Results of field geological survey: The formation made before Holocene Epoch in the area of Middle and Upper Youngsan river region is found mainly paleosols, It is found through analysis of volcanic ash and OSL age measurement that the age of paleosol ...
Results of field geological survey: The formation made before Holocene Epoch in the area of Middle and Upper Youngsan river region is found mainly paleosols, It is found through analysis of volcanic ash and OSL age measurement that the age of paleosols is 12,000 - 100,,000 years ago. The oldest age of the Quaternary formation in this region corresponds to OSL geological age of gravel layer of Hwasun Sachang site(Upper Jiseok river), which is about 100,000 years ago. As the result of the absolute dating of the second cultural layer of Dangga site(middle of Jiseok river, this region have three cultural layer, 1st layer is dated by 70-80 kyr., 2nd layer - 45kyr and 3rd kyr.-30,000. These chronological data is crosely related with whasun Sachang site.
Analysis of volcanic ash for Chongok and Sachang Formation: Volcanic ashes are found in loess and paleosols on the point from the uppermost part of the sites. This point coincides with the cultural layers. It is correlated with AT tephra of Japan and its age is 25,000 years ago. Consequently, it becomes possible to tell the sedimentation time of paleosols and loess located on the uppermost part of the Quaternary formation at these sites. This AT tephra is located under the first soil wedge.
The analysis of the Volcanic Rock of the Gohado area: The Gohado area is composed of a lapilli tuff, a rhyoite and a volcanic glass. The volcanic glass is much younger, having K-Ar whole rock ages 62.4±2.1 Ma for grey volcanic glass and 58.7±2.3 Ma for dark volcanic glass respectively. This kind of the fragment of volcanic rock is founded from the Sachang site. It is very important for the interpretation of the selection of the obsidian, as the raw material.
Pollen analysis: Palynomorphs were recovered from the Pleistocene sediments in the Youngsan river region, and provided some significant data on vegetational evolution and climatic condition during the last glacial in southwestern part of Korea. The palynoflora consists mainly of deciduous broad-leaved angiosperms, including Betula, Quercus, Carpinus, Castanea/Castanopsis, and Ulmus/Zelkova, and Pinus. Analysis of floral composition suggests cool temperate to subarctic condition, cooler than today.
Study of Distribution of Paleolithic sites and its Chronology: This research represent distribution of Paleolithic sites in middle and upper Youngsan river basin. According to the field research , there are almost 26 paleolithic sites. Most of all of them are located in the both side of terraces. General techno-typological character belongs to the 'pebble tool tradition in Northeast Asia'. Conclusionally, we can construct the chronology of the youngsan river region. First peopling of this river came to the Middle Paleolithic period(70-80kyr), such as 1 cultural layer of Dangga and Sachang site. The second is related with the transition period of the Middle to Upper Paleolithic(2nd layer of Dangga and Sachang etc.). Third peopling is migrated to the river about 30kyr years ago(3rd layer of Dangga and Chongok site), as the range of the Early Upper Paleolithic period. Forth peopling is settled in the 2nd layer of Yongdong site(22-25kyr.), as the Middle Upper paleolithic. Fifth Paleolithic people came to the this river in the Late Upper Paleolithic in the 1st layer of Yongdong site(17kyr). From the Middle Paleolithic to the Late Upper Paleolithic main characteristic of the stone tool tradition is related with Pebble tool tradition. It is very significant to provide the evidence of the multiregional theory in Northeast Asia. Finally, paleolithic peopling is migrated to this river in the end of the Upper Paleolithic period(1st layer of Sachang) with the classical Upper Paleolithic stone artifacts.