Holocene Moisture Variability and Its Lagged Response to Summer Insolation Revealed by Eolian Deposits in the Lake Qinghai Basin, NE Tibetan Plateau

Abstract

The East Asian Summer Monsoon (EASM) drives the distribution of heat and water vapor in east Asia, and has been linked to the survival of billions of people in the region (An et al., 2012; Chen et al., 2015). Understanding the dynamics and variability of the EASM since the Holocene is crucial for understanding current global warming, and for accurate prediction of future climate change. As a transition region between monsoon and arid inland climates, the modern monsoon marginal zone has a semi-arid to semi-humid climate, which is highly sensitive to global climate change and to the EASM response to the changes. There are abundant geological archives in the monsoon marginal zone containing information about the evolution of the EASM (Figure 1a) (

Geochemical evidence of provenance diversity in Holocene sandy land of Qinghai Lake Basin in the north‐eastern margin of Qinghai–Tibet Plateau and its implications for climate change

“…(C) to (E) Variations in Na 2 O/K 2 O, P 2 O 5 and Fe 2 O 3 /MnO from the CGL profile. (F) Grain‐size end‐member (DST3–EM1) indicating changes in monsoon precipitation intensity in the Hudong Sandy Land (HSL) (Ding et al ., 2021). (G) Redness records from Qinghai Lake sediment (Ji et al ., 2005).…”

“…For example, the grain‐size end‐member components representing effective humidity variation in the aeolian sand–palaeosol sequence DST3 profile from the HSL (Fig. 9F) indicate maximum effective humidity levels since the Holocene at 8.3 to 5.1 ka bp (Ding et al ., 2021). This result aligns with the maximum tree pollen content at 8.5 to 4.5 ka bp (Fig.…”

“…2E). Comparing the aeolian sand-palaeosol profile from Hudong Sandy Land with redness and pollen data from sediment cores in Qinghai Lake during these periods (Ji et al, 2005;Shen et al, 2005;Ding et al, 2021), along with the presence of freeze-thaw folds at 610 cm in the CGL profile, it Ó 2023 International Association of Sedimentologists, Sedimentology, 71, 54-80 is inferred that these two sedimentary hiatuses may be associated with the widespread 4.0 ka and 8.2 ka cold events in the Tibetan Plateau (Mischke & Zhang, 2010). This interpretation aligns with the age estimation obtained through linear interpolation and extension calculations.…”

“…Located in the south-east of the QLB, the Hudong Sandy Land (HSL) is the basin's largest active dune and semi-fixed dune concentration area, containing abundant Late Quaternary stratigraphy. Over the past several decades, many researchers have studied the formation age, vegetation evolution and aeolian activity history of this sandy land in the past geological period based on multi-proxies such as magnetic susceptibility, grain size, geochemical weathering and biological remains in stratigraphic profiles, and then further exploring the evolution process in the EASM and EAWM (Lu et al, 2011(Lu et al, , 2015Ding et al, 2021). However, sufficient knowledge of the source/provenance of the sandy land is lacking, and no studies have investigated its palaeoclimatic evolution pattern from the perspective of sediment source changes.…”

“…Conversely, redness data, also from Qinghai Lake sediments, indicate that monsoonal precipitation reached its maximum during the Middle Holocene at 8.0 to 4.0 ka bp (Ji et al ., 2005). Additionally, research results from palaeosol (sandy palaeosol) strata, closely related to pedogenesis and indicative of monsoon precipitation intensity changes, also show significant discrepancies (Lu et al ., 2011, 2015; Ding et al ., 2021). However, unlike the use of environmental proxies in the stratigraphy to trace the evolution of monsoonal precipitation and temperature, a comparative analysis based on possible source changes in sediments combined with reliable proxies may provide a new way to clarify the above controversy.…”