The authors (Fig. 60) gratefully acknowledge Giorgio Vittorio Dal Piaz for the accurate and constructive review. Simone Tumiati and Andrea Mambretti are thanked for having provided some of the illustrations. Dr. Bonetto and Regione Val d’Aosta are thanked for having permitted the use of the topographic base (C.T.R.). The participants to B02 excursion of 32nd IGC are thanked for having tested the trip with patience and good humour (see http://manhattan.unipv.it. and http://www.geocities.com/g_rebay/FI04_01.html).