Uranium isotopic constraints on the provenance of dust on the Chinese Loess Plateau

Distant Taklimakan Desert as an Important Source of Aeolian Deposits on the Chinese Loess Plateau as Evidenced by Carbonate Minerals

“…For the Alxa arid area and Ordos Desert, the Sr‐Nd isotope compositions (Chen et al, ; Li et al, ), detrital zircon age spectra (Che & Li, ; Zhang et al, ), and modern dust storm observations (Liu et al, ; Shao & Dong, ) have shown that they are important sources for the loess. Uranium isotopes (Li et al, ) and physical property of quartz (Sun et al, ) support the notion that the Mongolian Gobi has a material contribution to the CLP. In addition, the dust material of reworked Yellow River sediments may be important sources of loess (Licht et al, ; Nie et al, ; Stevens et al, ).…”

“…For the Qaidam Desert, Chen and Li () found that certain samples have secondary dolomite with extremely positive δ 18 O ratios (~2‰), which clearly differ from the δ 18 O ratios (~ −8.8‰) of loess detrital dolomite from the CLP (Li et al, ). Both the uranium isotopic compositions (Li et al, ) and the lack of any major dust‐producing storm activity based on modern observations within the past ~50 years (Sun et al, ) also support that the Qaidam Basin may not be the source of loess on the CLP.…”

“…In summary, the main sources of loess on the CLP were adjacent arid areas (<800 km), including either the Ordos Desert and Yellow River sediments (Nie et al, ; Stevens et al, ; Yang & Ding, ) and Mongolian Gobi (Maher et al, ; Sun et al, ) in the north, the Alxa arid area in the northwest (Chen & Li, ; Li et al, ), the Qaidam Desert in the west (Pullen et al, ), or a mix of some of these sources (Chen et al, ; Li et al, ; Sun, ; Zhang et al, ). Unfortunately, the mineralogical and geochemical compositions of aeolian sediments in these adjacent sources and the CLP are inconsistent.…”

The Sources and Transport Dynamics of Eolian Sediments in the NE Tibetan Plateau Since 6.7 Ma

“…Much research attention has been directed to the Chinese Loess Plateau (CLP), and comprehensive investigations have been made of the origin of the red clay and the overlying loess‐paleosol sequence (Bird et al, ; Chen & Li, ; Li et al, , ; Nie et al, ; Shang et al, ; Sun, ; Sun, Tada, et al, ) and their paleoclimatic record (An et al, ; Ding et al, , ; Qiang et al, ; Vandenberghe et al, ; Zan, Fang, Li, et al, ; Zan, Fang, Zhang, et al, ; Zhang et al, ). Several primary conclusions have been drawn: (i) The ultimate source materials of these eolian sediments are the northern TP (NTP) and the Central Asian Orogen (CAO), and shifts in these sources were determined by processes of mountain erosion within the two regions, and by desertification processes in the Asian interior (Chen et al, ; Chen & Li, ; Fan et al, ; Li et al, , , ; Nie et al, ). (ii) The winds transporting the red clay were weaker than those associated with the deposition of the loess‐paleosol sequences; in addition, the influence of the paleo‐East Asian Monsoon (EAM) on the CLP from the Miocene to Pliocene was not as strong as that since the Quaternary (An et al, ; Ding et al, ; Li, ; Li et al, ; Li, Fang, et al, ; Qiang et al, ; Vandenberghe et al, ).…”

“…In the present study, we measured the silicate Sr‐Nd isotope composition and the grain‐size characteristics of the XSZ red clay and loess‐paleosol sediments, and we also used the Halagu eolian sediments as supporting evidence. Silicate Sr‐Nd isotopes have been widely used to trace the origin of sediments (Chen et al, ; Chen & Li, ; Li et al, , , ). This is because different source materials are characterized by different Sr‐Nd isotopic signatures, which are relatively uninfluenced by the processes of transport, weathering, and deposition (Grousset & Biscaye, ).…”