View to the
west-northwest with Great Thumb Point in the upper left
quadrant. Galloway and Stone Creek Canyons enter from the
bottom edge while in the distance Deer Creek enters from
the right edge. Tapeats Creek enters from the lower right
The cliff at river level through this section
is a result of the river cutting down through the hard
Bass Limestone and a diabase sill intruded between the
underlying schist and the overlying Bass Limestone. In
places the heat of the intrusion has cooked the limestone
transforming it to marble.
Before reaching Deer Creek Falls the river
passes through Granite Narrows, which at 76 feet is the
narrowest portion of the river within the Grand Canyon. In
this view the river nearly disappears as it goes through
the narrows shortly before it gets to Deer Creek.
The narrows are a result of a landslide that
slid down from the right side of the canyon a few tens of
thousands of years ago. This blocked the old channel, and
the river was pushed to the left where it had to dig a new
gorge down through the bedrock. Digging a new gorge
downward wasn’t much of a problem for the river, but it
means the lowermost portion of the gorge is relatively
young here. “Relatively young” means erosion hasn’t had as
much time to widen the canyon – hence it is still narrow.
to river miles 120 to 128
river miles 136 to 144
the Index Page for the Grand Canyon Tour
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