Hantangang River Geopark

Like Chatancheon Columnar Joint, Eundaeri Planticular Joint corresponds to a place made by lava that flowed backward along Chatancheon and hardened. But, Eundaeri Region is a geological attraction with very high scientific and educational value because horizontal joints not easily observed in Hantan River and Imjin River are observed. As lava is cooled, columnar joint and horizontal joint are made depending on the environment at that time and the cause of horizontal joint observed in Eundaeri Region is not revealed clearly yet so it can be said to be very important academically. In Eundaeri Region, Baekuiri Layer is well developed at the bottom including horizontal joints and imbrication in which pebbles show the form of fish scales in the direction of water flowing is observed and pillow lava and clinkers are observed, enabling you to observe various geological phenomena. Rocks underlying Eundaeri Region correspond to Misan Layer of the Paleozoic and are known to be metamorphic rocks of sedimentary origin.

Rocks were made about 1.4 billion years ago and calcareous and siliceous deposits were repeated. That is, the calcareous layer which is estimated to be biogenic and silicic of clastic origin (sand and clay) were piled up repeatedly and then, transformed by metamorphism by crustal movements but they are called metamorphic rocks of sedimentary origin because stratification bedding at the time of deposition is preserved.Looking at the surface of rocks, the degree of depth is observed differently and the calcareous part is dug deep because it is weak to weathering and siliceous part seems sticking out because it is relative resistant to weathering.

Also, it shows the fold structure showing the shape of the bent surface of rocks and fold is the structure that horizontally sedimentary strata show a curved cross-section like a wave by lateral pressure and a kind of ductile deformation result accompanied by high temperature and compressive stress. Fold structure can be easily seen in rocks with bedding plane and be divided into various forms depending on inclination of fold axis, inclination of fold axial surface, angle between the wings etc.

Eundae-ri Planticular Joint and Fold Structure