大别山中生代构造演化:来自盆地充填记录的启示

通过对大别山周缘盆地的对比分析,研究了大别山中生代构造演化格局。盆地充填序列分析表明,尽管中生代大别山南、北盆山耦合关系不同,但构造体制均经历了前白垩纪挠曲向白垩纪伸展的转化;砂岩物源再造反映中生代南大别山源区剥露尚未大规模触及岩浆弧“根”,剥露深度浅于北大别单元。大别山邻区晚中生代巨厚磨拉石是陆内造山强烈阶段的沉积记录,它们的产出及相关的造山带隆升与该区超高压变质岩快速折返没有直接关系。进一步讨论了恢复大别山物源结构、建立盆地类磨拉石精细地层年代学格架等在造山带构造研究中的重要性及其现存的关键问题。

Mesozoic tectonic evolution of the Dabie Mountains:Evidence from basin-fill records

The Mesozoic tectonic evolution of the Dabie Mountains is studied through a comparison with the peripheral basins of the Dabie Mountains.Analysis of basin-fill sequences shows that all the tectonic regimes experienced the transformation from the pre-Cretaceous flexuring phase to Cretaceous extension phase though the basin-range coupling relations on both sides of the Dabie Mountains are different.Sand-stone provenance reconstruction indicates that in the provenance of the southern Dabie block erosion in the Mesozoic did not expose most of the"root "of the magmatic arc,whose exposure depth is shallower than that in the north Dabie block.The very thick Late Mesozoic molasses in the northern and southern foothills of the Dabie Mountains recorded intense intracontinental orogeny.Their occurrence and uplift of the Dabie orogen has no direct relations to the rapid exhumation of ultrahigh-pressure metamorphic rocks in the area.Finally,the paper discusses the importance of the reconstruction of the provenance in the Dabie Mountains and establishment of the accurate chronological framework of molasses in the basins in the tectonic study of the orogenic belt and the existing key problems.