Dating of sediments in the tidal-dominated Yangtze River delta remains a challenge because of extremely complicated processes during sediment transport and deposition in such a fluvial-marine transition zone. To better understand the late Quaternary sedimentary history of the Yangtze River delta, we explore the applicability of K-feldspar luminescence dating techniques to deposits through a case study on a 60-m-long borehole core (YZ07) in the delta and then establish a spanning ~50,000-year-long chronological sequence. A series of luminescence pre-tests, including dose recovery tests and determination of residual dose and fading rates, were implemented using the modified single-aliquot-regenerative dose (SAR) protocol for post-infrared (IR) IR stimulated luminescence (IRSL) measured at 150 °C after prior IRSL at 50 °C (pIRIR₁₅₀), respectively. Luminescence characteristics of the prior IRSL (IR₅₀) and pIRIR₁₅₀ were then analyzed to check their validity. Two fading-correction models were utilized to correct apparent ages obtained from IR₅₀ and pIRIR₁₅₀ signals. The newly obtained K-feldspar luminescence ages were compared with quartz OSL ages and ¹⁴C ages. Our results indicate that most of ages derived from pIRIR₁₅₀ signals were overestimated due to incomplete bleaching; in contrast, the fading-corrected ages from IR₅₀ measured in pIRIR₁₅₀ protocol are robust as they are consistent with quartz OSL ages and ¹⁴C ages as well as the stratigraphy. Additionally, IR₅₀ ages are characterized by negligible residual dose, and thus used for defining chronology of the investigated sequence over the past 50 ka. In combination with sedimentological and paleontological analyses of core YZ07, we find that fluvial to tide-influenced fluvial deposits were emplaced during the period 30–50 ka, which were then overlain by post-glacial tidal-river (13–11.5 ka), and Holocene estuarine-shelf, delta system, and tidal flat deposits in the Yangtze River delta. Together with other chronostratigraphy from the selected cores, we confirm the existence of Marine Isotope Stage (MIS) 3 depositional units along the marginal coast of the Yangtze River delta in relation to the interstadial sea-level highstand. Our stratigraphic correlation based on the refined chronology reveals offshore transition of the MIS 3 unit into facies deposited in deeper and offshore marine environments.

由于在这样的河流-海洋过渡带中，泥沙的运输和沉积过程极为复杂，因此在以潮汐为主的长江三角洲的泥沙定年仍然是一个挑战。为了更好地了解长江三角洲的第四纪晚期沉积历史，我们通过对三角洲一个60 m长的钻孔岩心（YZ07）进行案例研究，探讨了钾长石发光测年技术在沉积物中的适用性，然后建立了一个长石。跨约50,000年的时间顺序。使用改良的单等分蓄能剂量（SAR）方案进行了一系列的发光预测试，包括剂量恢复测试以及残留剂量和衰落率的确定，用于测量后红外（IR）红外激发的发光（IRSL）在先前的IRSL在50°C（pIRIR之后）在150°C₁₅₀）。然后分析先前的IRSL（IR ₅₀）和pIRIR _150的发光特性，以检查其有效性。利用两种衰落校正模型校正从IR ₅₀和pIRIR ₁₅₀信号获得的表观年龄。将新获得的钾长石发光年龄与石英OSL年龄和¹⁴ C年龄进行比较。我们的结果表明，由于不完全漂白，大多数从pIRIR ₁₅₀信号获得的年龄都被高估了。相比之下，在pIRIR ₁₅₀协议中测得的经过IR ₅₀衰落校正的年龄很稳定，因为它们与石英OSL年龄和¹⁴年龄和地层。此外，IR ₅₀年龄的特征在于残留剂量可忽略不计，因此可用于定义过去50 ka内所研究序列的时间顺序。结合YZ07岩心的沉积学和古生物学分析，我们发现在30-50 ka的时期内形成了从潮至潮影响的河流沉积物，然后被冰川后的潮汐河（13-11.5 ka）覆盖，并且全新世河口-陆架，三角洲体系和长江三角洲的滩涂沉积物。结合选定核心层的其他年代地层，我们确认了长江三角洲边缘海岸相对于陆际海平面高位存在海洋同位素阶段（MIS）3沉积单元。