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Supplementary Material for
Mineralogical evidence of reduced East Asian summer
monsoon rainfall on the Chinese loess plateau during the
early Pleistocene interglacials
Xianqiang Menga, Lianwen Liua, Xingchen T Wangb, William Balsamc, Jun Chena,
Junfeng Jia*
a Ministry of Education Key Laboratory of Surficial Geochemistry, School of Earth
Sciences and Engineering, Nanjing University, Nanjing 210023, China
b Division of Geological and Planetary Sciences, California Institute of Technology,
Pasadena, CA 91125, USA
c Department of Earth Sciences, Dartmouth College, Hanover, NH, USA
*Corresponding author: [email protected]
This document contains 4 supplementary figures.
Fig. S1
Fig. S1 (Continued)
Fig. S1 Comparison of calcite contents (blue lines and circles filled with white) in the
LC (a), LT (b) and BJ (c) sections with MS (black line) and stacked marine benthic
oxygen isotope values (d) (Lisiecki and Raymo, 2005) since 1.65 Ma (top figure) and
between 1.65 and 2.6 Ma (bottom figure). The horizontal green bands in (a), (b) and
(c) indicate loess leaching depth (LLD), and the green bands filled with yellow
indicate the maximum LLD. The top is paleomagnetic polarity. The labels represent
paleosol layers in (c) and marine oxygen stages in (d). The vertical grey bands
represent paleosol units and interglacials.
Fig. S2 The distributions of average precipitation in each month between 1950 and
2000 AD (left) at Xi’an (blue) and Xifeng (green) meteorological stations on the CLP.
There are linear correlations between mean annual precipitation (MAP) and summer
monsoon rainfall (May – September refer to left) (right) at two meteorological
stations. The figures show the rainfall on the CLP mainly concentrates on summer
monsoon seasons (May- September) and summer monsoon rainfall has a positive
correlation with MAP (R2 > 0.83).
Fig. S3 The estimated mean annual precipitation (MAP) (a) according to the
dissolution phases of carbonate in LC (blue diamonds), LT (green circles) and BJ
(orange triangles) sections on the CLP and normalized interglacial EASM rainfall
change (b) based on estimated MAP in (a). The synthesis in (b) is the average of
normalized EASM rainfall index from three sections.
Fig. S4 Correlation of interglacial EASM index with ENSO and global temperature
changes since 2.6 Ma. (a): EASM rainfall index (circles filled with yellow). The zonal
SST gradients (b) between ODP 806 (c, red triangles) and the ODP 847 (d, dark blue
circles) (Wara et al., 2005), between ODP 806 and ODP 846 (d, light blue circles)
(Martínez-Garcia et al., 2010; Wara et al., 2005) are represented by a dark blue line
and a light blue line, respectively. The labels in (a) indicate main paleosol layers.