Luminescence Dating of Holocene Fluvial Sediments from the Daluze Area in the North China Plain

Optically stimulated luminescence (OSL) dating is an important method for determining the ages of late Quaternary sediments. However, partial bleaching of quartz in fluvial sediments remains a challenge, with debates on grain-size effects in different sedimentary environments. The aim of this paper is to explore the bleaching degree and its influencing factors of different grain-size quartz in fluvial sediments from the Yanchi section in the Daluze area, North China Plain. According to sedimentological methods and grain size analysis, lacustrine and fluvial layers were identified, and the ages of sediments were determined by OSL and 14C methods. The key findings are as follows: (1) Fine-grained quartz can be better bleached than coarse/medium-grained quartz for early–middle Holocene fluvial sediments. (2) The OSL method can yield reliable ages for early–middle Holocene fluvial sediments, while it overestimates these for late Holocene fluvial sediments. This probably results from variations in sediment sources and hydrodynamic conditions. (3) The dating results show that there are three fluvial activity periods in the Daluze area: 10.8~10.2 ka, 5.3~4.7 ka, and after 1 ka. This paper provides a reliable chronological framework for the evolution of regional sedimentary environments and offers references for luminescence dating of fluvial sediments in similar environments.