皖南祁门-歙县地区元古界变质岩地层原始构造环境和形变

1975年和1976年,作者和安徽省地质局332队宿立先、黄清涛同志先后观测了皖南的铺岭组和井潭组剖面,并将部分资料作过初步介绍。1977年作者又到现场观测和收集了牛屋组、板桥组、漳前组的有关资料。本文就是根据已收集的初步资料整理而成。研究地区元古界变质杂岩包括休宁组以前的地层。安徽省区域地质调查队将它分为漳前、板桥、木坑(环沙)、牛屋、邓家和井潭(铺岭)六个组分别归于震旦系和前震旦系(表1)。

PRIMARY TECTONIC ENVIRONMENT AND DEFORMATION OF STRATA OF PROTEROZOIC METAMORPHICS IN THE QIMEN-SHEXIAN REGION OF SOUTHERN ANHWEI

From Proterozoic flysch deposits in the Qimen-Shexian region of southern Anhwei some evidences of turbidite have been discovered. The flysch deposits are widely distributed over the "South China Old Land" including the southern part of Anhwei province, where suites of preorogenic volcanic rocks were found recently in a few localities. Evidently, the primary tectonic environment of Proterozoic metamorphics concerned should be part of a eugeosynclinal or trench and in the region under study there may be found volcanic rocks underlying the flysh deposits which were overlain by synorogenic volcanic rocks.From each group of metamorphie rocks can be distinguished four periods or generations of folding deformation. During deformation the dynamic axis "C" rotated clockwise in ascending order, or in other words from east toward west. Besides, the intensity of folding and the ductility of rocks decreased gradually. Some metamorphics show simple folds which resemble those of the Appalachian fold belt in pea-nsylvania and the nearby States as well as those of the fold belt in the centre-western part of New South Walse.