朱光, 胡召齐, 陈印, 牛漫兰, 谢成龙. 华北克拉通东部早白垩世伸展盆地的发育过程及其对克拉通的破坏[J]. 地质通报, 2008, 27(10): 1594-1604.
    引用本文: 朱光, 胡召齐, 陈印, 牛漫兰, 谢成龙. 华北克拉通东部早白垩世伸展盆地的发育过程及其对克拉通的破坏[J]. 地质通报, 2008, 27(10): 1594-1604.
    ZHU Guang, HU Zhao-qi, CHEN Yin, NIU Man-lan, XIE Cheng-long. Evolution of Early Cretaceous extensional basins in the eastern North China craton and its destruction of the craton[J]. Geological Bulletin of China, 2008, 27(10): 1594-1604.
    Citation: ZHU Guang, HU Zhao-qi, CHEN Yin, NIU Man-lan, XIE Cheng-long. Evolution of Early Cretaceous extensional basins in the eastern North China craton and its destruction of the craton[J]. Geological Bulletin of China, 2008, 27(10): 1594-1604.

    华北克拉通东部早白垩世伸展盆地的发育过程及其对克拉通的破坏

    Evolution of Early Cretaceous extensional basins in the eastern North China craton and its destruction of the craton

    • 摘要: 在晚侏罗世华北克拉通东部破坏之初出现了区域性隆起,全区缺失上侏罗统沉积。在早白垩世早期,出现了区域性的伸展活动,断陷盆地形成,克拉通南、北缘伸展活动最强,北部燕山构造带以出现变质核杂岩为特征,南部出现宽裂谷型盆地。早白垩世中期华北克拉通东部普遍出现了火山活动与岩浆侵入。早白垩世晚期克拉通上以出现窄裂谷型盆地为特征,沿北北东走向的郯庐断裂带断陷活动最强。这些断陷盆地的演化过程揭示,经历地表抬升后,克拉通破坏之初的岩石圈热而弱,从而形成变质核杂岩或宽裂谷型盆地。这期间的破坏强度在空间上具有不均匀分布的特征,受控于早期岩石圈地幔的结构。经过早白垩世中期的大量岩浆活动之后,早白垩世晚期克拉通岩石圈温度降低、强度变大,从而利用早期大型断裂构造形成窄裂谷型盆地。这现象支持华北克拉通东部晚中生代的岩石圈减薄是以逐渐拆沉机制为主。

       

      Abstract: Regional uplift occurred at the initial stage of destruction in the Late Jurassic eastern North China craton and Upper Jurassic deposits are absent in the whole area. In the early part of the Early Cretaceous, regional extension occurred and downfaulted basins formed, with the northern and southern margins of the craton showing more intense extension. The Yanshan structural belt on the northern margin is characterized by formation of metamorphic core complexes while the southern margin was occupied by wide rift-type basins. Volcanic eruption and magmatic intrusion commonly took place in the area in the middle Early Cretaceous. Narrow rift-type basins occurred in the craton in the late Early Cretaceous, and downfaulting along the NNE-trending Tan-Lu fault zone was most intense. The evolution of these downfaulting basins demonstrates that after surface uplift the craton lithosphere was hot and soft in the initial stage of the destruction, leading to development of metamorphic core complexes and wide rift-type basins. The destruction intensity shows inhomogeneous distribution and might be controlled by pre-existing lithospheric mantle structures in the early stage. In the late Early Cretaceous, the temperatures of the lithosphere under the craton decreased and the destruction intensity became high after the middle Early Cretaceous magmatic activities, which is responsible for development of narrow rift-type basins along pre-existing fault zones. The basin evolution processes support the view that the Late Mesozoic lithospheric thinning of the eastern North China craton was mainly caused by the mechanism of gradual delamination.

       

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