skip to content »

jajis.ooo-specstroy.ru

Osl dating of sediments from deserts in northern china

osl dating of sediments from deserts in northern china-7

At a distance of 30 cm downwind from the sample, a trap with 30 cm width and 30 cm height was used to collect windblown material.

osl dating of sediments from deserts in northern china-7

In total, ninety-five samples were employed for further wind tunnel experiments. The results show that riverbeds are the dominant landscape for modern dust aerosol availabilities in the Qaidam Basin, while wadis, gobi, and interdunes are the main landscapes over the Ala Shan Plateau and Tarim Basin.The Ala Shan Plateau and Tarim Basin are potential dust sources in northwestern China, while the Qaidam Basin is not a major source of the modern dust aerosols nowadays, and it is not acting in a significant way to the Loess Plateau presently.The sampling criteria were as follows: geomorphologic characteristics of the sampling sites are typical landscapes within an area of 10 × 10 km, the underlying surfaces have no vegetation cover, no biological or physical soil crusts are present, and no human disturbance is detected. At each site, the samples were collected in horizontal intervals of approximately 100 to 200 m. However, global warming may enhance the processes of physical, chemical and salt weathering that occur on the surfaces of the gobi, wadis, riverbeds and lakebeds, which would increase modern dust aerosol availabilities.

Finally, more than 80% of modern dust aerosol availabilities in China are from the Ala Shan Plateau, Tarim Basin, and Qaidam Basin century to the present (S3).

The results improve our understanding of modern dust aerosol availabilities and aeolian sediment sources in China..

Landscapes with higher modern dust aerosol availabilities in the Qaidam Basin include riverbeds, wadis and lakebeds (Fig. In the Ala Shan Plateau and Tarim Basin, wadis have relatively higher modern dust aerosol availabilities than other landscapes.

In the Qadaim Basin, increases in precipitation, melted snow and glacial meltwater may promote sediment transport to riverbeds and consequently improve modern dust aerosol availabilities in the region.

This suggests that global warming on the Qinghai-Tibet Plateau may enhance modern dust aerosol availabilities.

The annual modern dust aerosol availabilities calculated from dust storm events over the three regions for PM2.5, PM5, PM10 and PM50 are approximately 18, 36, 56, and 105 Tg, respectively (S3).