摘要
先前研究认为老红砂是末次冰期沿海风沙沉积,近期发现老红砂形成于末次间冰期。在福建平潭青峰典型老红砂分布区采集114个老红砂样品,130冬季风沙样品,60个夏季风沙样品做粒度测量和光释光测年。粒度测量显示冬季风沙粒度频率峰值出现在400μm、夏季风沙280μm,老红砂粒度频率峰值出现在300μm与冬季风沙不同。夏季风沙和冬季风沙以7∶3混合可拟合老红砂粒度分布,表明青峰老红砂沉积期夏季风历时或强度远大于冬季风,对应于气候暖期,而不是末次冰期。老红砂剖面4个自然层光释光测年自下而上为122.5±6.7 ka B.P.、97.7±6.1 ka B.P.、83.1±4.2 ka B.P.、61.9±3.4 ka B.P.,对应末次间冰期,青峰老红砂是暖期气候的风沙响应。
Old Red Sands mainly distributed in China＇s southeast coast and the islands are special red sand de- posits during Quaternary. They were considered to be formed by vast continental shelf sands and beach sands transported under strong winter monsoon and deposited along the coast during 68-9 ka B.E,the last glaciation, low sea stage. In this study, 114 Old Red Sand samples, 130 winter wind sand samples and 60 summer wind samples were collected from typical Old Red Sand area Pingtan Qingfeng. The grain size measurements for the samples show that the size frequency distribution of winter wind sands peaked at 400 μm, of summer wind sands at 280 μm, and of Old Red Sands peaked at 300 μm. Which inconsistent with the winter wind sands. Ex- periments show that mixing summer wind sands sand winter wind sands with 7： 3 can fit Old Red Sands grain-size distribution. It is indicated when Qingfeng Old Red Sands depositing, the lasted or intensity of the summer monsoon is much larger than the winter monsoon, which corresponds to the climate warm periods, rather than last glaciation. OSL dating for Qingfeng Old Red Sands section with 4 natural layer shows a bot- tom-up years of the 122.5±6.7 ka B.P., 97.7±6.1 ka B.E, 83.1± .2 ka B.E, 61.9±3.4 ka B.E, mainly correspond- ing to the last interglacial, Qingfeng Old Red Sands formed during the last interglacial.
出处
《地理科学》
CSCD
北大核心
2014年第3期352-357,共6页
Scientia Geographica Sinica
基金
国家自然科学基金项目(编号:41210002)资助
关键词
青峰老红砂
夏季风沙
冬季风沙
末次间冰期
Qingfeng Old Red Sand
summer monsoon sand
winter monsoon sand
the last interglacial
