Basalt Gorge Along Daegyocheon Stream of Hantangang River

Basic information

Designation

Natural Monument No.436

Category

자연지형

Designated year

2004

Location

포천시, 경기도— 경기도 포천시 관인면 냉정리 1101 등, 강원특별자치도 철원군 동송읍 장흥리 725 등

Coordinates

38.181100, 127.287200

There are basalt gorges along Hantangang River as it runs through basalt plains. The valley at Daegyocheon Stream in Cheolwon is one of the most significant among them, since it is very important in understanding the formation of the geology and topography of the Quaternary period. The basalt rift valleys on either side of the canyon were dated with the K-Ar method, with the results indicating that the rock was formed about 270,000 years ago through three lava eruptions, leaving beautiful joints on the valley walls. Pillar-shaped points or columnar joints are hexagonal pillars of rock formed when lava cools and shrinks and can be found not only on the riverbed but also on the valley walls. The basalt gorges of Hantangang River is 1.5km long and 20-30m deep, offering spectacular scenery. The pillar-shaped points are in excellent condition; thus, the valley serves as valuable material for understanding the geology of the Quaternary period.

Location