Yu Gao, ITP Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China, Jishuai Yang, Lanzhou University, College of Earth and Environmental Sciences, Lanzhou, China, Zhikun Ma, Northwest University, School of Cultural Heritage, Xi'an, China, Yan Tong, Tibetan Cultural Relics Conservation Institute, Lhasa, China and Xiaoyan Yang, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Key Laboratory of Alpine Ecology, Beijing, China