An early aged ophiolite in the Western Kunlun Mountain, northwestern Tibet plateau and its tectonic implications
会议名称：《2004年全国岩石学与地球动力学研讨会》
会议日期：2004年
学科分类：0709[理学-地质学] 070901[理学-矿物学、岩石学、矿床学] 07[理学]
摘 要：正 The early aged ophiolites have attracted the studying from many geologists in recent decades （Colombo C. G. et al, 2001, Scarrow J. H. et al., Timothy M. Kusky et al., 2001.....）, because the early aged ophiolites can provide the information about the ancient oceanic processes relevant to the evolution of the plate tectonics in the early period of the earth, and also concem such problems as whether there existed a Protero-Tethys and the break-up and convergence of the Rodinia Supercontinent in the NW Tibet plateau. This paper reveals a definite complete ophiolite, the Kudi- ophiolite of late-Proterozoic-early Paleozoic, in the Westem Kunlun Mtns, NW. Tibet plateau, and reports the recent isotopic ages of 510±4Ma. And 502±13Ma （U-Pb ratio in zircon） for the middle and upper portions of the mafic cumulates of the Kudi-ophiolite, operated at the most powerful dating tool, the SHRIMP-Ⅱ. The geochemical and geochronological data integrating with the geological setting suggest that the Kudi-ophiolite might have formed in an Archipelago not in a vast oceanic basin, the so-called Protero-Tethys, and was tectonically emplaced during the early Paleozoic in the NW. Tibet plateau.