冀东青龙县一带中元古界与太古代基底滑脱构造厘定及地质意义

    Tectonic detachment zone between the Archean basement and the Mesoproterozoic cover rocks in the Qinglong region, eastern Hebei province and its implications

    • 摘要: 在区域地质调查的基础,通过构造分析、岩浆岩的分布以及构造岩的详细研究,厘定出冀东青龙一带太古代基底与中元古界盖层之间接触为构造滑脱关系。并认为构造滑脱经历了明显的两期活动,早期为挤压体制下的逆冲—褶皱作用,中元古代地层表现为同倒转褶皱,滑脱带内发育断层泥和断层角砾岩;晚期为伸展体制下伸展滑脱作用,表现为断层泥劈理化发育,指示明显的伸展滑脱特征。研究区太古代基底与中元古界盖层滑脱构造的厘定,对于再造该区构造格局和沉积古地理格局具有重要意义

       

      Abstract: Based on regional mapping, tectonic analyses and distribution of igneous rocks, together with studies on tectonic rocks, we infer that there is a tectonic detachment zone between the Archean basement and the Mesoproterozoic cover rocks in the Qinglong region, eastern Hebei province. This detachment event probably underwent two distinguished periods. The earlier period is characterized by overturned homoclinal folds, and fault gouge and breccia in the detachment zone due to thrust-folding process. The later period shows a detachment process, in which the fault gouge was cleavaged. Determination of the detachment contact between basement and cover rocks is of importance to paleogeographic reconstruction in this region.

       

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