关于巢北地区中下志留统沉积环境的再认识

Restudy of the depositional environment of Lower-Middle Silurian strata in northern Chaohu area

本文围绕着巢北地区中下志留统的岩性、沉积构造、生物化石、地层旋回以及大地构造特征等五方面,结合国内外前人研究成果,对巢北地区中下志留统"等深积岩"的沉积特征进行了详细的论述。通过反证与新近发现的大量新证据,得出了与前人不同的认识——巢北中下志留统是与潮汐作用有关的浅海陆棚沉积,而不是早期认为的半深海等深流沉积。这一结论将有助于统一巢北地区早古生代的古地理格局,进一步理清对该区志留纪大地构造背景和构造沉积演化的认识。

Based on previous researches in China and abroad,this paper expounds the depositional environment of Lower-Middle Silurian strata in Chaohu area in the aspects of lithology,sedimentary structure,fossil organism,formation cycle and geotectonics.According to the counterevidence and abundant new evidence,the authors have come to a conclusion different from previous researchers＇ understanding：the Lower-Middle Silurian strata in the northern Chaohu area belong to the tide-dominated continental shelf instead of to the contour current deposit held by some previous researchers.This conclusion will contribute to the correct understanding of the Silurian geotectonic background and tectonic sedimentary evolution of this area.