Geoheritage Values of the Quaternary Hantangang River Volcanic Field in the Central Korean Peninsula

Abstract

The Quaternary Hantangang River Volcanic Field (HRVF) in the central part of the Korean Peninsula hosts unique volcanic landforms associated with fluvial topography. The volcanic field consists of a series of basaltic lava flows, ca. 0.1 to 0.6 Ma old, which originated from two source vents in DPRK (Democratic People's Republic of Korea; North Korea) and flowed along a 110 km long stretch of paleo-river channels to the terminus in the northern part of ROK (Republic of Korea; South Korea). Afterwards, the lavas were eroded by the re-established river system, producing an array of precipitous exposures of columnar-jointed lavas along the channel walls, a number of waterfalls, and other fluvial landforms. The Hantangang River National Geopark was established in 2015 based on the volcanic geoheritage values of the region. Eighteen geosites in the geopark show high geodiversity and can be divided into five major groups of geotopes, including (1) volcanic landforms, (2) fluvial landforms, (3) pre-Quaternary basement rocks, (4) Quaternary deposits associated with archeological ruins, and (5) warm spring. Several geosites are related to ecological, cultural, and historical features. Here, we provide field-based documentations of the geoheritage values of these geotopes, regarding (1) the processes of terrestrial lava flows along a river valley, (2) landform evolution through the interplay between lava flows and fluvial erosion, and (3) the relationship between geological processes and ecological, historical, cultural, and archeological values. The geoheritage values of the Quaternary HRVF may justify for a UNESCO Global Geopark status in the future.