Friday, May 06, 2016

Museum of Northern Arizona Ventures - Three Trips in One Month to Utah Parklands

Since 1982, I have served as an educator and guide for the Ventures Program at the Museum of Northern Arizona. It has been an incredible experience and I have been privileged to share the beauty and geology of the Colorado Plateau with hundreds of Venturers. This year however, I got to share it with a special lady, my wife Helen, who served as my assistant on three trips to Utah during the month of April. I decided to use her photographs in this posting, that shows images from all three trips to Canyonlands and Arches national parks, Capitol Reef National Park, and Grand Staircase Escalante National Monument.

Canyonlands and Arches - April 4 to 8, 2016

On the way to Moab from Flagstaff, we always stop at Monument Valley and hike the 3.5 mile Wildcat Trail that circum-transits the West Midden (left).

The strata here play a huge role in the geologic story we tell in this part of the eastern Colorado Plateau. The lower "aprons" in the monuments are composed of Permian Organ Rock Shale with the caps composed mostly of DeChelly Sandstone (with minor amounts of Moenkopi Fm. and Shinarump Mbr. of the Chinle Fm. on the very top). This Organ Rock/DeChelly interval will coarsen to the northeast near Moab (see below).

Our first big hike was in Negro Bill Canyon, a well-watered stream that is a rarity in the desert southwest.

After 2.75 miles, Morning Glory arch appears at the head of a side canyon. This arch might more rightly be considered a bridge since the stream does underlay the span.

Later in the day, we stopped by Fisher Towers in the Professor Valley of the Colorado River. These fantastic spires have served as a backdrop in many a Western movie but their geology tells an even more compelling story. This is the same interval of strata as seen in Monument Valley (see above) but here the sediment is located much closer to the source, the Ancestral Rocky Mountains. Pebbles and boulders of schist and granite are found in these deposits suggesting that this was part of a proximal alluvial fan off of that ancient range. In Monument Valley, the strata were far enough away to differentiate into different formations.

Our little group at Fisher Towers!

The next day we began early to beat the spring-break crowds that might hime to Delicate Arch, carved into the Estrada Sandstone.

Looking south into the Salt Valley, where Pennsylvanian-age salt deposits bulged upwards after burial and later escaped and dissolved to form a salt valley. Note the dip on the strata to the left where overlying layers were hinged downward as the salt escaped and created a void in the subsurface.

Landscape Arch. Hmm? I wonder if the names Delicate Arch and Landscape Arch were mistakenly transposed on an old map??

Looking south from Broken Arch to the La Sal Mountain laccolith. In the middle distance is the Professor Valley near the Colorado River.

Balanced Rock has to be one of the most unusual rock formation anywhere.

Helen holds up the top.

The new day we headed uphill to the Island in the Sky section of Canyonlands National Park. The first hike was to Whale Rock.

Looking west into Upheaval Canyon and the Upheaval Dome. The block of Navajo Sandstone on the right is out of place having slipped down on a small fault from where the photographer stands.

Panorama view from the top of Whale Rock.

Near Grandview Point, at the south end of Island in the Sky, a trail leads past an outcrop of the Kayenta Formation. Here a small Jurassic-age channel is been filled with sand but at the channel base are rip-up clasts, sections of floodplain mud that were ripped up during a flood and deposited in the channel.

At the last moment we decided to take the Shafer Trail back to Moab. This uranium-era road descends the Wingate cliff in spectacular fashion and then traverses the Shafer shelf toward Moab. Here isa shot from Thelma and Louise point, where they filmed the final scene in the movie of the same name.

Our final stop was in the Needles District of Canyonlands where we hiked at the Elephant Hill trailhead. These strata, known as the Cedar Mesa Sandstone, are also part of the Cutler Group rocks that are associated with the paleotopography of Ancestral Rockies drainage system.

Interbedded shale and sandstone form wonderful mushroom rocks.

Cross-bedded sandstone of the Cedar Mesa Sandstone. Thanks to my fellow travelers on this one!

Capitol Reef National Park - April 18 to 22, 2016

Our Capitol Reef trip began by driving through eastern Arizona and Utah. This is a view looking upstream on the Colorado River near Hite. Note the Lake Powell deposits that fill the floodplain. The reservoir is currently down 108 feet from full pool.

Looking downstream from the same vantage, showing how high and dry the boat ramp is at Hite! That's it as the long concrete ramp beneath the red cliff. The river is barely visible in the foreground.

Giving a brief geology talk on the bench in front of the Park Visitor Center. On these trips we always get passers-by who hear the talk and become interested. To visit these parks with a knowledgeable scientist is totally unlike a visit without one.

The Fremont River near the beginning of the Hickman Bridge Trail.

Along the way, I found this channel cut and fill sequence within the Kayenta Formation (the angled line from upper right to lower left).

The clasts in this exposure were the largest I have ever seen in the Kayenta Fm.!

Capitol Gorge hike. Old Highway 24 used to go through here as late as 1962.

I had never before seen a contact like this! Kay C. puts her hand on top of a lee set (below), right where another dune laps up onto it from another direction. Normally, lee sets are truncated or beveled to near horizontal with the overlying sets covering them. The evidence here suggests that an active dune (below) was buried by another dune. Wow!

The next day we headed north in the park toward Cathedral Valley. The Bentonite Hills are fantastic exposures of the Morrison Formation.

You don't want to be here after a rain as the clay turns to goop. An artistic scene from Helen!

More of the Bentonite Hills toward the east. The sis the Brushy Basin Member, which admittedly looks a lot like a the Petrified Forest Member of the Chinle Formation. Students are often confused. But knowing the stratigraphic succession will reveal which is which. You have to see the sequence to know where you are at within it.

Jailhouse Rock with the Thousand Lakes Plateau in the distance.

An unnamed Cathedral Valley overlook. The soft brown sandstone is the Estrada Ss. with a cap of the whitish Curtis Formation.

Same sequence, different place.

This is the Temple of the Sun in the foreground and the Temple of the Moon behind. This ends the narrative about the Capitol Reef trip. We drove home through Grand Staircase Escalante National Monument, which is the subject of the final trip.

Grand Staircase Escalante National Monument - April 25 to 29, 2016

Our Grand Staircase Escalante trip this year experienced some interesting weather with snow, hail, rain and wind. Up to 3 inches of snow fell in Boulder Utah on Thursday April 28. Fo this reason, few photographs were taken. But we did visit Lower Calf Creek Falls, Anasazi State Park, petroglyphs, and the Burr Trail.

Large petrified wood specimen at the Wolverine Petrified Wood Special Use Area. The Chinle Formation is famous for its petrified wood and the wolverine area does not disappoint.

A giant specimen that has fractured during uplift of the Plateau.

Our secret lunch spot near the Burr Trail switchbacks. We always walk the switchbacks and get picked up below. It is the best way to see the tilt on the Waterpocket Fold.

Our group at the Strike Valley Overlook in Capitol Reef National Park. You can see the storm clouds gathering - we got this hike in just before it let loose that night.

On our way home, Helen had arranged for us to pay a visit to the Paleontology Lab for the Monument in Kanab, Utah. There are incredible dinosaur finds that have been made since it was declared a Monument 20 years ago. To those who decry the establishment of the Monument, these finds more than negate the selfish reasons to leave the area unprotected.

Helen poses with lab volunteer and Plateau photographer extraordinaire Gary Ladd, through the frill of a ceratopsian dinosaur (cast).

Some of the more exciting finds in the Monument include rare skin impression of dinosaurs. These were made when the carcass pressed against soft sediment.

The specimens are spectacular! One of the great finds in all of the digs at GSENM is that the area looks like it was a separate ecosystem from that of the same age up north in Montana and Alberta. Perhaps that system was more temperate with GSENM being more tropical - the species are different here for the same age rocks - about 71 Ma.

Alan Titus (left) is the Monument Paleontologist and his capable assistant is Scott Richardson (center). I was honored to pose with them both.

A final hike at the Toadstools off of Highway 89. This is Estrada Sandstone with a boulder of Dakota Sandstone as its cap rock. What a month it was! I cannot thank Helen enough for the excellent job she did in assisting me. These are great trips!

1 comment:

  1. Wow! Great trips, narrative, and photographs. Thank you, Wayne and Helen.


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