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: jijunfeng@nju.edu.cn

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.