This abstract gives the coordinates of a number of the project's candidate impact sites: [link|http://gsa.confex.com/gsa/2006AM/finalprogram/abstract_114274.htm|http://gsa.confex.co...stract_114274.htm]

If the Long Island crater is at 41.17N, 72.405W then perhaps the dunes at 41\ufffd 0'48.30"N 72\ufffd 2'3.27"W are the chevrons, though there's a bunch of land between the two.

Also, if the Indian Ocean crater is here 30.865S, 61.365E, then maybe it's the dunes at 25\ufffd15'58.97"S 44\ufffd39'50.76"E and elsewhere along the southern coast of Madagascar. They do look awfully large (15 miles in length at one point).

The dunes here seem to be right inline with where the crater is supposed to be, and they go way inland: [link|http://maps.google.com/maps?f=q&hl=en&q=madagascar&ie=UTF8&t=k&om=1&z=11&ll=-25.234758,44.520035&spn=0.475155,0.720291|http://maps.google.c...0.475155,0.720291]

Tha 2nd one appears to be volcanic
[link|http://www.kew.org/gis/projects/madagascar/images/simp_geology_very_large.gif|http://www.kew.org/g...gy_very_large.gif]