Sunday, June 26, 2016

Flying To and From a Grand Canyon Rafting Trip

My latest river trip in the Grand Canyon included some choice perks! In advance of the trip, there were three nights at The Enchantment Resort located in Boynton Canyon near Sedona and on the back end was a night at the Vdara Hotel on the Strip in Las Vegas. That might sound cheesy I agree, but sandwiched between these two luxurious bookends was a six-day rafting trip in Grand Canyon. It was a perfect ying and yang of a trip. Additionally, there were some fantastic flights to and from the river. This posting highlights only those flights - see some of my other postings for pictures of a river trip in Grand Canyon.

This is a view to the southwest of the Sedona Airport on Table Mesa where our flight to Marble Canyon began. Note the "21" on the bottom of the runway. These numbers tell pilots what orientation they are heading on take-off or landing and 21 is short for 210 degrees, or 30 degrees west of south, which is 180 degrees. In the far background is the House Mountain volcano, a 15 to 13 Ma shield volcano that erupted upon pre-existing topography. You can barely make out some of that preserved topography as the colorful sedimentary rocks beneath the volcano summit. Note the course of Oak Creek as the winding green line between Table Mesa and House Mountain. In fact, Table Mesa is capped by debris from a former alignment of Oak Creek and these deposits are now perched 700 feet above the modern stream. What a wonderland for the geologist.

Famous Cathedral Rock from above. Note the obvious joint pattern in the rocks which align parallel to local faults.

Oak Creek flowing southwest toward Mingus Mountain.

Heading north we cross the Mogollon Rim. These are essentially the same rocks as the upper one-third of the Grand Canyon with one notable exception. The Sedona area contains a 700 foot thick sequence of sandstones and limestone not found in the Grand Canyon called the Schnebly Hill Formation. This unit is seem as the red lower cliffs in this view.

Compare the view above with this one located in the south wall of the Grand Canyon. Between the two is about 100 miles where all of these rocks lay in the subsurface. These are in a sense opposing view of the same rock column, 100 miles removed. Some southern Arizona geologists do not ascribe to the Schnebly Hill nomenclature in the Mogollon Rim. But stratigraphers here know that both the Coconino and Schnebly Hill formations thin to the north and thicken to the south, showing a consistent pattern of deposition that cannot be negated by a few borehole data points.

Looking west into the Grand Canyon of the Colorado River. It is about 10 miles across here and one mile deep with the South Rim on the left side and the North Rim barely visible on the right.

A view north along strike on the Butte fault (where the strata are upturned in photo center). Rocks on the far left are uplifted some 2,500 feet relative to this on the right and place gray Precambrian Chuar Group sediments against red Pennsylvanian sandstones and shale. This is a mighty fault!

Looking down to the confluence of the Big and Little Colorado rivers. We had a great stop here on the following day, swimming in the turquoise blue and warm water. The color comes from dissolved calcium that originates in springs from the Redwall Limestone (seen as the sheer cliff standing 1,500 feet above the confluence).

From directly over the confluence this view is to the south toward Chuar Butte. Red-colored Temple Butte beyond Chuar Butte. Note how the top of Chuar Butte is tilted up to the west (right). This is a section of the flank of the East Kaibab monocline that has been isolated by deep erosion in the Grand Canyon. Note also the drainage and small canyon on top of the butte, trending away from the uplifted edge to the east. Amazingly, this drainage must predate the deep dissection of the Grand Canyon and it is safe to say that the small canyon located on top of Chuar Butte is older than the Grand Canyon!

Now turning 180 degrees and looking northwest along strike of the East Kaibab monocline. Marble Canyon to right and the top of the Kaibab Plateau in the extreme upper left. This is where the Grand Canyon intersects the trend of the monocline.

A wider view of the same area. The Colorado River comes in from the right in Marble Canyon and Nankoweap Canyon can be seen on the far left with Saddle Mountain located right on the crest of the monocline between the two. Here one can understand how the Grand Canyon becomes so deep after it crosses the uplifted portion of the monocline.

Drainage pattern atop the Marble Platform, related to the same drainage seen on top of Chuar Butte above. The dissection of the Grand Canyon in some cases interrupted this drainage.

The giant gooseneck of the Colorado River as it rounds Point Hansborough, visible in the upper right and sticking out toward the photographer. Here the Colorado takes three miles to travel downstream but has advanced only 1/2 mile south. Upper Saddle Canyon near the left bend at the top.

I think this is South Canyon coming into the river.

Marble Canyon.

Upper Marble Canyon.

The slope outside Marble Canyon dips to the north toward the photographer but the river is opposed to this. Curious.

Near the beginning of the Grand Canyon.

Ha! After landing here we completed a six day river trip. I have photos of the river elsewhere on this blog but for now, let's head west and a flight to Las Vegas after the trip.

We left the river at mile 188 from Lees Ferry. Catching a Twin Otter aircraft, we fly out over lava cascades int the Grand Canyon. Look at the "frozen" lava cascades filling an old canyon.

A cinder cone perched on top of the canyon walls is now being cut by Whitmore Wash.

More cascades. Imagine the fury here when this lava was red hot and flowing down into the canyon!

A tributary of Parashant Canyon, seen in the distance.

Twin Point and Kelly Point project out into western Grand Canyon.

This is the mouth of the Grand Canyon. Sedimentary rocks fill most of the frame but on the far right is the Grand Wash fault with 18,000 feet of displacement that has lower these same sedimentary rocks on the west (right). The Colorado River exits the canyon at this location after being "trapped" in the earth for 277 miles. The Hualapai Plateau is visible in the upper part of the photo.

The dark gray vegetation marks the former reservoir bed of Lake Mead when it was at full pool for the last time in 1999. From the upper right corner, a new road comes to the new Pearce Ferry take-out and landing (river boats only). In the center of the photograph is the new Pearce Ferry Rapid, formed when the river insides down into a formed ledge in the Muddy Creek Formation. The original river channel before the reservoir was located farther to the left.

The delta of the Colorado River into the Lake Mead reservoir. Will it ever fill again?

Looking down to The Temple near Temple Bar on Lake Mead reservoir.

Close-up of The Temple, carved into the Muddy Creek Formation.

Looking down into the channel of the Colorado River in the Black Canyon below Hoover Dam. As always, thank you for reading!

Wednesday, June 08, 2016

Join Me on the Alsek River in the Yukon Territory and Southeast Alaska on a Geology-Themed Raft Trip, August 2017

View of the Fairweather Range from the lower Alsek River  
Join me as we float the mighty Alsek River, located in the heart of North America's largest wilderness in the Yukon Territory and southeast Alaska, for 11 days in August, 2017. I will accompany this trip that begins in Haines Alaska, with an overland excursion to the put-in located in the Yukon Territory in Canada. We will float 142 river miles from the interior to the Pacific at Dry Bay. It is a spectacular journey that includes a mandatory 7-mile helicopter portage around the Tweedsmuir Glacier in Turnback Canyon.

If you are interested in this trip, please send me a note and I will forward to you more details. In the meantime, enjoy these pictures from my 2015 trip.
The Faiweather Rang from the air. The Alsek River is located in the background of this photo.

The Walker Glacier seen from the Alsek

Near the Walker Glacier

U-shaped valley as seen from the Alsek River crossing into Alaska from Canada
Interesting rock types from the Alexander terrane along the Alsek River
Interesting clouds on the Alsek River

The wildlife in this part of the world is spectacular. We often see moose, eagles, wolves and bears - all from a safe distance