Morphometric Comparison of Dolines in Three Karst Landscapes Developed on Different Lithologies

[EN] The present contribution compares the geomorphological characteristics of dolines developed in three different geological contexts in southern Spain: an evaporite tectonic melánge, a bare-carbonate massif, and an outcrop of inter-stratified sedimentary gypsum sequence. In the three cases, the closed depressions have been identified and mapped using digital elevation models with a spatial resolution of 5 m, and the results were validated in the field. To reveal similitudes and differences due to distinctive geological and climatological settings between the three sites, morphometric and spatial analyses were applied to the threes sites: size-distributions, relationships between area and depth, preferential directions, and point field analysis, among others. The results show apparent differences between the carbonate and the two evaporitic settings. Carbonate outcrop displays larger dolines, implying a lower doline density, while the density of depressions rises in the evaporite sites. The results also show a dominant ENE-WSW alignment of dolines in two areas, in agreement with the main fault families of the Betic Cordillera, which evidences the tectonic influence on the karst development. However, in the gypsum karst, other directions appear related to the surficial drainage network connected to dolines. Finally, in the tectonic melange, the uneven distribution of lithologies affects karstification distribution. Geological differences (both lithology and structure) imply changes in solubility and karstification dynamics that, together with other factors such as the climatic conditions and the exposure time, affect the genesis of the depression and, ultimately, its size and shape. All that combined explains the differences in morphometric parameters and spatial.