An article in journal of Geophysical Research disputes the origin of the what has been called the “Sirente crater”.The paper discussing this theory is:
Speranza, F., I. Nicolosi, N. Ricchetti, G. Etiope, P. Rochette, L. Sagnotti, R. De Ritis, and M. Chiappini (2009), The “Sirente crater field,” Italy, revisited. Journal of Geophysical Research. vol. 114, B03103, doi:10.1029/2008JB005759
http://www.agu.org/pubs/crossref/2009/2008JB005759.shtml
They concluded:
“Our data show that the Sirente crater and the minor depressions are simply the results of human activity and karstic processes, respectively.”
An article that discusses this paper is:
Bondre, N., 2009, Geomorphology: Crater or not? Nature Geoscience. vol 2, no. 3, p. 166.
TOC at
http://www.nature.com/ngeo/journal/v2/n3/index.html
PDF file at
http://www.tulane.edu/~kmstraub/Publications/Abrams_09/News_and_Views_09.pdf
Source: Paul H.