http://knau.org en http://knau.org/post/carving-grand-canyon-new-theories-about-old-canyon <p>Flagstaff geologist Wayne Ranney discusses&nbsp;some new theories of how - and when - the Grand Canyon formed.&nbsp;The second edition of Ranney's book,<em> Carving Grand Canyon, </em>was recently released. Thu, 15 Nov 2012 19:32:00 +0000 Gillian Ferris 23369 at http://knau.org Carving Grand Canyon: New Theories About An Old Canyon