Sedimentary organic matter(OM)is a major reservoir of organic carbon in the global carbon cycle.Despite many studies,there still exist many debates on the mechanism of OM accumulation and preser-vation in marine sediments.We present a new field study of a Lower Cambrian shallow marine shelf sequence in the north edge of the Yangtze Plate,China.Our results show that palynological OM and biogenic silica(Bio-Si)could be used alongside more conventional redox and paleo-productivity proxies to study the distri-bution of OM in marine sediments.The qualitative and quantitative study of palynological OM provides more detailed information on the nature of sedimentary organic carbon,which can be helpful in the assess-ment of primary productivity and OM preservation.In addition,the presence of Bio-Si stimulates the physi-cal preservation of OM.Further analysis indicates that an increase in Bio-Si can promote OM preservation.This case-study provides insight into the intertwined factors controlling OM accumulation in the Early Cam-brian.