J
JonClarke
Guest
That certainly looks like bedrock. So hydrothermal alteration or sediments as candiadates for the low iron rock are looking more likely.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em> Arthur Clarke</p> </div>