TRAIL OF TIME SAMPLE
A TANGIBLE TIME MACHINE
Prologue: When gazing at the stars, we are seeing backward in time measuring billions of light years. Viewing the cosmos through powerful telescopes, the distance goes back even farther: trillions of years. Take the remnants of the Crab Nebula Explosion of 1054 CE as an example, whose luminance caused by an imploding star was bright enough to see during the daylight. By the time its blurred impression in the cosmos was seen on Earth, the source was long ago destroyed. Indeed, by the time we see twinkling starlight in a seeming fixed position of the heavens, the distance and time that it takes for those starry beacons to travel are so great such stellar shine can’t even match the present. In other words, a veritable time machine effect, only in reverse.
Now compare the cosmos to another semblance of a macrocosm, the Grand Canyon. Its deep abyss also replicates a time machine, except the reference to time is terrestrial in contrast to sidereal time. Obviously, the view into the approximately 2-billion-year old chasm is also finite. Of course, the time equation encompasses far less distance. As a physical experience hikers can relate to, headed down the trail to the river begins on the rim marking the close of the Paleozoic Era (roughly, 540 to 250 million years). Once at the bottom where the Colorado River flows, the clock of time goes back to the Precambrian Era, some 2 billion years in the past. When returning to the rim, time reverses. Hence, a multidirectional time machine.
The intent of this simile is to prepare the reader for an upcoming imaginary tour relegated to time travel and corresponding with the age of the Grand Canyon. The aptly named Trail of Time, which was conceived by the National Park Service, is an engaging interpretative tour (i.e., educational) along the South Rim, whose pavement marks key geologic benchmarks. These inserted brass markers begin with so-called deep time, then gradually get younger headed toward the end of the trail (albeit still relatively primal). Moreover, educational signage along the way highlights the changing geologic age sequence that explains various marine and terrestrial events that occurred during each episodic phase.
This comprehensive and exhaustively researched textbook based on the Trail of Time theme, therefore, serves as a self-guided informative stroll meant to enlighten and entertain. All the facets of the Grand Canyon are featured: geology, flora and fauna, and human history entailing the prehistoric to the contemporary. Other miscellaneous information is also presented. For instance, trails and hiking descriptions, useful tourist information such as recommended places to stay and dine, and relevant background of the Colorado Plateau, whose sprawling province inscribes the Grand Canyon, as well as an array of other national parks and monuments, archeological ruins and State Parks.
With this brief description in mind, the information shared throughout this literary tour is factual as it is discernible and easy to comprehend. It also helps to have a vivid imagination by pretending to be on an actual tour in progress while walking along the rim and listening to what is being discussed. Because the emphasis is based on the scientific, namely, empirical and historical facts, the information is academically verifiable. Let it also be stated what the reader thinks and feels on a more personal level is entirely a subjective matter. It follows how the religious to the metaphysical, and the spiritual to the artistic, is geared to oneʼs thoughts, preferences, and imagination. Please note the subject matter discussed throughout the tour will be downsized (i.e., in segmented phases). Therefore, no topic is explained all at once and the mind doesn’t get too saturated at any vista along the way.
RK Alleman
Albuquerque, NM
Chapter 1
THE TRAIL OF TIME
Please note: The subject matter discussed throughout the tour will be downsized (i.e., in segmented phases). Therefore, no topic is explained all at once.This way, the mind doesn’t get too saturated at any vista along the way.
A Mountain Lying Down, So-Called: Through the stimulus of a creative imagination envision a gorgeous, balmy day, enhanced by an azure blue sky decorated with intermittent billowed clouds. Each provides shade relief and generates moving shadows and changing light across a Technicolor backdrop of features. In this feigned mental exercise, imagine the Grand Canyon is just there––a cavernous setting of compacted and congealed sedimentary formations. You can almost touch the sprawling multihued canvas, only the substance of the upper canyon features is entirely made of sedimentary materials while the basement rocks below are mostly metamorphic. Indeed, through the power of metaphor and imagery, it’s possible to meld with the picturesque scenery simply by falling into the view (in a literal sense).
Speaking of picturesque, and singularly picturesque most would agree, you might recall the Grand Canyon is one of the Seven Natural Wonders of the world (if not the natural wonder). It’s also a World Historical Site, where millions of visitors come here every year and marvel at this open geologic textbook on display. Those prominent and towering landmarks rising from the inner canyon commands attention to their various environs, as does the greater void left over from an uncut plateau template long ago eroded into such finely sculpted fabrication. What do these temples and cathedrals of rock remind you of––a Hindu stupa, whose hidden third eye at the summit seems to look back at you? A giant’s throne minus a figure seated on top? Perhaps the raised wings of an angel? Take a closer look by moving toward the edge, but not too close. In places, the walls are hundreds of feet straight down to the next outcropping. Thus one must always heed the potential peril beyond the compelling view!
This pavement that we’re standing on forms the upper crust of both rims. It’s called the Kaibab Limestone Formation, a sedimentary rock, whose compacted and congealed residue was once a shallow sea. The name is pronounced kai-bob (or “kai-bab” to some) and originates from a Southern Paiute word meaning mountain lying down. That’s how these tribal people first perceived the jutting landmarks beyond and below the rim. From this vantage, the central corridor defining the main view from Grand Canyon Village, we see numerous iconic effigies of mixed rock formations that confirm the suggestive description.
For instance, east of Phantom Ranch (at the bottom of the canyon though not visible from the rim), the conspicuous Bright Angel fault line extends across the canyon (i.e., a literal crack in the Earth’s crust resulting from the displacement of one side compared to the other), Directly to the east (right side of the fault) there is a prominent edifice dubbed Zoroaster. Behind this namesake for a Persian prophet are Brahma and Deva, two stupa-like Hindu deities. Further east is Wotan’s Throne, a flat-topped monument that does indeed resemble a giant’s throne; also, the nearby winged edifice called Angel’s Gate that easily could replicate just that––a pair of wings (and some might even say an enormous gun site). To the west (of the celebrated tourist setting, Phantom Ranch) is another notable landmark called Buddha. Further west Isis appears to lord over the inner canyon in its sector.
Consider other and equally exotic appellations, and many that closely resemble their named counterparts: Horus and Osiris temples, Cheops Pyramid, Tower of Set, Holy Grail Temple, Tower of Ra, Mencius and Confucius temples, Rama Shrine, Hindu Amphitheater, and a gallery of smaller buttes (many named after historical figures). Most of these life-sized sculptures were named by Clarence E. Dutton (1814 - 1912), who is one of the Grand Canyon’s most prominent geologists. He obviously had a penchant for Eastern religion, Egyptian iconography, even Arthurian legend, among other themes he used for Grand Canyon hallmarks that befell his scrutiny. All these inner canyon landmarks are regarded as temples though the geologic name, “amphitheater,” is more common for the larger structures. Indeed, there are one hundred and forty-seven mountain figurines of assorted shapes and sizes, each carved by erosion.
Within the Grand Canyon’s depths between the South and North Rims, each erosional byproduct is a testament of meticulous sculpturing abetted by ideal materials and a predominately arid climate. Their distinguishable remains are constantly altered by the physical and chemical elements of erosion. For millions of years, these eye-catching features with striking names have been honed, and will continue to be honed, for millions of years until there is nothing left to whittle. So, yes, the Grand Canyon will one day become a wide spot in the rocky road of time.
By the way, we can be thankful Dutton, et al., didn’t decide to apply more common names such as cities or states, composers or authors. Believe it or not, there were attempts to suggest epithets named after classical composers.
Other than these enticing particulars about the Grand Canyon there comes the usual questions that beguile most visitors: So, what happened here? Specifically, how did this showcase of such finely chiseled features come about? The answer is simple, yet in a way baffling––erosion over time. The baffling part of the story is that it didn’t take a lot of time to create this masterpiece. For instance, in light of the geologic age of materials, as a process of time and erosion, the Grand Canyon is a relative newcomer. Even knowing the facts behind the explanation does not tend to downplay a cogent awareness one usually feels at a visceral or cognitive level when gazing at the canyon’s panorama. In fact, when describing the Grand Canyon in its more technical details, superlatives, like accolades, somehow are lacking. It follows the purely aesthetic perspective overrules the mind. and the intellect tends to shut down.
From the polychromatic banded formations before us––these buff, gray, brown and reddish hues that augment the beauty and appeal of the setting––to the rough-hewn fashioning of the canyon’s unique stair-stepped facade, the overall portrayal is venerated; at least, in a secular sense. Without question, this shrine of the ages does indeed act like a primordial touchstone to our hearts and souls.
Let’s take a wee walk toward the Trail of Time that starts its ancient clock and time travel modality in this vicinity. First, let me remind you of something park rangers are particularly fond of pointing out given three primary directives that must be followed to the letter:
1): Refrain from throwing rocks or sticks over the edge. Yes, itʼs tempting (but also lame) to see how far one can toss an object, then watch it soar hundreds of feet below. The fact is there may be critters below the flight path, even hikers, where the smallest object can be injurious, if not lethal. That being said, we have a saying here that applies to those who insist they’re merely testing Newton’s laws of gravity or doing something else that’s frowned upon by the park service: RAS––Rocks Are Smarter!
2): Always be prudent when approaching the edge! It is indeed a breathtaking view and perspective. It can also be construed as breathless in another sense. TCA: Take Care Always!
3): Gathering plants and flowers or pocketing archeological artifacts is a big no-no. As the common sign states: Take only pictures; leave only footprints.
Them’s the rules, folks! Poor grammar or not, it’s just the way things are in all national parks and monuments. Feel free to pass these mandates along to others. It’s common sense networking for a good cause!
A Literal Trail Of Time: The usual starting point for most people visiting the South Rim is Grand Canyon Village. This bustling year-round metropolis is the most visited side of the canyon. On average, some 4.5 million people enter the park at either the eastern entrance (Desert View) from the south (Tusayan) and roughly a half million who make it to the North Rim (near Jacob Lake, Utah).
And now you’re here, standing on the rim. Maybe this is the first time you have visited the Grand Canyon. Rustic, to be sure though nonetheless modernized, Grand Canyon Village has all the amenities of a medium-sized city. Getting around is also easy. Just park your vehicle and take advantage of the free shuttle service. For those who enjoy walking, viewing the canyon from the rim is what most tourists do on their visit. The second option is hiking or riding a mule to Phantom Ranch. That being said, only a relatively small percentage of visitors get their heads below the rim, either embarking on a short or long hike. Far fewer among them ever go all the way to the bottom. The third option is booking a seat on an airplane or helicopter. However, don’t expect to see or hear such craft anywhere near this sector because a no-fly zone is in effect. Consequently, quiet. For those who can afford it, the fourth option is to take a rafting excursion on the Colorado through the Grand. (More about the mule riding and rafting options will be discussed further along in the tour.)
For orientation, remember north is where the village boundary ends. It’s also sometimes windy on the rim, so keep your hat snug and mind where you’re stepping. Those Beware of falling! signs are not just meant for critters who already know how gravity works.
Near one of the oldest buildings in the park is Verkampʼs Trading Post. It’s now one of the canyonʼs visitor centers, which doubles as a bookstore and information desk. Just east of the building is the suitably named Trail of Time (hereafter, “T of T”). This is also our starting point on the tour.
Skirting the rim close to the edge, the paved, and mostly level, pathway winds its way beneath a semi-shady canopy of trees: mostly juniper and piñon pine mixed with the taller and more stately ponderosas. In place, the trail undulates though not to the point walking is strenuous unless toting a barge or something. By the way, the pavement is suitable for wheelchairs though battery-operated designs are recommended. However, skateboards, roller skates, and bicycles are verboten. People, either walking or riding wheelchairs also have the right-a-way; that is unless encountering deer, elk, and bighorn sheep. More about these and other critters will be mentioned a bit later on.
Regarding the length of this interpretive walking timeline, it’s about 2 miles (3.2 km). By interpretive means educational, with frequent signage (i.e., informative explanations, graphics, and illustrations). From start to finish, each step of the way is like a ticking clock, where each brass insignia embedded in the pavement amounts to millions of years. In this case, we begin where the Grand Canyon also leaves off. In this case, some 270 million years ago. The end of the trail is the Yavapai Observation Station, marking the 1.8-billon-year benchmark. The ticks also represent geologic time. Hence, the reason the route is given the designate, Trail of Time. Time travel also relates to human history measured in thousands of years.
When dealing with the above-mentioned benchmarks, the accurately-spaced brass insignias relate directly to the dates used on today’s tour. Benchmark figures are also calculated on a plus and minus factor assigned by geologists. Confirming what was mentioned in the FYI notes, the Earth’s geologic history is not 100% accurate, but can be off by a few or so million years, which is akin to mere pocket change (for geologists). Nevertheless, geochronology dating such as radiometric dating, has vastly improved over the years. Science is, therefore, capable of pinpointing geologic dates with more accuracy. Just be clear about the fact that dating rocks or geologic eras are not a precise science. It follows a geologic date, say, figured at 250 million years ago (hereafter, “myr”) may be 5% less or more. Some geologic dates may even reflect said adjustments (i.e., the Paleozoic Era may be written 540 myr or 570 myr or 525 myr in some geologic textbooks).
Kindly note: The geologic dates on this tour will be given further along on the tour, whose benchmarks appear to be standardized by a majority of geologists.
As far as the T of T’s linear exposition relates to our tour, it helps comprehend the sheer magnitude of geologic time encoded by the Grand Canyon’s formations and landscape environments. Using a 24-hour clock of time simile, you would be surprised where, in the scheme of things, the canyon was fabricated to its present stage of development. (Hint: sometime just before midnight.) You would be surprised to learn our species barely made it just before the twelve chimes sounded. Well, I should qualify this mark by indicating our recorded history, which is about 10,000 years in the making. (Naturally, by some standards, anthropologists might peg the number much higher, say, 20,000 to 30,000 years.)
To be sure, a lot of thought went into the planning for this popular rim trail, including keeping the spirit of the outdoors, where visitors likely will encounter a variety of wildlife, small to large to extra large. For instance, the previously mentioned big three critters: mule deer (Odocoileus hemionus), their larger cousins, elk, also known as “wapiti” (Cervus canadensis, which is one of the largest species of the Cervidae or deer family), and desert bighorn sheep (Ovis canadensis nelsoni). These four-legged mammal residents are used to their personal space and can get a bit testy with folks who challenge this common sense park rule. It follows how these free-to-roam mammals always have the right-of-way. Period. And there is another big no-no that irks park rangers: Feeding or petting or trying to get close and personal with critters. Ergo, keep your distance. Always.
Then there are the other critters that need mentioning. In this case, the most notorious ones that can be downright pesky––rock squirrels (Spermophilus variegatus), which belong to the family Sciuridae. They likely cause more problems for visitors than any other critter in the park. In fact, it’s people who are likely to cause more problems for themselves because they feed these rather aggressive rodents. Rock squirrels, even the smaller antelope chipmunks (also from the family Sciuridae), are notorious for suddenly swiping food from tourists. More often it’s the hand trying to feed or tease the squirrel or chipmunk that gets bit in a nanosecond. Then the blood flies because these rodents sink their teeth down to the bone. But guess who gets the ticket if a ranger witnesses anyone attempting to feed these pesky critters? D’oh!
Back to the bigger critters. . .chances are on today’s tour deer, elk or bighorn may wander back and forth across the trail. So, let ‘em. Elk weighs around 800 pounds (362 kg) and can be as hefty as 1,100 pounds (498 kg). That’s a lot of mass on four hooves, and if the bull elk happens to be romancing the cows, they get especially testy. Ergo, forget about taking a selfie with wildlife. The best thing is to stand still and let the mammal traffic do its thing.
Regarding other mammals, namely bobcats and pumas (aka “mountain lions” or “cougars”), they’re here, as well, but chances are you won’t see these magnificent cats. Desert bighorn sheep during the warmer months are frequent, however. Like elk and deer, they’re tame, but only as long as they have their space. Rams are especially notorious for taking the right-of-the-way on canyon trails. In other words, they may challenge a hiker if the ram feels he’s challenged. Ranging anywhere from 115 to 280 pounds (55 to 90 kg), if the charge happens, the hiker is sure to go flying. Not good.
And above the ground are other canyon residents, only with wings. If you happen to notice a distinctive and large black bird casually riding the thermals, and one with a rather unattractive head, that would be the California condor (Gymnogyps californianus). It kind of looks like a smaller Cessna with a patch of white beneath its wings. What condors lack in facial beauty is easily compensated by their outstretched wings measuring nearly 10-feet long (3.04 m) from tip to tip. Peregrine falcons (Falco peregrinus), red-tail hawks (Buteo jamaicensis) and a variety of other raptors also are seen. Ravens (Corvus corax) are the most common among them. They’re also much larger than their crow cousins. A raven’s dazzling aerobatic display, like a midair ballet, puts on quite a show for spectators. Like coyotes (Canis latrans), many Native American tribes consider ravens as guileful tricksters. Both species are also revered for their antics and cunning characteristics. So, yes, keep snacks close at hand or watch your treats suddenly whisked away. Coyotes, however, prefer rabbits, mice and such. Live, of course.
Parenthetically, during the warmer months, a variety of lizards are out and about dodging foot traffic on the rim, but donʼt expect to see snakes. The canyon has lots of those, but not up here. Like most other reptiles, snakes prefer warmer altitudes, starting around the mid-level of the inner canyon, but especially slithering about on the bottom floor. The canyon is also warmer and drier the further down trail you travel. This piece of information means you can stand on the rim and shiver during the colder months while at the bottom and likely sweating would make you feel more comfortable. Hence, a direct
In case some of you on the tour may wonder or worry about the danger of a plethora of canyon critters, both on the rim and in the interior of the canyon, I think that catchy New Jersey expression, forgetaboutit, applies. You stay away from them, and theyʼll likely stay away from you. That being said, and reiterating what was mentioned earlier (because it’s worth repeating), some tourists insist being in a national park with wildlife somehow makes it safe to encroach on some animals. That’s a fallacy. The only reason the previously mentioned mammals appear docile is because they have a sense they are protected. They’re also used to seeing tourists all the time. On the other hoof, every creature has its personal space. Violate this rule and risk a close encounter of the worst kind. Sometimes injuries and fatalities occur, but not to the four-legged natives. (Remember the rule: RAS!)
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Now that you know the rules here always favor the beasties, which are comfortable hanging about as long as they’re not being disturbed, follow me to a hard-packed spur leading off from the main trail. The insignia benchmark (hereafter, “insignia”) on the right is 270 myr. Think of it as the geologic textbook is open and marks a date when this particular formation, the Kaibab, formed, and later hardened. Another way to think about it is we begin the time machine effect this many millions of years ago. And before we get to our destination today it’s going to get a lot older for time travelers on this pathway.
In some places on the tour today, we’ll get off the main trail and check out some vistas by getting closer to the edge. Keep in mind there will be no leaning forward at such places! And for obvious reasons. The reason we’re checking out this vista near the start of the T of T is to point out something about the previously mentioned geologic textbook. Let’s start with a fancy word called lithology. It means the general physical characteristics of rocks. Although the river isn’t visible from this sector, indeed small slices of the Colorado show up sporadically along the rim in this vicinity, the textbook from the inner canyon gorge to the rim is open and subject to review. Think of what you’re seeing out and down there as lithified pages of time and events that went into the making of the Grand Canyon’s foundational materials. Even if one doesn’t know the names of these varying and changing events that began some 2 billion years ago, the different events are discernible by color, placement in the stack, and the overall profile. These mentioned aspects, therefore, denote why some formations are cliffs while others are ledges and slopes. Moreover, at the bottom of the canyon is a distinctive V-shaped inner canyon gorge, and most of which lacks distinctive colors such as displayed above the gorge.
All of this and more will be explained along the way. For now, I want you to consider some key questions to get the proverbial ball rolling. Namely, queries about the Grand Canyon’s creation story.
First, why is the canyon’s appearance so unique? Let me reframe the question that might make better sense: What does this multitiered facade remind you of, given the striking contour of features on display, and most especially the upper formations laid over the darker recesses below (i.e., the so-called gorge where the river flows)? Is this a typical canyon we’re seeing? Bear in mind there are no wrong answers on the tour. It’s more the case some answers are more correct than others.
Here’s something to think about while you mull over your answer: there are two disparate views in the overall setting. Let me explain. The gorge is quite distinguishable compared to the upper canyon layers. Can you see why?
Here’s another question meant to elicit the answer––your answer––because that’s the kind of usual Socratic means of teaching and sharing I do. Namely, suggesting questions that suggest their particular answers. In other words, most of the time people know the answer even if, at first, it doesn’t come to mind. It follows how the question comes down to this finer point: Why is the Grand Canyon not a typical V-shaped chasm? True, in the gorge there is such a shape. But not on top of its V-shaped chasm. Why? Think of another chasm, say, Idaho’s Hell’s Canyon, or Colorado’s Black Canyon of the Gunnison. Both are prime examples what canyons typically look like. Obviously, the Grand Canyon’s appearance below the rim and all the way to the top of the gorge does not follow suit; at least, not the usual shape of a canyon.
This stereoscopic backdrop before us tends to create a greater void enhancing the depth of perception, almost illusory, and it’s the canyon’s upper features that lend itself to this artistic depiction. Indeed, if it wasn’t for these upper features, this canyon would be like any other typical canyon, still impressive, but nowhere as majestic. In short, the inner canyon gorge begins at this sector and not some two-thirds below the rim.
Here’s the answer some of you might already have figured out: What makes the Grand Canyon so wonderfully unique has to do with its source materials representing different marine and terrestrial environments that came and went here over millions of years! In other words, the different formations that originated from primal seas and terrestrial events. For instance, deltas and lagoons, near-shore environments, floodplains, swamps, rivers, even a Sahara-like desert or two. Once these materials were dried out, then compacted and hardened and their particles cemented, these depositions that began around 540 myr (i.e., the so-called upper sedimentary layers) were archived by Mother Nature. Once exposed, however, erosion took over and began the fabrication process.
This explanation, of course, is simplified, but it gets us started in the right direction thinking about how the Grand Canyon earned this complimentary designate. Considering there were all these different events one after the other, which took millions of years to lay down the deposits, then turn into hard-rock formations, geologists use the term differential erosion to explain why each of the many layers viewed in the walls creates a different profile. Thus, the cliff-slope-ledge contour. The reason for this is because limestone tends to form cliffs because it’s a very hard and solid sedimentary rock while relatively softer sedimentary rocks, like shale and siltstone, then form either slopes or ledges. Sometimes within a formation, there is a mixture, which means a cliff and slope or cliff and ledge appearance.
Again to mention the point––the simplified explanation is presented here and now and a more detailed explanation will follow later in the tour. For now, what you see out there denote different events over time, where repetitive seas, a quiet ocean or two, and all the other above-mentioned environments added to the superstructure of this part of the future canyon in the making. In fact, the different pigmentation in the banded layers is due to these changing events. Some of these tinctures indicate the sediment originated, say, in a swamp environment, where high levels of oxygen later in time rusted the iron in the mud. Flowing water is also a primary source of oxygen. Rivers, floodplains, and title flats eventually turned into a brilliant reddish-brown color in some rock formations. For instance, count down four banded layers and note how this part of the upper canyon is the first to show up with such a gorgeous color. The name, by the way, is the Hermit Formation, which is mostly shale. Just below is an even thicker reddish formation called the Supai Group (which has four distinct inner layers). These terrestrial red siltstones and sandstones stem from swampy environments. Likely, when this deposition was laid down it was a coastal lowland plain crossed by various streams.
To say any more about such geologic facts might be a bit much for some folks, so suffice it to say you, at least, have a reliable answer why the upper two-thirds of the Grand Canyon are very distinctive; that there are depositions of materials in the walls accounting for sedimentary rocks that are stronger (i.e., harder) or weaker (i.e., softer), and that’s why some formations show up as cliffs while others are slopes or ledges. You also are aware of the fact varying environments over millions of years, both aquatic and terrestrial events, account for many of the canyon’s distinctive tinctures.
With this very basic introduction in mind, we’re walking again. The questions you still have will all be answered in good time. The way the tour lends itself from the easiest to more entailed facts means we don’t have to learn all the intricacies here and now. Spread over the duration of today’s tour, however, the facts will eventually fall in place. That’s a promise.
Meanwhile, here’s another question I would like you to think about because the answer has everything to do with the how-what-why-where-and-when factors about the Grand Canyon’s creation story: Why is the Grand Canyon in this locale and not somewhere else on the planet?
If You Build It, They Will Come (to the South Rim): Why the Grand Canyon is entirely within the State of Arizona, specifically the northern tier, has everything to do with the timing of key events, foundational materials, prevailing aridity, and the dimensions that encompass such a king-sized abode. It can also not be duplicated anywhere on the planet though you are free to try to create something similar wherever you like. In a way’s you would be duplicating the fundamental steps in the process, and in the precise order. That being said, here’s an experiment anyone can try at home:
Start with an exceptionally long garden hose, turn on the spigot, and let the water flow over an excessively large and fairly flat terrain. The next thing is to find a way to hang out for millions of years and thereby transcending space and time until your experiment is ready to be reviewed. What you’ll be looking for is how relentless forces of erosion must work in tandem with the flowing water, thereby resulting in a canyon of notable size and dimension. If this idea doesn’t prove useful, then you’ll have to try the experiment again, only the next time make sure you have the right materials to work with. Namely, a predominantly arid climate and sedimentary materials, and eventually a stronger catalyst (meaning, a more potent garden hose). If you get it right, erosion will hone the excavation project into something similar to the Grand Canyon (hopefully). Oh, I left out one important and final detail: to abet the process, something below the foundation first has to happen, so that the water maintains its hold on a level landscape and chisels a groove that will only get deeper as time passes.
Consider this experiment a major clue to help you understand the nuances of what this tour is all about. And good luck with your intentions to create a rival canyon of similar scope.
Here’s a question that should be obvious, yet some people don’t even think about it: What defines a canyon? For instance, is it the length, width or depth of its chasm? If so, when do such measurements change Nature’s planning stage into the potential designate––a canyon? First, let me mention how canyons, like valleys, are formed through erosion, and yet the comparison stops because a canyon is best defined as a cavernous gash in the Earth’s crust, with steep sides and a relatively narrow chasm at the bottom. Hence, the actual depth doesn’t seem to matter. True, canyons throughout this part of North America, the Southwest’s sector, can be massive in size, yet the bed topography is a much smaller width compared to the height and sides. Canyons are also significantly steeper than valleys.
The second distinguishing factor is why the Southwest, particularly the canyon country embellishing a large portion of the Colorado Plateau Province, came into its special creation. (This expansive territory entails the Grand Canyon and all the other winsome canyons incised here.) As for the unnamed catalyst and its name and function, it will have to be put off until later; that is once other geologic facts are in place. For the time being, you need only understand canyons in this part of the continent are first begun by rivers. Moreover, the volume of water and elevation drop that eats away at underlying rock strata. The higher the volume of water, the more scouring power grinds into the bedrock, and not just flowing across the bedrock. Thus, an effective means to transport some of the material making up the floor of the canyon. It follows how the canyon gets deeper over time.
Naturally, the further the canyon progresses in its evolution, the faster the erosion process. The canyon walls also begin acting like a monumental sluice while channeling the force of the water into a progressively smaller area. Now you might understand why canyons typically tend to be wider at the top than they are at the bottom. The steeply sloping sides of the canyon also provide another clue. In this case, the slope is caused by the action of the water transporting debris away from the canyon walls, with the material moving toward the far end of the river’s course; also, when canyon walls reveal a greater surface area, erosion, by wind and water, increases.
The third distinguishing factor is how canyon walls typically show visible layers of rock strata from top to bottom, like the Grand Canyon formations just beyond the rim. Harder rocks naturally erode much slower than softer rock materials. It follows how hard rock strata of the canyon walls denotes the common material in the canyon walls.
The purpose of mentioning these three important facts come down to this finer detail: not all canyons are the same, even though initially created by a river. And, yes, the volume calculated in cubic feet per second (hereafter, “c.f.s.”) and elevation drop has something to do with the depth of a chasm. For instance, the Missouri Breaks (of the upper Missouri River), the Middle Fork of the Salmon rivers, and the Columbia River Gorge each has impressive segments of wild rapids (whitewater) funneling through deep recesses, at least, in some sectors. Nevertheless, it’s still not the kind of canyon country and scenery the Southwest’s has fashioned over millions of years.
The bottom line comes down to this salient fact: rivers, like the Mississippi, are flat (meaning, no rapids to speak of). They do not, and cannot, create canyons in their wake. This declaration is not intended as a comparison of scenery or whitewater rapids thundering and running through chasms, like the Grand Canyon or the Green River’s litany of canyons. Rather, it’s the nature how some rivers are born to be wild. Let me also assure you how the Colorado River flowing through the Grand Canyon is mostly flat (i.e., no rapids) because it tends to pool in great lengths. Between these frequent and longer calm water stretches, however, and due to the steep elevation drop in parts of the canyon, hundreds of rapids throw down a gauntlet to boatmen and their passengers. Indeed, some sixty cataracts are considered ultra challenging which provides the biggest adrenaline thrill for river rats (an affectional term for boaters). Running the Grand is also considered the granddaddy of whitewater in the Southwest.
Changing the subject, and, this time, mentioning some trivia you will find interesting, the earlier remark about a canyon’s profile that typically expose different rock layers is not a categorical statement. Here’s why: where a chasm is defined as one main rock formation, only that particular sedimentary material lines the walls, at least, the majority of the canyon denotes a single rock layer type. Zion Canyon, in Utah, is one such place. In fact, it’s considered the deepest canyon in the Southwest, but only in the sense, one predominant formation defines the lining of its chasm: Navajo Sandstone. For some 2,000 feet, the seeming docile body Virgin River has cut this amazing canyon depth over time. However, for most of the year, this relatively narrow river is little more than an indolent and fast-running stream. Of course, when monsoonal flash floods swell the river and greatly increase the measured c.f.s. flow and volume, the Colorado is anything but indolent. Those raging floodwaters over the eons have also unharnessed the river, thereby augmenting its scouring power. Moreover, sandstone is easily malleable. Hence, a spectacular narrow gorge defines part of Zion National Park’s handsome features.
With these details of canyons and rivers in mind, we will learn something about the Grand Canyon’s staggering dimensions. But first another question: How much of the Grand Canyon do you think is visible from any vista? I ask this because some people tell me they have seen my ‘other office,’ and so I respond, “Yes, and what part?” The innocent retort usually surprises some people but shocks others. They ask me what do I mean by this, inferring while insisting, they did, in fact, visit and see the Grand Canyon. Again, I reiterate, “Yes, you said that. But what part of the canyon did you see?”
Eventually, I stop the ribbing and relate how the Grand Canyon is so lengthy that it’s only possible to see a portion of its dimensions from any locale, say one-fifth of the overall size. For instance, from the village, we see part of the eastern boundary, but mostly the view takes in the central corridor spread out below the rim. There is also a generous view that extends to the west. The fact is, there’s a lot more of the canyon to see. For instance, east of Desert View is Marble Canyon, which defines the eastern ramparts. Part of the western sector, namely, the Havasupai and Hualapai Indian reservations, is also absent from the view.
The point I’m making is just this: the Grand Canyon may seem like the same extensive view from one end of its domain to the other, yet to the informed eye there is quite a remarkable difference given what each sector highlights. For one thing, the trinity of monumental amphitheaters that I mentioned earlier, Zoroaster, Brahman, and Deva, may resemble one another in size and feature, yet each is a distinctive inner canyon landmark. Let’s just say from any vista on either side of the canyon the panoramic view stretches only so far.
I think another question is called for because it will give you something more to think about given a comparison factor: What canyon do you think is longer or deeper? I mentioned at the outset the Grand Canyon does not qualify for besting either dimension. Moreover, there are several other canyon locales to choose from that are longer and deeper. Let me also say it’s another trick question based on the fact defining canyons as largest or deepest is too imprecise. The reason has to do with the difficulty of measuring length, total area, height, width, depth, even different geographic locations. Besides, not all canyons and gorges can be measured accurately due to inaccessibility. Still, you might as well consider these other reputedly larger or deeper canyons in case youʼre ever chosen as a contestant on Jeopardy (if so, don’t forget to precede the answer with “What is. . .”):
Chinaʼs Yarlung Zangbo Grand Canyon; Peruʼs Cotahuasi Canyon (11,597 feet/3,535 meters deep, a big wow); Mexicoʼs Barranca del Cobre (Copper Canyon), which is a group of six canyons combined, and Nepalʼs Kali Gandaki Gorge, considered the deepest gorge of all. Note: this gorge separates the major peaks of Dhaulagiri (26,795 feet/8167 meters on the west) and Annapurna (26,545 feet/8,090 meters on the east). If measuring the depth by the difference between the river height and the heights of the highest peaks on either side, Gandaki is indeed the worldʼs deepest. Hence, an even bigger WOW compared to Cotahuasi Canyon!
With this additional trivia aside, these places are all very impressive in size and feature. Then again, all things being relative let’s consider the monumental Valles Mariner. Itʼs the largest and deepest canyon measuring some 2,500 miles/4,023 kilometers long, 667 feet/203 meters wide and 4 miles/6.4 meters deep. Now that’s a canyon, folks! Then again, to see it youʼd have to book a flight to Mars or take my word for it.
So, the winner is? That’s easy because we’re looking at it. Most assuredly, the Grand Canyon’s abyss is in a class of its own. Now for those dimensions and other pertinent details, I am sure most people are eager to know.
Canyon Dimensions: Given the geologic display and dimensions of the Grand Canyon, just how deep is deep and how big is big? This question typifies the what aspects of the Grand Canyonʼs process of creation. And the adjective that best describes the answer is enormous. Hereʼs why. . .
Grand Canyon National Park (GCNP) encompasses 1,904 square miles (4,931 km2), which translates into 1,217,262 acres (nearly 493 hectares). Originally, the park’s parameters originated where Marble Canyon ends (at the junction of the Colorado and Little Colorado rivers, mile-60). However, GCNP extended its jurisdiction and acreage in 1975 and now includes Marble Canyon. This annex begins not too far downstream from Lees Ferry (mile-0), which is the put-on point for all rafting parties. This historic site is some 14 miles (22.5 km) below the Glen Canyon Dam. Consequently, the length is 277.7 miles (446.9 km)measured from Lees Ferry to Pearceʼs Ferry, which is across from the Grand Wash Cliffs (overlooking Lake Mead). If you have ever driven from, say, Chicago to Saint Louis, Los Angeles to Las Vegas, or Boston to Philadelphia, the distance between these locales is around 300 miles (482.8 km)
The depth of Grand Canyon averages 6,000 feet (1,828 m), and the width varies between 4 to 18 miles 6.4 - 28.9 km), with an average distance of 10 miles (16 km). You can also hike across from rim-to-rim, which is about 24 miles (38.6 km). From this central corridor of the canyon, there is a choice of crossing the Colorado River by either the Silver Bridge––via the Bright Angel Trail––or the older and original Black Bridge––via the South Kaibab Trail. Parenthetically, these are the only bridges inside the Grand Canyon, both only used for foot or hoof traffic.
Another fact about the Grand Canyonʼs striking dimensions is the lofty elevation. The South Rim averages 7,000 feet (2,133 m) above sea level while the North Rim is about 8,000 feet (2,438 m). However, the eastern sector on that side of the canyon can go as high as 8,900 feet (2,712 m), but to the west, the altitude drops significantly––about 4,200 feet (1,280 m). For the most part, the North Rim, being the highest elevation, attracts weather systems, like a magnet. It follows how this side of the canyon gets the bounty of precipitation, rain or snow. Strangely, it may be raining or snowing on the North Rim while across the canyon itʼs a balmy, sunny day. Since you already know the South Rim is open year-round, be advised the North Rim is closed from late autumn to late spring.
Now that you have an idea of the dimensions and a couple of other insights thus far shared on the tour, letʼs continue our walk and consider the names of the canyon’s formations. On this tour, knowing these names, as well as everything connected with their respective layers (formations), is very helpful. I mean, if someone asks you to go for a hike, but only as far as the Redwall Formation, which is the sixth major formation below the rim, consider the invitation as you would be going for a swim in the ocean. In this case, hiking down to the Redwall is hefty exercise, just like swimming beyond the beach entails a rather vigorous workout. Then again, at least, inside the canyon, you don’t have to worry about sharks and such!
Given this insight, there is something else to think about: fossils in the rocks, which will be discussed at length later in the tour. For now, and strictly FYI, fossils usually show up in limestone. Sharks, for instance, in the Redwall Limestone denotes a great inland sea some 335 myr. However, the only remains of their species are teeth because a shark’s greater mass is composed of flexible connective tissue (i.e., cartilaginous skeleton).
Folks, we’re walking and headed for another overview I’ve selected for a special reason. While geology and fossils and critters make for interesting subject matter, the human history of the Grand Canyon is also interesting. Starting with prehistoric history, we’ll open the book on the long-running chronicle of human occupation of both the canyon and this region. Can you guess how long humans have even been in this region? As a reliable estimate, you will be surprised when you hear the answer!
End of Chapter. . .Shall We Continue?