Late Quaternary glacial history of the Karlik Range, easternmost Tian Shan, derived from 10Be surface exposure and optically stimulated luminescence datings

Abstract

The Karlik Range, located in the easternmost part of the Tian Shan, is a key area in reconstructing paleoclimate in Central Asia, but few studies have been conducted to constrain the timing and extent of Quaternary glaciations in its highlands. We investigated the late Quaternary glacial history in the Turgan Valley on the northern slopes of the Karlik Range using cosmogenic 10Be surface exposure and optically stimulated luminescence (OSL) dating techniques. Four major glacial events were dated to 0.79 ± 0.59ka (Little Ice Age, LIA), 15.8 ± 1.6ka (Lateglacial), 37.4 ± 4.0–44.2 ± 4.3ka (Marine Oxygen Isotope Stage (MIS) 3), and 60.2 ± 3.3–79.3 ± 5.2ka (MIS 4 or older) with a pattern of continuously restricted glaciations after MIS 4. This glacial chronology is consistent with the studies from other parts of the Tian Shan. The overall pattern of glaciations across the Tian Shan suggests that change in precipitation brought by the westerlies was the primary factor influencing the timing and extent of glacial advances during the Last Glaciation. However, lower temperature of the Karlik Range affected by the Siberian High may counteract the effect of lower precipitation to drive a relatively extensive glacial advance in the easternmost Tian Shan.