太白山西佛爷池沉积物有机碳、氮同位素记录的过去1800多年的气候-环境变化

Climatic and Environmental Changes in More Than the Past 1800 Years as Recorded by Isotopic Carbon and Nitrogen in Organic Matter of Sediments from Western Foye Chi (Buddha Pond) on Taibai Mountain

在秦岭主峰太白山南坡的冰蚀湖西佛爷池中取得一个深50 cm的沉积物柱芯(XFYC12-2)。对XFYC12-2的样品做加速器质谱(AMS)^(14)C测年和有机碳、氮稳定同位素分析,并据此重建这一高山湖泊周边过去1800多年的气候-环境变化。结果表明:1811~1380(或1440)a BP偏冷干;1380(或1440)~840 a BP温暖湿润,这一阶段可能与中世纪暖期相当;840~460(或520)a BP转为寒冷干旱,这一阶段或许相当于小冰期;460(或520)~100 a BP又趋暖湿。上述气候-环境变化过程与太白山南坡高海拔地段另外两个湖附近的变化过程、中国东部地区的总体变化趋势及4个代表性地点的变化过程相似。

A 50-cm core （hereafter referred to as “XFYC12-2”） was retrieved from western Foye Chi （Buddha Pond）, a glacier-scour lake on southern slope of Taibai Mountain that is the main massif and peak of Qinling Mountain Range. Accelerator mass spectrometry （AMS） 14C dating and analyses of isotopic carbon and nitrogen of organic matter were performed on samples from XFYC12-2. Climatic and environmental changes occurring around this alpine during over the past ~1800 years were therefore reconstructed. Climatic and environmental conditions were still fairly cool and arid during 1811？1380 （or 1440） aBP. In 1380 （or 1440）？840 aBP, the climate and environment were warm and humid. This episode is probably corresponding to Medieval Warm Period （MWP）. Climatic and environmental conditions deteriorated subsequently and were thus cold and dry over the period of 840？460 （or 520） aBP. This phase may correspond to Little Ice Age （LIA）. Climatic and environmental conditions have turned to be warm and wet again during 460 （or 520）？100 aBP. The aforementioned process of climatic and environmental changes appears quite similar to what was reconstructed around another two lakes at the high altitudes of Taibai Mountain, what was generalized for eastern China and what was identified at another four study areas in eastern China.