Francesca Liberi (*), David Shimabukuro (**), Eugenio Piluso (*), John Wakabayashi (***) & Walter Alvarez (**)
(*) Dipartimento di Scienze della Terra, Università della Calabria, Arcavacata di Rende (CS), Italy. E-mail: e.piluso@unical.it
(**) Department of Earth and Planetary Sciences, University of California, Berkeley, California, USA.
(***) Department of Earth and Environmental Sciences, California State University, Fresno, California, USA.