晚冰期以来月亮湖生物硅含量变化的古气候意义

根据大兴安岭中段小型火山口湖月亮湖沉积序列生物硅含量（BSi）替代性指标的分析,结合总有机碳（TOC）、总氮（TN）含量等分析结果,重建了该区末次冰期晚期（21cal.kaBP）以来的高分辨率古气候演化序列。研究结果表明：月亮湖生物硅含量变化范围为0.52%～15.88%,其中末次冰期晚期（21～14cal.kaBP）...

Climatic Variability since Late Glacial Period Inferred from Biogenic Silica Records in Moon Lake Sediments

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 14 cal.kaBP 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.