Quaternary glacial history of the Kanas Valley, Chinese Altai, NW China, constrained by electron spin resonance and optically stimulated luminescence datings

Abstract

The Chinese Altai is located on the northern edge of Central Asia. Rich geological records of Quaternary glaciations are preserved in this area. However, the glacial history in the Chinese Altai has hardly been investigated. This study aims to rebuild the regional glacial history in the Kanas Valley of the Chinese Altai. We present 14 electron spin resonance (ESR) ages and 3 optically stimulated luminescence (OSL) ages from glacial landforms. By integrating with ages from previous studies, five major glacial advances are identified during Marine Oxygen Isotope Stages (MIS) 6, 5, 4, 3 and 2, with ages of 167.0±16.0–123.0±18.0ka, 97.0±19.0–78.0±7.0ka, 76.0±16.0–73.1±6.6ka, 52.1±7.8–34.4±4.2ka, and 28.0±3.3–16.1±1.5ka respectively. The glacial advance during MIS 5 is the local Last Glacial Maximum, and glaciers became successively more restricted from MIS 5 to MIS 2. In addition, the extensive MIS 3 glacial advance in the Chinese Altai contrasts with the absence of MIS 3 glacial advance in the Mongolia Altai. These glacial patterns reflect that precipitation brought by the westerlies might play a primary role on driving glacial advances during the Last Glacial in the Chinese Altai. This glacial chronology is in reasonable agreement with existing glacial chronologies from other parts of the Altai, Tian Shan and Pamir, indicating similar climate controls on the patterns of Quaternary glaciation across Central Asia Highlands.