Early to mid‐Holocene rapid sea‐level rise and coastal response on the southern Yangtze delta plain, China

Abstract

We used accelerator mass spectrometry (AMS) 14C‐dated sediments of the Holocene basal supratidal flat to upper tidal flat facies in 11 cores on the southern Yangtze delta plain to reconstruct relative sea levels of 8.5–8.0 cal ka BP. Three cores were further AMS 14C dated and used to examine the evolution of sedimentary geomorphological environments in response to the rapid sea‐level rise during the early to mid‐Holocene. Results demonstrate relative sea‐level rise of around 30 mm a−1 from 8.5 to 8.3 cal ka BP and around 10 mm a−1 from 8.3 to 8.0 cal ka BP. Retrogradation from supratidal to lower tidal flat environments occurred in response to the rapid sea‐level rise at 8.5–8.3 cal ka BP, and aggradation from middle to upper tidal flat occurred at 8.3–7.9 cal ka BP. Further retreat of the tidal flat at 7.9–7.2 cal ka BP implies a mean sea‐level rise rate exceeding 5 mm a−1 at this time. We suggest that the rapid relative sea‐level rise during 8.3–8.5 cal ka BP and subsequent slower rise caused drastic changes in the coastal zone and that these changes are key phenomena for understanding the coastal response to future sea‐level rise.

Rapid flooding of the southern Vietnam shelf during the early to mid‐Holocene

“…A similar rapid sea‐level rise has been observed in other South‐East Asian coastal sediment records. This rapid sea‐level rise was first observed in supra‐ to intertidal sediments of the Yellow and Bohai Sea and initially dated to between 9.8 and 9.0 ka BP (Liu et al ., ), which is currently revised to 8.5–8.3 ka BP (Wang et al ., ). This period of accelerated sea‐level rise has been related to the final melting phase of the glacial ice sheets and was referred to as MWP‐1C (Liu et al ., ).…”

Pollen evidence to interpret the history of rice farming at the Hemudu site on the Ningshao coast, eastern China

“…As the sea level rise began to decelerate at the mid-Holocene (Wu, 1983a;Zhu et al, 2003;Qin et al, 2011;Zheng et al, 2012;Wang et al, 2013), the Ningshao coastal plain initially formed at ca. 7000 years ago (Lang, 1987;Liu et al, 2014).…”

Generic 3D interpolation of Holocene base‐level rise and provision of accommodation space, developed for the Netherlands coastal plain and infilled palaeovalleys

“…Palaeovalleys are common phenomena in the substrate of deltas and coastal plains (e.g. Yangtze: Wang et al ., ; Tokyo Kanto Plain: Tanabe et al ., ; Mississippi: Blum et al ., ; Mekong: Hanebuth et al ., ). Buried palaeovalleys are topographically complex, as a result of different sizes and lifespans of valley forming rivers and receiving basins.…”