Beach ridges of Dali Lake in Inner Mongolia reveal precipitation variation during the Holocene

Abstract

Variability in East Asian summer monsoon precipitation during the Holocene remains of debate. In this study, we use a closed lake with well‐dated lake beach ridges located on the margin of the East Asian summer monsoon, a region highly sensitive to monsoon precipitation changes, to obtain a temporal sequence of water volume in North China. The elevation of each beach ridge calibrated to the modern lake level was surveyed. Optically stimulated luminescence dating of undisturbed sediments of beach ridges was performed. The lake area and water volume corresponding to each beach ridge were calculated using a digital elevation model. This study reveals relatively reduced monsoon precipitation from ~12 to 7 ka interrupted by strengthening of the monsoon circulation to a maximum from ~7 to ~5 ka and followed by greatly reduced monsoon intensity until the present day. These results demonstrate that changes in the East Asian summer monsoon precipitation may not be directly driven by global temperature or atmospheric CO2 content. Rather, we suggest that variation in the the monsoon margin precipitation is probably mainly driven by ice volume and subordinately by the summer solar insolation difference between mid‐latitude land and low‐latitude ocean.

Asynchronous variations of East Asian summer monsoon, vegetation and soil formation at Yulin (North China) in the Holocene

“…Previous studies have shown that the sand field in northern China was dry and experienced widespread aeolian activity during the early Holocene, with considerable dune stabilisation and soil formation during the middle Holocene (Lu et al , 2005, 2013b; Mason et al , 2009). These findings are supported by the regional lake sediment records (Chen et al , 2015, 2020; Jiang et al , 2020; Xiao et al , 2004) but conflicted with speleothem records of the monsoon intensity during the Holocene (Cai et al , 2010; Wang et al , 2005). Thus, a multiproxy investigation of the loess–palaeosol sequence with a high sedimentation rate can be used to elucidate the relationship among monsoon precipitation, vegetation, aridity and soil formation, and may explain the debates from diverse palaeoclimatic and palaeoenvironmental archives.…”

“…As discussed above, δD wax can represent changes in monsoon rainfall amount in Yulin, which can also explain the change in ACL. Pollen records from lakes in the marginal monsoon regions, including Bayanchagan Lake (Jiang et al , 2006) and Daihai Lake (Xiao et al , 2004), as well as a recent lake shoreline study (Jiang et al , 2020), all show a decrease in the proportion of woody plants and monsoon rainfall since ~6 ka, which has been attributed to a decrease in humidity in this region (Wang and Feng, 2013). This decrease is also supported by simulation results for summer monsoon rainfall in this region (Liu et al , 2014).…”

“…However, other proxy records, such as magnetic susceptibility (MS) (Gao et al, 2019), grain-size distributions (GS) (Lu et al, 2005(Lu et al, , 2013a, soil δ 13 C, total organic carbon (TOC) (Lu et al, 2005(Lu et al, , 2013a, bacterial branched glycerol dialkyl glycerol tetraethers (GDGTs) (Duan et al, 2019) and pollens (Chen et al, 2015(Chen et al, , 2020, suggest a 3000-4000 year lagged response of monsoon intensity to peak solar insolation, probably resulting from the retreat of the remaining Northern Hemisphere ice sheet, CO 2 -forced northern high-latitude temperature increases, or the tropospheric temperature variations (Chen et al, 2015;Liu et al, 2014;Lu et al, 2005Lu et al, , 2013a. These conflicting results lead to the debate on whether speleothem δ 18 O values can represent monsoon precipitations and what is the role of Holocene boreal summer insolation on monsoon changes in East Asia (Chen et al, 2015(Chen et al, , 2020Goldsmith et al, 2017;Jiang et al, 2020). The fundamentals of these questions might lie in a more convincing interpretation of different palaeoclimatic and palaeoenvironmental proxies.…”

Abrupt Contraction of the Indo‐East Asian Monsoons Ended the Holocene Humid Period

“…This age resolution is unprecedented in other lakes in East Asia and provides a high-resolution history of this large and rapid drying. (Goldsmith et al, 2017;Jiang et al, 2020). (c) Lake Chagan (Li et al, 2020).…”

Optical Stimulation Luminescence Dating of Deltas Revealed the Early to Mid-Holocene Lake-level Fluctuations of Daihai, Inner Mongolia, Northern China

“…(Xiao et al, 2008;Xiao et al, 2009). However, reconstructed lake-level fluctuations based on the OSL dating of beach ridges of Dali Lake reflected the lower lake level related to the reduced monsoon precipitation from 12 to 7 ka and the high lake level with a maximum monsoon precipitation during 7-5 ka (Jiang et al, 2020). In addition, lakes in eastern Inner Mongolia also revealed the distinct timing of highstands.…”