th。稀土元素配分模式为轻稀土略富集的右倾曲线。鲁西基性岩墙群的微量元素和稀土元素特征反映源区为略富集的地幔。从时空分布特征、构造特征、岩石化学相关性、岩浆源区和古构造应力场分析,鲁西基性岩墙群与燕辽—中条拗拉槽系有一定的成生联系。A lot of Meso-Proterozoic undeformed and unmetamorphic NW-trending or N-trending mafic dyke swarms develop in the western Shandong, which are conspicuous extensional structures emplacing into Early Precambrian crystal basement. The mafic dyke swarms in the western Shandong are an unorogenic igneous activity as the tholeiite series basalt in the intraplate continental rift environment relative to the continental rifting. The dyke swarms are enriched in LILE, relatively depleted in HFSE, enriched in Cr and Ni and intensively depleted in tholeiite. The mode of REE with enriched LREE is right-dip curve. The trace elements and rare earth elements show that the magma source of the mafic dyke swarms in the western Shandong are from enriched mantle.The mafic dyke swarms in the western Shandong is with the original relation to the Yanliao—Zhongtiao aulacaogens based on the distribution, structural character, geochemistry,magma sources and paleotectonic stress field.

关 键 词：鲁西地区 寒武纪 基性岩墙群 伸展构造标志 玄武岩 非造山岩浆活动 

分 类 号：P588.124[天文地球—岩石学]