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应用地质、地球化学及地球物理3个方面已有的研究结果, 探讨大别-苏鲁造山带碰撞后岩石圈拆离发生的可能性及发生时代. 大别山超高压变质(UHPM)岩第1次快速冷却时代(226～219 Ma)与秦岭-苏鲁地区同碰撞花岗岩年龄(220～205 Ma)的一致性, 说明UHPM岩石第1次快速抬升与俯冲板块断离有关. 因此它们的第2次快速抬升(180～170 Ma)需要碰撞后的岩石圈拆离, 同时导致大别山170 Ma左右的岩浆事件. 此外, 早白垩世(130～110 Ma)大别山穹隆的迅速隆升及相对应的大规模岩浆事件也需要另外一次岩石圈拆离. 碰撞后幔源镁铁-超镁铁岩侵入体的同位素年代学及相互关系的研究表明, 大别-苏鲁造山带碰撞后的早白垩世大规模岩浆事件源于深部软流圈地幔上涌. 辉石-辉长岩随MgO降低, SiO2也下降的分离结晶演化趋势, 及典型的下地壳地球化学特征表明, 这一幔源岩浆在侵入地壳之前曾经历过岩浆的板底垫托(underplating)过程及与下地壳相互作用. 岩石圈拆离可能是引发造山带碰撞后地幔上涌及岩浆板底垫托事件的原因. 大别-苏鲁造山带的地震层析结果显示, 大别山南北两侧岩石圈均已显著减薄. 除合肥盆地靠近郯庐断裂部分的岩石圈减薄可能与新生代玄武岩事件有关系外, 因为大别山缺乏新生代玄武岩事件, 大别山区的岩石圈减薄可能主
Based on the existing research results of geology, geochemistry and geophysics, the possibility of the detachment of the lithosphere after the collision of the Dabie-Sulu orogenic belt and its occurrence times are explored.The first UHPM rocks in the Dabie Mountains The agreement between the rapid cooling age (226-219 Ma) and the collisional granite age (220-205 Ma) in the Qinling-Sulu region indicates that the first rapid uplift of the UHPM rock is related to the break-off of the subducted slab. Therefore, The rapid uplifting (180-170 Ma) requires the detachment of the lithosphere after the collision and the magmatic event of about 170 Ma in the Dabie Mountains.In addition, the rapid uplifting of the Dabie dome in the Early Cretaceous (130-110 Ma) and the corresponding large-scale The magmatic events also need another lithosphere detachment.The isotope chronology and correlation of the mantle-derived mafic-ultramafic intrusions after the collision show that the Cretaceous after the collision of the Dabie-Sulu orogenic belt was large-scale The magmatic events originated from the upwelling of the mantle in the deep asthenosphere.The evolution trend of pyroxene-gabbro decreases with the decrease of MgO and SiO2 also, and the typical geochemical characteristics of the lower crust indicate that the mantle magma was Experienced the underplating process of the magma and interacted with the lower crust.The detachment of the lithosphere may be the cause of the upwelling of the mantle and the magmatolithic backfill after the orogenic belt collision.The Dabie-Sulu orogenic belt The results of seismic tomography show that the lithosphere in the both sides of the Dabie Mountains has been significantly thinned, except that the lithospheric thinning near the Tan-Lu fault in the Hefei Basin may be related to the Cenozoic basalts. Because of the lack of Cenozoic basalts in the Dabie Mountains, The lithosphere thinning in the Dabie Mountains may be the main