地质学报2016，Vol.90Issue(4)：769-784,16.
江西相山酸性火山－侵入杂岩体地球化学特征与岩石成因
Geochemical Characteristics and Petrogenesis of the Acidic Volcano-intrusive Complexes,Xiangshan,Jiangxi
摘要
Abstract
The Xiangshan volcanic basin comprises volcano-intrusive complexes that are composed of tuff, rhyolite dacite,porphyry rhyolitic dacite,porphyroclastic lava,coarse grained porphyry and porphyritic granite.The paper discussed the origin and evolution of these igneous rocks based on their whole rock major and trace elements,as well as Pb-Sr-Nd isotopes.Different lithologies have similar elemental and isotopic compositoins,indicating that they were derived from the same source region.The rocks are rich in silicon and alkali,low in calcium and magnesium.LREE and HREE differentiate significantly,REE distribution curve presents four component model and obvious negative Eu.Nd model ages (T 2DM )of rhyodacite,Porphyroclastic Lava, rough spots granite porphyry and porphyritic granite is closer, respectively 1.67Ga,1.66Ga,1.66Ga and 1.63Ga,slightly lower than the residual zircon 207 Pb/206 Pb age (1787.9Ma)and the the oldest rocks exposed (amphibolite)of Cathaysian Block within the magmatic zircon SHRIMP U-Pb age of (1766 ± 19Ma).There is a negative correlation between SiO2 and P2 O5 , combining the facieology and the two element mixed mode petrography of Sr-Nd,calculating that the material source of the complexes has a small amount of mantle source involved,the average content of 22.82%.;each sub cycle between the different rock types with diagenesis sequence,Na2 O and K2 O increased,but SiO2 content decreased gradually,may indicate that the magma has occurred in the differentiation of normal. acidic component is on the upside, and the partial distribution of basic components at the bottom,at the end of the first sub cycle or timeout period,acidic component join in the magma.The first subcycle variation degree is strong,the separation of plagioclase and potash feldspar,at the second sub cycles,mainly potassium feldspar.At the late Yanshan,Jiangxi in the dynamic background of the earth is different,gradually evolved into intra plate rift trend from south to north.In 141Ma ~132Ma the Xiangshan area is post orogenicr,in the vicinity of 125Ma gradually evolved into an intraplate rift environment.关键词
Pb-Sr-Nd 同位素/火山-侵入杂岩体/岩石成因/构造背景/江西相山Key words
Pb-Sr-Nd isotope/volcano-intrusive complexes/Petrogenesis/Tectonic setting/Xiangshan,Jiangxi引用本文复制引用
郭福生,杨庆坤,孟祥金,谢财富,时国,陈留勤,蒋振频,曾涛,罗能辉..江西相山酸性火山－侵入杂岩体地球化学特征与岩石成因[J].地质学报,2016,90(4):769-784,16.基金项目
本文为国家自然科学基金项目（编号41572185）、中国地质调查局项目（编号1212011220248，1212011120836）、江西省“赣鄱英才555工程”领军人才培养计划项目（赣才字［2012］1号）和放射性地质与勘探技术国防重点学科实验室开放基金项目（RGET1402）联合资助的成果。 （）
