Lo sbarramento di travertino delle Marmore (Bacino di Rieti, Italia centrale): Aspetti geomorfologici, faunistici ed ambientali

Abstract

A study of the natural travertine barrier at the confluence of the Velino and Nera rivers in the Marmore area is described. The natural travertine barrier, during its development, caused the formation of a 160 m high waterfall and has long governed - up to Historical times - the development of fluvio-lacustrine and palustrine environments upstream, in the "Cuor delle Fosse" area, the upper part of the travertine plate outcrops; this consists of a 20 m thick sequence of superimposed autochthonous and detrital travertine bodies, rich in fresh-water and terrestrial mollusks. An anthropic colluviai horizon containing archeological remains attributed to the late Bronze Age (about 3,000 years B.P.), occurs within the travertine sequence. On the basis of sedimentological and malacological features and of the isotopic composition of studied sediments, together with aminostratigraphic analyses and radiometric age determinations, it has been possible to reconstruct the environmental and climatic conditions and to date sediments to Holocene times.