下扬子东南缘北段加里东期构造形迹新资料

New information of Caledonian tectonic features in the northern part of the southeastern margin of the Lower Yangtze valley

皖浙交界的宁国、于潜一带,上奥陶统和下志留统厚度巨大且具有浊流沉积的特征,导致长期以来对这一地区加里东期大地构造背景的不同认识。通过1∶25万区域地质填图,在震旦纪—下古生代地层中发现大量加里东期构造变形形迹和数处不整合接触关系,表明本区加里东运动强烈,华南地区广泛发育的加里东运动已经强烈地影响到扬子板块的南缘。这些发现为研究本区加里东期的大地构造环境和变形特点、扬子板块与华南板块的相互作用提供了新资料。

The Upper Ordovician and Lower Silurian sediments at Ningguo and Yuqian in the Anhui- Zhejiang border region are very thick and have the features of turbidity current deposits. This causes different views about the Caledonian tectonic setting. Through 1：250000 regional geological mapping, many Caledonian tectonic deformation features and unconformable contact relationships at several sites were found in Sinian-Lower Paleozoic strata, indicating that Caledonian movement was strong in this area and that the Caledonian movement widespread in South China strongly influenced the southern margin of the Yangtze plate. These findings provide new information for the study of the Caledonian tectonic setting and deformation features in the area and the interaction between the Yangtze and South China plates.