| Morden coastal aeolian sand dunes are distributed widely around coastal area of China's Fujian province,and coastal aeolian sand dunes of Late Pleistocene,named after Old Red Sand(ORS),are also interruptedly distributed in Southeast of China.Many scholars have been sustematically studied on many scientific issues of Fujian's aeolian sand dunes and made a series of achienements on several challenges,such as formation time and reddening mecharism of ORS,distribution of aeolian sand and clarification and origion of sand dunes in South China.Adhering to the research results of many other scholars,this paper discussed the provenance of ORS,regional sea-level changes and East Asia Winter Monsoon impaces on the process of aeolian sand deposition,and anylized regional envirometal evolution recorded by aeolian sand deposition based on data of optically stimulated luminecence and other climate proxies.The results shown that:(1)Based on the comparison of optically stimulated luminecence chronology of Qingfeng and published OSL data of other ORS profiles,we found that the starting times of ORS deposition in South and North Fujian extended to the last Interglacial which is breaking previous research results.The youngest OSL data from Hutoushan(Zhangpu,Fujian)and Anshan(Jinjiang,Fujian)ORS profiles is about 1 ka.It is a important evidence that the reddening process of ORS just need about 1 ka.Meanwhile there are prominent difference in ORS development process from different areas,maybe it is closely related to geomorphology and construction activities of coastal area of Fujian province and Taiwan Strait,also related to the regional sea level changes.(2)the ORS were mainly deposited in Last Interglaciation and Glaciation,there appears to be disappearance in Last Glaciation Maximum(LGM).The active periods of ORS deposition process usually be high sea level periods.That is to say the deposition process of ORS is related to the regional sea level change.The changes of regional sea level can regulate and control ORS provenance further.(3)Five sedimentary periods and three sedimentary discontinuity in the Dongshan dune can be defined,which reflects that the change of the East Asian monsoon,and the developmental process of Dongshan dune are the result of regional response to the East Asian winter monsoon,and they are well correlated with volcanic activity,winter temperatures of East China and precipitation of summer monsoon at the same time.Meanwhile,it has preserved the sea-level change information of the Fuzhou Basin since nearly 6 ka BP.The widespread thalassocratic periods were recorded clearly in South China at 5.6-2.8 ka,2.8-1.7 ka and 1.7-0.8 ka,respectively.(4)In this study,optically stimulated luminescence(OSL)technique was employed to establish the chronological framework of the site.Samples from the top and bottom of cultural layer yield OSL ages ranging from 1.4 to 6.1 ka,providing a systematic geochronological evidence for the development of 'Anshan culture' in coastal area of southern Fujian province and eastern Guangdong province.In the meantime,there is a clear link between the varying regional sea levels,the chronology of regional(5)wind-sand deposition and the period of Anshan culture since the mid-Holocene.Artificiality and the mark of human activity are observed in the Dongshan dune,and porcelain shards and conchs have been found in the cultural layer.The development processes of the Dongshan dune accord well with the records of human activities and neolithic cultural sequences in northeast Fujian. |
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