摘要
Two types of granitic intrusives occur in the lower Paleozoic strata in north Qilian. One is the hornblende- bearing granitic body in Jingzichuan, characterized by the REE total of 90×10-6-106×10-6, LREE/HREE ratio of less than 8 (ranging from 6.9 to 7.8) and zircon SHRIMP age of 464 Ma. These intrusives have island-arc affinity. The other is biotite-bearing granitic body in Huangyanghe with the REE total of 214×10-6-250×10-6, LREE/HREE ratio of more than 8 (ranging from 8.2 to 9.7) and zircon LA-ICP-MS age of 383 Ma. They were tectonically intruded in a post-collisional or within-plate environment.
Two types of granitic intrusives occur in the lower Paleozoic strata in north Qilian. One is the hornblende- bearing granitic body in Jingzichuan, characterized by the REE total of 90×10-6-106×10-6, LREE/HREE ratio of less than 8 (ranging from 6.9 to 7.8) and zircon SHRIMP age of 464 Ma. These intrusives have island-arc affinity. The other is biotite-bearing granitic body in Huangyanghe with the REE total of 214×10-6-250×10-6, LREE/HREE ratio of more than 8 (ranging from 8.2 to 9.7) and zircon LA-ICP-MS age of 383 Ma. They were tectonically intruded in a post-collisional or within-plate environment.
基金
the NationalNatural Science Foundation of China(Nos.40472034 ,49732070)
Chinese National Key Project for Basic Research(2003CB716500)
National 973 Project(G1988040800)
China Geological Survey Project(200313000058).
