Where They Almost Damned the Grand Canyon...

 Is there a limit to the destruction that humans can do? Yesterday's post concerned our desire to control the natural world around us, which in the case of the Colorado River meant the building of mega-dams, giant piles of concrete that pretend to hold back the floods, and dole out the riches of gravitationally produced electricity. Unfortunately such mega-dams were built with a priority of utility over beauty.

Of course, hardly anyone can profit from beauty, and if only a few people know of a place or have ever seen it, it can be easy to subvert a place to the profit of a few. After visiting one of the mega-dams, we explored a little-known road that actually reaches the bottom of the Grand Canyon. It follows Peach Springs Canyon and Diamond Creek to the Colorado River in about 20 bumpy dirt road miles. It is well known to river-runners, as the road serves as a take out point for river trips.

As we cooled our feet in the water, we had to contemplate that sixty years ago, this place was slated to become the next big dam on the river. The reservoir would have inundated miles of national park land upstream. It was unthinkable, and in the fashion of the thinking of the time, the dam was built instead in a place that only a few hundred people had ever seen: Glen Canyon.

It's hard to contemplate what was lost.  And only slightly a relief to know that at least one place was saved.

The Abandoned Lands...A Journey Through the Colorado Plateau: Where the Rivers Changed Direction

...it's gone away in yesterday
Now I find myself on the mountainside
Where the rivers change direction
Across the Great Divide...

from Kate Wolf (a folksinger sorely missed...)

Abandonment as a theme for my current blog series about the Colorado Plateau doesn't always involve people and cultures. It can include rivers and other natural features as well.

Peach Springs Canyon and Diamond Creek provide the only vehicular access to the Colorado River in the entire length of Grand Canyon. As noted in a previous post, it is a spectacular introduction to the geology of the Paleozoic and Proterozoic rocks of the region. The route also reveals a neat little riddle.

Peach Springs Canyon is a very deep gorge, one of the larger tributaries of the Grand Canyon. Peach Springs Creek is a dry wash most of the time, but it would be understandable that it could have been carved by huge flash floods over the years. But what gets interesting is that Peach Springs Canyon also has tributaries, and they are also huge. But they also have practically no drainage area that could efficiently collect cloudburst runoff. How did these tributaries get carved?

It gets better...check out the GoogleEarth image below (click it for a larger image). Why do the winding canyons bend away from the linear fault-line creek bed, and then bend back? And notice how they don't drain in one direction, but instead each canyon has a drainage divide, with water flowing two directions from a high point within each gorge. Shouldn't a drainage in a single canyon segment be one way?

Before I point out the third strange item, understand that the Grand Canyon and the Colorado River as we see them today didn't exist prior to six million years ago. The present course of the Colorado River was not even possible until the Gulf of California (Sea of Cortez) formed around 5 millon years ago. And deposits along the Grand Wash Cliffs where the Grand Canyon ends at Pierce Ferry show that no large river existed there 17 million years ago. Why is this a problem?

As one starts down the road into Peach Springs Canyon, the rolling hills reveal sediments that are filling some of these odd tributary canyons. and they are old sediments; some are as old as Paleocene, the earliest part of the Cenozoic era which began 65 million years ago. These abandoned channels were carved in latest Cretaceous time. These tributaries are older than the present day Grand Canyon! Much older...they've been exhumed by the carving of the present day Colorado River. But these valleys may once have been inhabited by the dinosaurs!

Today, the Peach Springs area lies near the western edge of the Colorado Plateau. The Basin and Range province lies to the west and south, a much lower area on average, providing an avenue for the Colorado River to reach the sea. 65 million years ago, the region was much different. What are today the low areas of the Basin and Range were once a high mountainous region that we call the Mogollon Highlands. Rivers drained from these highlands through the Peach Springs region, carving the channels and canyons towards the northeast, pretty much the opposite direction that the Colorado Plateau flows today. At some point in the last few tens of millions of years, the rivers changed direction through a combination of headward erosion and stream piracy, and ultimately the "old" Colorado River of Colorado and Utah was diverted west and the Grand Canyon was the happy result.

What an incredible adventure of the mind! The history of the Colorado River and the carving of the Grand Canyon have been complex problems that have kept some of the very best field geologists busy for decades, and the full story of how the grandest canyon on the planet came to be is still only partially complete. For more information, check out

Colorado River Origin and Evolution (free ebook at http://www.grandcanyon.org/booksmore/booksmore_epublications.asp)

and Richard Youngs recent work in Peach Spring Canyon at:
http://repository.azgs.az.gov/sites/default/files/dlio/files/nid1362/cr-11-o_peach_springs_quad_0.pdf

The Abandoned Lands...A Journey Through the Colorado Plateau: And not a single sentient being ever laid eyes on the mountains

What an incredible story can by told by rocks that are not there! Seriously, the Grand Canyon is full of rocks, but some of the most important parts of the geological story emerge when we realize just how much rock is missing. In the picture above, erosion has scooped out a small alcove on the right side. The rocks forming the roof of the alcove are crossbedded sandstones that formed on a beach around 500 million years ago. The rocks underneath are composed of schist and granite pegmatite (an extremely course-grained type of the plutonic rock) that date to between 1.4 and 1.8 billion years. The picture below shows a typical intrusion of the pegmatite between the layers of schist. What's missing? Just a billion years or so of geologic history!

Imagine: An ocean in the tropics...but no palm trees, no coconuts. No visible life at all except for a hint of green in the water; single-celled microorganisms rule the ecosystem. The air is unbreathable, as there is only a fraction of the oxygen we find in our atmosphere today. Our own world would be a foreign place to visit; we would need spacesuits to survive.

On one horizon, a landmass...it is large, more than a thousand miles across, the core of the North American continent.  It has existed already for most of a billion years. In the other direction, an island is visible in the distance. It is also large, hundreds of miles long. The two lands are on a collision course. It is not an overly fast collision, as they approach at the stunning speed of three or four inches a year. But over millions of years, they collide, first disturbing and folding the sediments on the seafloor between them, and then a vast mountain range grows as one land mass is pushed up and over the other. And within a few tens of millions of years, a second island collides, pushing the mountains even higher. A vast range now extends across the edge of the continent, from what is now the southeastern United States to California, and an unknown distance westward.

It was a mountain range that no eyes ever saw. Eyes would not develop in this world for another billion years. No trees ever graced its slopes, not a blade of grass, no terrestrial life at all. The mountain was composed of barren rock, and was touched only by snow and flowing water. But no life. The mountain range was pushed to great heights, and erosion tore away at its flanks. Over several hundred million years the mountain range was eroded away until it was a low plain, interrupted here and there by low hills no more than a few hundred feet high. The rocks that now lie exposed were once buried 12 miles deep in the crust. They have been changed by the extreme heat and pressure into schist and gneiss.

It is that surface that my students are exploring in the picture above. They are laying their hands on the core of a mountain range that no eyes ever saw, but whose existence is indicated by the rocks and by the erosion surface. 500 million years ago, a rising sea covered this region, leaving behind a sequence of sandstone (the Tapeats), shale (the Bright Angel), and limestone (the Muav). John Wesley Powell, the leader of the first team of people to navigate the Colorado River through the Grand Canyon, called the surface the Great Unconformity.

The Great Unconformity was one of our objectives while traveling down the Peach Springs Road into the Grand Canyon on our trip last month. In 21 miles we drove 4,000 feet into the canyon to the Colorado River at Diamond Creek. I'm not superstitious or anything, but in May we only got to the 17 mile mark before our car broke down, so this time our vans made the trip to the river without stopping, except for the rather incredible distraction of a herd of Bighorn Sheep grazing by the road.

 Yeah, we get sidetracked by furry mammals every time...

Back on the road, we made it to the river at the head of Diamond Creek rapids. I had not been this close to the Colorado River in the Grand Canyon in many years, and had forgotten what power the river exudes, even as her water is processed through dams and reservoirs. The river ran fast and surprisingly cold. It was a relief in the 113 degree temperature.

After cooling off in the water, we started back up the road, with several stops to visit the Great Unconformity and to have a look at the formations that are the most difficult to see and access from the rim of Grand Canyon. We were able to see the sandstones of the Cambrian beach, lying over the unconformity.

A few hundred feet higher, and we were able to check out the former muds of the Bright Angel Shale. We could see the trails of worms, trilobites and other creatures that squirmed and disturbed sediments for the first time in three billion years of Earth history. Ripplemarks can be seen in the picture below, on the left.

The Bright Angel Shale yields under pressure, and if not buttressed from below, it slides readily. A huge slide block was visible in the canyon wall on the west side of the Hurricane fault. The exposure of Bright Angel in the picture below is tilted about 45 degrees despite being sandwiched between horizontal layers.

Up close, the deformation of the greenish shale and siltstone is obvious....

The road to the bottom of the Grand Canyon, the only road to the river, is a fascinating journey. It is all gravel, it's bumpy in places, and the entrance fee is pretty steep. I didn't mind paying it, as tourism is essentially the only income for the Hualapai people who own this part of the Grand Canyon. But it provides unparalleled exposures of the Proterozoic rocks of the Grand Canyon Metamorphic Suite, the Paleozoic Tonto Group (the Tapeats, Bright Angel, and Muav formations), and the Devonian Temple Butte Limestone, a layer that is almost impossible to see from the rim of the Grand Canyon in the national park.

We made it back to Peach Springs without incident, and headed to our campsite on the south rim of Grand Canyon. Between our exploration of Hole in the Wall and the trip down to the river, it had been a full day! And it was only our second day out in the field...

PS: I forgot...there were more furry distractions on the way out of the canyon. I don't know how wild they were, given the rope on one of them, but there they were on the open range....

Here is the explanation of my "abandonment" theme for this series: http://geotripper.blogspot.com/2012/06/abandoned-landsa-journey-through.html

The Abandoned Lands...A Journey Through the Colorado Plateau: The Grandest Canyon

"The region . . . is, of course, altogether valueless. It can be approached only from the south, and after entering it, there is nothing to do but leave. Ours has been the first and the last party of whites to visit this profitless locality. It seems intended by nature that the Colorado River, along the greater portion of its lonely and majestic way, shall be unvisited and undisturbed."

Joseph Ives (1851)

Joseph Ives did a lot of hard and dangerous work to be remembered only for the famous quote shown above. His expedition spent months exploring the region, collecting huge amounts of data on the geology, hydrology and biology. Often cited as one of the most incorrect predictions ever uttered, the statement to a certain extent is actually true. Nearly five million people do in fact visit Grand Canyon National Park every year, but the vast majority of them merely stand on the rim and look down. Tens of thousands may hike down the handful of popular trails, and a few thousand float down the Colorado River. But hundreds of square miles of the park see no visitors at all most years. The canyon is mostly inaccessible, and I have no doubt that there are many new discoveries to be made about the geology and biology.

Profitless? Pretty much true. A handful of mines in the Grand Canyon made modest profits, but most mining ventures failed, due to poor ore values and lack of access.There is no lumber to speak of within the canyon, and utilizing the water of the Colorado River was impossible until the great dams of the twentieth century, and they aren't actually in the Grand Canyon. Tourism is the only economic gold mine around here.

It is possible to look at the canyon and not be impressed. When Coronado's troops reached the rim in 1540, their perspective was so skewed that they thought the mile-deep canyon was only a thousand feet deep and that the Colorado River was only six feet across. A day spent trying to scramble down the cliffs quickly cleared the misconception, and they left the region. For literally centuries.

I think the same sort of thing happens with casual tourists, too. It is so easy sometimes to step out of an RV where one has been watching a large screen tv and see the vast depth of the canyon as a flat canvas, very colorful, but without depth. It's so easy to snap a few pictures and head on to the next overlook or the next park. As has been said so many times, the only way to really appreciate the scale of the Grand Canyon is to see it from the inside out, to walk it, to ride a burro into the depths, or to float on a raft down the Colorado River.

I have no doubt that someone also thought of the other alternative: build paved roads and let people wear out their brakes on a drive down to the bottom and look back up before destroying their transmissions and radiators on the steep climb back out. There are just one or two problems with that: besides invading the precious wilderness that lies below the rim, there is the Coconino Sandstone, and the Redwall Limestone. There are engineering problems with practically all the Paleozoic and Proterozoic formations of the canyon, but these two are especially troublesome. They are cliffs of such uniformity throughout the Grand Canyon that there are only a few dozen places where trails can breach the inner canyon. Roads? It just can't be done (or else it would have done in the formative years of the National Park Service; think of Going to the Sun Highway at Glacier, Tioga Pass in Yosemite, or the Crater Lake Rim Highway). If you have only that precious few days of vacation, you are going to want to see as much as you can of all the parks in the region, and leave the four day backpack to that unspecified future time when you get back into shape...

Yeah, they got the trail through the Redwall Limestone here; but where would you put a highway?

Seeing the Grand Canyon on foot made me a geologist. The week-long trip I took in 1976 was one of the pivotal events of my life. There is simply no substitute for walking the full depth of each of the layers of the canyon in turn, seeing the crossbedding, the ripplemarks, the fossils, the faults and folds to truly appreciate the magnitude of geologic time and the complexities of the history of these rocks. It is awe-inspiring to lay one's hands on the Great Unconformity and touch a billion years between your fingertips. There is nothing like it, and it is an almost impossible experience to offer in the confines of today's budgetary limitations in education. We can no longer take just eight students and make a viable class that will pass muster with the bean-counters in the administration.

So that was my conundrum last month. How could I share the incredible story of the Grand Canyon with my students when there were 34 of us, and only a day? It turns out that there was one place where I could drive them down the canyon: Peach Springs Road and Diamond Creek on the Hualapai Reservation in western Grand Canyon. It's a winding 21 mile road that reaches the Colorado River 4,000 feet down in the gorge. But how could they have constructed this road? I don't know when it was built or why (anyone out there have some info?), but they did it. It was all the fault of...well...the fault. The Hurricane fault to be specific. The fault has dropped the rocks on the west side over a thousand feet, so a route could be selected that simply never had to cross the cliffs of the Coconino or Redwall (see the diagram below). The road starts in the Devonian Temple Butte Limestone, and only has to drop through the Cambrian sediments and the underlying complex of Proterozoic gneiss and granite, which is rugged enough, but the erosion of Diamond Creek did most of the work before the roadbuilders arrived.

The road is utilized as a major take-out point on the Colorado River by the rafters. It is not a particularly good choice for the casual tourist. It's not so much that it is too rugged, but in summer the temperatures are sizzling, and this exacts a toll on radiator and electrical systems. You may remember reading about my own failure to reach the Colorado River a month earlier due to car problems. It's also expensive; the Hualapai nation charges $25 per person to drive the canyon (I didn't mind paying; tourism is pretty much the sole income for the tribe). But we did it with students this year for the first time ever. That story comes in the next post.

Here is the explanation of my "abandonment" theme for this series: http://geotripper.blogspot.com/2012/06/abandoned-landsa-journey-through.html

If You Have to be Stuck Somewhere, It Might As Well Be Here

I mentioned in yesterday's post about the engine worship ritual method of fixing broken down cars. I didn't realize that Mrs. Geotripper was playing the anthropologist yesterday and taking pictures. As some of you may know, the Engine Ritual is a highly structured approach to appealing to the car gods to make a car run again. All the men in the group (this is a religious issue, not a sexist issue; I'm told by Mrs. Geotripper that women look for the trouble-shooting section of the car manual) must gather around the open hood of the car. They form a semi-circle with the high priest (the elder)in the center, and the car's owner closest to the door on the driver's side (only the driver is allowed to turn the key). Each in turn murmurs the chant to the gods, which starts out as "Did you try...", followed by leaning over into the engine and jiggling something. The gods are rather easily insulted, so the ritual rarely works, but when you are stuck anything is worth a try.

This is a largely western European tradition, but I was on reservation land, so it turns out that after the others gave up and left, I was paid a visit by a mysterious Native American shaman (the truck he drove was labeled "ranger". He considered me with a philosophical stare (it was 5 PM and he was considering whether this tourist was going to cause him to miss dinner). He looked at the engine and said (in that mysterious spiritual connection voice) "Did you try unlocking the transmission with the little switch next to the gearshift?". Voila! It unlocked the transmission! But the car still wouldn't start, but at least we had made progress.

In the end, we solved the problem in the age old method familiar to all who work with technology: "Is the broken thing plugged in?". In this case, I said "Let's try the jumper cables" just to see what would happen. Somehow the supplication and desperation in my voice appeased the car gods and the car started.

So we were delayed a day, and my car has a new battery this morning (I don't get it, the car had the original battery and only 114k on the odometer). We are moving once again! In the meantime, Mrs. Geotripper snapped a few other shots while we were deep in the Grand Canyon. Enjoy!

 Above is a great shot of the Great Unconformity (across the middle of the picture). The rock in the lower half is the 1.7 billion year old granite and gneiss that was once a mountain range but was reduced to a plain over hundreds of millions of years. The horizontal layers of the Tapeats sandstone can be seen immediately above. The Redwall limestone forms the higher cliffs.

 Diamond Peak is a large block caught between the Hurricane and Three Springs faults.

And a Beavertail Cactus bloom...

On to more adventures! Will post when I can!

What's Missing From This Picture? Only a billion years or so...

Geology is good for perspective. The bookends of this particular day: the very very long hour spent trying to restart a dead car in a remote canyon, and a billion years in one hand. I'm on the road researching a field seminar for the AAPG in Arizona and Nevada, and I saw some incredible things.

1.7 billion years ago, fragments of continental crust were colliding to form the core of a new North American continent. Those mountains climbed to the sky, rivaling the Himalaya or the Andes in their grandeur. The time was so ancient that not a bit of life existed on the mountain flanks. The only lifeforms at all were single-celled organisms in the oceans.

The forces pushing the mountains upwards ended, and the ice and rain tore away the flanks. The gigantic peaks eroded to hills, and in hundreds of millions of years, the hills eroded to nearly flat plains. They were gone, but the rocks that formed the roots of those mountains remained. Around 530 million years ago, the continent had begun to break up, and the edges subsided slowly while a shallow sea advanced. The beach sands swirled back and forth across the roots of the ancient mountains.

An unconformity is a buried erosional surface. Sometimes the time missing might be a few hundred thousand or a few million years. The unconformity in the Grand Canyon is profound, representing a gap of a one thousand million years. Get to the right place, and you can place your hand across 1,000,000,000 revolutions around the sun: nearly a quarter of the age of the Earth.

The problem with the Great Unconformity, as the early geologists called it, is that it is mainly exposed in the bottom of the Grand Canyon. There are only a few ways to see it and touch it: you can float down the Colorado River in a raft, or you can walk down the long difficult trails from the rim of the canyon. Or, as it turns out, you can drive.

I left Las Vegas this morning and traveled up Lake Mead Boulevard. The growth of the town has slowed with the depression, but over the last twenty years I've watched the urbanization of the valley wash up the slopes of Frenchman Mountain on the eastern edge of town like a tsunami. Fortunately, the wave stopped at the boundary of the city limits and the federal lands around Lake Mead. It turns out that the rocks making up the Great Unconformity are exposed no more than a mile from the residential neighborhoods of Sin City. The sand layers of the Tapeats Sandstone cover the weathered granite and schist of the 1.7 billion year old basement complex.

The geologists at the University of Nevada, Las Vegas knew of the treasure in their backyard. Years ago they set up a trail and some very nice interpretive exhibits. I regret to say that vandals and garbage dumpers destroyed the exhibits in a short time, but you can still see the rocks.

If the exposure lacks anything, it is grandeur. The oldest rocks of the Grand Canyon are at the bottom of one of the deepest and longest gorges in the world, and there is much to be said for seeing the rocks in their full perspective, underneath a mile of subsequent sedimentary layers. When time or health is short, hiking or rafting is not feasible. But I was on a mission today, to see the only place in all of the Grand Canyon where one can drive to the Great Unconformity. It is well-known to rafters as it is the take-out point for the river voyagers. It's called Diamond Creek, and Peach Springs Canyon. The road starts at the administrative headquarters of the Hualapai Nation in Peach Springs, and winds 19 miles and 3,500 feet down to the Colorado.

Anyone who has seen the Grand Canyon, either in pictures or in person, has to wonder how any road could intrude into such rugged terrain. There are so many cliff-forming layers that a road seems next to impossible (which it is, given that only one exists). But Grand Canyon is also crossed by faults and folds, and the disruption of the cliff-forming layers is what makes roads and trails possible. The road starts innocently enough, dipping into rolling terrain composed of Mio-Pliocene sediments that have huge significance in understanding how the Grand Canyon was carved. We actually follow canyons that originated at the end of the age of the dinosaurs (the Cretaceous Period) and were subsequently filled, and then exhumed in the last hiccup of geological time.

Heading deeper into the canyon, we see some evidence of deformation; in the picture below, we can see a gentle monocline crossing the picture where the layers step down in elevation without splitting. A major fault zone, the Hurricane fault, crosses the canyon in front of the fold. The road turns and follows the fault zone.

The gorge becomes deeper and deeper, and we pass into older and older layers. The Mississippian Redwall limestone forms the highest cliffs, and the lower cliffs are dominated by the Devonian Temple Butte limestone and Cambrian Muav limestone. The gentler slopes cover exposures of the Cambrian Bright Angel shale. The rocks on the left side of the canyon sit around a thousand feet lower than the rocks on the right due to displacement along the Hurricane fault.

The cliffs grow higher and higher, and we finally reach the base of the Paleozoic rocks with exposures of the Tapeats sandstone, the same layer seen at Frenchman Mountain in Las Vegas. The Tapeats can be seen in the first picture of this post, forming the prominent layers at the lower left. The orange-brown rocks at the base of the cliff are the 1.7 billion year old granite and schist.

It would take only a moment's walk to lay one's hand on the unconformity, but we also wanted to see the Colorado River. We were nearly 16 miles into the canyon, with only three to go. We got into the car, turned the key....and nothing. Not a click, not a warning light, nothing. 16 miles into the depths of the Earth, and we had a dead car.

So we had the longest hour I've ever felt (aside from the births of my children), trying anything and everything to get the car going again. A construction crew stopped by, five guys in one truck, and we did the engine worship thing where all six of us stood around the open hood and jiggled connections. A river runner came up the road with his boat trailer. He had room, so Mrs. Geotripper jumped in to go arrange for a tow truck. River runners like this guy drive this road all the time, so the Missus had a regular Mr. Toad's Wild Ride up the bumpy road. Meanwhile, I stayed with the car, pretty much preparing to camp out for the night. The ranger for the Hualapai tribe showed up, and we did some more jiggling of engine connections, and he helped me get the transmission unstuck, but we still weren't getting anything when I turned the key. In final desperation, we tried the obvious, and pulled out the jumper cables. They worked.

I zoomed up the road, picked up Mrs. Geotripper, and sped on to Williams without turning the car off once. Thus, our unexpected night in a motel, and a delay, looking for a saturday mechanic before we head on to Grand Canyon tomorrow. And internet access! We'll see what surprises tomorrow holds for us.

By the way, the ocotillos were blooming in the lower canyon...enjoy!

NOTE: Tourism is almost the sole source of income for the Hualapai tribe. You need to pay an exploration fee of $25/person at the Hualapai Motel in Peach Springs. Looking at the town of Peach Springs, I was glad to give them some support.