Uncomforming

 Oh, we won't give in

Let's go living in the past

Oh no, no we won't give in

Let's go living in the past

– Jethro Tull, Living in the Past

“After a time, you stopped tallying the specific hazards.  In its totality, the landscape was predicated on risk.”

To photograph an unconformity is to attempt to capture an image of nothing. You are not shooting a presence but an absence, a record of time that has been erased. It is a subtle and intellectual pursuit, one that begins with understanding the library in which you stand. The Colorado Plateau is that library, a 130,000-square-mile province of flat-lying sedimentary rock lifted thousands of feet into the arid air. The Grand Canyon is its primary archive, a book whose pages are strata, each one once the surface of the Earth. As geologist you know that every single horizon you see was a landscape in its own time. The story is all there, except where it isn't.

An unconformity is a gap in the geologic record. It is a surface, not a layer—a plane of contact where the rock below is vastly older than the rock resting directly upon it. It represents a period of profound erosion or a long spell of non-deposition, a time when the Earth, in this specific place, was taking away rock instead of putting it down. To the photographer with a certain kind of mission, these are the most dramatic scenes on the plateau. They are the scars of lost worlds.

Your eye must be trained to see them. Some are glaringly obvious. An angular unconformity is a story of tectonic violence and subsequent peace. You see tilted layers of rock, the evidence of an ancient mountain range, that have been sheared off perfectly flat, as if by a giant planer. Sitting on that flat surface are horizontal layers, deposited by a later, placid sea. The photograph must capture that relationship: the chaotic, angled energy of the old world capped by the serene horizontality of the new.

A non-conformity is a meeting of two entirely different classes of rock. It is where sedimentary layers—the sandstones, shales, and limestones born of water and wind—come to rest directly upon the igneous or metamorphic basement of the continent itself. This is the Vishnu Schist and Zoroaster Granite at the bottom of the Grand Canyon. To photograph this is to capture the contact between the surface world and the deep, cooked roots of the landmass.

The most difficult to capture is the disconformity, for it is the most subtle. Here, the layers above and below the gap are parallel. There is no tell-tale angle, no dramatic shift in rock type. It appears to be just another bedding plane, another page in the book, except that a geologist has read the fossil record and determined that one hundred million years of history are missing between the two seemingly contiguous layers. Photographing this requires context—capturing the named formations, the Redwall Limestone separated from the Tonto Group, and letting the caption do the heavy lifting. It is an image of a purely intellectual landscape.

To truly tell the story, the photographer must go to the places where these gaps are rendered most starkly. The first destination is, of course, the Grand Canyon, but not just the rim. The work is down in the Inner Gorge. You make your way to Blacktail Canyon, a narrow side canyon off the Colorado River. The source material notes this spot as uniquely accessible. Here, the story is not viewed from a distance of a mile but is available to the touch. The photographer can place one hand on the dark, crystalline Vishnu Schist, rock that is 1.75 billion years old, and the other hand, just inches above, on the coarse, brownish Tapeats Sandstone, which is a mere 525 million years old. More than a billion years of Earth’s history—a quarter of the planet’s entire existence, as some have calculated—is missing in that single handspan. The photographic challenge is to convey this temporal abyss. It is an exercise in texture and light: the way light catches the metamorphic sheen of the schist versus the grainy, sedimentary surface of the sandstone. The resulting image is a portrait of the Great Unconformity, a name given to this specific gap by Clarence Dutton in 1882. Ah yes, Dutton, more about him in a later post.

The Black Canyon of the Gunnison near Montrose, CO. The rock overlaging the basement rock, which forms the canyon, is Dakota Sandstone and Mancos Shale. This same basement rock can be found at the Colorado National Monument. Above the basement rock time is missing, the Mancos unconforms.

From there, the journey continues northeast, to the Colorado National Monument, just outside Grand Junction. Here, the Great Unconformity is, by the numbers, even greater. The time missing spans not 1.2 billion years, but 1.5 billion. The photographer frames a shot of the colorful, banded Chinle Formation—rock laid down some 220 million years ago, when the first dinosaurs were appearing in North America—sitting directly upon the 1.7-billion-year-old Precambrian basement. The story the image tells is of the dawn of the Age of Reptiles resting on the eroded nubs of a world that existed before complex life had even truly begun.

To capture these images is to ask a question: Where did the time go? The running hypothesis points to a global-scale scouring. One theory suggests the breakup of the supercontinent Rodinia initiated a continental, perhaps worldwide, outbreak of erosion. A competing idea is that the glaciers of a “Snowball Earth” ground the continents down to their foundations. In either case, the unconformity is the scar tissue from that planetary trauma. This great erasure, this grinding down of the old world, may have filled the oceans with the chemical building blocks—the phosphorus, the calcium, the iron—that fueled the Cambrian Explosion. The photographer, standing in a quiet canyon, framing a simple line between two different kinds of rock, is capturing the faint, distant echo of the moment the world nearly ended, and in so doing, cleared the stage for everything that was to come.

All images posted on the buzzshawphoto.blogspot.com 2025 are copyrighted. All rights reserved.

Moments

My present work has been to pull together my notes and the literature on unconformities—the gaps in the story, the missing time in the rock. As with any such subject, the approach is to go back over it, to think about the deep time you are trying to 'think about', and to wrestle with the words and phrases that might frame it. You are on a path of discovery, walking terrain that is a cornerstone of the science, missing spaces of time, visited by every student of geology. You are rereading a book with pages known to be torn out, trying to infer the missing chapters. And in the course of this work, while sorting through the knowns and the missing millions of years, as thoughts arrived unannounced, and I wrote them down. I’ll discuss Unconformities another ‘time’.

The is one of a series of images captured about 10 minutes after Sunrise. Memorable because I had also managed to crack several rigs, getting to the spot in the dark.

The sun comes up and the temperature rises. The air warms the metal of the lens barrel, which warms the glass within, and the point of critical focus, once so carefully set in the predawn chill, drifts. You failed to recheck. This is but one of the ticks in the machine you are trying to keep, and its failure can negate all the others. There is the geologic clock, ticking in ten-million-year intervals, its face displayed in the rock before you. There is the sun’s clock, which offers a brief window of slanting, golden light before it hardens into the flat glare of day. And there is your own clock, the investment of hours in preparation and, later, in post-production, trying to true up what you saw with what the sensor recorded.

The whole enterprise is a wager against chaos. Sunrises and sunsets are fickle beasts. You can take the risks—the hike in the dark, the careful setup on an exposed ledge—only to watch the sky lighten behind a solid ceiling of cloud, the sun itself a hidden premise. The light arrives, but not the shadow, not the color. The investment is lost. The enterprise has its physical costs, as well. In Canyonlands, a trip in the dark on the way to a sunrise shoot over the basins ended with a set of cracked ribs, a sharp and lasting reminder of the terrain’s indifference to your schedule. You take the pain. It sharpens the mind. You get the shot.

Sometimes the fault is not in the clouds or the rock but in you. You make mistakes. A technique you weren’t wholly familiar with produces an effect you did not intend. The light was changing too fast—a race you were losing—and in the flurry of adjustments, you failed to protect the highlights, blowing them out to a pure and featureless white. The camera, in these moments, is not an instrument of capture but a theatre of potential failure, its settings a complex grammar you have just misspoken.

Then there are the few times, seared into memory, where the apparatus of consideration simply ceases to function. The workflow, the timing, the careful technical sequence—it all dissolves. You are there to trigger the camera, but the beauty of the scene triggers you instead. It is so complete, so overwhelmingly present, that you forget your purpose. You just watch. The ideal picture forms and then fades, recorded nowhere but in your head. It becomes the fish that got away. You can talk about it, describe its perfection, but the evidence is purely anecdotal, inadmissible. That is a mistake you don’t mind making. It is a failure of the photographer, perhaps, but a success of the human being, who for a moment saw something too profound to be reduced to a digital file.

The passions that drive this are a spectrum. On one end, there is simply a reason for going out into the quiet open spaces, for watching the slow parade of moments as the sun moves the shadows. To be in those moments as the day’s heat fails, to feel the coolness descend as the sun falls, and at the same time to feel the stored warmth of the rock and soil radiating around you. At the other end of the spectrum is the pleasure of manipulating the technology itself, the machine that allows the scene to be brought home.

You have begun recording audio of the environment. It has proven to be a valuable resource, a way to put you back in the moment while editing the captured light. The sounds reconstruct the feeling. The sound of a wing beating the air, a distant crow, the communal chatter of prairie dogs, the high whine of a wave of midges looking for a blood meal. It all serves to recall the specific quality of the light you were seeing, the light you were feeding into the camera.

Moments of pleasure, moments of time. It is all out there, in the rocks. Ages of moments, piled, compressed, buried, stressed, and finally, the old bones of the world exposed as you watch, and capture your own.

Thanks for stopping by and having a read.

All images posted on the buzzshawphoto.blogspot.com 2025 are copyrighted. All rights reserved.

The day in which he wrote about composition

 

“If you never try, you’ll never know” .. Cold Play

A recent run of weather has worked over the backcountry, sending water down arroyos that have been dry for months, rearranging the regolith. The loose mantle of rock and soil shifts, roads are cut, and the landscape, for a time, is made new again. Up high, the aspens are beginning their annual transaction, trading chlorophyll for gold, and down here in the valley the summer’s accumulated heat is slowly migrating out of the rock. You can feel it in the evenings.

The days, meanwhile, have become a litany of what must get done, a list perpetually backfilled by the fine-grained sediment of the day-to-day. In the midst of this, I find a certain enjoyment in returning to the principles of photographic composition, a kind of structured musing. There has always been, for me, a truth in the idea that the surest way to learn something is to prepare to teach it. The exercise forces a clarity, a distillation. It has also sent me down a path of considering my own technique against what are held up as the rules of composition. Not that I operate in defiance of them. As with any practiced craft, the rules don't so much dictate the outcome as inform the workflow. They are the accumulated wisdom against which you test your own eye.

To be your own worst critic is, I suppose, an unlisted but essential part of that workflow. I can look at an image captured and edited a year ago and see only its deficiencies, its failure to communicate. It feels inert. Then I pull up the original RAW file—the flat, uninflected data from the sensor—and remember the distance traveled in post-production, the quiet labor of turning the photograph into what I was seeing, and not necessarily what the camera gave me.

My memory works that way, seeking a certain fidelity to the moment. You pull a black-and-white print from decades ago, and the day it was made comes rushing back, the memory filling in the color, the temperature, the sound—all of the attendant verisimilitude the flat paper could never hold on its own.

Geologic Interlude: Before I begin a review of photographic composition techniques, I'd like to share a New website that has been published. This is an incredibly valuable resource for someone like me, and it aligns with my work here. Its value in general is literally priceless. This is an interactive geologic map, the Cooperative National Geologic Map. This is a product of the United States Geological Survey, USGS, and the American Association of State Geologists, AASG. With this I can zoom into any spot in the continental United States and see the geologic unit at that spot. There are many layers of information, beyond the stratigraphy, available for analysis. This is a treasure. Take a look, and you’ll learn a lot of geology just by interacting with the map. Good stuff! Have a look

https://ngmdb.usgs.gov/nationalgeology/#lat=24.0000&lng=-66.0000&zoom=3&theme=esurf&symbology=synthesis

=================

Clouds and Cows

To speak of photographic composition is to speak of a language, one that arranges the world within a four-sided frame. At its most fundamental level, it is, as one has said, the “arrangement of elements within a photo to create the desired effect.” But to leave it there is to describe a hammer by only its weight and dimensions. The essence of the thing is in its purpose, which is not merely to make an image “look pleasant” or “good,” but to build a connection. Robert Rodriguez Jr., a photographer who spends a great deal of time thinking about this, puts it plainly: if the composition is careless, the picture will “fail to resonate with the viewer.” It will be a collection of objects, but it will not be a statement.

The discussion often begins with the so-called rules, though they are better understood as creative suggestions, a set of foundational grammars from which one can build. The most famous of these is the Rule of Thirds, a simple tic-tac-toe grid laid over the frame. The theory holds that our eyes are drawn to the intersections of these lines, and placing a subject there lends a natural balance. Sean Gallagher, who has made his living framing the world for National Geographic, confirms its utility. It’s a starting point, a way to avoid the static, bullseye obviousness of dead-centering everything. But it is no guarantee. You can follow the rule and be left with a composition thrown off balance by a vast and meaningless void.

From this basic grid, the language expands. You learn to see leading lines in a curving road or a fence line, guiding the eye into the scene and creating a sense of travel. You find a frame within a frame in a stone arch or a stand of trees, a device that adds depth and isolates your subject from the visual noise of the world. One technique suggests you fill the frame, getting so close to a subject that all distraction is eliminated, creating an intimate connection. Its direct opposite advises using negative space, leaving vast empty areas to give a subject breathing room, to emphasize its solitude against an empty sky. None of these are laws; they are strategies, conscious decisions made in service of an idea.

As the grammar becomes second nature, one begins to explore a more nuanced syntax. You start to understand the inherent energy of a diagonal line, the way it creates a “dynamic composition and tension” that a horizontal placidity lacks. You see the world in terms of patterns—the repeating texture of rock, the ordered ranks of aspens—and you understand the electric effect of breaking that pattern with a single, dissident element. You begin to feel what is called visual weight, the intuitive sense that a dark, heavy object feels unnatural when placed at the top of a frame, creating a subtle unease in the viewer. You might even find your compositions aligning with the mathematical elegance of a Golden Spiral, though as many photographers admit, this is more often discovered in hindsight than constructed by design. It is the result of a practiced eye arriving at a solution that feels correct, a solution that happens to echo a fundamental principle of aesthetics.

The art itself, however, resides less in the catalog of techniques than in the photographer’s process—the quiet work that happens before the shutter is ever pressed and long after the image is captured. It begins with an intentional decision to slow down, to survey a scene and conduct what one photographer calls a “mental inventory” of what you find compelling. What is it here that you love? That question, and its answer, provides the pieces of the puzzle. From there, you move your feet. A small shift in position can straighten a crooked line, separate a tree from a mountain, or reveal a foreground of immense interest. You become vigilant about the edges of your frame, knowing that a stray branch or a clipped object can pull the eye away from your intended focus.

You wait for what is called the decisive moment—the instant a flock of birds enters the frame, or a ray of light breaks through the clouds. This is the culmination of preparation and patience. And the work is still not done. In post-production, a crop can distill the image to its strongest form; a distracting element can be removed. The goal, through it all, is intent. It is the effort to turn the raw data from a sensor into the feeling you had standing in that place at that time. It is a process of learning to see, of developing a visual literacy so deep that it becomes intuition. You are no longer just following rules; you are composing for what matters. 

Composition, then, is an act of translation. It endeavors to communicate not only the particulars of what you see, but the internal resonance you feel from having seen it.

These thoughts are distilled from my own field notes on composition, which I have since formatted and, in a concession to the modern workflow, passed through an artificial intelligence for the sake of clarity. For those interested in a more granular treatment of the subject, a comprehensive PDF of these notes is available. A comment below with your email will find its way to me.

Thanks for stopping by for a read.

All images posted on the buzzshawphoto.blogspot.com 2025 are copyrighted. All rights reserved.

The Morrison Formation

 

The Morrison Formation

To see it is to be centered in a section of time. The road cuts through the high desert of the Colorado Plateau, a landscape of heroic scale and subtle color, and there it is: a particular set of bands, a sequence of muted purples and battleship greys, decorating the hills. It’s a marker bed. Geologists know it as the Brushy Basin Member, the most widespread and recognizable face of the Morrison Formation. But for anyone with a passing interest in the deep past, it is something more. It is a signal, a signpost in stone. When you see it, you know, with a certainty that resonates deeper than academic knowledge: here were dinosaurs.

Rabbit Valley, Colorado  Red, Purple, Gray Mudstones and Bentonite Paleosols (ancient soils) of the Brushy Basin Member of the Morrison Formation

The story of the Morrison is written in mud, but it begins with fire. Picture the world 150 million years ago, in the waning days of the Jurassic Period. The map of North America is a half-formed thought. The Atlantic is a nascent rift, widening slowly, pushing the continent westward. From the north, a shallow, speculative finger of the ocean, the Sundance Sea, probes down into what will one day be Wyoming and the Dakotas. And to the west, along the continental edge, a chain of volcanoes, immense and active, stands as the consequence of a tectonic collision, a subduction zone where one plate dives beneath another. These volcanoes are the engines of the Morrison.

For millions of years, they pump ash into the sky—a fine, glassy dust that drifts eastward on the prevailing winds and settles like a blanket over a vast, low-lying basin. This basin is not a desert but a sprawling alluvial plain, a depositional apron sloping gently toward the distant Sundance Sea. It is a landscape defined by water. Great river systems, ancestors to none we would recognize, meander across the plain, carrying sediment from highlands that are now long gone. They are the circulatory system of this world, and their primary cargo is that volcanic ash.

The ash itself is geologically unstable, a temporary substance. Over the immense span of time, as it is buried, soaked, and compressed, its glassy silica structure breaks down. It alters. It devises a new identity, transforming into a peculiar type of clay mineral called bentonite. This is the material that forms the "candy-striped hills" near Hanksville, Utah, the pastel badlands that look so much like a "Mars almost like landscape." Bentonite clay has a singular, dramatic property: it shrinks and swells with phenomenal force. When wet, it becomes a slick, impassable gumbo; when dry, it cracks into a popcorn-textured crust. This constant turmoil in the soil makes it profoundly difficult for plants to gain a foothold, which is why, to this day, the exposures of the Brushy Basin can be so "completely devoid of vegetation." The chemistry of a long-extinct volcano dictates the botany of the present.

The rivers, though, were not merely passive conduits for ash. They were dynamic, energetic systems, and they left their own signatures in the rock. A river is a sorting machine. In its main channel, where the current is strongest, it moves sand and gravel. During flood stages—"higher pulses of energy," as a geologist might say—it can roll pebbles the size of a fist. In calmer times, it lays down fine sand. As the river snakes across its floodplain, it abandons old channels and carves new ones, leaving behind lenses of sandstone and conglomerate embedded within the finer muds of the floodplain.

Morrison Formation, Rabbit Valley  Remnant River Channel Sands of the Saltwash Member

These sandstone bodies are the architectural bones of the Morrison today. Being harder and more resistant to erosion than the surrounding bentonitic clays, they form cliffs, ledges, and caprocks. You see a feature that locals call a "toadstool," a whimsical balanced rock, and you are looking at a cross-section of an ancient river. A durable cap of sandstone, the fossilized riverbed, protects the soft pedestal of clay beneath it from being washed away. Look closely at the side of that sandstone. You might see fine, angled lines cutting across the main horizontal layers. This is cross-bedding, the preserved structure of ripples and sandbars that migrated along the river bottom 150 million years ago. The rock remembers the direction of the current.

It is within these river channel deposits—the sandstones and conglomerates—that the Morrison yields its most famous cargo. The formation is, by a wide margin, "the most fertile source of dinosaur fossils anywhere in North America." The bones are not found in the altered volcanic ash of the floodplains. An animal that died on the plain would have its bones scattered, weathered, and ultimately dissolved. But an animal that died in or near a river channel stood a chance of being quickly buried by sediment, its bones protected from the elements, beginning the long process of fossilization. A river in the Jurassic was both a giver of life and a potential tomb.

And what a life it was. The roster of the Morrison fauna is a litany of superlatives. This was a world of giants, an ecosystem seemingly designed to test the limits of what vertebrate life could achieve. The dominant herbivores were the sauropods, the long-necked titans that have defined dinosaurs in the popular imagination. There was Camarasaurus, the most common of them, a 75-foot-long, 50-ton behemoth built like a fortress. There was Diplodocus, whippet-thin by comparison, stretching nearly 80 feet but weighing a mere 15 tons, much of its length taken up by an incredible whip-like tail. And then there was Brachiosaurus, the giraffe of the Jurassic, its front legs longer than its back, holding its head high above the floodplain, standing nearly 70 feet tall and weighing upwards of 64 tons. These creatures, all of them, would go extinct at the end of the Jurassic, a "total wipe out" that cleared the stage for new forms to evolve.

Preying on them, or perhaps just scavenging their immense carcasses, were the large theropods. The king was Allosaurus, the most abundant large predator in the ecosystem, a 39-foot-long carnivore with a massive skull and serrated, blade-like teeth. It was the apex predator, the top of the food chain. But it had competition. There was Ceratosaurus, a medium-sized predator with a distinctive horn on its snout, and the truly formidable Torvosaurus, a massive, 33-foot theropod that may have specialized in hunting near waterways. Alongside the giants lived a menagerie of other creatures. Armored dinosaurs like Stegosaurus and the early ankylosaur Mymoorapelta browsed on lower vegetation. Bipedal plant-eaters like Camptosaurus and the small, nimble Dryosaurus filled out the middle tier of the herbivore community.

For a long time, the life of these animals was understood only through their skeletons. But in recent decades, paleontologists have begun to decipher the more subtle traces they left behind, reading the finer print in the Morrison’s pages. The story of dinosaur eggs is a case in point. For years, the utter lack of sauropod eggs from the Jurassic led to wild speculation. Perhaps, some suggested, these animals were viviparous, giving live birth to their enormous young. The discovery of soccer-ball-sized titanosaur eggs in Cretaceous rocks proved that at least some later sauropods laid eggs, but the Jurassic mystery remained. The working hypothesis now is that shelled eggs evolved independently in different dinosaur lineages, and that perhaps the Morrison sauropods laid soft-shelled eggs that were far less likely to fossilize.

Another view from the Rabbit Valley. It may not look too appealing, but here there be dinosaurs and other treasures.

The Morrison has, however, given up the oldest known dinosaur eggshell in North America. It is not from a sauropod, but from an ornithopod, likely belonging to the family of Dryosaurus. At sites like the Young Egg Site in the Salt Wash Member and the Sheets Nesting Site, discovered by a 12-year-old boy, paleontologists have found troves of eggshell fragments and the bones of baby dinosaurs. The evidence from these nests paints an intimate picture of dinosaur family life. Unlike the colonial nesting grounds of later hadrosaurs, these Jurassic dinosaurs appear to have been "solitary nesters," returning to the same favored locations year after year.

More intriguing still, the nests contain bones from two distinct size classes: tiny hatchlings and much larger "yearlings." This suggests the young were precocial—able to walk and follow the adults almost immediately after hatching, like ducklings. The theory is that the hatchlings would mimic the adults to learn what to eat, rather than being fed in the nest. The yearlings found dead at the site may have been the ones who failed to follow, waiting in vain to be led to food. The nests also contain the remains of another creature: a small terrestrial crocodile, nicknamed the "bunny croc," perhaps a nest thief, adding a layer of ecological drama to the scene.

Reading these stories requires an understanding of the grammar of the rock itself. At a certain level in the Brushy Basin Member, there is a "dramatic change." Below this line, the clays are of one type; above it, they are the puffy, swelling bentonites derived directly from volcanic ash. Geologists call this line the J-7 Unconformity. An unconformity is a break in the record, a missing piece of time. This particular line represents a major shift in the volcanic activity that defined the region, a moment when the character of the ashfall changed fundamentally. The book of the Morrison has missing pages, moments of the story that were never written down or were erased before they could be preserved.

For a visitor today, driving north of Highway 24 near Hanksville, with the solemn peaks of the Henry Mountains in the distance, this deep history is written across the land. The "candy-striped hills" are the legacy of ancient volcanoes. The "toadstool" hoodoos are the ghosts of ancient rivers. The dark patina on a rock, a desert varnish that a geologist might chip away to see the stone’s true color, is a thin veneer of the present drawn over an immense past. To stand in this landscape, to see the purplish band of the Brushy Basin, is to feel the presence of that past. It is to understand that the ground beneath your feet is not merely ground, but the compressed and altered remnant of a world stranger than any you could imagine, a world of giants that walked here when the rock was just mud.

In a future post, I'll provide a walkabout of the Colorado Walk Through Time in Rabbit Valley. There is a trail through the Morrison Fm. where you can see dinosaur bones in situ. It's a great walk to get a good feel for what is around you in dinosaur country.

Thanks for stopping by and having a read.

All images posted on the buzzshawphoto.blogspot.com 2025 are copyrighted. All rights reserved.

 To call oneself a GeoPhotographer is to coin a term, but it feels apt. Before any field trip, my preparation involves not just maps and lenses, but a review of geologic columns and descriptions of the paleoenvironments I will be traveling through. Living in the arid American West makes this a uniquely visceral experience. Here, the geology is not hidden beneath a blanket of soil and green; it is right in front of you, a brazen, sun-bleached pronouncement. You don’t have to dig for the story; you simply travel through it. You read the rock like the book of time.

With a little knowledge, you can become a deep-time traveler. The greatest events in Earth's history are written here, and none are more dramatic than the mass extinctions. We are still learning about the whys and wherefores, the full causality of these global catastrophes, but the evidence of how they happened is clear, etched into the canyon walls and badlands. The story of how the Earth recovers, and the changes in life that follow, is an incredible one that remains unknown to too many. I have summarized these events for my own reference. I have taken some of the information I keep in notebooks and have attempted to make it readable and offer it to you. I hope it enlightens and informs. Please take this as a jumping-off point to explore further. It is a profound story, and it is the story of us and all the creatures we share our world with.

Mass Extinctions

Of all the books in the world, the thickest and most violent is the one whose pages are made of rock. To read it is to walk through the canyons and badlands of the American West. The cover, so to speak, is the soil under your boots, the present day. But as you descend, as you drop through the strata, you are turning back the pages into a time so deep it defies human comprehension. Each layer of sandstone, shale, or limestone is a chapter, telling of ancient seas, sprawling forests, and bygone creatures. But sometimes, between two thick chapters, you find a single, thin, almost imperceptible line. This is not a pause in the narrative. It is a tombstone. It is the epilogue for a world that was, a world that ended so abruptly the planet scarcely had time to record its passing. These are the scars of mass extinctions, and the American West is a library of them.

The First Poison: A World Rusted Shut

Before the dinosaurs, before the fish, before even the first wriggling trilobite, life had a catastrophic falling out with itself. It was an act of planetary self-poisoning, and its evidence is written in stone across the continent. Two and a half billion years ago, Earth was a "Pale Orange Dot," a world swaddled in a methane haze, its oceans a murky green with dissolved iron. In these shallow seas, a revolutionary microbe, cyanobacteria, began to harness the sun. Its great innovation was oxygenic photosynthesis, a brilliant new way to make a living. Its great flaw was the waste product: oxygen, a gas so corrosive it was toxic to nearly every other living thing on the planet.

For millions of years, the planet's chemistry buffered the assault. The oceans, rich in dissolved iron hydroxide, effectively rusted. As the cyanobacteria pumped out oxygen, it bonded with the iron, which then precipitated out and settled on the seafloor in crimson layers. This rhythmic cycle—oxygen buildup, iron precipitation, microbial die-off, recovery—created one of the planet’s most striking geological features: banded iron formations. A 19th-century surveyor named William Burt, working in Michigan, first noticed his compass needle going haywire, leading him to these immense deposits of iron ore, the very signature of this ancient atmospheric revolution. You can find their equivalents in the ancient rocks of Wyoming, remnants of a time when the world’s oceans were bleeding rust.

Around 2.4 billion years ago, the oceans simply ran out of iron to absorb the poison. The oxygen flooded the seas and, for the first time, the atmosphere. It reacted with the potent greenhouse gas methane, stripping the sky of its warming blanket. The planet, having rusted, now froze. The Huronian Glaciation was an ice age of unimaginable scope, a "Snowball Earth" that lasted 300 million years. The chemical revolution and the climate crisis it triggered caused the Great Oxygen Extinction, the single largest disappearance of life in Earth’s history. An estimated 99% of all species, overwhelmingly microbial, were wiped out by the very air they breathed. Life survived, huddled in oxygen-poor refuges or by evolving a tolerance for this new, volatile world. But the planet was forever changed, its atmosphere now charged with the gas that would, paradoxically, fuel the rise of all complex life to come.

The Paleozoic Culls: When Plants and Pangaea Wreaked Havoc

The next few chapters of Earth’s stone-bound book tell of a flourishing. The oceans teemed with life—trilobites, sea scorpions, and strange, armored fish. Then, around 445 million years ago, another thin line appears in the rock. This was the Late Ordovician mass extinction, and once again, a biological innovation was the culprit.

The first tiny, moss-like plants had begun to colonize the barren, rocky continents. Clinging to the rock, they accelerated the process of weathering, breaking down minerals and releasing them into the rivers and seas. A key nutrient, phosphorus, poured into the oceans, triggering colossal algal blooms. When these blooms died and sank, their decomposition sucked the oxygen from the water, creating vast dead zones. The supercontinent Gondwana drifting over the South Pole didn't help, triggering a massive glaciation and a sharp drop in sea level. The one-two punch of glaciation and anoxia was devastating. In two distinct pulses, up to 85% of marine species vanished. In the exposed Ordovician limestones of Nevada and California’s Death Valley National Park, you can stand on the seafloor of this ancient world and touch the graves of countless trilobites, victims of life's first tentative steps onto land.

The planet recovered, and life grew even more ambitious. The Devonian period saw dense forests of primitive vascular plants spread across the land, populated by giant tree-like fungi called Prototaxites and early four-legged vertebrates like Ichthyostega. The oceans were ruled by monsters like the 10-meter-long armored fish, Dunkleosteus. But this greening of the planet had consequences. The explosion of plant life drew down enormous amounts of carbon dioxide from the atmosphere, causing global temperatures to plummet once more. This, combined with more ocean anoxia—perhaps from the same nutrient run-off problem as before—triggered the Late Devonian mass extinction around 375 million years ago. It was a prolonged agony, a series of extinction pulses spanning millions of years that ultimately wiped out 75% of all species. The great coral reefs were massacred, taking 100 million years to recover. The mighty Dunkleosteus was gone forever. Land life was largely spared, but the oceans were once again a graveyard.

The final act of the Paleozoic Era was the assembly of the supercontinent Pangaea. This colossal landmass, stretching from pole to pole, brought with it the most severe extinction event the world has ever known. The Permian-Triassic extinction, or "The Great Dying," was an apocalypse. The prime suspect is the Siberian Traps, a volcanic event that beggars belief. For roughly a million years, fissures in modern-day Siberia bled lava, covering an area larger than Western Europe and releasing staggering quantities of carbon dioxide and other toxic gases.

The world cooked. Oceans acidified. Methane, a greenhouse gas far more potent than CO2, may have belched from the warming seafloor, pushing the climate past a point of no return. Around 252 million years ago, the curtain fell. In what may have been as little as 50,000 years, an estimated 96% of marine species and 70% of terrestrial vertebrates vanished. The trilobites, survivors of two previous mass extinctions, were finally erased after a 270-million-year run. The sail-backed Dimetrodon and the giant dragonflies were gone. It is the only time in history that insects have suffered a mass extinction.

To witness this boundary, one can travel to the Grand Canyon. The Permian Kaibab Limestone, teeming with the fossils of marine invertebrates, forms the canyon’s rim. Below it lie older layers, but above it, after a gap in time, lie the red Triassic rocks of a new, emptier world. That boundary represents the greatest reset button in the history of complex life. In the silence that followed, a few hardy survivors, the archosaurs, began to radiate, setting the stage for the next great dynasty.

The Dinosaur Disruption: Rain, Rupture, and Reign

The world the dinosaurs inherited was a strange one. For those who visit Petrified Forest National Park in Arizona, you are walking through the Late Triassic, a world defined by a bizarre and transformative extinction event: the Carnian Pluvial Episode (CPE). Around 230 million years ago, massive volcanic eruptions from the Rangelia province—a slab of crust that now makes up parts of Alaska and Canada—pumped the atmosphere full of CO2.

The result was a supercharged water cycle that triggered a rain that lasted for over one million years. This "Million-Year Rain" transformed the arid interior of Pangaea. While it was an extinction event for many species stressed by the acid rain and acidified oceans, it was a "reinvention period" for others. It wiped out many of the archosaurs' competitors, and in the new, wetter world, the dinosaurs thrived. In the park’s Chinle Formation, the fossil record shows this takeover in stark relief. Dinosaur footprints, once non-existent, suddenly account for over 90% of all fossilized imprints. The CPE cleared the stage, and dinosaurs like Herrerasaurus took the lead.

But one final hurdle remained. At the Triassic-Jurassic boundary, 201 million years ago, another wave of volcanism tore the world apart. As Pangaea began to split, the Central Atlantic Magmatic Province (CAMP) erupted, an event even larger than the Siberian Traps. More CO2, more ocean acidification, more death. The Triassic-Jurassic extinction wiped out 75% of species, including the last of the giant amphibians and the remaining reptilian rivals to the dinosaurs.

Now, the world truly belonged to them. Visiting Dinosaur National Monument on the Utah-Colorado border is like stepping into their kingdom. Here, the Morrison Formation preserves a world from 150 million years ago. This was the Jurassic at its peak: a hot, high-CO2 world where towering sauropods like Supersaurus grazed on ferns and conifers, stalked by the formidable carnivore Allosaurus. In the skies, pterosaurs soared, and in the undergrowth, small, furry mammals like the multituberculate Tabis scurried, their time yet to come. The dinosaurs had passed through the crucible of two extinctions and emerged as the undisputed rulers of the planet. Their reign seemed eternal.

The Day the Sky Fell

The end, when it came, was not a slow burn from within, but a sudden, violent blow from the heavens. Sixty-six million years ago, a 10-kilometer-wide asteroid struck the Yucatán Peninsula with the force of billions of nuclear weapons. This was the Cretaceous-Paleogene (K-Pg) extinction.

The story of its discovery is centered on a thin layer of clay. In the 1980s, the father-son team of Luis and Walter Alvarez were studying rock layers in Italy when they found a strange anomaly at the boundary between the Cretaceous and the subsequent Paleogene period: a concentration of the element iridium hundreds of times higher than normal. Iridium is rare on Earth's surface but common in asteroids. They had found the murder weapon.

That same iridium-rich layer can be found all over the world, a geological breadcrumb trail leading back to the Chicxulub Crater. In the American West, it is starkly visible in the Hell Creek Formation of Montana and the Dakotas. Below the line, the rock is filled with the fossils of the last great dinosaurs. Above the line, they are simply gone.

The immediate effects of the impact were apocalyptic. A blast of thermal radiation incinerated everything for a thousand kilometers. A fire rain of superheated debris burned 70% of the world’s forests. For at least 15 years, a thick shroud of dust and soot blocked the sun, creating an "impact winter" that collapsed food chains. Sulfuric acid rained from the sky, acidifying the oceans. The ongoing eruptions of the Deccan Traps in India may have already been stressing global ecosystems, and the impact pushed them over the edge.

Seventy-five percent of all species were annihilated. All dinosaurs, save for their avian descendants (the birds), were gone. Being large was a death sentence. The survivors were the small, the adaptable, and the lucky. Mammals, no bigger than rats, survived in burrows. Crocodiles and turtles survived due to their versatile diets and slow metabolisms.

In the eerie quiet of the Paleocene epoch, the mammals emerged. In a world with few predators, they exploded in size, their bodies growing much faster than their brains. Thinking, it seemed, was "overrated" in a post-apocalyptic world. But as ecosystems recovered and competition returned, intelligence again became an advantage. Brains grew, diversified, and set the stage for the Cenozoic Era—the Age of Mammals.

The Sixth Act

To walk the canyons of the West is to be humbled by the sheer scale of geologic time and the brutal fragility of life. From the rusted rocks of Wyoming to the dinosaur boneyards of Utah and the iridium scar in Montana, the land tells a story of five great interruptions in the history of life. Each time, the world was irrevocably changed.

Today, scientists warn that we are living through the Sixth Mass Extinction. This time, the agent of change is not a volcano or an asteroid, but a single species. Extinction rates are a thousand times higher than the background average, driven by deforestation, climate change, and pollution. We are the first species to knowingly preside over a mass extinction. The stone pages of the future are being written now. The question that hangs in the quiet air of the badlands is what story they will tell. Will it be another thin, dark line in the rock, or will it be the chapter where the one species aware of the pattern chose to write a different ending?

All images posted on the buzzshawphoto.blogspot.com 2025 are copyrighted. All rights reserved.