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The our recent research revealed that coastal dunes along the west coast of Korea were episodically formed and mostly driven by the (relatively) short-term fluctuations in sea level and stronger northwest winds under the higher intensity of Siberian High,although it still opens to debates mainly because of the insufficient supporting data.We found in this research that the sequential pattern of the content of sand in the core sample in mountain wetlands is well coincident with the identified periods of coastal dune building,which suggests ‘comparatively temporary dryness’ be another forcing of episodic dune development.Such interpretation is highly plausible because dryness could induce the remobilization of coastal dunes by reducing the stabilized capacity of vegetation upon coastal dunes.The content of sand (in % unit) in mountain wetland sediment can be an indicator of the degree of rainfall intensity on the upslope area of wetland.Pollen analysis supports such assumption: the lower the content of sand in a layer of core sample,the higher pollens of dryer climate vegetation is observed in the same layer.The age is reconstructed based upon calibrated years by radiocarbon dating.Focus is upon the temporary decrease of the sand content,i.e.short-term minima in the sequential data,rather than the absolute value of the sand content.Such patterns are assumed to represent ‘comparatively temporary dryness’.11 lower peaks in the sequential data of sand content,since c.a.7.7 ka,are mostly well correlated with the identified dune forming periods in the former research,though several exceptions are observed.Dune building periods of 5.7 ka,4.5ka,4ka,1.5ka,0.7ka,0.3ka and 0.1ka (seven periods in total) are represented by lower peaks in the sand content.Lower peaks in sand content data of 7.5ka,6.5ka,2.8ka and 2.2ka are not shown in dune chronology data.While the periods of 7.5ka and 6.5ka in sand content data are beyond the temporal scope of previous data,other two periods (2.8ka and 2.2ka) are within the ‘hypothetical dormant periods of dune building’ between 3.5ka and 1.7ka,articulated by the our previous research.These new sets of evidence raise the new question whether the hypothesis of ‘long dormant periods of dune building’ can survive or the periods of dune building but the already identified ones will be expectedly found around 2.8ka and 2.2ka.