江苏金坛和尚墩旧石器遗址地层的古地磁年代与磁化率研究

北方黄土研究中磁化率分析已越来越多运用到第四纪风尘堆积研究中。采用古地磁极性柱结合磁化率曲线比对定年的方法,初步确定江苏金坛和尚墩遗址750cm厚的地层年龄为330kaBP,对应磁化率曲线判断该区域分别经历了24kaBP左右、110kaBP左右、190—240kaBP左右、300kaBP左右的4个暖湿期,其中间隔有3个干冷时期,具有完整的3个气候旋回。对应地层发育的4个古土壤层、3个黄土层的风尘堆积—古土壤序列。研究表明,虽然古地磁极性定年的方法有一定的局限性,但在以磁化率信息为辅助的条件下,可在一定程度上消除这些局限,获得较为准确的地层年代,多种证据表明这种方法是可靠的。

PALEOMAGNETISM AND MAGNETIC SUSCEPTIBILITY OF THE QUATERNARY SEDIMENTS AT THE HESHANGDUN PALEOLITHIC SITE IN JINTAN, JIANGSU PROVINCE

Recent years, more and more susceptibility analysis has been applied in the study of Quaternary aeolian sediments in northern China. In this article, we use systematic paleomagnetism and susceptibility to determine that the age of the Heshangdun Paleolithic Site in Jintan, Jiangsu Province is 33 kaBP for a thickness of 750 cm. Based on the magnetic susceptibility data, this area experienced four warm-wet periods: 24 kaBP, 110 kaBP, 200 kaBP and 300 kaBP. In between, there are 3 dry and cold periods. There paleoclimatic periods are represented by 4 paleosol and 3 loess beds. Despite potential limits paleomagnetism in combination with magnetic susceptiblity can provide accurate age constraints on the Quaternary aeolian sediments.