Cosmogenic nuclide ~(10)Be dating of the glacial threshold of the “Taibai glaciation” in the Qinling Mountain range

Taibai Mountain(3767 m), the main peak of the Qinling mountain range in eastern China, preserves typical Quaternary glacial remains. The timing and extent of the Quaternary glaciation in the study area has important scientific significance for reconstructing Quaternary environmental change. However, the absolute ages of the glaciation have not previously been well resolved. Using terrestrial in situ cosmogenic nuclides, we dated four samples collected from the surface of the Sanyehai and Eryehai glacial thresholds near the main peak. The results show that significant glacial retreat took place in two stages during the late part of the last glacial cycle at 18.62±1.08 to 16.87±0.95 ka and 16.88±1.08 to 15.07±0.92 ka. From the horizontal and vertical distances from the Sanyehai and Eryehai glacial thresholds, and neglecting the climate difference during the late stage of the last glacial cycle and the post-glacial stage, the horizontal and vertical retreat rates were 0.396 and 0.09 m a?1, respectively. The retreat rates also show that glaciers and permanent snow disappeared from the main peak at about 0.73 to 1.3 ka.