大别山南坡蕲春等地榴辉岩的发现及相关问题

Discovery of eclogites in the Qichun areas in the southernslope of the Dabie Mountains and some related problems

20世纪90年代早、中期,一些研究者根据榴辉岩的出露情况,将大别山腹地的大别杂岩出露区划分为“北大别地体”、“UHP地体”和“宿松地体”3个不同性质的大地构造单元,其中“北大别地体”和“宿松地体”2个地体被视为不含榴辉岩的构造单元。然而,自90年代后期以来,在“北大别地体”中陆续发现了大量的榴辉岩露头。近期笔者在“宿松地体”中也首次发现了榴辉岩露头。上述事实表明前人仅仅根据榴辉岩的出露将大别杂岩划分为3个构造单元的认识是不妥的,大别杂岩应该为一个具有一定成因联系的构造-岩石单元,属于同一个大地构造单元。

In the early to middle 1990s, the outcrop area of the Dabie complex in the interior of the Dabie Mountains was divided into three tectonic units of different natures: the northern Dabie terrane (or migmatite unit), central UHP terrane (or eclogite unit) and Susong terrane (or amphibolite unit) based on whether eclogites are exposed, of which the northern Dabie and Susong terrane were regarded as the units containing no eclogites. However, many eclogite outcrops have been found successively in the northern Dabie terrane since the late 1990s, and recently the authors have also found eclogite outcrops in the Susong terrane. It shows that it is not advisable for the predecessors to divide the Dabie complex into three tectonic units, and that the three units of the Dabie complex should be genetically related and belong to the same tectonic-rock unit and thus should be merged into one tectonic unit.