Depósitos de glaciares rocosos en Sierra Nevada (Granada)

Abstract

En las cumbres de Sierra Nevada aparecen depósitos de morfologia acordonada que están constituidos por acumulaciones de cantos angulosos de gran tamaño y una pequeña o nula proporción en matriz. Estos han sido interpretados como depósitos de glaciares rocosos, generados en una última crisis climatica acontecida entre los 13.000 y 10.000 años B.P

Among the variety of deposits in the high mountain zone of Sierra Nevada, some coarse-grained detritic acumulations are worthy to remark. These appear related to glacial scarps and have been interpreted as ancien rock glaciers deposits. Two types have been distinguished: the first has a string-like morfology, the matrix is very scarce and hollow can be found between the pebbles; the second tends to show lobulate forms and higher contents of matrix. In both cases the pebbles are extremely angular and heterometric. The mechanism which probably originated these depositional forms has been gravitational displacing of a rock fragments mass with interstitial ice, wich confered a plastic behaviour to the assemblage. The age for these processes is estimate between 13.000 and 10.000 years B.P