鞍山小岭子花岗岩地球化学及锆石SHRI MP年代学

Geochemistry and zircon SHRIMP U-Pb chronology of Xiaolingzi granite in the Anshan area

鞍山小岭子花岗岩岩浆锆石离子探针年龄为130.2±2.7Ma,形成于早白垩世。小岭子花岗岩高SiO2、Na2O+K2O、TFeO/MgO,富集轻稀土元素和高场强元素Zr、Nb、Y,低CaO、Ba、Sr,地球化学组成与该区大范围分布的千山花岗岩十分相似,具A型花岗岩特征,其形成与古太平洋板块俯冲至中国大陆东部之下引起的拉张有关。

Zircon SHRIMP U_Pb age dating indicates that the Xiaolingzi granite in the Anshan area was emplaced during Early Cretaceous(130.2±2.7 Ma). It is enriched in SiO_2, Na_2O+K_2O, TFeO/MgO, LREE, Zr, Nb and Y, and depleted in CaO, Ba and Sr, thus similar to the widely distributed Qianshan granite with the geochemical characteristics of A type granite in this area. It is suggested that the magmatic activity was related to an extension following the subduction of the paleo_Pacific Plate beneath eastern China.