where Mind is Shaped by the Earth ....
July 17th, 2013
Pictured above is the inner north wall of Cerro Colorado. This structure is about one kilometer (3300 feet) in diameter, and about 110 meters (360 feet) deep. You can just barely make out our vehicles in this image. They are the small white dots, across the crater, along its rim. A dark lava flow can be seen in the distance.
Just across Arizona’s southern border, on the way to the Gulf of California, lies one of the Sonoran Desert’s most spectacular geologic features – the Pinacate Volcanic Field. Few of the many thousands of tourists that each year visit the party-place we call Rocky Point (Puerto Peñasco to the Mexicans) even know that it is there. That’s a good thing, too, for part of its beauty is its desolation. It is one of the most similar places to the surface of the Moon that you will find anywhere on Earth. Not because of its loneliness, though.
From the highway to the coast, you cannot see that out there in that barrenness lie a number of impressive craters. Get up in the air, however, and it looks much like what you see through a telescope focused on the lunar landscape. Massive, ring-shaped, and deep, those craters show that the now-quiet countryside was once a pretty violent place.
Previously, I’ve written about the explosive San Francisco Peak(s) of northern Arizona, towering above Flagstaff, and not hard to miss at all. But the craters of the Sierra Pinacate region of Sonora are not readily apparent until you are right there.
This area lies within a Mexican National Park – the Parque Natural del Gran Desierto del Pinacate – which also features a sea of sand dunes, lava flows, and a number of volcanic cinder cones. It is not the kind of place you want to venture into light-heartedly, with your passenger car and beach clothes. Take a lot of water – that is some good advice, too.
To me, the craters are the most interesting things to see, and these are some really good ones. They are different from craters on the Moon, though, because the lunar ones were formed by impact – asteroid, meteoric. Same with Meteor Crater, near Flagstaff.
The Pinacate craters were created by relatively shallow explosions in the crust of the Earth. They are a type different even from the volcanic craters and cones of northern Arizona, like Sunset Crater. In “geology-speak”, they are called maars, and these happen to be some especially young ones.
The Gran Desierto (Grand Desert) is a dry, dry place. Yet, deep underneath the sparse desert scrub that does exist there, is groundwater, or very recently was, apparently. That water occupied layers of rock, in turn overlying lower rock units that become hotter with depth.
Remember, and I’ve written about this in many other articles as well, that this part of North America is very active, geologically. Earth’s crust is and has been breaking up in this zone, and the fractures run deep. Molten rock can move upwards along those fractures, eventually making its way to the surface, hence the cinder cones and lava flows.
In the past, here in the Pinacate Field, some of that molten rock moved upwards, and encountered groundwater deposits (known as aquifers). When it did, it converted the water instantaneously to steam – massive amounts of it – and the ground literally exploded outward, creating maars.
Then, at least in some of the cases in the Parque Natural, those exploded chambers collapsed back into themselves, expanding them additionally into structures known as calderas – gaping holes in the ground. There are at least ten of these maar / calderas in the Volcanic Field.
It is possible that humans witnessed some of the eruptions. Hohokam relics have been found along some of the erosion surfaces in the area. Studies show that the blasts occurred within the last few million years, and some only within the last few thousand years. Very jagged, black, and barren, the basalt lava formations that you drive by between the craters look like they flowed yesterday.
As you can see, the starkness of the vista adds much to the otherworldly look of this place, so if you can’t make it to the Moon (and most of us won’t have that chance), you can at least get an idea of the lunar scenery by visiting the Pinacates.
Breathing is easier there, too.
September 28th, 2012
That the native inhabitants of the Americas had a different way of relating to the landscape is without much question. Their sacred sites and temples were placed in special geographic places.
But what led to such a view? Could it be because that within their culture, they value fitting in with nature, not trying to change it? Seeing yourself as part of something is, to be sure, not the same as seeing yourself as separate from something.
What we are all part of is a vast web of life that covers our planet. So far, based on the current state of scientific knowledge, it is that web which makes Earth distinct and unlike any other place we know of in the Universe.
That “coating” of life includes plants, of course, and animals, fungi, and microbes of many kinds. Life lives in the air, in the water, and on the land. And, now it turns out, inside the planet, too. It thrives even in the rocks.
In last month’s GeoStory™ (“Top Coat” — also in gemland.net), I talked about life on the surface of rocks. However, that layer pales in comparison with what is underneath.
Geologists and other scientists are beginning to realize that in what we once thought was barren, lifeless stone, is, in many cases, teeming with microorganisms. Some of those microscopic life-forms are strange indeed, and can feed from the rocks, without needing air or light.
Sedimentary rocks (which are deposited by water or wind) usually have small pore spaces within. These pores can and many times do, contain water, oil, or gases. It is from this porosity that we pump groundwater, petroleum, or natural gas.
Other kinds of rocks, by nature of the way they formed, have no pores per se. But they frequently contain fractures of all sizes, and water or hydrocarbons can occupy those cracks, too. Living things – microbes – can occupy them all.
Various experiments over the past few decades have shown that certain bacteria can flourish in such environments. No sunshine. No fresh air. Sometimes stiflingly hot temperatures. Yet, there they grow and multiply. The only thing that seems to be required in all cases for life to exist is the presence of water. We have lots of that, and we know now that our neighbor planet Mars probably does (or at least once did), too.
No wonder that space scientists look with intense interest upon such organisms. If they can exist in the rocks here, then maybe they can exist in the rocks of Mars, or other worlds, too. And for earth scientists, such “deep life”, is leading to a new level of understanding of how the world works.
Based on data derived from deep-drilling projects, the late, brilliant, and controversial Cornell University astronomer Thomas Gold did some calculating. His reasonable estimates indicate that the top five kilometers (about three miles) of the Earth’s crust could contain as much as 200 trillion metric tons of live bacteria. This would be like covering the entire planet with a layer of bacterial organisms one and a half meters (approximately five feet) deep!
This is more than a hundred times as much living mass (called biomass) as all of the other life-forms (including us) of the world put together! If aliens from another world were studying our planet, they would easily conclude that the rocks are the most alive part of it.
There are, of course, visible remnants of past subsurface life: coal beds, fossils, tar sands and other petroleum formations. There are metallic mineral deposits which seem to have been “helped along” in their genesis by organic life.
Professor Gold has even suggested that diamonds come from deep-seated organic materials, and we know today that diamonds must form in an environment at least 75 miles down. If hydrocarbon compounds can exist that far below us, and the rocks are alive, so to speak, then the Earth we all know and love is a very unusual place.
Perhaps, though I can’t prove it, life gravitates towards other life, and I don’t mean just to eat it, either. Maybe it’s a stretch, but think about it the next time you pull into an almost-empty parking lot, and you park right next to another person’s lonely vehicle.
The Indians (and to be fair, many other ancient cultures) may have subliminally recognized the existence of places where life was, in effect, somehow concentrated nearby, though not apparent on the surface. Some of those places became special to them.
Ponder that the next time you are out in the great outdoors somewhere, and “feel alive”. Look around and see what makes that so, and then look down, too.
It may all be underneath you.
June 22nd, 2012
If you look through some of the various articles I’ve written, you might think I’ve got a slight obsession with time.
And you’re right.
I do! Sometimes I think the reason I love geology so much does not have to do with rocks per se. It has to do with time — the concept of deep time. It’s something akin to looking into the night sky high overhead and being enthralled by the great distances to the stars — the depth of space.
They are so, so far away that even with our best technology today, just getting to the nearest (not counting our sun) star, Proxima Centauri, only a little over 4 light-years distant, would take over 120,000 years!
The depth of time has that same kind of fascination for me, and, for sure, lots of other geologists. “Deep time” is another name (and, I think, a more appealing one), for “geologic time” — those time-spans of millions and billions of years that are so incomprehensible to all of us.
I’ve mentioned in previous stories that many of the rock formations encircling Phoenix are very, very old, like those around Squaw Peak aka Piestewa Peak (nearly 1700 million years old). And I’ve talked about others that are quite young — the basalt on Moon Hill, for example (some 15 million years old). So where are the ones that are in-between? What is their story?
It’s simple. Around the Phoenix area, they just don’t exist anymore. This was something I didn’t really grasp when I first moved here, until I hiked up Camelback Mountain. There are places there where you can walk up and put your finger on a thin line which has replaced those missing rock formations — a line representing essentially all the deep time that elapsed during the time they were deposited, and then eroded away.
You don’t have to take that heart-pounding jaunt up the Echo Canyon Trail, though, to see that line. Just drive around the west end of the mountain a bit. Or you can even see it from Camelback Road, anywhere from 44th Street to say, 56th Street.
The west end of the mountain, what some people see as the head and neck of the reclining camel (it must have been the heat that got to him!), is formed of reddish sandstone (and conglomerate — a rock made of mixed sand, gravel, and boulders) layers. They are tilted gently towards the west, and they lie on top of coarse-grained granite, which further to the east of there forms the highest part of the mountain.
The granite also looks reddish here, but that’s because of a thin coating of rust-colored sand grains, loosened from the rocks above, now covering it.
The place where the two different rocks contact each other is called an “unconformity” in geology-speak. In other words, there was no direct transition from the formation of the lower rock to the other one above it. In this case, that line of contact represents over a billion and a half years of time — time in which many thousands of feet (probably) of younger rocks were deposited by wind and water over the older granite, and then subsequently eroded away back down to the granite.
Then, on top of the granite, the younger red sandstone formations we see now were laid down by more wind, water, and maybe some really destructive landslides. These layers of stone are approximately 25 million years old. In my photo, taken along the Echo Canyon Trail on the north side of Camelback Mountain, you can see where the line separates the two rock types.
It runs from near the center of the picture towards the lower left corner. The sandstone is seen in the vertical face. The lumpy-looking rock below the line, or unconformity, is the very old granite. Here, confusingly, as I mentioned above, both look reddish-orange, due to the dusty coating. Far in the background and across the valley, you can see the McDowell Mountains.
Any of you who have traveled to our spectacular Grand Canyon may have seen another and famous (but unrelated) unconformity. Down by the river, the flat-lying rock formations that make up all those colorful layers visible in the canyon walls are sitting directly on much, much older rock.
There, that contact is called the “Great Unconformity”, and it is a classic, textbook example, well-known to generations of geology students from, where else, their textbooks, where it is always prominently discussed.
April 17th, 2012
Organic. That’s the word I gravitate towards when I think of the landscape of southern Utah. A myriad of canyons, incised into bands of vermilion, mauve, ivory, ochre and chocolate — rocks from the depths of time in living color.
It’s a fractal place, if there ever was one. Big gorges branch into smaller gorges. They, in turn, divide into even smaller canyons, subdividing and subdividing, right down to the seemingly microscopic level. Life forms of all sizes cling to those tributaries, however big or small, as those very furrows are the arteries of water, the lifeblood of this high desert plateau. The panorama is rumpled, folded, and convoluted like some kind of living tissue, like a dissected brain of gigantic proportion.
Just recently, I drove north along one such magnificent artery: White Canyon. There the road skims over surrealistically-shaped Permian sandstone ledges, and I was just beginning a long awaited August vacation. I looked from my speeding vehicle down into the winding chasm I was paralleling, hoping to catch sight of some ancient Anasazi ruin, that (of course) no one had ever noticed before.
That highway, which runs between the “middle-of-nowhere” towns of Blanding and Hanksville, is among the most inspiring drives I have ever seen. That I could spot some prehistoric cliff structure was not impossible. There are plenty in those canyons. There used to be a lot more.
I crossed several bridges, looking down into overgrown streams below. Even there, the rich smell of murky stream water in the hot sun reminded me of the life-giving power barely flowing beneath the steel girders. A cobalt sky overhead only accented the scene. Now the road wound up and up, away from the water, through immense vertical cuts in the rock strata, blasted and carved away to oblige the road — as if to enforce upon us all the fact that humans can do anything once they put their minds to it.
High above the Colorado River, the biggest artery in the plateau, is one of the most expansive viewpoints anywhere. I got out of my car, as I always do at that spot, ready to bask in the vista for a few moments. I walked over to the edge, and looked down.
Unprepared for what I saw, I gasped (it was only a short one), and then a big, wide smile started to break across my face. I almost started to jump up and down with delight. There you go, boys. Try water-skiing on that. What goes around, comes around.
Far below, where wakes from motorboats and “personal watercraft” once crisscrossed Lake Powell, lay mudflats. Miles and miles of mud, baking in the sun. I couldn’t believe it. In all my years of driving back and forth across the American West, I had never seen anything like that. I thought again of that idea of “humans being able to engineer anything”. Now, really?
Do we really think we can just remake Earth’s surface without consequences?
There is probably no greater symbol of the defacement of the American West than “Lake” Powell — actually a reservoir. It is formed behind Glen Canyon Dam, the concrete wall that stands further downstream in the way of the once relentless Colorado.
And there is probably no greater insult to a true nineteenth-century American legend, the first explorer of Glen Canyon, than to have his name affixed to what he surely would abhor. John Wesley Powell must be rolling over in his grave, smiling, too, at the cubic miles of mud and silt accumulating in Glen Canyon, and he would probably say to us now, “I told you so”. At least he got to see its splendor. So the symbol is not a mark of progress, after all. It is a symbol of hubris, indeed, even death.
In my picture, you can see what looks like a long, sloping runway above the mudflats, below the cliff. That is the huge boat launching ramp of the now-closed Hite Marina. Or was the ramp, I should say. The reservoir is almost 100 feet below “full pool”, and therefore lies hundreds of feet from the bottom of that ramp.
A result of drought in the West, this situation will almost certainly get worse, for the foreseeable future anyway. Combine that with the fact that when you block a river as muddy as the Colorado, lots of silt drops out of suspension, and it starts to build up. All of that grayish sludge you can see now is covering a lost world.
These realities will render Glen Canyon Dam useless — for either storing water, or for generating electric power. Somehow, people just don’t get it — how fast it is happening here. Those motivated by politics would have us all believe that dismantling the dam is some wacko idea, selfishly promoted by those awful environmentalists. That the aforementioned are so skilled at calculated nuance and misinformation does little to dismiss the facts.
The Colorado River averages a sediment load of about 100 million tons a year. That’s about 30,000 dump truck loads every day. And as of the time of this writing, the reservoir is dropping about one foot every nine days! The drying-up of the reservoir, coupled with the filling-in by silt, means that it is losing on both fronts: from the top down, and from the bottom up. If you don’t believe me, drive there and look for yourself.
Beneath that mud and what’s left of the water, are countless archaeological ruins, and the remains of the most intricately beautiful canyon on Earth. By most estimates, present climatic conditions will actually worsen, causing an increase in the rate of the water level’s decline.
Eventually, the silt accumulation will start to block the dam’s outtake portals, making operation of the power generators unsafe. And by then, even more irreplaceable canyon beauty will be lost to the muck.
In recent publications, I have written about the modification of Earth’s geology by humans, and how it can be either good or bad. This modification (Glen Canyon Reservoir began filling in 1963), will go down as one of the most calamitous and short-sighted ever.
If for no other reason, Glen Canyon Dam should be demolished, and what’s left of its reservoir drained, as an admission of our arrogance and conceit in living with nature. Let life return to the landscape.
If we had real vision, and cared at all about people yet to come into this world, we would leave them something of magnificence and meaning, not the entrenched wasteland that is inevitable under current policy.
January 8th, 2012
Take take a look at the boulder in the picture above. You will notice that it is literally covered with markings and drawings. We call these “petroglyphs”, and they were created by pecking through the layer of desert varnish that coats many rocks in arid climates (as opposed to “pictographs”, which are painted onto rocks). Research has shown that petroglyphs in central Arizona were created between about 10,000 and 700 years ago, by peoples we now refer to as Paleo-Indian, Archaic, and Hohokam.
But, as those of you who read my GeoStories know by now, there is more than that about them that would interest me. What really arouses my curiosity is why they are there.
They are found in various places around the Valley of the Sun. But why in one place and not another? There are plenty of rock faces and walls scattered around our area. Some have no markings, and others, like the boulders at the Deer Valley Rock Art Center, just off I-17, north of Phoenix, have hundreds or more. Operated by Arizona State University’s Department of Anthropology, this place alone preserves over 1500 such works of art.
Here, a trail approximately .25 mile long, leads along the base of outcrops of Tertiary age basalt on the edge of the Hedgpeth Hills. This is some of the youngest rock in our area — only about 15 million years old.
I first visited this place on a beautiful, warm, autumn day, and it seemed that I had it all to myself. The sweet, dry smell of the desert surrounded me with comfort. I was walking along this peaceful trail, looking up at the cascade of dark rocks from above, when I was startled by an abrupt, booming voice from the chaparral around.
“Hello, sir! May I be of help to you?”
Totally surprised, I quickly turned around, and saw a man wearing a ranger’s uniform coming towards me from out of the bushes. He was Native American, or Indian (which is the designation he later told me he preferred), stocky, strong looking, with graying hair and chiseled features, and somehow he just “beamed”.
He introduced himself, and I could see he was “official” by the badge on his uniform.
In a very amiable manner, he immediately started dispensing information about the Rock Art Center, its history, and of course, the petroglyphs. But I was still trying to figure out why I had not seen him at first, how I had missed noticing him as I walked along that trail. After all, the chaparral there is not that thick or tall. And it seemed that he just “didn’t fit”; as if he had just materialized on the spot. I even had the thought that he was just posing as a ranger! I liked him at once.
We stood in or near that same place for quite some time, talking about all sorts of things — his background, American Indians, history, artwork on stone that he produces on the side — it was fascinating. I never even made it to the end of the trail! I had to leave, as it was getting late, and I had another appointment. I apologized for having to end our enlightening conversation.
Then one thing occurred to me strongly. I felt that I had finally met someone who really knew what the petroglyphs there, and elsewhere, were really about. I mean, what were those Indians really up to with all these drawings? I know, I’ve read all the ideas posited by present-day researchers about the markings being religious art, communication symbols, or maybe just plain graffiti.
But why, in places like this? Why, in some places and not others? What was it about this rubbly, remote (in ancient times), harsh location that inspired people for thousands of years to spend a huge amount of energy creating all these drawings?
Finally, here was someone who knew.
So, before turning back along the trail, I explained to my guide my quandary. Those of you familiar with my other writings know where I am going with this: what is it about the rocks that energized the ancients here?
“I am searching for that answer,” I pleaded, “and maybe you, being a knowledgeable Indian, and an artist, can tell me.”
His answer was, to say the least, totally unexpected, and it came without hesitation: “Perhaps, sir, what you are really searching for is your own spirituality.”
If you want to do some “searching” along your own path, this is one place to begin. Go out there, and see what you feel in this special place. Take the Deer Valley Road Exit off I-17, and follow the signs, going west for several miles. The Center is closed on Mondays, and hours during the rest of the week vary with the season and day. You can get more information by calling 623-582-8007.
December 10th, 2011
Let’s talk about gold. Not just any gold, but lost gold. If there’s one thing more appealing than found gold, it’s lost gold. Because that means that the gold – maybe an unknown, vast quantity of it – is still out there somewhere, just waiting to be found. Like fairy-dust sprinkled from a magic wand to vitalize some situation, a dusting of the lure of gold can make a place attract people – those people looking to make it big.
Sometimes they win; sometimes they lose.
And sometimes they die.
We have our own place of temptation right here in our backyard: the Superstition Mountains. For the past century or more, this rugged range of desolate, inhospitable, and yet beautiful rock formations just to the east of Phoenix has drawn countless treasure seekers. The goal? A mysterious cache of gold, or gold ore, or maybe even a mine itself. Who knows which? That’s part of the mystery, and the draw of the place.
In 1891, one Jacob Waltz, a German immigrant and prospector, known locally as the “Dutchman” (men from both the Netherlands and Germany were then frequently called that in America), died in the Phoenix home of a friend, Julia Thomas. On his deathbed, Waltz described to her the location of a gold deposit of which he knew, deep in the Superstition Mountains. But in his possession then were only a few gold nuggets, and he never had appeared to be a wealthy man.
Yet, Ms. Thomas and two of her friends, the Petrasch brothers, believed that there was something to his story, and they set out to find it. They spent weeks roaming the wilderness, searching for whatever they could find, which ended up being nothing. Julia Thomas did find a way to capitalize on the Dutchman’s fate, however. She drew up and sold some “treasure maps”, as well as told Waltz’s story to at least one freelance writer, who in turn embellished it even further.
Hence, the story grew, and multiplied. And so today, there are almost too many “Lost Dutchman” stories of which to keep track. (And remember, it is the gold that was lost, not the Dutchman.)
There are variations which include Mexican miners (who supposedly originally found the gold), Apache Indian raiders (who killed the Mexicans and maybe even Waltz’s sometime mining partner, Jacob Wiser), high-graded gold ore stolen by Waltz himself from near Wickenburg and stashed in the Superstitions, and even Jacob Waltz having murdered his partner to hoard the gold for himself.
The wildness of the terrain, the relentless, blazing sun and lack of shade, the dearth of water in the remote desert canyons of the Superstitions, and a colorful cast of crazies, desperadoes, and dream-seekers who have over the years spent countless time seeking out the rumored riches have only added to the luster of the story.
The details of all these legends and maps do not matter so much as the fact that they exist, and that the story of the lost gold endures – the fascination goes on. Over the years more than two dozen adventurers have lost their lives, in one way or another, while exploring the range.
The derivation of the name “Superstition” is not even certain. One version is that in the 1500’s, the Spanish explorer Francisco Vasquez de Coronado apparently gave the mountains that name, based on the Apaches’ claim that therein lay the abode of spirits, ones who did not look kindly upon intrusion, especially in the name of profit.
Only a few years after Jacob Waltz’s passing, hard-rock gold was discovered not far from the north side of the range, near what is now the little mining town of Goldfield. Millions of dollars were taken from the ground during the heyday of mining operations there.
That a true in-situ gold deposit does exist in the Superstitions themselves is very unlikely. As I’ve mentioned in the past, the range (in this case, the western end, of which is to where the legends refer) is built-up of thousands of feet of ancient volcanic ash, fused into thick, resistant layers which today have eroded into a maze of pinnacles, ridges, and gorges. Barren volcanic cinders – now rock – and that’s all. Barren of precious gold, that is, but not of dreams.
Take a look at the Superstition Mountains from a distance, in the setting sun sometime. If you give pause for a moment, they look yellow, even golden. It’s that would-be coating of gold dust out there that you see.
That and the glimmer in your eyes.