Eolian evidence from the Chinese Loess Plateau: the onset of the Late Cenozoic Great Glaciation in the Northern Hemisphere and Qinghai-Xizang Plateauuplift 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 rec ord of delta(18)O values from the equatorial East Pacific Ocean and eolian Quartz nux variations from the North Pacific Ocean, the evolutionary proces s of the Late Cenozoic Great Glaciation in the Northern Hemisphere can be d ivided into three stages: the arrival stage around 7.2-3.4 Ma BP, the initi al stage at shout 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 st rong winter and weak summer monsoons, or weak winter and strong summer mons oons. The Late Cenozoic global tectonic uplift, particularly the Qinghai-Xi zang Plateau uplift and the associated CO2 concentration variation, control s the cooling processes of the onset of Great Glaciation and the long-term changes of East Asian monsoom 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 chang e.