철원 및 연천 지역 용암대지 현무암의 형성 시기 및 형성 과정

Abstract

The Cheolwon-Pyeonggang Lava Plateau on the Chugaryeong tectonic valley is one of the most extensive volcanic areas in central Korea. However, formative age and process of the plateau still remains a controversial issue. This study presented OSL ages on the upper and lower sedimentary layers of basalt from four sites in the Cheolwon and Yeoncheon areas and estimated age and process of plateau formation based on sedimentary- and chrono-stratigraphy and topographic analysis. The results suggested that most of the initial topography of the plateau on the Cheolwon and Yeoncheon areas had been almost completed before approximately 90 ka. However, the last lava flow around Jangheung-ri, Cheolwon, seemed to occur until 20- 30 ka and had led to complete the present plateau, while the last lava flow in the Jeongok area, Yeoncheon, was estimated to occur at approximately 40 ka.