• 责任者：Liu Jianqing (Chengdu Institute of Geology and Mineral Resources ; Chengdu 610082 ; China) ; Xie Yuan
• 刊名：Earth Science Frontiers
• 出版年：2013
• 卷期：20(5
• 关键词：SHRIMP定年 ; SHRIMP dating ; 裂变径迹计时 ; fission-track dating ; 花岗岩 ; granite ; 湖南 ; Hunan Province
• 页码：p.25-35
• 图表：9 illus., 2 tables, 51 refs.
• 分类号：0801
• issnNo：ISSN1005-2321
• isbnNo：CN11-3370/P

     The SHRIMP U-Pb zircon and apatite fission track chronologic characteristics and its geotectonic significance of Baimashan granite are first studied in this paper. The SHRIMP dating results show that there was no magma activity during the Caledonian period in the Xuefengshan area, and that the granite mainly formed from the Indosinian to the early Yanshan movement （the data of the measured points centralized from 219.3±5.2 Ma to 176±4.4 Ma）, with feeble activity from the middle- to the late-Yanshan （some data of the measured points scattered in the range from 219.3±5.2 Ma to 176±4.4 Ma）, which was the result of crust plying and partially melting. This granite has obviously undergone hot fluid activity since the late-Yanshan with less upheaval （the apatite fission track dating ranging from 53.8±5.4 Mato 91.5±4.6 Ma）. Furthermore, combined with the study of the geological feature of the Xuefengshan area and regional tectonic characteristics, it is suggested that the above-mentioned data are consistent with the tectonic background during the late Indosinian to the early Jurassic, i. e. , at the transition from the close of the Tethys Sea to the subduction of the Paleo-Pacific plate. There have been five ~tectonie movements since the [ndosinian in the Xuefengshan area, including the late-lndosinian, the early-Yanshan, the middle-Yanshan, the late-Yanshan, and the early-Himalayan. The late-Indosinian movement in this area was related to the close of the Tethys Sea and the collision of the Indosinian plate to the Huanan plate. Since the early-Yanshan, the tectonic evolution in this area was under the control of the Paleo-Pacific plate subduction, manifesting the spatial-temporal differences, as the tectonic extrusion and thrust, or as the tectonic extension.