大别山东段的变质地层格架

METAMORPHIC STRATIGRAPHIC FRAMEWORK IN THE EASTERN PART OF THE DABIE MT.

上世纪80年代末以后完成的大别山区1∶5万区域地质调查,将大别山的中深变质杂岩解体为变质变形侵入岩和变质表壳岩两部分,但所建立的构造岩石/地层单位大多沿用了1∶20万区域地质调查的地层名称。与之同期,大别山超高压变质岩发现以来的地质研究也揭示出大别山中深变质岩的主体为正片麻岩,并以变质特征及其构造属性划分出4个构造单元。本文依据前人的地质调查和研究成果,将大别山的变质地层划分为4个岩石地层(构造岩石地层、构造岩石)单位,3个非正式岩石地层单位。论述了它们与区域地质调查所划分的地层单位的对比,以及与4个构造单元的对应关系。

As shown in 1：50000 regional geological survey finished in the Dabie Mt area at the end of 1980s and thereafter, meso-and hypo-metamorphic complex was decomposed into two parts--metamorphic and deformed intrusion and metamorphic supercrustal rock in the area, however, most of the established structures and rocks/stratigraphic units continued to follow the stratigraphic titles of 1：200000 regional geological survey. In the same period, geological research made since discovery of ultrahigh-pressure metamorphic rock in the Dabie Mt disclosed that the bulk of meso- and hypo-metamorphic rock is orthogneiss, which is divided into 4 structural units by metamorphic features and structural attribute. Based on previous geological survey and research results, this paper classified metamorphic strata into 4 lithostratigraphic （tectono-lithostratigraphic, tectono-litho） units, and 3 informal litho-stratigraphic untis in the Dabie Mt, discussed their comparison with stratigraphic units divided by regional geological survey, and their relations with the said 4 structural units.