Advances in Earth Science
), Huayu LU(
Chenghong LIANG, Huayu LU. The Application of Leaf Wax
δD in Aeolian Sediments as a Proxy for Reconstructing Quaternary Humidity Variations in the Monsoonal East Asia[J]. Advances in Earth Science, 2021, 36(1): 45-57.
Leaf wax n-alkanes are widely distributed in sediments； they have a clear formation process， and they are resistance to environment change. δD composition of leaf wax n-alkanes is a newly developed biogeochemistry proxy with great potential in paleoenvironment reconstruction. In this paper， we reviewed the formation process of leaf wax n-alkanes and their hydrogen isotopic fraction， evaluated the relationship between leaf wax n-alkanes δD and regional humidity， and summarized recent applications of them to paleoclimate reconstruction. Based on the studies of n-alkanes δD of surface sediments， we find n-alkanes δD is a good proxy indicator of humidity in semiarid and arid climate region in monsoonal East Asia. Compared with other proxies from loess-paleosol sequences， the n-alkanes δD is a direct indicator of humidity variations； it shows direct response to environment change， and it reveals precession signal of solar insolation variations in orbital timescales paleoclimate record. In this case， the n-alkanes δD is a good proxy for humidity variations in sedimentary records in East Asia monsoon region， and， further research on the influence of the variations of precipitation isotope and local isotope fraction process to the n-alkanes δD is compulsively needed.