Descubrimiento y caracterización geográfica de una depresión ultramáfica en Sierra Bermeja: nuevos datos geomorfoedáficos, fitogeográficos y paleoecológicos

Abstract

Is presented the recent discovery and characterization of a endorheic basin at the summit of the Sierra Palmitera, an abrupt foothill of the peridotite massif of Sierra Bermeja (SW of Spain) that reaches 1,473 meters above sea level. Given the nature of this littoral ultramafic mountain, this basin is considered a geomorphological exceptionality for the whole of the known peridotite outcrops. Fieldwork and interpretation of photographs, main methodological procedures of the research, and the use of GIS have allowed a first geographical reconnaissance and the mapping of the main physical features to detail scale (1: 5.000). The obtained results are: (1) a topographic map (equidistance of 5 meters) as basis of the thematic mapping; (2) the identification, characterization and mapping of the major geomorphological and edaphic units to the mentioned scale; (3) the characterization of the vegetation and flora of the basin through the phytosociological analysis, and the development of a vegetation map to scale detail. These results provide knowledge about the origin of the basin, its operation and its ecological role. As outstanding feature, the accumulation of sediment at the bottom of the basin allows the paleo-ecological study of vegetation from the charcoals deposited on the soil, highlighting the finding of charcoal of Abies pinsapo , species of spruce threatened currently absent in the location.