Environmental evolution of Gongwang Mountains during Holocene in northeastern Yunnan,China

This paper presents the study on two continuous glacio-lacustrine sedimentary deposits, Laotanfang (3 597 m) and Shibantang (3 689 m) located on the southern and northern sides of Hulifang peak in Yunan, China. Environmental change indexes are constructed for each deposit, based on grain size, geochemical and pollen analysis, environmental magnetic susceptibility, and 14C dating. The study of climatic environmental change since the Holocene epoch in this region shows that the climate fluctuated at different stages during the early Holocene, that is, the climate was cool and wet during 8.4-7.7 ka, cold and wet during 7.7-6.5 ka, cold and dry during 6.5-4.7 ka, cool and wet during 4.7-2.1 ka, warm and wet during 2.1-1.0 ka, and warmer and wet since 1 ka. These findings reflect the overlapping influences of the southwest and southeast monsoons in different times during the Holocene in the north part of southwestern China are in accord with other Holocene climate change models in this part of China.

Much late onset of Quaternary glaciations on the Tibetan Plateau:determining the age of the Shishapangma Glaciation using cosmogenic 26Al and 10Be dating

The onset of Quaternary glaciations is a critical event in the climate and tectonic history of the Tibetan Plateau.The Shishapangma Glaciation,defined based on the till deposit from the northern slopes of Mt.Shishapangma,has been identified as the oldest glaciation on the Tibetan Plateau.However,the timing of this glaciation has not been constrained.We measured^(10)Be and^(26)Al concentrations of a set of boulders on top of this till and simulated their complex exposure-burial histories.The simulated results indicate that the formation age of this till is likely around 835.2±241.0 ka,representing the minimum timing of glacial onset on the Tibetan Plateau.The Shishapangma Glaciation is apparently much younger than the glacial onset in many other areas of the world,such as Europe and North America,and was likely driven by the coupled effect between tectonic uplift and climate cooling during the early–middle Pleistocene transition.

The discovery and environmental significance of Chifeng wind route and huge pots of Inner Mongolia and Hebei Province

The pots discovered in Inner Mongolia and Hebei Province are huge with a maximum diameter of 9 m and a depth of 3.5 m, singular in shape,caused by weathering and wind erosion and have certain direction. They are a kind of typical climatic geomorphology. This

AMS dating on glacial tills at the source area of the Urumqi River in the Tianshan Mountains and its implications

Using accelerating mass spectrometry (AMS) dating method, a dating has been made on the primary calcium carbonate in tills and secondary calcium carbonate coating on till gravel and the roche moutonnee formed since the Last Glaciation at the source area of the Urumqi River valley in the Tianshan Mountains, northwestern China. The results reveal that the carbonate content in the tills in this noncarbonate area is high enough to date by AMS, that the carbon in the coatings on the newly exposed roche moutons and in the modern till is modern carbon and so the 14 C dating results in the ancient till can represent the actual ages of the till formation, and that the warm period during the Holocene began as early as 6 500 a B.P. and lasted to 1 800 a B.P.