The stories tell us the rocks

TThe walls of the Wyoming Bighorn canyon rise above a thin lake which once ran like a river. This river sank for several thousand years, increasing at the end of the last glacial period while the melting glaciers sent torrents to the rocky mountains and towards tributaries that sculpted through the earth like blades through soft wood.

This flow and sculpture ended here, in the 1960s, with the construction of a dam. Since then, the waters have groped calmly against the sedimentary layers which mount more than a thousand feet, capped with a tray on top.

A network of hiking trails extends on this set today in the national leisure area of Bighorn Canyon, where I found myself walking a few summers. While I climbed along a dusty path, I conscientiously obeyed signs before warning me to pay attention to scorpions and bell snakes. I looked behind the bushes and under rocks for about a mile, until I follow a turn on the way and came across this massive scar in the ground, the Bigorn Canyon.

I put my backpack and fold my legs under me to sit on the pale floor. The hunted blue birds fly through juniper and sagebrush; Wild Mustangs have touched on a nearby hill. I could hear families screaming on snakes or scorpions in front. But all of this was around me while I took the strata, these layers carefully arranged with sand, silt and clay placed on the walls of the canyon in a striped pattern, to the water below. Taken from the moment, I plunged at the time, caught somewhere in the paleozoic – long before human voices resonate on earth, even before snakes or hooves or herbs occur here.

Stability came and returned and returned so many times before.

I sat for a while, taking the remains of old beaches or seabed or other sandy environments that have long been transformed into stone. My mind has dragged into the winds and rains that had spread these sediments, and all the dramas that had taken place over the millions of years. The rise and the fall of species; The merger and disintegration of continents. Storms larger than the previous ones, the clouds that are too heavy to hold the snow.

I imagined my own short life in the context of all the time locked in this canyon wall and I felt tiny. Smaller than tiny, a grain of dust.

In this smallness, I felt a kind of relief.

On the way back at the start of the path, I came across a plot of friable rock, an extension of the canyon wall. I crouched up and I found a perfectly sculpted ripple collection, the ones you could find by a sea. I traced the peaks with my index and curves felt water that flows from millions of years earlier. A free moment in time, whispering the memories of a world without us.

SO A large part of what we know about the history of 4.54 billion years of the earth, we know thanks to strata like those of this Wyoming canyon wall. It is through these lines in stone that we can see the ancient iterations of this planet and gain context for the moment we are now turning. Along the canyon walls and hills on the seven continents, geologists flock to these types of sedimentary rocks to reconstruct the history of the way in which the earth has become the place where we live today. By collecting pieces of stone which they bring back to the laboratory, they reduces how our atmosphere was formed in the air that we breathe, or how the thermostat of the planet fluctuated in time, or how the landscapes have transformed, and how life has shaped and been shaped by all these upheavals. They turn to these rocks to understand the foundations of our current environmental crises, looking for proofs of past periods of tumult to help us cross it.

But the language of stratigraphy is not in the common lexicon. Most hikers along this canyon wall in Wyoming probably take the wide sky and the river underneath, then continue, sculcing poisonous things without thinking a lot about the strata. I had arrived there with a conscience that borders the reverence for these stone lines, but only because of a geology class that I fell during my first year at university. Before that, I would not have thought much about the strata either.

In this first geology course, we went to lakes and rivers and beaches throughout Maine, collecting samples of silt and sand that we brought back to the laboratory and fell through sieve and weighed on scales to disentangle the models in the landscapes around us. I had not signed up for this class with a particular interest in sediments. Above all, I wanted an excuse to make bites outside for credit. But during this semester, I grew up to appreciate the silt and the sand for the way they drew my attention to the details of the landscape to which I had never thought of paying attention. How the interior turn of a river flows more slowly and drops finer sediments than the outdoor turn, or how one side of a beach can contain larger sediments than the opposite side. How this sorting is not random, but is orchestrated by winds and tides and currents which, in turn, orchestrated by a larger network of activities that I have known as a terrestrial system. This hidden organizational force, I learned, spread all around us, weaving an order precise even by the smallest of the grains.

I plunged into deep time, caught somewhere in the paleozoic.

I declared myself a major geology and, over the next four years, I started to see the world through an entirely different lens. The reliefs that I had once perceived as virgin sets for the work of daily life began to overflow with their own silent sagas. I found stories in the country’s curves around the campus, I could not jog through the city without thinking of the glaciers that had sculpted the river to which I was running out. I stopped to examine the foundations of the buildings and the contents of the slate aisles, often to perplexed looks of my friends.

I continued to work as a field assistant and laboratory technician for a group of stratigraphs for about a year after obtaining my diploma, before replacing my rock hammer with a voice recorder and a laptop of the journalist. By always digging in the stories of the planet, but from a human point of view rather than that of the rocks. Even after leaving geology for journalism, however, my appreciation for the strata has only surrendered. The crises confronted with our planet are increasingly calling for the ideas and the context linked to these strata, the wisdom they hold.

As I arrived on this Wyoming trail, I have been working as an environmental journalist for more than a decade, covering history after the history of the troubleshooting of the earth. I had spoken with the glaciologists of the disappearance of the ice, of the oceanographers of the disappearance of the coasts, of the geochemists of the disappearance of the permafrost. I arrived at this canyon wall with a desire for a version of the planet that I knew that I would never see in my lifetime. A version that did not burn, the floods, the killer of our own annuments.

While I sat on this pale tray with my legs under me, however, I remembered that stability came and came back so many times before now. That geological time scales are too wide to witness a single human life, but have always turned to a kind of new stasis.

I know that it does not let us take down, or means that it is time to stop relying our wrongs to the environment. The changes that we have triggered today take place much faster than the past periods of change, and they were not geologically inevitable. We are the agents of this geological moment.

But the strata reminded me that we are also part of the terrestrial system, this network of much larger connections which spin between the atmosphere, the continents, the water, the ice and the life. The fact that these sons relax and tighten over time and adapt to each other with more brilliance than the human mind cannot easily grasp. That we live in this system and that the system lives in us. We carry his iron in our blood and star dust in our bones, and its strength is our strength because we are.

We are, but we are not a fact. The only given is the change and the sphere that contains it.

Read Laura Poppick’s “3 Greatest Revelations” while writing her new book here.

Extract from Strata: depth stories. Copyright © 2025 by Laura Poppick. Used with the publisher’s permission, WW Norton & Company, Inc. All rights reserved.

Lead image: photo.eccles / Shutterstock

• Laura Poppick

  Published on July 15, 2025

  Laura Poppick is a scientific and environmental journalist whose stories appeared in the New York Times, Scientific American, National Geographic, And elsewhere. It was listed as a finalist of the National Association of Science Writers Science in Society Journalism Award and Maine Literary Awards. His first book, Strata: depth storiesprovides a context for modern environmental change by exploring four other moments of global transformation in the deep geological history of the earth. She lives in Portland, Maine.