• The Korean Journal of Quaternary Research
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• v.31 no.2
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• pp.13-22
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• 2017

The age of the Sorori old fluvial deposits is assumed as old as Last Interglacial(MIS 5) when appying the thalassostatic terrace formation in mid- to downstream Keum river basin, while the young fluvial deposits are interpreted to be formed since the post-LGM(last glacial maximum), including both the Bølling-Allerød (B/A) Interstadial(12,700~14,700 cal-yrBP), and the Younger Dryas Stadial(11,700~12,900 cal-yrBP). The wild rice seed like Oryza rufipogon found in the middle organic muds of the young fluvial deposits dated after about 15,000 cal-yrsBP, when the transition from the subalpine conifer forest to the deciduous broad-leaved forest was conspicuously evidenced in the upper part of OC-2 palynofloral zone of the in Cheonju Sorori site, In particular the OC-2 palynofloral zone ranging towards the upper part of middle organic muds(peaty muds) is interpreted to be formed in the B/A Interstadial. It is regarded that Cheongju Sorori rice seeds are associated with warm palynological evidences and backswamp insects during the Lastest Glacial, showing appearance of relatively warm climate similar to the present.

• The Korean Journal of Quaternary Research
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• v.16 no.2
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• pp.9-21
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• 2002

In Korea, many open-air upper palaeolithic sites are located at the river valley, particularly exposed in gently rotting terrain along the river course. They are situated at an altitude less trail 30 m above present river bottom, and covered with the blankets of slope deposits of several meters in thickness. The purpose of this research is to eluridate depositional and vegetational environment of the alluvial upper palaeolithic Jangheung-ri sites on the basis of analytical properties of grain size population, chronology, palynology, soil chemistry and clay mineralogy and magnetic susceptibility of the Jangheung-ri Quaternary formations. The lithostratograpy of Jangheung-ri sit is subdivided into 3 layers based on the depositional sequence and radiocarbon ages. From bottom to top, they are composed of slope deposits with lower paleosol layers, young fluvial sand and gravel with backswamp organic muds, and upper paleosol layers. The upper paleosol was formed under rather dry climatic condition between each flooding period. Dessication cracks were prevalent in the soil solum which was filled with secondarily minuted fragments due to pedogenetic process. The soil structure shows typical braided-typed cracks in the root part of cracking texture, and more diversified pattern of crackings downward. The young fluvial sand gravel were formed by rather perennial streams after LGM. The main part of organic muds was particularly formed after 15Ka. Local backswamp were flourished with organic muds and graded suspension materials in the flooding muds were intermittently accumulated in the organic muds until ca. 11Ka. This episode was associated with migration of Nam River toward present course. Organic muds were formed in backswamp or local pond. Abies/Picea-Betula with Ranunculaceae, Compositae, Cyperaceae were prevalent. This period is characterized with B$\Phi$lling, Older Dryas, Allerod, and Younger Dryas (MIS-1). Stone artefacts were found in the lower paleosol layers formed as old as 18Ka-22Ka. Based on the artefacts and landscape settings of the Jangheung-ri site, it is presumed that settlement grounds of old people were buried by frequent floodings of old Nam River, the river-beds of which were heavily fluctuated laterally and river-bed erosions were activated from south to north in Jangheung-ri site until the terminal of LGM9ca 17Ka).