Figure 2

(a) composite N-S cross-section, correlating different outcrops and borehole logs along the Tiber valley (see Fig. 1 for location), showing the stratigraphic position of the pyroclastic-flow deposits of Tufo del Palatino (TP), Tufo Giallo di Prima Porta (TGPP) and Grottarossa Pyroclastic Sequence (GRPS)²⁴, which are interbedded with the sedimentary deposits of the Valle Giulia Formation (VGF)³, and of Tufo Lionato (TL). (b) Reconstruction of the erosional/depositional phases during aggradation of the VGF, showing the occurrence of an early aggradational phase coeval with emplacement of TP (I-II-III), followed by a regression coeval with emplacement of TGPP (IV-V) and by a new aggradational phase (VI); reported ages according to this study (see text for detail).