Sedimentary Geological Characteristics and Tectonic Environment of Luojiamen Formation in Northern Zhejiang, Eastern Section of Jiangnan Orogenic Belt

Abstract

This study advances our understanding of the Jiangnan Orogenic Belt by integrating high-precision geochronological data with interpretations of sedimentary and tectonic environments. Specifically, it addresses the controversy over the geological significance, origins, and tectonic significance of the Shengong Unconfomity: at the base of the Luojiamen Formation. This paper shows that the formation developed over four stages with the primary source of detritus lying in a volcanic arc to the south. The study also reassesses the “unconformity” between the Luojiamen Formation of the Heshangzhen Group and the Zhangcun Formation of the Shuangxiwu Group, concluding that it does not demarcate the end of the orogenic collision between the Cathaysia and Yangtze blocks.