Above the glacial layers sits a red sandstone containing hematite—a mineral that forms only under oxygen-rich skies. (Hematite has also been found at the landing site of the Mars rover Opportunity.
Above the glacial layers sits a red sandstone containing hematite—a mineral that forms only under oxygen-rich skies. (Hematite has also been found at the landing site of the Mars rover Opportunity.
覆盖于冰期地层上方的砂岩，则含有只在含氧丰富的环境中才会形成的赤铁矿（火星巡迴者机会号探测车的著陆点亦发现赤铁矿的存在，然因颗粒较粗，故呈灰色。）