苏北-胶南地体构造初探——江苏响水至内蒙古满都拉地学断面研究报道之二

A PRELIMINARY STUDY ON SUBEI-JIAONAN TERRANE OF THE SECOND REPORT OF GEOLOGICAL OBSERVATIONS ON GEOSCIENCE TRANSECT FROM XIANGSHUI, JIANGSU, TO MANDULA, NEI MONGOL

胶南群中发育大量的超基性岩、榴辉岩和强烈变形的糜棱岩,它们在空间上呈带状分布。超基性岩-榴辉岩带和糜棱岩带多赋存于胶南群洙边组之中,具有明显的层控特点。因此,它们可能是同一套变形地层单位被褶皱的产物,并且可能代表了一条形成于中深地壳、现已褶皱并出露地表的大型滑脱带。 海州群变质较浅,发育许多中高压矿物,并有蓝片岩产出。因此,它可能是一条高压变质带。

A great number of ultrabasic rocks and eclogites exist in Jiaonan Group, Subei (Northern Jiangsu)-Jiaonan(Southern Shandong Peninsula) Terrane. They mainly distribute in three belts extending in NE or NEE direction. There are also widespread mylo-nite zones. All of mylonite zones and ultrabasic rockeclogite belts almost occur in the upper Zhubian Formation of Jiaonan Group(Pt1-2). It means that they might be of strato-controlled characteristics. So it can be inferred that they perhaps represent a large scale detachment zone in the middle crust, which is folded and exposed in the surface. Thus Subei-Jiaonan Terrane is situated in a suture zone between the North China Craton and Yangzi Craton with a complicated deformation history.