Geochemical characteristics of Holocene aeolian deposits east of Qinghai Lake, China, and their paleoclimatic implications

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

“…However, the a* and b* values for the three sections (QHH, DST3, and SQG) are lowest in the sandy paleosol unit, and highest in the eolian sand and sandy loess units, which is contrary to what is suggested by the relationship to loess-paleosol from Loess Plateau. This is, however, consistent with results from Otindag Sandy Land in northern China, and with other eolian sand-paleosol sequences in Lake Qinghai (Ding et al, 2019;Fu et al, 2016). These studies suggest that the variation of a* in eolian sand-paleosol may be affected by the source of the sand material.…”

“…Recently, Ding et al. (2019) used geochemical evidence to suggest that sand material from Lake Qinghai in HSL is derived from a combination of local bedrock weathering products and transformed reworked river and lakes. Under terrestrial surface geochemical weathering and pedogenesis, the chemical weathering of unstable minerals (e.g., plagioclase and k‐feldspar) gradually reduces the grain size, causing the coarse‐grain peak in the GSD to decrease, and the fine‐grain peak to gradually increase (Porter & An, 1995; Prins et al., 2007; Prins & Vriend, 2007; Xiao et al., 1995).…”

“…Lu et al (2011) show that the highest effective moisture levels in the LQB occurred at around 11-9 ka BP in the early-Holocene, and 4-3 ka BP in the late Holocene, while the mid-Holocene was associated with low effective moisture levels and frequent eolian activity. In contrast, R. Lu et al (2015) found that the eolian activity in the LQB was strong at around 12-9.5 ka BP, and concluded that the PHM occurred there at around 8.5-4 ka BP, finding supported by Ding et al (2019). However, in these studies, the paleoclimate information recorded is incomplete due to the low accumulation rate and possible occurrence of sedimentary hiati in some sections (such as the BHPA section from H. Y.…”

“…An alternative view is that the EASM driven PHM occurred in the mid‐Holocene (Chen et al., 2016; Ding et al., 2019; G. Li, Zhang, et al., 2020; X. Liu et al., 2018; R. Lu et al., 2015). Chen et al.…”

“…Lu et al, 2011). In addition, previous studies have found that some of the paleoclimatic interpretations of eolian deposits in this region may different from those of eolian deposits in other regions, such as the redness from Loess Plateau (Ding et al, 2019). Therefore, additional high-resolution records with an absolute chronology are required, and a comprehensive analysis that combines lithologic characteristics and multiple proxies are needed.…”