Here is an interesting short article from NASA looking at Hawaii as an analog to the Mars volcanoes (and pits). It is not directly cave related, however.
DirtDoc http://www.nasa.gov/centers/goddard/news/topstory/2007/mars_volcanoes.html _______________________________________________ nmcaver mailing list nmca...@caver.net http://mail.caver.net/mailman/listinfo/nmcaver_caver.net
