Refining the late-Holocene coastline and delta development of the northern Yangtze River delta: Combining historical archives and OSL dating

Abstract

Historical documents provide a general chronological overview of the environmental evolution of the Yangtze River delta (YRD) during the last ca. 2000 years; however, absolute dating of the region’s late Holocene sediment is relatively rare. Optically stimulated luminescence (OSL) dating has been increasingly applied to the age determination of Holocene deposits in deltaic environments. In this study, three 23–27 m long drill cores running from south to north were collected from the Qihai plain of the northern YRD in order to reconstruct the history of this region’s formation since the late Holocene. A total of 24 samples from the three cores were subjected to OSL dating using coarse silt-sized (45–63 μm) quartz. The OSL ages range from approximately 190–3490 a revealing that the age of the delta front and delta plain facies in the coring sites are younger than 500 a while the sediments in the underlying prodelta facies are older than 2000 a. On the basis of the large age gap between the two set of deposits, we suspect that the coring sites remained submerged from 2000 to 500 years ago. As the central core has older and coarser sandy deposits than the neighbouring cores, we infer that the central core was located on a sandy mouth bar, while other cores sat within distributary channels within the estuary. The OSL ages are consistent with both the chronology implied by historical documents and other stratigraphic records in the area. This study enhances the chronological framework of land formation and delta evolution in the Qihai plain area of the YRD and thereby consolidates the conclusions derived from the application of a single technique alone.

Integrating Geomorphological Data, Geochronology and Archaeological Evidence for Coastal Landscape Reconstruction, the Case of Ammoudara Beach, Crete

“…Often, sparse artifact scatters are incorporated into sand deposits without clear indication of whether they are in their original context or perhaps within a buried lag surface, making the interpretation of OSL dates and their relationship with the original occupation time extremely difficult. Even if that is the case, careful examination of OSL data can provide insight into the conceptual development of a coastal landscape [95,[130][131][132].…”

“…Optically Stimulated Luminescence (OSL) dating [86] has become a promising technique for dating fluvial, deltaic, and coastal sediments [27,[87][88][89][90]. Thus, the Luminosity method is preferred as the most appropriate for investigating the location of the coastline [89,[91][92][93][94][95]. The ages of the sediments from different depths, as they are determined by the method of luminosity, allow us to calculate the rate of sediment deposition over time and, therefore, the advance or erosion of an area such as the area of Ammoudara.…”

Integrating Geomorphological Data, Geochronology, and Archaeological Evidence for Coastal Landscape Reconstruction. The Case of Ammoudara Beach, Crete

“…Often, sparse artifact scatters are incorporated into sand deposits without clear indication of whether they are in their original context, or perhaps within a buried lag surface, making interpretation of OSL dates and their relationship with the original occupation time extremely difficult. Even if that is the case, careful examination of OSL data can provide insight into the conceptual development of a coastal landscape [109,[143][144][145]].…”

“…Following relatively recent applications of luminescence techniques in a variety of sedimentary environments [93], such as alluvial and colloquial sediments, glacial and peripheral deposits [94], riverbed sediments [95], sediments associated with cracks and seismicity [96,97] as well as terrace materials [98], these proved to be quite reliable, as the obtained ages were in chronological agreement with the already existing reports. Thus, the Luminosity method is preferred as the most appropriate for investigating the location of the coastline [102,[106][107][108][109]. The ages of the sediments from different depths, as they are determined by the method of luminosity, allow us to calculate the rate of sediment deposition over time, and therefore the advance or erosion of an area such as the area of Ammoudara.…”

Yellow River's Contribution to the Building of Yangtze Delta During the Last 500 Years ‐ Evidence From Detrital Zircon U‐Pb Geochronology

“…Hengsha Island and Chongming Island are located at the YZR Estuary (Figure 1), which mark the eastern boundary of the land part of YD. In general, sediment composition of the southern core HSD (Chen et al, 2021) is coarser than the northern WB core (F. Wang et al, 2019) (Figure S3). We also collected one sample from the OYR delta (Figure 1c).…”