| 拉萨地块林芝杂岩体石榴角闪岩的地球化学特征和年代学研究 |
| |
| 关键词:garnet amphibolite metamorphism chronology Lhasa Block |
| 基金项目:国家自然科学基金青年基金(编号: 41202034);面上项目(编号: 41572051);中国地质调查工作项目(编号: 12120115026801);中国地质科学院地质研究所基本科研业务费项目(编号: J1518) |
|
| 摘要点击次数: 3801 |
| 全文下载次数: 2137 |
| 摘要: |
| A Study of Geochemistry and Chronology of Garnet Amphibolite from the Nyingchi Complex in the Lhasa Terrane |
| In this paper, the authros studied the geochemistry and chronology of garnet amphibolites distributed in the Nyingchi region within the southeastern segment of Lhasa terrane. The studied samples consist of staurolite-bearing garnet amphibolites and quartz-bearing garnet amphibolites, which experienced the high-pressure amphibolite facies metamorphism. The staurolite-bearing garnet amphibolite has a mineral association of garnet, amphibole, staurolite, chlorite, plagioclase, mica and minor ilmenite and apatite. The quartz-bearing garnet amphibolites has a mineral assemblage of quartz, garnet, and amphbolite. Petrological and geochemistry studies show that the protoliths of the garnet amphibolites are characterized by MORB affinity. Detrital zircons from the paragneiss yielded a 206Pb/238U age range of 800~202 Ma. With main populations at ~430 Ma, ~268 Ma, and ~216 Ma. ~268 Ma and ~216 Ma metamorphic ages are related to the HP metamorphism of the Lhasa Block. ~268 Ma age is similar to the age of peak metamorphic eclogite in Sumdo, and ~216 Ma is similar to the age of the garnet-bearing schist, i.e., the host rock of eclogite. In combination with regional chronology of Lhasa Block, the authors hold that the Nyingchi Complex not only experienced the metamorphism and magmatic activities in Cenozoic but also experienced the UHP metamorphism in Permian and the HP metamorphism in Triassic following the closure of the Paleo-Tethyan Ocean and the collision between the south Lhasa terrane and the north terrane. |
| HUANG Jie,ZHANG Cong,YANG Jing-sui,LI Peng,WANG Shu.2016.A Study of Geochemistry and Chronology of Garnet Amphibolite from the Nyingchi Complex in the Lhasa Terrane[J].Acta Geoscientica Sinica,37(6):711-722. |
| 查看全文 查看/发表评论 下载PDF阅读器 |
|
|
|
|
|