摘 要 :钻孔取自上海青浦县赵巷镇 ,柱长 1 9.8m,5个14 C年龄 ( AMS测定 )年代跨度从 1 3 4 60± 60 a B.P.到 2 660± 60 a B.P,但缺失全新世早期沉积。对 1 5m以上 ( 8.5a B.P.)部分系统采集了 3 5孢粉样品 ,样品分辩率在 1 50 a左右 (少数样品除外 ) ;通过有序分割并综合图谱特征划分出 7个孢粉带和 2个亚带 ,据此恢复和重建了本区 8.5ka B.P以来植被变化和气候波动历史。具体结果为 :与现今气候相比 ,8.5a B.P.~ 8.2 ka B.P.为冷干期 ,但气候呈上升趋势 ,地带性植被为含常绿阔叶树种的落叶阔叶林 ;8.2 ka B.P.~ 8.0 ka B.P.为暖湿期、常绿阔叶林 ,气候处于峰值 ,温度高于现今 2℃左右 ,降雨量高于现今 4 0 0 mm左右 ;8.0 ka B.P.~ 7.6ka B.P.为冷干期、落叶阔叶和针阔混交林 ,气候处于谷值 ,温度低于现今 2℃左右 ,降雨量少于现今 4 0 0 mm左右 ;7.6ka B.P.~ 6.2 ka B.P.为暖湿期、常绿阔叶林或常绿、落叶阔叶混交林 ;6.2 ka B.P.~4.0 ka B.P.为温干期、含常绿阔叶树种的落叶林或针阔混交林;4.0 ka B.P.~3.0 ka B.P.为温凉略湿期、含常绿阔叶的落叶阔叶林;3.0 ka B.P.~1.5 ka B.P.为暖湿期、常绿阔叶林,但2.6ka B.P.以来又有变冷趋势。
Abstract:A 19.8m long sediment borehole ZX 1 was recovered in Zhaoxiang of Qingpu County,Yangtze delta plain of eastern China.Five samples were selected from lower core section through upper core section for Accessory Mass Spectrum(AMS)dating.Dates obtained range from 13 460±60 a B.P.to 2 660±60 a B.P.Thirty five samples were taken from upper 15 m core sediment(since about 8.5 ka B.P.)and were analyzed for spore pollen.Seven spore pollen zones and two sub zones were distinguished by means of constrained cluster...