EDIACARAN-CAMBRIAN BOUNDARY SECTIONS AND EARLY CAMBRIAN CHENGJIANG NONMINERALIZED FOSSILS IN EASTERN YUNNAN PROVINCE, SOUTHWESTERN CHINA: INTRODUCTION

摘要

Eastern Yunnan lies on the southwestern margin of the Yangtze Platform, South China. Lower Cambrian strata are extensively developed and well exposed in the area (Fig. 1). Since the beginning of the last century (Depret, 1912), eastern Yunnan has been a special place for the study on the Neoproterozoic-lower Cambrian in China (Zhu et al., 2001), because of the following reasons: 1, the presence of well developed, well exposed Lower Cambrian strata containing the most complete sequence of lower Cambrian shallow-water environments in China; and 2, the presence of abundant fossils recording a clear succession of Early Cambrian communities.