Asian summer monsoonal variations during the Holocene revealed by Huguangyan maar lake sediment record

High-resolution records of summer monsoonal evolution in the Holocene are essential to paleoclimate reconstruction but are hard to obtain. Here we provide a continuous, well-dated, high-resolution record from Huguangyan maar lake located in the west Pacific climate regime. Multi-proxies including chlorophyll a, TOC, Sr/Rb ratio and magnetic susceptibility have been used to reconstruct the monsoon variations in the Holocene. Higher chlorophyll a values are related with stronger summer monsoon, and vice versa. High-temporal resolution radiocarbon dating enables us to divide summer monsoon evolution stages. Summer monsoon in Zhanjiang area was strongest in the early Holocene but began to decline at 6080 yr BP, and weakened substantially since about 3600 yr BP. The transition around 6080 yr BP, supported by our high-resolution dating, lags the previous estimates by ~ 1700 years. The decreasing summer solar radiation at 30°N through the Holocene is probably responsible for gradually weakened summer monsoon. The anti-phased co-variation of summer monsoon intensity and ENSO activity throughout the Holocene suggests that they could be interlinked, driven together by solar radiation at orbital scale.