Optically stimulated luminescence dating of loess in South-Eastern China using quartz and polymineral fine grains

Loess deposits distributed in southeastern China play an important role for paleoclimate reconstruction of the subtropical regions. These loess-paleosol are mainly spread within middle and lower reaches Yangtze River as well drainage area Huai River. The ages loess paleosol sequences that along not constrained. In this study, standard single-aliquot regenerative dose (SAR) optically stimulated luminescence (OSL) protocol two elevated temperature post infrared-infrared SAR protocols (pIRIR 225 pIRIR 290 ) were applied on 4–11 μm quartz polymineral fine grains, respectively, order to obtain first numerical chronology a sequence northern Jiangsu Province. Our results show good agreement between SAR-OSL up ~70 ka. findings confirm Xiashu accumulated during Last Glaciation. For samples older than this, increasingly deviate with depth. Fine beyond 70 ka interpreted underestimates, previous studies reported >70 from various sedimentary origins worldwide may underestimate even if they pass rejection criteria recovery tests. On other hand, most likely overestimating true depositional indicated by tests, where 30–60% overestimation recovered is values larger ~400 Gy. was also confirmed obtained when large beta doses added top natural accrued dose. Moreover, our dating suggest L1/S1 transition (corresponding MIS 5/4 boundary) occurred much higher stratigraphic have been magnetic susceptibility enhancement. This inconsistency can be assigned invalidity chronostratigraphical proxy due ferrimagnetic minerals dissolution or transformation paedogenesis processes humid region China.