The Colorado Plateau, Part 2

CONTINUATION OF THE COLORADO PLATEAU SERIES

THE COLORADO PLATEAU CONTINUED DIARY
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Prologue
This diary continues where previous diary left off. Thus a continuum of just about everything you ever wanted to know about this multifaceted, and typically high country province. . . a landscape of dazzling scenic icons where superlatives go to die!



Nature’s Palette Of Cool Colors
The Colorado Plateau is sometimes referred to as the land of flat-lying features (i.e., its originally horizontal strata that accumulated to some 15,000 feet thick before erosion and faulting set in). It's also known as the land of red rocks due to this predominate tincture in a variety of sectors. For instance, Sedona, Arizona, Bryce Canyon, Vermillion Cliffs, Buckskin Gulch, the neighboring Coyote Gulch and Paria Canyon are exemplary examples of such gorgeous color. Each backdrop adjusts the tincture up or down, depending on the mineral content in the rocks. Indeed, parts of Utah likely takes home the grand prize for the greatest parade of color adorning its celebrated landmarks. So let's add a few more examples to the top of the list: the Kaiparowits Plateau, the Escalante Canyon, and the Waterpocket Fold country (Capitol Reef National Park) overlooking the Glen Canyon-Lake Powell National Recreation Area.

The engaging color scheme in these, among many other settings of the Plateau, is especially at its optimum in the late afternoon. Those who are aware of the magic of sunlight working the veneer of rock features often hang out at a preferred vista, just waiting and watching a seeming living landscape come alive with a variety of colors. The spectrum comes from your everyday sedimentary rocks, where the ordinary becomes the extraordinary in strong or soft light. Consider also the Painted Desert terrain that earns its reputation as the most colorful desert on the planet. Its common Mesozoic Era rocks (principally Moenkopi, Chinle and Shinarump) blanket an extensive area ranging from Cameron, Arizona to the Petrified National Forest (near Holbrook), whose landscape literally cooks in the afternoon or early sunlight: a veritable beatific vision on a grandiose scale.

So, where eactly do the colors come from? What makes these tinctures in the rock formations so outstanding? Here’s the answer: reds, pinks, and yellows are created by tiny particles of iron oxides; greens and blues originate from unoxidized iron minerals; and lavender originates from manganese. There are also contrasting gray tones from igneous rocks––basalt and granite––and dark browns and purples from desert varnish, or what is commonly calledpatina. Lichens also add a variety of tincture to some rock surfaces, notably, green, yellow, and orange blotches. In some places, polished cliff faces are embellished with long and decorative ribbons of brown, black, or blue-black stains (again, "patina") that appear to move and trickle down the smooth, colossal panels of sandstone. In some gaping alcoves, like Keet Seel’s ruins (inside the Navajo National Monument, near Kayenta, Arizona), the decorative markings appear like tiger stripes painted on a tan-colored panel of sheer rock. The artistry and palette of Nature typically embellishes her gallery of natural wonders throughout the Colorado Plateau.

The question is: would the charm and magic still be there if all the formations were merely gray or brownish in color? One can also ask if the spectacle of geologic design would still be interesting? True, the panoramic view throughout the Plateau would still be spectacular. Then again, without the color scheme a monochromatic display would be like seeing the Sistine Chapel in black and white.

Ambience In A Comprehensive Setting
The combined effect of elevation difference, changing hues, and differential erosion honing dissimilar types of rock formations all work in concert throughout the typically arid Southwest, particularly throughout the Colorado Plateau. There is harmony here. There is abundant space and seclusion here. There is vast open space here. There is also a pageant of splendid geologic wonders just about everywhere you look. In view of the abundance of hundreds of scenic icons, people may wonder if there is any particular landmark in this province that can be called the crescendo of creation. One might even assume the Grand Canyon is the focal point of the Plateau’s magisterial offering and therefore gets the trophy. Monument Valley’s citadels and temples of sandstone may also be another contender. The same can be said for the pinkish amphitheater facade of Cedar Breaks escarpment, which is quite similar to nearby Bryce Canyon (and is a much larger series of open-faced auditoriums). Aesthetics being what it is––a subjective state of mind––there really are too many available choices to consider one among them that is considered penultimate. It really comes down to what appeals to one’s fancy.

Goosenecks of the San Juan, Mexican Hat, Utah:



Arguably, the reputation for having the most fastidious geologic creations on the planet solely belongs to this province. Plateaus downsized to mesas and buttes, and embellished by views with an assortment of loftier add-on features––the isolated volcanic protrusions standing above the fractured landscape––each facet of creation compliments the other. However, there are no mountains here per se; at least nothing typically created in the sense how mountains are upthrusted through the crust of the planet. Instead, the mountain-like dark shapely profiles are not typical granitic formations, such as the Rocky Mountains. The Plateau's variety are classified as laccoliths, whose mass of igneous rock have intruded between layers of sedimentary rock, resulting in uplift and a doming effect.

Remember
The Plateau's predominate features denote the land of flat-lying rocks throughout a relatively flat plane at varying elevations. Hence, the landscape is not a vertical aspect mimicking real mountainous terrain. Those anomalous higher profiles highlighting sectors of the Plateau––the laccoliths––merely grow upward and overtop a horizontal plane.

Grand Canyon North Rim, Arizona:



Grand Canyon South Rim, Arizona:



The Colorado Plateau's Layer Cake Design
Because each horizontal strata laid down over the eons builds upon the other, with the oldest formations always stacked at the bottom, the Plateau manifests a delectable, huge cake displaying each congealed and compacted depositions from the primal past. With its layers showcasing a typical polychromatic facade of mostly sedimentary rocks (sandstone and limestone from a variety of terrestrial and marine environments), the risen cake might be deemed Nature's whim when the original pile was uplifted. Perhaps subduction of tectonic plates can be construed in such a way, though it's more correct to say the proximity of merging plates doing such a thing (i.e., one plate overriding the other) is fortuitous. However, the uplifted terrain so far from the epicenter of such plate interaction can be thought of as a miracle of creation, at least some of us feel this way. The miracle, in this case, is how the gigantic Colorado Plateau cake did not just fall apart during or after its uplifting phase or phases.

FYI
Sticking with the implied or assume miracle, erosion and faulting abetted the graceful fashioning throughout the downsizing of the original estate––a process once begun that never finishes until the last rock features has been reduced to its finest clastic particle. Sedimentary rocks are thus composed of fragments, or clasts, of pre-existing minerals and rock fragments. So, yes, one day everything that once stood solid and strong will eventually break down to bits of terrestrial and marine particles. In fact, such a breakdown began long ago when elements of erosion went to work, whose agents include tree roots, plants and lichens.

As mentioned in the first diary of this series, the Plateau has preserved its unique features all through the process initiated by subduction and the consequential uplift of its base cake-like foundation. The geologic record is also mostly intact, because there were no mountain-building events that alters (read "destroy") the record by creating a new template of design. In view of the territory's expansive boundaries, perhaps a pseudonym for this revamped landscape (i.e., its before and after look due to its uplifted status) should be renamed Paradise Plateau. Certainly, no other plateau-based province on the planet features the plethora of natural attractions that comes anywhere close to rivaling this province’s geologic assets. Hence, paradisal from the aesthetic point of view. The following list describes some of the more outstanding locales, as facets of a greater jewel-like setting, that attests to this assertion.

Hovenweep National Monument, Utah



Distinct Sectors Of The Plateau Country
Bounded by mountainous and desert terrain on all sides, the Colorado Plateau is a highly picturesque territory unevenly divided into seven distinct sections: the Unita Basin, High Plateaus, Grand Canyon, Canyonlands, Navajo, Datil-Mogollon, and Acoma-Zuni. In Unita, which is where the Unita Basin is located, the Plateau province also includes several higher fault-separated plateaus: Awapa, Aquarius, Kaiparowits, Markagunt, Paunsaugunt, Sevier, Fishlake, Pavant, Gunnison and the Tavaputs. Possibly, this aptly named Grand Staircase (in Utah) is the most majestic feature, where the lowest to highest plateaus rise above the Colorado River drainage with an elevation gain of nearly 7,000 feet. The Staircase’s increasingly younger east-west trending escarpments extend north of the Grand Canyon and are named for their awe inspiriting color: Chocolate Cliffs, Vermilion, White Cliffs, Gray Cliffs and Pink Cliffs.

Hopi Mesa Country, Arizona:



Essentials of the Plateau Country
When people see and explore the many facets of this territory, many questions come to mind. For instance, what precisely is the Colorado Plateau? This inquiry naturally spawns similar others that frame a series of specifics about how this geologic turf was formed. For instance, why are there so many deep canyons here? What makes rock formations fold, seemingly like sticks of taffy? What’s behind the exquisite sculpture representing a galley of shapes and sizes, from the larger plateaus to the smaller spires and totem poles? These questions, once answered, open minds, perhaps even hearts, to the majesty of this setting connecting four huge Western states.

To partly address the what of the Colorado Plateau, it’s a physiographic region of the Intermontane Plateaus. Indeed, the entirety of this province typifies a huge basin ringed by highlands and literally filled with an assortment of plateaus. This stair-stepped inclusive landmass of changing elevations is also extremely old. As a distinct mass of continental crust, it’s probably somewhere between 540 to 560-million years old, and possibly older. Such longevity is especially impressive when one considers the literal globetrotting adventures of the North American continent from the perspective of the so-called continental drift theory (i.e., how tectonic plates migrate around the world, which are pushed along by upwelling thermal currents deep within the bowels of the earth).

FYI
The speculation that continents might have 'drifted' was first put forward by Abraham Ortelius in 1596. Later, this concept was independently (and more fully) developed by Alfred Wegener in 1912. The theory of continental drift was since superseded by the theory of plate tectonics, which builds upon and better explains why the continents move. More about this intriguing plate migrating business follows further along in this subject matter. Indeed, we are going to add another virtual tour by way of imagining ourselves standing on a continental plate drifting across latitudes, all for the sake of a sound demonstration of why and how plates move, and what happens when the come in contact with other plates.

Kodachrome Basin, Utah:



Here is an example of Wegener's perspective of moving plates, which by the way, this German climatologist, when he first proposed his seeming outlandish idea, was thought to be daft, and therefore mostly ignored by scientists. (His theory, along with the original notion proposed by Ortelius, a Flemish cartographer and geographer, was eventually validated by scientists in the 1960. Sometimes it takes a long time to convince others of the truths some enlightened others already know. Notably, Copernicus and Galileo come to mind.) Anyway, over a period of 300 to 400-hundred million years a large landmass that would eventually become the North American continent separated from an even larger landmass. Indeed, all the world's former and single landmass, called Pangea, began breaking up around this time, with different segmented landmasses going this way or that. Here is what the planet's continental amassed configuration once looked like:



Let's cut to the chase and just say how our continental plate was going places, though no in a hurry. Besides, plates are never in a hurry. They just crawl along the lithosphere, sort of like slow-moving bumper cars in an amusement park, only with epic consequences––earthquakes, volcanoes and mountains created by plate collisions.

Meanwhile, the part of the plate that was destined for a major transformation of its lackluster features, namely the dried out remains of one environment after the other, drifted across changing latitudes, whose prevailing climates were the building blocks for these varying depositions over time. Thus the part of the continental plate that defined the future Colorado Plateau sector merely drifted along comfortably (i.e., without deformation and loss of materials) on its western edge. Now shoreline, now inundated by rising seas, its entire turf accumulated mega quantities of sediment, gradually sinking under its own weight until heat and pressure hardened the deposits into a mantle of sedimentary rock several miles thick. Even when the entire western United States began to rise millions of years ago, and eventually climbing to elevations as much as a few miles above sea level, the Plateau region remained stable––perhaps floating on a cushion of molten rock.

Little Colorado River Gorge, adjacent to the Grand Canyon (South Rim):



Grand Falls of the Little Colorado (at the upper end):



FYI
As a reminder, the uplifting geophysical event has preserved a vast geologic display of attractive features, including safeguarding the Plateau's geologic record for all these millions of years! In other words, the foundation's extraordinary stability cannot be underestimated. By comparison to other neighboring provinces in the East and West (including a sector to the Southwest) where mountain building activity was the usual blueprint of creation, throughout the Colorado Plateau's estate it's not the case of what happened here that is so important to comprehend, as it is what didn’t happen. For example, relatively little rock deformation, such as faulting and folding has affected the Plateau's high, thick crustal block formation within the last 550-million years or so. In contrast, regional provinces that have suffered severe deformation surround its preserved foundation. Mountain building has therefore thrust up the Rocky Mountain, while tremendous earth-stretching tension created the Basin and Range Province. Additionally, sub ranges of the Southern Rocky Mountains (in Colorado and New Mexico) are scattered on the fringes of the Colorado Plateau, thereby altering more of the original geologic record.

The most significant aspect about the Colorado Plateau's unparalleled landscape is therefore what geophysical force created it. The subtopic below, The Migration of the Plates, will explain in more detail how tectonic plate collisions were the major shaping force behind the uplifting of the Plateau, as well as all mountainous terrain throughout the Rocky Mountain West, and extending westward toward the Coastal Range. This example is also a simpler explanation of what happened long, long ago and continues to this day.

Let's Take A Virtual Ride On A Tectonic Plate
Let imagination take you on a journey through time. You begin hundreds of millions of years ago and you’re standing on a rather mundane-featured tectonic plate, precisely the North American plate (or what will one day bear this name). You begin the journey somewhere below the equator just after the breakup of a larger supercontinent mass, the above mentioned called Pangea (meaning, "One World"). This so-called supercontinent amounts to welded landforms surrounded by a global body of water, the so-named Tethys Sea. There are many individual pieces of varying sizes accounting for this huge, composite landmass that may have coalesced sometime toward the closing of the Paleozoic Era (say around 250 million years ago). Partway into the Mesozoic Era the entire foundation breaks apart again, each segment moving in different directions, and each headed toward various sectors of the globe.



For this exercise of demonstration, you will be standing on a migrating plate casually drifting north-north east until it bumps into another landmass. Afterward the plate definitely shifts direction, this time vectoring away from its original northeast bearing. Hence, you are headed north by northwest. A change in direction is also what happens when plates slam into each other. In short, a dynamic force that also causes a chain reaction of various events (the aforementioned birthing of mountains and volcanoes). The new direction is also pivotal given what eventually will happen when the plate comes in contact with the outer edge of the Pacific Plate, a so-called oceanic plate. Moreover, the dimensions of the tectonic plate (the one you're riding) will grow and diminish in size during its migration. But the main and larger portion (the so-called "craton") remains relatively undisturbed and includes its shield and platform layers. Be patient with the journey and enjoy the slow ride. Besides, the best speed, as distance gained, that you can expect is about a centimeter a year, though plates some can put the pedal to the metal and crank out maybe two or three centimeters (give or take).

FYI
For those who firmly believe the world was created in, say, a 6,000 to 10,000-year timeframe. . .this now proven theory of plate tectonic migration obviously questions such estimates, that is, unless there was a time when the world rearranged its landmass furniture in a blink of an eye. Later, when the pieces were in place, everything purportedly had returned to a normal space-time continuum, though nonetheless still fast work. Thus if confronted with the problem of a very young and dynamic earth said to be no more then ten or eleven-thousand years, and solving same, good luck with that.

As mentioned, though here presented in more detail, as the migration of the plate continues northward, you drift along like a tumbleweed on the relatively thin skin of the lithosphere, which entails crossing various latitudes. Each geographic coordinate also marks a distinctive and prevailing climatic zone, starting from below the equator, followed by tropical and subtropical zones and reciprocal changes in prevailing climates relative to those latitudes. Eventually, you end up somewhere between the 32nd and 38th parallel (today's placement of the overall Plateau's askew circumference). You are now breathing in the planet’s northern Temperate Zone (and officially the plate is dubbed the North American continental plate). Reflecting on what happened during the drifting continental migration, you remember how the driving force beneath the plate (likely upwelling currents from deep inside the planet) experienced various continental and oceanic crustal masses amounting to minor collisions along the way (and one major collision). That biggest bump in the series was running smack into the edge of a large continental plate (whose collision altered the course from northeast to northwest). Otherwise, any moving plate will continue in its original direction until merging with another plate. Sometimes the collision means one plate overrides the other. Thus subduction.

The Two Kinds Of Plates
Continental plates are mostly granitic, while oceanic plates are basaltic. Since granite is heavier than basalt, continental plates overtop oceanic plates. The world's inventory of its plate furnitures is thus a mix of continental and oceanic crustal plates. What we see on a globe or world map today is merely a contemporary floor plan denoting appearance and configuration. However, millions of years ago the location of plates was wholly other. Millions of years from now the floor plan will continue to change. If, whatever Supreme Being really did create the world in six days, though rested on the seventh, then all that follows is indeed a protracted retirement plan entailing millions or billions of years left in the lease and divine order of things. I mention this trivia not in the sense of mockery, but only for the sake some of us feel this old or young Earth spaceship has a long, long life ahead of its evolution. Whatever esoteric purpose, as defined by varying religious outlooks, will allow plenty of time for we humans to get our act together, including for whatever metaphysical purpose, if any.

Subduction, like so:



A Helpful Summary
This over simplified explanation comes down to one thing and one thing only: most tectonic plates are mobile. Thus each crosses latitudes representing various environments––wet, dry, cold, hot, and so on. More importantly, when plates collide big events happen. Specifically, mountain-building and volcanoes, which are nearly always preceded by earthquakes. Sometimes tsunamis roil the ocean surface and race outward from an epicenter where the earthquake began. This overly simplified scenario describes an ongoing topographical and geographical blueprint change on a global scale. Plate revision and collisions is simply how a mundane landscape can be altered to something more inspiring. For example, think of Colorado, Wyoming or Montana without mountains. Think of Hawaii, the big island, without a volcano. Now reverse your thinking and consider these parcels of land without attractive and visceral scenery. So, would you even vacation there or buy property? I'm thinking not.

Mesa Verde National Park, Colorado:



Meanwhile, there is something else you should know about the North American plate you rode (and still may be continuing the exercise by seeing yourself standing on its pavement: as the plate migration continued it eventually came in contact with the even larger Pacific oceanic plate. Consequently, there was a chain reaction of events entailing two separate oceanic plates, the so-named Kula and Farallon plates. Both eventually were subducted, that is, each dove deep beneath the North American plate. Thus keep in mind the subduction of these two smaller plates had everything to do with the birthing of the Colorado Plateau, and most directly the Farallon plate not too far west of present-day San Francisco, California.

The gist of this imaginary voyage you just completed demonstrates the transforming of the planet's continental pieces, including what we don't see deep below the water: oceanic crustal segments. Thus the bumping and scraping of terrestrial and marine environments, as plates, continues the dynamics of this ever-changing planet.

Mystery Valley, Arizona:



The Greatest Canyon Country On The Planet
Regarding the forming of the Plateau's original landscape-turned-splendorous, its terrain could not have uplifted some two miles into the atmosphere without the force of the aforementioned plate subduction sequence. This geophysical force, subduction, is therefore essential to everything that happened this far inland. Uplifting, followed by erosion typifies what ultimately happened after the main event (the micro oceanic plate diving beneath the larger North American plate). Naturally, another process, called downcutting by rivers and streams, played an equally important role in the process. Because of the uplifted terrain beneath their pathways, these furrows effectively breached the crustal rind. Two of the rivers were also potent enough to carve deep chasms––the Colorado River and its sibling drainage, the Green.

It follows why there are so many canyons carved throughout the Colorado Plateau. The shorter and least complicated version coordinating all the processes comes down to this main point: A vast inland territory denoting a former low-lying basin of so-so features set the stage for an epic transformation to come. For millions of years various marine and terrestrial environments came and went in this locale, each deposition accumulating and forming an immensely thicker foundation. Thus the repository of congealed and compacted sedimentary materials were stored one layer (formation) at a time.

If you're searching for a reliable figure just how long the transformation took, sorry, geologists don’t really know the precise details. Still, their science can take an educated guess how the initial forming of the Colorado Plateau Province (before its erosion and downsizing) may have taken place sometime between 71 and 31 million years ago, and likely in distinct pulses. Uplifting of a stable landscape foundation also entails a simultaneous downcutting action by rivers and streams that enables drainages to hold their course and groove furrows deeper. Thus it's sort of like a knife held in place, while slicing into a rising loaf of bread. As geologist's are prone to say: Without uplift, no down-cutting. Hence, no chasms of any appreciable depth.

In time, landscape features exposed to the elements are subject to fabrication. Hence, with uplifting, downcutting, and later faulting, the original template of this territory’s features made it possible for erosion to do a fantastic sculpting process.

Natural Bridges National Monument, Utah:



FYI
Although there are many rivers in North America that are longer and have much larger drainage areas, or claim a higher volume of water, such as the Mississippi and Ohio, none can create any significant chasm. Rivers and streams on the Plateau, however, have this advantage because the landscape foundation beneath their channels has already been uplifted. Moreover, these bodies of water steadily lose elevation and are headed down to sea level, that is, unless the river or stream happens to end up in a basin. For the Southwest, most of the rivers and streams merge at some point (the Yampa joins the Green, the Green, like the San Juan joins the Colorado) and therefore most of the water empties into the Gulf of California.

A Providential Set of Circumstances
The backstory of the Plateau’s uplifted landscape is revealed in its circumstances. Namely, the kind of environments that happened here over millions of years, along with a prevailing arid climate. Remember: all the foundations remained intact, even though erosion had set in and began the fabrication process. Then again, it was the luck of the draw what ultimately happened here (mainly, subduction by which all else followed). More importantly, the base foundation would not have become an elevated platform between two neighboring provinces (though not counting the immensity of height of mountain ranges adoring the Rockies or Basin and Range). Thus the lofty elevation of the Plateau’s subaerial (literally "under the air") landscape, though the elevation gain does not include the add-on volcanic superstructures.

Here's another tidbit about the benefit of subduction: its process not only favored this inland territory but was also responsible for the opening of the Gulf of California, which in turn was a consequence of California’s San Andreas fault activity. This coincidental circumstance may have started some eight or so million years ago, whose most significant benefit created the aforementioned exit point for rivers and streams in this quadrant of the continent. Otherwise, before the gulf’s opening the course of rivers and streams flowed and emptied into vast inland basins.

Paria Canyon, Arizona-Utah:



FYI
For those of you who have the patience and understanding to know more of the precise details governing what has been said thus far, don't just take my word for it. Instead, consider this scientific explanation replete with its typical jargon defining a reliable geologic abstract:
The Colorado Plateau is blanketed by Phanerozoic marine and non-marine strata as young as the Cretaceous Period that are now exposed at elevations of about 1.2 miles. Crustal thickening due to magmatism and horizontal crustal shortening was far less than necessary to cause the uplift of the Plateau, which is commonly attributed to the consequences of mantle lithosphere thinning and heating. The Plateau and mid-continent region around Iowa consist of Precambrian bedrock overlain by a similar amount of Paleozoic platformal strata, and thus both regions once had similar lithospheric buoyancy. Mesozoic sedimentation increased the crustal thickness and lithospheric buoyancy of the Colorado Plateau relative to the mid-continent region. Backstripping calculations yield elevation without these sediments and lead to a calculated elevation difference between the two areas of about 3,937 feet, which represents unexplained plateau uplift. Review of constraints on uplift timing finds little support for a late Cenozoic uplift age and allows early to middle Cenozoic uplift, which is consistent with uplift mechanisms related to low-angle subduction that ended in the middle Cenozoic. Finite element heat flow calculations of low-angle subduction and lithosphere attenuation, using a range of initial lithosphere thicknesses and degree of attenuation, indicate that required uplift can result from tectonic removal of about 74.5 miles of mantle lithosphere from an initially 124-miles-thick lithosphere. This allows for partial preservation of North American mantle lithosphere with its distinctive isotopic signature in some late Cenozoic volcanic rocks and is consistent with normal Pn velocities in the uppermost mantle beneath the plateau.
I’m thinking such an explanation is a bit much for most people, even though in this abstract is likely found the more accurate explanation. To translate in laymen’s terms, what this highly technical abstract means is how the Plateau could not have been elevated without a prior tectonic plate collision event and an ensuing subduction event. On average, this part of the continent's craton is also thicker crust (24 to 25 miles) compared to the rest of the continental plate (19 or so miles). The temperature below the landscape is also hotter. Thus the lithosphere––the outermost crustal shell of our planet––behaves elastically and is therefore dynamic. Now you have a better idea why continental plates literally float on its surface. Thus plates are always in motion.

The upshot of plate tectonics and subduction in this part of North America has something to do with why there are hundreds of volcanic outlets throughout the province, including towering laccolith mountainous forms solely created by magma and therefore associated with volcanic activity.

San Rafeal Swell, Utah:



Erosion
I think by now that it should be obvious the master trump card behind the fabrication throughout the Plateau is none other than erosion; an erosional process to be exact that has occurred for hundreds of millions of years and will continue until there is nothing left to hone. Again to mention the point: what happened here is not the usual overt destructiveness of the planet’s heat, force, and pressure that creates mountains or drops huge parcels of land, such as happened in the adjacent Basin and Range province (the Mogollon Highlands). Rather, it is simply a measure of steadily wearing away of base materials that fashions the geography in unique ways. In many places, the effects of water and wind (the main agents of erosion in the Plateau), helped along by faulting and folding of rock formations. In concert, this is what creates such a stunning topographical relief, notably in abrupt and changing elevation from the desert pavement to higher mountainous landmarks.

And here’s a helpful formula to keep in mind that will immediately relate the essentials of everything discussed to this point:

Uplift + Downcutting + Erosion over Time

Sedona, Arizona:



Let’s continue this seminar in the concluding diary. There’s some other details I want to impart, which will complete the story and make the reader feel duly qualified to seek out an audience and illuminate minds regarding this subject matter.



As always, thoughtful and intelligent commentary is most welcomed.

Rich Holtzin
Albuquerque, NM

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