晚更新世以来闽东南老红砂沉积粒度特征与古气候变化

Grain-size Characteristics of Old Red Sand and Palaeoclimate Change during Late Pleistocene in Southeast Fujian,China

对闽东南深沪湾老红砂风沙沉积进行粒度测试,提取对环境变化敏感的粒级组分,结合年代学数据,初步划分了研究区晚更新世中晚期以来的气候变化阶段和气候驱动因素。研究发现,研究区经历了较冷干-暖湿-冷干-暖湿4个气候变化过程。气候变化主要受控于太阳辐射,表现出明显的23 ka长岁差周期、14.2 ka、11.8 ka半岁差周期,叠加约0.25 ka的双世纪周期,陆地-海洋-大气系统的内部因素对表现出来的百年周期可能产生放大或缩小影响。70.8—46.4 ka BP和21.3—11.6 ka BP两个阶段老红砂沉积速率较大,是老红砂风沙堆积的两个主要时期,两个阶段沉积速率分别达到30 mm/(100 a)、650 mm/(100 a)。

On the basis of environmental sensitive grain-size analysis and combinated with chronologic data,the process of paleoclimate change was preliminary divided and the drivers of climate change was discussed.As a result,we have found that it was going through a colder-dryer,warm-wet,cold-dry and warm-wet process of paleoclimate change.The process of paleoclimate change is controlled by the solar radiation.Power spectral analysis presented remarkable 23 ka of long period of precession,14.2 ka,11.8 ka of period of half precession,and 0.25 ka of period of double century.Internal factors of land-ocean-atmosphere system maybe enlarge or reduce the secularcycle.The deposition rate of old red sand was large in 70.8~46.4 ka BP and 21.3~11.6 ka BP,and they are the major phases of sand accumulation with 30 mm/（100 a） and 650 mm/（100 a）.