단양 수양개 유적의 고고지질과 제4기 환경

Abstract

Geoscientific analysis was carried out for the selected representative litho-profiles of three Suyanggae sites (LOC I, LOC III, LOC VI) to illuminate the site-forming processes. The properties of geological marix, grain size, magnetic susceptibility are primarily examined and site-forming process is explained with the help of C-M patterns constructed from the fine-grained sand and silt fractions of the Geosols. As a result it is indicated that in Suyanaggae LOC I site silts, sands and pebbles were transported in general either in the form of mudflow derived from the slope process, suspension of the floodplain, or saltation or traction loads moved in accordance to the flowing regime of the river bottom. From Suyanggae LOC III site sedimentary deposits are characterized that they are generally controlled by the various types of slope process, particularly dominant by the poorly-sorted mud deposits derived from mudflow, which are minorly associated with the intercalations of suspended silt deposits of flooding origin. From Suyanggae LOC III site it is typified by the cyclic sedimentary deposits alternated between slope mudflows and sandy silts transported as suspended loads. Slope mudflows and debris flows are dominant above the 127.3 m (asl) of the representative litho-profile (-5D pit). Below the altitude of 127.3 m (asl) it shows that slope mudflows and debris flows are gradually decreased, but fluvial suspended muds are more dominant than the above part. Lastly Quaternary sedimentary deposits began to form since the stadial (MIS 4) of the last glacial period, but the formation of artefact layers of Suyanaggae sites (LOC I, III, VI) were initiated during the interstadial of last glacial period, when the paleoclimate was relatively milder than the previous stadial. It means that early part of artefact layers belongs to middle or late interstadial, approximately ranged between 44,100yrs BP and 30,360 yrs BP, when blades are widely produced as the major artefactual type of the early to middle upper paleolithic. The late part of artefact layers belongs approximately to the last glacial maximum (LGM, MIS 2), ranging between 20,470 yrs BP and 17,550 yrs BP, when microblades were produced consistently as typical artefacts of late upper paleolithic.