WANG Li-xian¹，LIU Qiang²，YOU Hai-tao¹

（1. Key Lab. of Computational Geodynamics of Chinese Academy of Sciences; College of Earth Science, Graduate Univ. of the Chinese Academy of Sciences, Beijing 100049, China;
2. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China）

Abstract：The paleoclimatic variability since the Late Glacial period recorded in the Moon Lake, which is located in the middle part of the Da Hingan Ling Mountain Range, is reconstructed by analyzing biogenic silica concentrations in combination with TOC, TN contents in the sediments. The result revealed that biogenic silica concentrations of the Moon Lake range from 0.52% to 15.88% with an average of 5.95%. During the Late Glacial period (21～14 cal.kaBP), BSi contents were low and had no obvious change. From 14cal.ka BP on, BSi contents gradually increased and fluctuated frequently, suggesting the climate turned warm and wet with frequent fluctuations. There were several abrupt climate events which lasted for a comparatively short period but had a significant magnitude during 14.0～10.8 cal.kaBP, which indicated that climate shift from cold and dry to warm and wet was rapid and acute. The climate during the Holocene can be divided into six types: cool and dry (10.8～7.9 cal.kaBP), warm and wet (7.6～6.9 cal.kaBP), cool and dry (6.9～3.9 cal.kaBP), warm and wet (3.9～3.4 cal.kaBP), cool and dry (3.4～2.4 cal.kaBP), cool and dry with fluctuations (2.4～0.6 cal.kaBP), warm and dry (from 0.6cal.kaBP on). The cold events during the Holocene occurred at around 10.2 cal.kaBP, 9.8 cal.kaBP, 9.4 cal.kaBP, 8.2 cal.kaBP, 5.2 cal.kaBP, 2.9 cal.kaBP, 0.9 cal.kaBP and 0.6 cal.kaBP, respectively.

Key words：Moon Lake；biogenic silica；late glacial period；Holocene；paleoclimate

EARTH AND ENVIRONMENT Vol. 40, No.3, Tot No.289, 2012, Page 328-335