摘要
本文报导了鲁东蓬莱地区五里桥—赤山剖面和鲁西临朐地区鹁鸽山—角页山—尧山剖面新生代大陆碱性玄武岩主要元素和稀土等25种痕量元素的含量。与海洋玄武岩化学体系对照,讨论了鲁东和鲁西玄武岩的成因及其地幔源区的特征。石榴石橄榄岩型地幔的部分熔融和镁铁矿物的结晶分异在两地玄武岩形成中有重要作用。鲁西玄武岩的地幔源区较鲁东的相对富Mg而贫Fe、Na、K和P,富相容元素Ni、Cr、V和Sc,贫不相容元素LREE、Sr、Zr和Nb。鲁东玄武岩的地幔源区曾在近期内发生过交代作用。
The marjor and trace element (REE, Rb, Nb, Sr, Zr, Zn, Y, Cr, V, Ni, Sc) abundances of 19 samples for Cenozoic continental akalic basalts from the Penglai and Lingju areas, Shandong Province, are reported in the papei. In comparison with the geochemistry of oceanic basalts, the petrogenesis of basalts from Shandong and their geochemical characteristics of mantle sources are discussed.The Cenozoic alkalic basalts distributed over the Penglai and Lingju areas consist of olivine nephelinite, bas-mite and alkali olivine basalt in terms of the CIPW classification. Part of lavas incorporate ultramafic mantle xenoliths and rnegacrysts.The basalts in the Penglai area were prabably derived from a fairly homogeneous mantle source developing in a closed system. The contributions of partial melting and fractional crystallization of mainly olivine in the petrogenesis of hasalts from eastern Shandong are very important. The mantle from which basalts were derived had underwent metasomatism before melting.The contrbutions of partial melting and fractional crystllization of mainly pyroxene are also important in the petrogenesis of basalts from the Lingju area, western Shandong in the view of trace element geochemistry.
出处
《地质论评》
CAS
CSCD
北大核心
1990年第5期385-393,共9页
Geological Review
