This marks the final post in my Story of Sand project, thank you all for following along!
In the past several weeks, I’ve tried to share some of the rich detail that exists in a handful of sand by way of diving into its endo-story (the little worlds contained within it) and its exo-story (the role they play in the world around them).
In this final post, I want to speak to one final principle that, to me, makes the story of sand one of the most profound and interesting things on earth. My favorite thing about the story of sand is that it is cyclical: sand is its own marvelous material, but it's also just a transition state: the interim form that rock takes between its reincarnations. A handful of sand is a million unique stories of a landscape being disassembled and rearranged, and also a tiny sample of the raw materials for land that is yet to be. To hold it is to hold the ashes of the past and the seed of the future-- fragments of a once and future world.
This picture encapsulates that cyclical nature. In it, the Colorado river snakes through the bottom of the grand canyon, carrying both the remnants of the Rocky Mountains and recycled sediments of the Colorado Plateau to the pacific. Within those muddy waters, sediments on their inaugural journey mingle with others that have been through the wringer many times. Those that are swept up from the canyon walls today may be moving for the first time in 500 million years, roused from their temporary rest to rejoin the procession downward. Sand might travel through this cycle many times and in many ways- but ultimately it will all undergo the same fate: being buried so deeply that it is subsumed back into the earth, to be melted and reformed anew. With this final transformation, the stage is set for the Story of Sand to play out once again, and give its gifts to some future world.
This photo also speaks to the profound impact of that cycle on past worlds. On the canyon’s inner rim, @maddie.zug sits atop Cambrian-era sandstone laid down just as the first complex life exploded into Earth's oceans. Directly below that is the Vishnu schist, a gnarled and jagged metamorphic bedrock more than a billion years older. The missing rock and time between these two layers is a gap in the rock record known globally as the Great Unconformity, which represents a period of intense continental erosion with profound consequences. By stocking the ancient oceans with the raw materials for biomineralization, the formation of the Great Unconformity appears to have helped trigger the evolutionary arms race that led to complex life on earth. What goes unseen between those layers may be the single most dramatic impact that sediments have had on life as we know it.
Just as it has since the dawn of complex life on earth, the story of sand continues to underlie our everyday lives in more ways than most people can fathom. In diving into these stories, I hope I’ve helped bring out some of the wondrous depth that exists within a handful of this incredible, ubiquitous, utterly mundane stuff. And I hope next time you’re at the beach, or the grand canyon, or just thinking about the ground beneath your feet, you think, “Thanks, sand.” 😉