Geodiversity estimate of the Arxan–Chaihe Volcanic Field extending across two geoparks in Inner Mongolia, NE China

Abstract

Abstract The Arxan–Chaihe Volcanic Field is located SW of the Great Xing'an Range in Inner Mongolia, NE China. This monogenetic volcanic field formed in the Pleistocene, with its latest activity a fissure eruption c. 2000 years ago. Here we present the first geodiversity estimate for the region, applying a method combining the geomorphological and geological elements into a grading system, weighting their rarity, significance and uniqueness. To outline the geomorphological diversity, the geomorphon concept was used alongside a watershed analysis of the theoretical fluvial network of the region. In addition volcanic geomorphological elements were provided. Available geological maps, field surveys and volcano geology classification were utilized for the geological diversity estimates. Geology and geomorphology are the core parameters of the qualitative–quantitative assessment of geodiversity. Geographical Information Systems (GIS) were used for calculations of geomorphological and geological parameters to provide geodiversity estimates for the Arxan–Chaihe Volcanic Field region. The variables used to estimate the geodiversity include geology (rock rareness from a global perspective) and geomorphology (slope variations). In addition we used channel systems and terrain characterization (geomorphon) to describe the morphodiversity of the study area. Our study assessed recent volcanic features and concluded that they have a high geodiversity and elevated geoheritage value. However, the uplifted and structurally complicated old terrains with mature fluvial networks provide high geomorphological diversity to the region, therefore keeping the overall geodiversity score high.