A framework for quantifying geodiversity at the local scale: a case study from the Rokua UNESCO Global Geopark

Geoconservation and related quantitative and qualitative geodiversity assessments are gaining increasing attention. However, methodologies for measuring geodiversity at local scale are currently rare. Here, we present a framework for assessing local-scale geodiversity of different landforms using field-based and digital elevation model (DEM-) derived data from the Rokua UNESCO Global Geopark in Finland. We observed the presence or absence of various geodiversity elements, such as geological or topographical elements in our study sites, and used these data to quantify alpha (α), gamma (γ) and beta (β) geodiversity of various landforms. In addition, we measured topographical heterogeneity in the field and from DEMs. The results showed distinct patterns in the geodiversity and topographical variation of the landforms. The differences between α, γ and β geodiversity of different landforms were particularly clear. According to the results, measures of topographical variability can be used to some extent as surrogates for geodiversity, but the choice of optimal variables is context and scale dependent. These results provide perspectives for further local-scale geodiversity assessments in different study areas and are applicable for a range of purposes, from scientific research to practical management and geoconservation. This article is part of the Theo Murphy meeting issue 'Geodiversity for science and society'.

Lonar Impact Crater, India: the Best-Preserved Terrestrial Hypervelocity Impact Crater in a Basaltic Terrain as a Potential Global Geopark

Lonar Impact Crater is a simple meteorite impact crater carved out on the ~ 65 Ma old Deccan tholeiitic flood basalts. The crater, though scoured in a basaltic terrain, is still preserved in its most pristine form, with a central crater lake. The geomorphology, geochemistry, geochronology, hydrology, geophysical parameters, and structural aspects of Lonar Crater have been explored in detail, but still continue to contribute valid scientific insights into the geology of terrestrial impact craters. Lonar serves as a potential analog site for studying impact cratering on planetary surfaces with basaltic terrains such as the Moon and Mars. Besides being a highly recognizable impact crater in India, the Lonar crater and its hinterland stand out with its archeological relevance and spiritual influence among the people. The numerous temples in and around the crater premises uphold the cultural significance of the region. The crater and adjacent areas are rich in flora and fauna representing a diverse ecosystem in the vastness of the arid Deccan Flood Basalts. Hence, the astrobleme and its surrounding is declared a Ramsar site and is also a protected wildlife sanctuary. The Indian Government has also declared the crater a National Geological Monument as well as an archaeological monument. Furthermore, the astrobleme is a unique site with socio-cultural and economic significance. With these plethoras of importance, combined with the geological and socio-cultural aspects in its hinterland, together with the most acclaimed UNESCO world heritage centers Ajantha and Ellora caves in the neighborhood, it stands as the right candidate for a UNESCO Global Geopark. However, the crater and its ecosystem are not preserved well enough, and the uniqueness of the crater is diminishing. But after selection as a Ramsar site, the area shows increased vegetation growth. The SWOT analysis conducted in this study accounts for Lonar Crater and its adjoining areas as a potential global geopark. Thus, through this study, we try to propagate the vivid and myriad importance of the Lonar crater and the necessity of protecting this geological monument from both anthropogenic and natural processes and to appraise the necessity for nominating this area as a UNESCO Global Geopark.