Last-glacial terrace alluvium in the Metauro river basin: Some remarks about new radiometric ages

Abstract

Last-glacial terrace alluvium in the Metauro River Basin: some remarks about new radiometric ages - II Quaternario, 7(2), 1994, 607-612 - Radiocarbon dating of two wood macrofragments collected in the "3rd-order" ("Würmian") terrace-alluvium from the mid-Metauro river basin provide further data on older aggradation phases, thereby allowing significant refining of the recent evolution of valleys throughout the northern Marche Apennines. The two new radiocarbon ages - >43,000 and >44,000 yr. B.P. - are consistent with the only date so far available for a comparable terrace alluvium from this basin (>41,000 yr. B.P.; Alessio et aL, 1987). The dated sandy-silty deposits make up the lowermost unit of the "3rd-order" terrace alluvium; their occurrence, also known in nearby hydrographic basins, is remarkably discontinuous because of the recurrent cut-and-fill processes which affected the aggradation, during the last glacial stage. The new radiometric ages coupled with geomorphologic and stratigraphic evidence, further support the hypothesis that a main aggradation phase, repeatedly interrupted by cut-and-fill processes, took place over the time span from the "lower-middle Würm" through the entire "middle Würm".