海南岛东北海岸风沙沉积的光释光年代学意义  

Optically Stimulated Luminescence Dating of Aeolian Sand Deposits in the Northeast Coast of Hainan Island

作　　者：张文静[1,2] 李志忠[1,2,3] 靳建辉[1,2,3] 郑斐[1,2] 李志星 徐晓琳 程延 ZHANG WenJing;LI ZhiZhong;JIN JianHui;ZHENG Fei;LI ZhiXing;XU XiaoLin;CHENG Yan(Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education,Fuzhou 350007,China;College of Geographical Sciences,Fujian Normal University,Fuzhou 350007,China;Institute of Geography,Fujian Normal University,Fuzhou 350007,China;School of Earth Sciences,China University of Geosciences,Wuhan 430074,China)

机构地区：[1]福建师范大学湿润亚热带山地生态国家重点实验室培育基地,福州350007 [2]福建师范大学地理科学学院,福州350007 [3]福建师范大学地理研究所,福州350007 [4]中国地质大学(武汉)地球科学学院,武汉430074

出　　处：《沉积学报》2021年第4期995-1003,共9页Acta Sedimentologica Sinica

基　　金：国家自然科学基金(41771020)。

摘　　要：选取海南岛东北部JSD2和PQR2两个典型海岸沙质沉积剖面进行研究,共采集10个测年样品和89个指标分析样品,在室内进行了光释光(OSL)测年和粒度分析。结果表明:1)JSD2和PQR2剖面砂样以中细沙为主,粒度众数在225~400μm之间。风沙沉积后受化学风化作用呈现淡红棕色至红棕色;2)JSD2剖面OSL年龄范围为(2.20±1.09)~(9.89±1.65)ka,属于全新世风沙沉积;PQR2剖面年龄范围为(3.41±0.78)~(22.50±1.07)ka,上部为全新世风沙沉积,下部为末次冰期和晚冰期的老红砂层;3)综合海南岛和华南其他海岸沙丘、海岸风沙年龄数据分析,研究区全新世海岸风沙沉积年代序列可划分为10.5~6.0 ka B.P.和6.0 ka B.P.以来两个阶段,华南热带与亚热带海岸风沙活动趋势基本一致。Sand dunes are widely distributed along the northeastern coast of Hainan Island.The aeolian sediments in the coastal area contain good information about the development history and paleoenvironmental information.In this study,two typical coastal sediment profiles,JSD2(0-7.2 m)and PQR2(0-3 m)in northeastern Hainan Island were selected as the research object.A total of 10 dating samples and 89 index analysis samples were collected,and optically stimulated luminescence(OSL)dating and particle size analyses were performed in the laboratory.The results show that:(1)The sand samples in JSD2 and PQR2 sections are mainly composed of fine and medium sand,with grain size mode between 225μm and 400μm.The aeolian sand is light reddish brown to reddish brown after chemi-cal weathering.(2)The OSL age range of JSD2 profile is(2.20±1.09)-(9.89±1.65)ka,which places it in the Holocene.The PQR2 age range is(3.41±0.78)-(22.50±1.07)ka.The upper part is a Holocene aeolian sand deposit;and the lower part is an ancient red sand layer dating to the last glaciation.(3)Based on this age data and other coastal sand dunes in south China,the Holocene coastal aeolian sediments in northeastern Hainan Island is divided into two stages,10.5--6 ka B.P.and since 6 ka B.P.Coastal aeolian activity was weak during the Holocene megathermal stage 9.0-7.0 ka B.P.The trend of aeolian activities in the tropical and subtropical coasts of south China is basically the same.

关 键 词：海岸风沙 光释光测年 全新世 海平面变化 海南岛 

分 类 号：P931[天文地球—自然地理学] P597.3