摘要
Field observation, petrological and geochemical characteristics of plagiogranite from Kuerti ophiolite indicate a similar origin to those in shearing zones. It isderived from partial melting of amphibolite that is developed from gabbro within the ocean layer 3 shear zone by the low-angle shearing deformation during the oceanic crustmigrating process. Zircon SHRIMP age of 372±19 Ma for the plagioganite from Kuerti ophiolite indicates that thisophiolite formed in the Devonian period and it alsorepresented the time of extension of the Kuerti backarc basin that is relevant to the northwards subduction of thePaleo-Asian oceanic crust. Therefore, the northwardssubduction of the Paleo-Asian Ocean beneath the Siberian Plate began in the early stage of the Late Paleozoic era.
Field observation, petrological and geochemical characteristics of plagiogranite from Kuerti ophiolite indicate a similar origin to those in shearing zones. It isderived from partial melting of amphibolite that is developed from gabbro within the ocean layer 3 shear zone by the low-angle shearing deformation during the oceanic crustmigrating process. Zircon SHRIMP age of 372±19 Ma for the plagioganite from Kuerti ophiolite indicates that thisophiolite formed in the Devonian period and it alsorepresented the time of extension of the Kuerti backarc basin that is relevant to the northwards subduction of thePaleo-Asian oceanic crust. Therefore, the northwardssubduction of the Paleo-Asian Ocean beneath the Siberian Plate began in the early stage of the Late Paleozoic era.
基金
supported by the State Key Basic Research Development Program(Grant No.2001CB409805)
the National Natural Science Foundation of China(Grant No.40073006).
