Acknowledgements
This paper represents the synthesis of the authors' decades of research activity carried out with the financial support of national and regional grants, namely: PRIN 1999, PRIN 2001, PRIN 2003, “Progetto Dimostratore Campi Flegrei” of the Centro di Competenza Regionale per lo Sviluppo ed il Trasferimento dell’Innovazione Applicata ai Beni Culturali e Ambientali “INNOVA” (to M. d. G.), Legge Regionale 5 2002 (to P. C.) and Legge Regionale 5 2005 (to V. M.).
The authors would like to dedicate this manuscript to two illustrious Masters of the Federico II University: Prof. Renato Sinno, whose deep knowledge on the Phlegrean subjects is still a notable stimulus for interesting discussions on topics of great scientific relevance and the late Prof. Enrico Franco, unforgettable friend and scientific guide.