Tuesday, May 10, 2011

More Cross Bedding

There we were, at the end of the Canyon Overlook Trail in Zion National Park, looking west toward the southern end of Zion Canyon, where the North Fork of the Virgin River flows through (not that you will see it the Virgin in this post).
Reddish brown to orange cross beds of the Jurassic Navajo Sandstone (Jn) were everywhere, available for angled sun bathing, photography, and a bit of careful climbing. And beyond and above, there is the ever-present white (and still cross-bedded) upper portion of the Navajo.
I zoomed in on a fascinating section of white to yellowish sandstone in the cliff below the upper white sandstone: cross beds amongst cross beds.
A small tree, and a mini-tree below it, grow near the edge of the 400-foot drop into the lower canyon of Pine Creek. Wedge and trough cross strata can be seen in the nearby reddish cliff behind the tree. In the distance, an inset arch may eventually form beneath the uppermost reddish layer, below the upper white sandstone.
I looked over the edge at the actual trail end, which has a convenient metal railing. One of the windows for the mile-long tunnel on the Zion – Mount Carmel Highway (Utah S.R. 9) can barely be seen in the deep shadow to the right of the sunlit cliff.
If we could hang way over the edge, we'd see The Great Arch, an inset arch just beneath us. I took the photo from one of S.R. 9's many switchbacks (six, to be exact) as it makes it's way up to the west tunnel entrance. This kind of inset arch is sometimes called a blind arch.
Finally, we have to turn away from the overlook to head back towards the trailhead and the road east.
Indian paintbrush on sandstone.
A narrow part of the trail, with a small dropoff, heads back toward the cave seen in the last post. The inset arch visible from the cave, across the slot-canyon portion of Pine Creek, can be seen in the shaded background of this photo.
Around the corner, the trail goes into a sandy narrows between pale orange sandstone and a reddish brown layer. The cross beds here (and in much of Zion) are generally dipping to the south, as can be seen in the far cliffs, indicating that the wind blowing the dune sand came from the north. Here, the the pale orange beds we've been walking on are dipping to the south, and the reddish brown layer we're about to walk on dips to the north.
Cross bedding! (With foot and lichen.)
On the way back, the Bighorn Sheep we passed on our way out had moved closer to the trail (right on the trail!) and closer to the trailhead. This one was munching on bushes near this magnificent exposuring of cross bedding. I'll show more pictures of these critters in another post.
Even more cross bedding, with some tafoni-like weathering accentuating some of the layers.
We're now in the home stretch on our way to the parking area, having passed the overhung cave. This is one of the heavily hand-railed sections of the trail: there's a ledge about 5 feet below the trail, then a couple-hudred-foot drop to the slotted canyon of Pine Creek below. Ahead, the trail goes around a corner to turn more easterly, goes past the leaning tree of the first post, and then goes into relatively steep, somewhat slippery, sand-covered sandstone ledges and the doubly railed steep stairs carved in sandstone at the beginning of the trail.

I strongly recommend going out of your way to take this hike.

This mini-series will now go in at least two directions, one being the road from St. George, Utah, to Zion, through the tunnel and over the pass to Mount Carmel Junction, with a couple photos on the loop road toward Cedar Breaks and into Cedar City. There will be no pictures from Cedar Breaks: the highway department hadn't even considered plowing snow from the south entrance, where it was at least two feet deep.

3 comments:

Diane AZ said...

I hope to take that hike someday. Really enjoyed this post, gorgeous pictures!

Evelyn Mervine said...

Beautiful pictures! Imagine when all that sandstone was sand dunes!

Silver Fox said...

Thanks!

Diane, I hope you do take that hike.

Evelyn, I imagined sand and dunes all around and above me, and would love to see someone create a movie of some sort showing the formation of the dunes and development of Navajo as it is today.