This shows a typical section of deposits in the Loess Plateau. The darker bands are ancient soils that indicate warm and moist conditions similar to the present; the intervening layers are pure loess and indicate cool and dry conditions, equivalent to glacial periods in Europe. The deposits in the photograph are between 1 and 1.5 million years old.

This shows one example of a stone artefact that has been exposed in a soil horizon. Finds like this are important because they are in a secure stratigraphic context, the age of which is already known from previous investigations, and if found in a palaeosol, they indicate that the climate was like the present. The specimen shown here is in a horizon over one million years old.

The Paleolithic and Pleistocene of Asia

Professor Robin Dennell 

The Loess Plateau of Central China has one of the best climatic sequences of the last 2.5 Ma in the world. It is formed of up to 500’ of yellow wind-blown dust, known as loess, which originates in the deserts of Central Asia and is transported by the winter monsoonal winds that blow southwards across China. In warmer, wetter periods, the summer monsoonal winds from the western Pacific Ocean and the South China Sea can penetrate further north, resulting in higher rainfall over the Loess Plateau, and consequently more vegetation. As loess is very soft and easily eroded, the Loess Plateau is heavily dissected by deep gullies. These reveal 33 periods in the last 2.5 million years when conditions were cold and dry, and 33 periods when the climate was warmer and moister, and palaeosols developed because there was more vegetation.

Because each climatic episode can be precisely dated, the Loess Plateau offers excellent opportunities for documenting the history of occupation by our ancestors over the last 1.66 Ma for which they have been in China. Since 2010, I have been collaborating with a team led by Professors Zhaoyu Zhu from Guangzhou and Huang Weiwen from Beijing that has been looking for stone tools in sections with loess or palaeosol deposits in the southern part of the Loess Plateau near the city of Xi’an. This work is in progress, and so far numerous stone tools have been found that are >1 Ma-old. This research will help provide a secure framework for documenting when, and under what climatic conditions, our earliest ancestors were able to colonise this part of NE Asia.