江汉平原6000年以来的古降水变化:江陵剖面沉积物粒度记录

PALEO-PRECIPITATION EVOLVEMENT OVER 6 kaBP IN JIANGHAN PLAIN: RECORDS FROM GRAIN SIZE OF JIANGLING SECTION SEDIMENTS

通过对江陵剖面沉积物的高密度采样和粒度分析,重建了江汉平原江陵地区近6.0 kaBP以来的古降水古气候变化序列:6.0～4.6 kaBP为干旱阶段;4.6～2.5 kaBP为湿润时期,该时期可以进一步划分为前、后两个阶段:前期阶段4.60～3.44 kaBP降水波动频繁,其中4.60～4.27、4.16～3.95、3.80～3.68 kaBP为湿润时期,而4.27～4.16、3.95～3.80、3.68～3.44 kaBP为干旱时期;后期3.44～2.50 kaBP为稳定的湿润阶段,湖沼泥炭发育,其中3.1～2.87 kaBP为干旱阶段;2.50 kaBP以来,由湖沼堆积转化为洪水漫滩堆积,气候变干或冷干.江陵地区6 kaBP以来的古降水古气候变化与国内相邻区域及国外的研究资料一致.

Through the high-resolution sampling and grain size analysis, the paleo-precipitation evolvements during the last 6 kaBP at Jiangling area, Jianghan Plain, China, is reconstructed. The climate in this area was cold and arid in the period of about 6.0-4.6 kaBP, and warm and wet between 4.6-2.5 kaBP. Climatic fluctuation was especially frequent between 4.60-3.44 kaBP, and then altithermal between 3.44-2.50 kaBP,with limnic peat wide development. It was cold period after 2.50 kaBP. The climatic changes over 6 kaBP in Jiangling area were coincident with large numbers of research data from domestic neighboring areas and overseas. Moreover, many obvious climatic events are in good agreement with many international study results.