Geochemical Features and Petrogenesis of Houcheng Mafic Dyke in Hebei: Evidence from Major and Trace Elements
详细信息
- 责任者：Yang Yuhong (State Key Laboratory of Ore Deposit Geochemistry ; Institute of Geochemistry ; Chinese Academy of Sciences ; Guiyang 550002 ; China) ; Liu Shen
- 刊名：Geological Bulletin of China
- 出版年：2013
- 卷期：32(4)
- 关键词：岩墙群 ; dyke swarms ; 基性岩 ; basic rocks ; 河北 ; Hebei Province
- 页码：p.607-616
- 图表：illus., 2 tables, 33 refs.
- 分类号：0801
- issnNo：ISSN1671-2552
- isbnNo：CN11-4648/P
摘要
Systemic studies of major elements and trace elements of the mafic dyke from Houcheng in Hebei Province indicate that SiO2=47.07%~50.28%,Na2O+K2O of the mafic dyke vary from 2.83% to 3.75%,LREE((La/Yb)N=4.40~4.86),with the enrichment of LILE(Rb,Th and U) and depletion of HFSE(Nb and Ta).The geochemical features of the mafic dykes show that they were derived from an intraplate extensional setting and experienced fractional crystallization of olivine +pyroxene +hornblende +biotite during the magmatic evolution.In addition,the La/Sm,Ta/La and Nb/La ratios suggest indistinct crustal contamination during the upward migration of the magma.Based on the ratios of trace elements and REE,the authors hold that the magma source belonged to transitional mantle.The parental magma of the maific dykes was formed in the garnet+spinel mantle with 10%~20% partial melting;moreover,the magma came from about 75km lithosphere mantle.