Zircon U-Pb Ages and Geochemistry of Volcanic Rock from Linzizong Group in Zhunuo Area in Middle Gangdise Belt, Tibet Plateau
LIANG Yin-ping
ZHU Jie
CI Qiong
HE Wei-hong
ZHANG Ke-xin
Abstract：The Paleogene volcanic rock in Linzizong Group is developed in the Gangdise belt, southern Tibet plateau and it is deemed to represent the result of Neo-Tethys from its subduction to the India-Asia collision. Its precise age is significant to constrain the time of the India-Asia collision. Herein a systematic study, including zircon U-Pb ages, major and trace elements and Sr-Nd isotopic geochemistry, has been done to volcanic rock from Linzizong Group in Zhunuo area in middle Gangdise belt.We obtain Linzizong Group volcanic rock LA-ICP-MS zircon U-Pb data showing the following ages: the Dianzhong Formation,64. 8±1.6 Ma, the Nianbo Formation, 59. 7±1.8 Ma, the Pana Formation, 48. 9±0. 8 Ma. The data of elementary and isotopic geochemistry suggest that the characteristics of these formations in Zhunuo area are similar to regional characteristics. Among them, Dianzhong and Nianbo formations are calc-alkalic and high-K calc-alkalic rocks with characteristics of arc-island volcanic rocks. Pana Formation contains shoshonite and is syn-collision volcanic rock. It is proved that suture of the Yarlung Zangbo oceanic basin and the beginning of collision between India and Asia were about 50 Ma.
Keywords：zircon U-Pb agegeochemistryLinzizong Group volcanic rockmiddle Gangdise belt.
Publication Date：2010-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：13( 211-223 )