Geochemical Characteristics and Origin of the Wangpingshi Syenogranite in Xinglong County, Hebei Provience

• 责任者：Li Xiaowei (School of Earth and Space Sciences ; Peking University ; Beijing 100871 ; China) ; Mo Xuanxue
• 刊名：Acta Geologica Sinica
• 出版年：2010
• 卷期：84(5)
• 关键词：正长花岗岩 ; syenogranite ; 岩石地球化学 ; lithogeochemistry ; 河北 ; Hebei Province
• 页码：p.682-693
• 图表：13 illus., 8 tables, 39 refs.
• 分类号：0801
• issnNo：ISSN0001-5717
• isbnNo：CN11-1951/P

Wangpingshi syenogranite intrusion is characterized by 1) supersaturation of silica with concentrations of SiO₂ ranging from 73% to 76% and existence of quartz); 2) from meta-aluminous to pera-aluminous (Al₂O₃=12.48%～14.23%); and 3) alkali-rich (Na₂O+ K₂O=7.83%～9.41%). The rocks is relatively low in the total rare earth element concentrations (ΣREE)((54.41～140.21)×10^-6), enrichment in LREE and depletion in HREE.The primitive mantle-normalized trace element spiderdiagram exhibits strong LILE (K, Pb)and strong incompatible element (Rb, Th, U) enrichment, and other LILE(Ba, La, Ce)and HFS (Nb,Ta,P,Ti) depletion. The feature values of Sr-Nd isotope have relatively low initial ⁸⁷Sr/⁸⁶Sr values (0.70 498～0.70 503) and negative εNd(t)values (-10.9‰～-12.1‰),which indicates that the source of syenogranite are mainly old metamorphic rocks (metagraywacke) of lower crust with contamination of mantle end member.