Obliquity-paced summer monsoon from the Shilou red clay section on the eastern Chinese Loess Plateau

Abstract

The red clay of the Chinese Loess Plateau (CLP) is an important geological archive for understanding the variability in the late Neogene East Asian monsoon. The periodicity of the summer monsoon of the red clay on the eastern CLP is dominated by eccentricity cycles within the constraints of the palaeomagnetic chronological framework, whereas global climate change characteristics represented by the deep-sea oxygen isotope record at that time show a dominating obliquity cycle. Here, we analyzed the East Asian summer monsoon proxies from the Shilou red clay section with the cyclostratigraphy method. The results show that the summer monsoon variation was dominated by obliquity, the optimum deposition rate was 4.451 cm/kyr, and the floating age of the Shilou red clay section was ca. 1.7 Ma. The late Neogene East Asian summer monsoon inferred from the eastern CLP was thus paced by the obliquity cycle, which is consistent with global change.