Granulometric characteristic of the alluvial formations in the Cartagena field (Spain). The succession semi-arid environmental conditions which have affected the area of Cartagena, in the southeast of Spain, from the Quaternary up to now, gave rise to torrential rainfalls which can be appreciated in the landscape's alluvial formations. The granulometric analysis of these accumulations helps to tell apart the dífferent morphogenetic processes affecting their deposit, as well asto characterize their sedimentalfacies. In this respect, the common índices ofheterometry, acuity, asymetry, and those of dynamic classification, energy rate (N) and thickness índex (X) of Riviére (1977) have been calculated. The interpretation of those facies with bends of accumulative frequency, and the description of the sedimentary structures, where the analyzed samples are located, round of this study on the alluvial formations of a semiarid Mediterranean area