地质学报2018，Vol.92Issue(5)：908-927,20.
夹皮沟片麻杂岩对吉林南部地区太古宙地壳演化的制约——来自岩相学、地球化学、锆石U-Pb年代学方面的证据
Constraints of the Jiapigou Gneiss Complex over Evolution of the Archean Terrain in Southern Jilin Province: Evidence from Petrography Geochemistry, and U-Pb Chronology Analysis
摘要
Abstract
The southern Jilin district is an important place in the northern margin of North China Craton (NCC),where the Archean is exposed.In order to study the tectono-magmatic thermal event of the NCC during Late Archean and the formation and evolution of the Early Precambrian continental crust,this study chose TTG gneisses of the Jiapigou complex as the research objective.The results show that the gneisses are characterized by high Al (Al2O3 =14.97％～16.28％) and high Na (Na2O=3.73％～4.54％),and poor Mg (MgO=1.96％～2.56％) with an average Mg index (Mg#) of 43;enrichment of LREE and depletion of HREE,without obvious Eu anomaly;enrichment of LILE {Sr(358 × 10-6～ 1114 × 10-6) and Ba (613×10-6～1200×10-6)},and depletion of HFSE {Nb(6.39× 10-6 ～11.2×10-6) and Ta (0.384× 10-6～0.679×10-6)},with low Yb (1.17×10-6～1.89×10-6) and Y (9.93×10-6～19.3×10-6) and very high Sr/Y ratio (36.0～57.7).These geochemical features show that the main residual phase contains garnet,amphibole and Ti-bearing minerals in the source,indicating that the gneiss should belong to the highpressure TTG series.LA-ICP-MS zircon U-Pb age data indicate that the rocks formed in the nearly 2509 Ma,suggesting that they were the result of the Late Archean.Combined with previous geochemical research of TTG gneiss and the data of Nd model ages,this period magma events may represent the remelting of older ancient crustal materials (～2.8 Ga).The study of petrography and zircon morphology shows that the area has experienced multiple metamorphism,among which the 2509 Ma high-degree metamorphism was coeval with magmatic event,likely related to underplating of mantle-derived magmas in the setting of mantle plumes.关键词
夹皮沟片麻岩/TTG/地壳再造/～2.5Ga岩浆热事件/吉林南部Key words
Jiapigou complex/TTG/crustal reworking/～2.5 Ga magmatic event/southern Jilin Province引用本文复制引用
宋健,刘志宏,王超,高翔,孙理难..夹皮沟片麻杂岩对吉林南部地区太古宙地壳演化的制约——来自岩相学、地球化学、锆石U-Pb年代学方面的证据[J].地质学报,2018,92(5):908-927,20.基金项目
本文为中国地质调查局工作项目(编号1212011085484) （编号1212011085484）
国家自然科学基金项目(编号41072150)联合资助成果. （编号41072150）
