|
The Supai Group forms the red stairsteps
below the Hermit Shale slopes and above the high red cliffs of the Redwall
Limestone. The group comprises four formations composed of rust red sandstones,
siltstones, shales and a few limestone beds containing a beautiful red
chert called jasper. The Supai Group represents a wide variety of environments,
but recent study shows the most prevalent is coastal desert eolian (wind-blown)
sands. Each formation was covered by the sea at least once, but most of
the formation represents dry land. As in the Hermit, the red color is from
iron oxide. |