Eolian evidence from the Chinese Loess Plateau: The onset of the Late Cenozoic Great Glaciation in the Northern Hemisphere and Qinghai-Xizang Plateau uplift forcing

On the basis of a newly-constructed record of magnetic susceptibility (SUS) and the depositional rate change of eolian loess-red clay sequences in the last 7.2 Ma BP from the Loess Plateau, together with a comparison of a record of δ¹⁸O values from the equatorial East Pacific Ocean and eolian Quartz flux variations from the North Pacific Ocean, the evolutionary process of the Late Cenozoic Great Glaciation in the Northern Hemisphere can be divided into three stages: the arrival stage around 7.2-3.4 Ma BP, the initial stage at about 3.4-2.6 Ma BP, and the Great Ice Age since 2.6 Ma BP. The evolution of the East Asian monsoon is characterized by paired winter and summer monsoons, and it is basically composed of the initial stage of weak winter and summer monsoons, the transitional stage of simultaneous increase in intensity of winter and summer monsoons, and the prevailing stage of strong winter and weak summer monsoons, or weak winter and strong summer monsoons. The Late Cenozoic global tectonic uplift, particularly the Qinghai-Xizang Plateau uplift and the associated CO₂ concentration variation, controls the cooling processes of the onset of Great Glaciation and the long-term changes of East Asian monsoon climate in the Northern Hemisphere to a large extent. The accelerating uplift of the Qinghai-Xizang Plateau between 3.4 and 2.6 Ma BP provided an important driving force to global climiatic change.