Age and Provenance of Loess deposits on the Northern Flank of Tianshan Mountain

• Published in: 地质学报（英文版） Vol. 83; no. 3; pp. 648 - 654
• Main Authors: YUAN Qingdong, ZHANG Zhicheng, WU Chaodong, GUO Zhaojie
• Format: Journal Article
• Language: English
• Published: Key Laboratory of Orogenic Belts and Crusml EvolutionPeking University,Ministry of Education,Beijing 100871,China 2009
• Subjects: North Tianshan; loess; granulometric properties; optically stimulated luminescence dating
• ISSN: 1000-9515
• DOI: 10.3321/j.issn:1000-9515.2009.03.022

P5; The distribution,optically stimulated luminescence dating and granulometric properties suggest that the loess on the northern flank of Tian Shan should be divided into two types.One which is Hke mantle and iS named type A.iS located on the windward slopes and dated to about 54.5±5.73 Ka. The other,called type B,lies flatly on the terraces of the rivers or low hills and penetrated 30.8±2.05 Ka ago.Here we study the origin and the age of two types of loess,and a model of loess formation is proposed.The dust was entrained from the Gobi Desert located to the north of Tian Shan by the monsoon from Mongolia,obstructed by the high moun~ins and deposited on the windward slopes of the mountains.The rivers and flows then transported the aeolian loess to IOW terraces and piedmont alluvial plains.