雷州半岛北部晚更新世晚期气候环境变化的泥炭沉积记录

THE CLIMATIC CHANGES DURING LATE LATE-PLEISTOCENE INDICATED BY PEAT DEPOSIT IN THE NORTH LEIZHOU PENINSULA

对雷州半岛北部湛江市郊屋山村和遂溪县下录村两个泥炭剖面的沉积地层和多种气候指标进行了分析，发现两个剖面呈现大致相同的变化特征，表明区域气候是影响此地区泥炭发育的重要因素。在50～30cal．kaBP期间，此地区气候表现出显著的相对温暖湿润特征，且期间存在多次短尺度的波动，其中千年尺度的Heinrieh事件H3-H5在本文中有很好的揭示，其他的一些气候快速变化事件与南京葫芦洞石笋和格陵兰冰心氧同住素记录也有较好的吻合。30cal．kaBP之后，气候转向相对冷干。气候指标的红色噪声谱分析揭示出约1440a全剖面最为显著的周期，与大洋热盐环流推动的约1500a的D-O循环周期相似。雷州半岛北部地区晚更新世晚期中气候变化与高纬度地区冰量以及东亚季风环流的变化密切相关。

The studied area, north Leizhou Peninsula, which is considered as the south limit of the subtropic areas and the north limit of the tropic areas, is sensitive to climate changes because the area is influenced by both southeast and southwest monsoons. Two peat deposit core sections were retrieved respectively at the Xialu .Village in Suixi County and the Wushan Village near Zhanjiang City of the north Leizhou Peninsula, and give us the history of climatic changes from ca 50-10 cal kaBP. Based on the chronological analysis, the bottom of the peat section is determined at ca 42 cal kaBP. Sedimentary characteristics and multi-proxies of climatic changes such as humification degree （HD）, loss on ignition （LOI） and organic matter （OM） reveal that during 50-30 cal kaBP, climate was dominated by evident wet and warm conditions,with several short-scale climate changes Heinrich events HS-H3 indicated. After 30 cal kaBP, climate became cold and dry. However, climatic change during Holocene was not recorded in the sections. Comparisons show that climatic change since 50 cal kaBP revealed by peat deposit in north Leizhou Peninsula, possibly had something to do with the insolation and change in ice volume in Northern Hemisphere. Red noise spectrum analysis shows several remarkable periodicities such as ca 1 440 a, 700 a, 650 a,and 500 a. The most evident period of ca 1 440, which is similar to the quasi-1 500 a cycle, is considered to be the O-D cycle driven by the Thermohaline Circulation（THC）.