Sedimenti lacustri dell'area di Castelliri (Frosinone, Italia centrale): dati aminostratigrafici, faunistici e palinologici

Abstract

An aminostratigraphic, fiorai and faunal study of a continental sequence outcropping in the Castelliri area (Frosinone, Central Italy) has been carried out.The sequence is composed of two lithostratigraphic portions, separated by an erosion surface.The lower portion contains faunal and floral associations of (lacustrine)-palustrine environment, that evolved firstly into a typical lacustrine basin characterized by deeper, partly running waters, rich in fauna and vegetation, and afterwards again into a palustrine environment. Faunal and floral analyses indicate a temperate-wet climatic phase with small variations within it. Amino Acid racemization dating of Valvata and Pisidium shells of the lower portion of the sequence suggests an age attributable to the stage 7 of the isotopie oxygen curve. The correlation with the stage 7 is pointed out as well by the character of the palinological diagram. The overlying travertine portion has been deposited in a fluvio-lacustrine and palustrine environment, characterized by shallow, partly stagnant waters, bordered by forest cover. Faunal and floral data suggest the occurrence of a temperate, more or less wet climate. This portion is still attributable to the Upper Middle Pleistocene, though a younger age cannot be excluded. The lacustrine phase of the studied sequence could have deposited because of the formation of a travertine threshold downstream, in the middle Liri valley.