Dreams of Summer and Southwest Travels: Grand Stories Exposed in a Canyon

No one place on Earth can ever tell the whole story of the Earth. But there are lots of places that tell part of the story. That's the fact that makes geology one of the most fascinating sciences there is. It's an incredible detective story that must be pieced together from disparate bits and fragments that must be correlated and organized into a coherent narrative. Some places tell more of the story than others, and some places do it in a fashion that is awe-inspiring. Grand Canyon is one of those places. It is one of the greatest places on the entire planet to teach the basic principles of geology. The geology is in your face, exposed perfectly, largely free of soil and vegetation, and yet the canyon is still a place of mystery and unsolved questions.

We are in the depths of winter this week, so I've been traveling back through the photo archives for a look at warmer times, our field studies trip to the Colorado Plateau last summer. We spent two days on the South Rim of Grand Canyon, which barely gave us time to scratch the surface of the fascinating place.

For me, a nice moment came while staring into the depths of the canyon from Lipan Point. The view, seen in the first picture, reveals a labyrinth of tributary canyons, but the Colorado River is visible in the center of the photo. I zoomed in (photo two). What's remarkable about this one spot is that it is one of very few flat open areas on the floor of the Grand Canyon. It's called the Unkar Delta, and I have wonderful memories of an exploration there two years ago.

The "delta" (really kind of an alluvial fan) formed as debris poured onto the canyon floor from Unkar Creek. It is one of the few arable spots in the depths of the canyon, and the Ancestral Puebloan people utilized the soils to grow food there for more than three hundred years, from about 850 to 1200 AD. We stopped there during my one and only rafting trip down the Colorado River 813 years later in 2013. I wrote about the spot in my blog series "Into the Great Unknown". It was around 112 degrees as I explored the ruins that dot the delta, while the rafters scouted Unkar Rapid. The rapid is one of the first of the big rapids one encounters in the canyon, rated as high as 7 out of 10 on the difficulty scale (we made it through without incident other than getting wet, which was a relief in the sweltering heat).

The deep maroon color of the canyon walls at Unkar Delta reveals an interesting period of the Earth's history. The rock is part of a layer called the Dox Formation, which was deposited in estuaries, tidal flats, and deltas during the Mesoproterozoic era, just over 1.1 billion years ago. The rock is mostly composed of easily eroded shale and siltstone, which explains the open aspect of this part of the canyon. The Dox also contains fossils.

Life existed on Earth a billion years ago, but it was only of the simplest forms, algae and bacteria. The algae grew on pebbles in tidal flats, and as the tides ebbed and flowed, mud stuck to the algae-covered surfaces eventually forming layered structures called stromatolites. The stromatolites seen in parts of the Dox formation are among the oldest fossils found in the American west.

The Dox is part of a larger sequence of tilted layers in the Grand Canyon called the Grand Canyon Supergroup. The Supergroup is upwards of 12,000 feet thick, more than twice the depth of the canyon itself. How do the rocks fit in the canyon? They've been tilted and subsequently eroded. The exposures can be followed for a number of miles along the river in the depths of the canyon, but they have otherwise been covered by 4,000 feet of later (Paleozoic) sediments deposited between 540 and 250 million years ago. The rocks are fascinating to study, but the only way to do it is to hike to the bottom of the canyon, or raft the river (I've had the privilege of doing both). They can easily be seen from viewpoints in the eastern part of the canyon on both the north and south rims.

The Grand Canyon region exposes more than sedimentary rocks. There are numerous faults and folds throughout, including the unique monoclines, folds that are draped over step faults. One can be seen as the dark ridge in the middle of the photograph below.  Volcanism is a part of the story of the Grand Canyon as well. The peaks on the skyline in the same picture are the San Francisco Peaks, a group of cinder cones and a very large stratovolcano. Humphreys Peak, the high point on the rim, is the highest mountain in Arizona at 12,633 feet (3,851 meters). Prior to extensive erosion, the peaks may have exceeded 16,000 feet. The origin of the this massive volcano is somewhat enigmatic. The volcanic field is youngest on the eastern side, suggesting a possible origin as a hot spot in the mantle.

The volcanoes are more easily explained in the western Grand Canyon, far away from the tourist haunts. Crustal stretching has caused extensional faults to form (normal faults), allowing magma to rise from the underlying magma. Some of the lava flows spilled over the rim into the canyon, forming gigantic lava dams that produced giant lakes that extended hundreds of miles upstream.

The Paleozoic rocks (541-251 million years) of the Grand Canyon are mostly horizontal layers, and include limestone, sandstone, siltstone, and shale recording the transgression and regression of shallow seas across the region. A mountain-building episode took place in the region around 300 million years ago. The bright red and brown sediments of the Supai Group record the erosion of the Ancestral Rocky Mountains, and deposition in floodplains and deltas in the Grand Canyon region.

The origin of the canyon itself, and the carving of the rocks by the Colorado River perhaps are the biggest mystery for those who study the geology of the region. The river carved the canyon, but it's not entirely clear which Colorado River did the work! Different parts of the river system formed at different times, some many tens of millions of years ago, and other parts only 4 million years ago. It's a complex story, far beyond the scope of this short post, but I highly recommend the book by Wayne Ranney on the subject, available here: https://www.grandcanyon.org/shop/online-store/geology/carving-grand-canyon-evidence-theories-and-mystery-2nd-edition-wayne.

We took a break at Desert View at the east end of the canyon, and headed down the highway. There was a lot more to the Colorado Plateau than the Grand Canyon, as spectacular as it is.

Dreams of Summer and Southwest Travels: A Canyon Grander than All

It's winter, and it's cold outside. I won't be in the field for another six weeks, so for now I'm reveling in the memories of this last summer, a journey through the Southwest states. We started our field studies trip at Hole in the Wall in the Mojave National Preserve, and after spending the morning hiking in Banshee Canyon, we hit the road and moved on to the state border with Arizona. We were on our way to the grandest of all canyons: Grand Canyon.

The canyon is more than 200 miles long, and averages a mile (1.6 km) in depth. It cuts through 1.7 billion years of Earth history. There really is no place in the world like it. It's a spectacle, but it's also one of the world's greatest outdoor laboratories. We arrived late in the day, and strangely enough we had to drive through ice to get there. A fierce hailstorm had dumped inches of ice granules along the highway. We reached the rim as the storm cleared.

As the sun reached the horizon, it peeked out from under the clouds, and the upper canyon walls lit up with soft warm orange light. This wasn't a moment for learning, it was a moment for awe. Most of our students had never been to the Grand Canyon, and they seemed stunned. It's one of the times I love as a teacher, because after the awe comes the questions, and with questions comes true learning. But the learning could wait until tomorrow.

America's Never Never: North Rim or South Rim? It's a Grand Canyon everywhere, does it matter?

It means a lot to these guys anyway. The Kaibab Squirrel is a (sub)species of squirrel that lives only in the ponderosa forests of the North Rim of Grand Canyon. The most closely related species is the Abert Squirrel that lives on the South Rim of the canyon (and other parts of the Colorado Plateau), and never do the twain meet. The populations became separated at the end of the last ice age, and geographic isolation in different climates has led to differences between them.

We continued our exploration of America's Never Never, arriving at the North Rim of Grand Canyon National Park (after making our way through a herd of buffalo). I've been using the term "Never Never" after a region in Australia that is far off the beaten track, though full of fantastic geologic scenery. In a similar way, the Colorado Plateau is largely a barren wilderness, but it also encompasses some of the most beautiful landscapes on the planet. And some corners can hardly be described as isolated and lonely. Grand Canyon is one of those places: it gets as many as 5 million visitors a year.

It's a grand place, and one can choose to visit the developed parts of the park on the North Rim or the South Rim. One might wonder if it makes much difference which rim to visit if one is visiting for the first time. It's an interesting choice.

It really depends what you are after. If you are after the complete "industrial tourism" experience with IMAX theatres, four-star hotels, fancy visitor centers and complete visitor services including grocery stores, curio shops, restaurants, and full cellular service, then maybe the South Rim should be your destination. It is in fact the destination for something like 90% of the people who visit the canyon.

The North Rim is the flip side of the Grand Canyon experience. It usually takes several hours more to get there, and the nearest town of any sort is more than an hour away. There is a single hotel complex offering cabins, and a simple camp store. There is a one room visitor center, a laundromat/shower house, and not much else. What is the serious tourist to do?

In my mind, there's not much of a contest. I enjoy my visits to the South Rim, but I prefer the quiet and the coolness of the North. It is as much as a thousand feet higher than the South Rim, and instead of a dry pinyon forest with occasional ponderosa groves, the North Rim has meadows with extensive forests of ponderosa, fir and aspen. The road to the viewpoints on the Walhalla Plateau is rarely crowded, and the viewpoints are stunning. Cape Royal and Angels Window offer excellent views of the Proterozoic Grand Canyon Supergroup and the famous angular unconformity that separates it from the overlying horizontal Paleozoic sediments (above).

Point Imperial offers a unique perspective on possible origins of the Grand Canyon. It looks over the edge of the Butte Fault and East Kaibab monocline into the lower country to the east. The Colorado River comes from this lowland and crosses the 8,000 foot high plateau heading west. The question that geologists have been struggling with for decades is how the river could have done it. There are many ideas, and few conclusions.

And then there are the quiet walks along the rim. The Widforss Trail goes five miles past the head of a deep gorge called the Transept, and to a beautiful view down into the Granite Gorge. The Uncle Jim Trail loops out to Uncle Jim Point at the head of Bright Angel Canyon. And if you aren't feeling particularly ambitious, follow the Transept Trail from Bright Angel Lodge to the Campground. That's what I did with my free time that day (oh, not to mention the pizza at the deli; it's not a completely savage wilderness).

Anyone on the North Rim should walk the short distance to Bright Angel Point. You'll have company, but the view is memorable. A fairly large number of people walk the Transept, but on the day I was there, I shared the trail with just four other people. It was quiet, cool and beautiful. I've never been closer to California Condors than here along the trail. They hang out, waiting for a tourist to drop I suppose.

In any other setting the 3,000 foot deep Transept would be a national park in its own right. Here it is but a tributary to Bright Angel Creek, which is a tributary to the Colorado River. The trail follows some gentle ups and downs through shallow swales and passes a modest Ancestral Puebloan ruin.

The campground is perched almost on the edge of the Transept, and the best-situated campsites offer views, but scenery is a short walk in any direction. It is a wonderful place.

This discussion of North Rim vs. South Rim leaves out a lot of other possibilities...there is the drive through the Hualapai lands to the bottom of Grand Canyon at Diamond Creek or that strange glass walkway perched on the rim of the western Canyon. There is the road that accesses Hualapai Hilltop and the isolated village of Supai. There is the road out to Toroweap and Vulcan's Throne. There is the wilderness of the Shivwits Plateau out west, a "twin" to the Kaibab Plateau with barely a road or trail anywhere. And there's that totally opposite way of seeing the canyon, from the bottom looking up rafting along the Colorado River, an adventure I am eagerly awaiting in less than two weeks.

Ten Overrated Places to See Before You Die...Part Two

The sacred cows must be slain...we continue an exploration of the overrated places to see before you die. Let's get right to it:

6. The Grand Canyon (the South Rim):
I can hear the howls already. How can I, a blogger who spent literally months extolling the wonders of the Grand Canyon and other parts of the Colorado Plateau put the incredible gorge on a list of overrated places? Well, there's a subtle distinction here: I define it as the rim. If you take a tour of the canyon, say with a bus company, or heavens forbid, a geology class, you could conceivably end up driving from one road pullout to another. Amidst the diesel fumes and crowds of tourists, you walk the short distance to the rim, snap a series of wonderfully well-planned and executed digital photos and video panoramas, get back in the vehicle and go to the next overlook, and think to yourself "I took this picture and this video at the last overlook". Yeah, it's colorful and all, and looks pretty deep, but after about four of those stops, you are starting to think about the coffee at Bright Angel Lodge.

Need more evidence? Think about what happens when you offer to show your pictures to your friends? The hemming and hawing...

What's the problem? We are so geared to looking at scenery in only two dimensions, such as on a television or computer monitor, that we end up being isolated from the full width and depth of the canyon. We have no perspective (as I put it in a previous post, "The vastness of the scene has been shrunk to a single image in the back of my eye, and my ego makes me much larger in relation to the canyon in front of me"). We are spectators set apart from the geography, and have no sense of scale with which to compare the panorama we gaze at. Truth be told, the Spaniards who "discovered" the canyon in the 1500's had the same problem: they thought the gorge only a few thousand feet deep, and the Colorado River only six feet across.

How to solve this problem and turn the Grand Canyon into the stunning place it actually is? One thing you can do is what the Spaniards did: try climbing in. It took almost no time for them to realize they were in a truly huge hole, an unprecedented gash cut through the earth's crust. It doesn't take much, a few hundred yards, maybe to base of the Kaibab Limestone. When you've walked through one layer, you start to appreciate that there are many such layers in the canyon, and your mind will start to provide the scale you need.

One other trick is to escape the tour mentality; escape from the crowds (it is possible: walk a rim trail, or even better, head for the North Rim, an utterly different experience). Spend time, and watch the canyon change moods over the course of a day. Walk out at night, especially a moonlit night.

And finally, learn the story of the layers. If you do this, you will won't see a two-dimensional color pallet, you will be reading a novel of the Earth. It's a fascinating story.

I said "ten" didn't I? Yeah, there are ten, but this took longer than I thought. More soon!