摘要
在14C测年的基础上,分析了雷州半岛北部湛江市屋山泥炭剖面和遂西县下录泥炭剖面的沉积特征及其腐殖化度、有机质含量变化,发现两个剖面在相同时段内的沉积特征和气候环境特征都比较吻合,充分证明了研究区区域的气候环境变化是控制两个地点泥炭发育的主要因素。研究表明:泥炭腐殖化度敏感地记录了古气候信息,其高值指示气候相对暖湿,低值指示气候相对冷干。50―30calkaBP期间雷州半岛北部气候暖湿,30―10calkaBP期间气候则相对冷干。将其腐殖化度与格陵兰NGRIP冰芯δ18O对比发现:50―30 cal ka BP期间雷州半岛北部存在多次短尺度的气候冷干事件,其中千年尺度气候事件很好地响应了Heinrich事件H5-H3。
The northern Leizhou Peninsular, considered as a climatic transition between the south limit of the sub-tropic and the north limit of the tropic, is sensitive to climate changes because it is influenced by both SE and SW monsoons. Two peat deposit cores were retrieved respectively at Xialu, Suixi and Wushan, Zhanjiang in the northern Leizhou Peninsula. By the chronological analysis, the bottom age of the peat at Xialu is determined at ca 42 cal kaBP and the one at Wushan is determined at ca 50 cal kaBP. According to sedimentary characteristics, organic matter and humification, the history of climatic changes during 50-10cal kaBP is reconstructed. The climate was wet and warm during 50-30 cal kaBP, then, it was dominated by relative cold and dry climatic conditions during 30-10 cal kaBP. However, climatic change during the Holocene was not recorded in the cores. The high-resolution analysis of humification degree reveals several cold and dry climatic events. The millennium-scale climatic event is of resemblance to Heinrich events H5-H3, and some other short-scale climatic change records tally closely with those of δ^18O ice core from North Greenland Ice Core Project （NGRIP）. The study shows that the humification degree is an ideal proxy for paleoclimatic changes, the high value of humification degree indicates humid-warm climate, and low value implies dry-cold climate.
出处
《热带地理》
2008年第6期498-503,共6页
Tropical Geography
基金
国家自然科学基金项目(440671189)
广东省自然科学基金项目(06025042)
教育部霍英东基金项目(91021)
关键词
雷州半岛北部
泥炭
腐殖化度
晚更新世晚期
气候变化
northern Leizhou Peninsula
peat deposit
humification degree
Late-Pleistocene
climatic change
