Scientific education in the United States has been characterized in the last two decades by a dizzying program of modernization and experimentation. An average high school student can now take classes in robotics, computer science, and environmental science that were only available in the swankiest of private schools twenty-five years ago, and the curriculum for AP courses like chemistry and physics has been evaluated and stream-lined (some would say too stream-lined) time and again. And yet, amid all of this progress and science literacy boosterism, there is one persistent dark spot that has remained for years and decades: the abysmal attention given during secondary school and beyond to geological science.
While most scientifically minded students end up taking a biology course three times during their middle and high school years (as life science, biology, and AP biology), for the most part they take a geological course all of once – an Earth Science course dumped unceremoniously at the beginning of their middle school experience, rarely to be referenced or spoken of again. It’s the lingering shame of American science programs, and it has created a geological illiteracy in this country with far-ranging and profound consequences. We have let the rocks around us become strangers, and in that alienation have grown deaf to the tales they tell.
Fortunately, the stones have been recently given new voice by a series of scientists and authors who have wed their deep knowledge of chemistry and physics to their gifts for presenting the passage of geologic time as a breath-taking progression upon which the existence of life is dynamically, but precariously, balanced. We are as we are because the rocks have evolved as they have, and to ignore the latter is to imperil the former, our new geo-advocates call us to realize, and perhaps none so eloquently as Lawrence University’s Marcia Bjornerud.
Bjornerud’s books, Reading the Rocks: The Autobiography of the Earth (2005) and Timefulness: How Thinking Like a Geologist Can Help Save the World (2018) have been among the most profound reading experiences of my life. As ravenous consumers of science books, like you and I are, we are pretty well used to two scales of reading experience – stories of space and the atomic processes that determine the course of the stars above, and then stories of life and the biochemical processes that keep it humming along. What Bjornerud provides, which I hadn’t really been conscious that I was missing before (largely thanks to my position as a product of American education) is the link between those two worlds, how the nucleosynthetic processes in the stars are etched into the rocks, and how the slow dance of those minerals and compounds forms the substrate upon which biochemical processes are rendered possible. It is the rocks that hand us the life-giving legacy of the stars, and with that simple shift of perspective, it was like a light went on in my brain, and instead of thinking of the ground below as a dead static mass we can largely ignore except when we want lithium or gold, I see it now as a vast and shifting cosmic laboratory, fascinating in its smallest detail.
The excitement of undergoing that change in point of view is one I wish for everybody, and which I don’t think I can ever be quite grateful enough to Bjornerud’s words and insights for providing, as if she were a doctor providing me suddenly with a sense I never knew I had. Now my question is, how do you make such a person, who can think so easily on such scales, and find ways through words to bring the rest of us along with her? Part of the answer lies in something that regular readers of this column are well familiar with in the story of the great natural scientists: a youthful freedom to roam. Bjornerud grew up in a house in the woods in Wisconsin, about 45 minutes east of the Twin Cities (that’s Minneapolis-St.Paul for those not of a midwesterly persuasion), where she was more or less free to ramble however she cared to until her parents called the kids back inside with a blast on a plastic summoning horn, much as the family’s Scandinavian ancestors must have done a thousand years previously.
Both of Bjornerud’s parents were the first people in their families to attend college, and both were teachers, her mother an English teacher on a nearby reservation, and her father an expert in wood technology who taught at a vocational university. They were both influenced by the great social movements of their day, and resided intellectually, in Bjornerud’s words, “on the fringe of the Back to Land movement,” building their house in the woods and constructing on their land a saw mill for general use.
It was the perfect location for a child to absorb a love of natural investigation through regular contact with its seasonally offered wonders, but that process was very nearly killed over the course of high school by a string of indifferent to just plainly awful science teachers, to the point that the child who had compiled a booklet in her spare time about the different varieties of snow and ice that she had experienced found herself leaning towards linguistics as her future career, as a gateway to becoming a free roaming citizen of the world.
Fortunately for us, in college Bjornerud found her way back to the sciences, helped along by the spectacular Field Camp offered at the University of Minnesota, which gives students the immersive experience of doing real mapping work for the US Geological Survey as a preview of what geological fieldwork entails. Being out on one’s own, entrusted with important work, while getting into the real fray of the planet’s deep time was a heady experience which set Bjornerud distinctly on her life’s course. In graduate school, she had the opportunity to deepen that experience with fieldwork in Svalbard, the Norwegian archipelago that extends from 74 to 81 degrees in latitude, the very northern reaches of which experience perpetual sun for 141 days and perpetual night for 128 days every year. Bjornerud got to experience this location in the rough and tumble era when you were expected, as a student, to provide your own equipment. Days were spent collaborating in rotation on each team member’s project, keeping a good eye out for polar bears, and returning at night with bags full of rocks to huddle for warmth around a Franklin stove in a small collection of antique boards somewhat optimistically called a cabin while the team oiled their boots and cleaned the gun in preparation for the next day’s work.
Bjornerud’s research of the last decades has spread across a number of topics, but I want to talk about two in particular that strike at some of the mysteries of the shifting world beneath us – eclogite and pseudotachylyte. To start with the one with the scarier name, pseudotachylyte is a glassy rock which generally results from seismic events – an earthquake occurs, the pressure and friction cause rock along the fault to melt, and pseudotachylyte is formed. The problem is that there is way less of it than there should be. For all the seismic activity occurring around the world (around 500,000 earthquakes a year, according to the US Geological Survey) there should be loads of pseudotachylyte to be had, and yet it is comparatively rare. The explanation for that used to be that water gets in the way – any moisture in the rocks will absorb heat, expand, and in the process separate the rocks lying along a fault, reducing their frictional contact, and barring the way for pseudotachylyte formation.
Bjornerud, however, showed that the presence of water was not as strong a disqualifier as it was once believed to be, by doing what she does best, widening our field of perspective. If the rock surrounding a seismic event is permeable, if there are microchannels where water can go so that it is not restricted to expanding along the fault, then “wet” rocks should be able to still form pseudotachylyte. It’s a really cool idea that harnesses multiple branches of science to solve a mystery wherein the major players are titanic entities flung at each other in acts of unspeakable violence, and yet the solution lies in the finest of structures.
If pseudotachylyte is the main player in a mystery novel, eclogite is the central hero in a classical epic, and the fact that more students know how to calculate the pH of a polyprotic acid than what eclogite is speaks worlds about how off-kilter our scientific priorities have become. Eclogite is what runs our planet. As basalt (which makes up most of our oceanic tectonic plates) is drawn down into the Earth through subduction, the increase in pressure and temperature at lower depths generally causes it to metamorphose into a new form, eclogite, the higher density of which serves to further drag down the basalt above it, powering the process of subduction and along with it the creation of mountains and the dazzling symphony of tectonic motion that distinguishes our geologically vibrant planet. Ordinarily, we don’t get to really see eclogite in formation, as it occurs at significant depths and the product is so dense it rarely returns to the surface. Bjornerud, however, found a location in Norway where the process of eclogite formation was frozen in time, thanks to the presence of some particularly dry rocks.
Eclogite likes water – it helps immensely to move large ions where they need to go in order to construct the eclogite crystal formation. Without water, that process can take hundreds and thousands of times longer than it does with it. The Norway rocks Bjornerud studied had started to metamorphose, never quite got there before dehydrating a billion years ago, then had another go at it 450 million years ago, but again were not able to complete the process, remaining in a metastable halfway state in spite of the surrounding pressure being some 50% greater than basalt usually requires to undergo eclogite conversion. What they represent, then, is an exciting and rare snapshot of a process usually hidden from our eyes which governs the rise and fall of the landscape around us, and demonstrates once again what a difference something as simple as a dash of water can make in determining our mineral destinies.
In addition to her work as a researcher, Bjornerud’s other great gift to us is her ability to convey the breadth of her geological perspective in a way that we can begin to grasp. In a world where we make decisions for the day, and political decisions for the year, with our gaze drifting from our own immediate economic advantages only under duress, what is most needed is someone who can get us to think in deep time, to see in our actions the consequences that will sprawl out over decades and centuries and beyond, impacting those mighty geochemical processes that we take for granted as eternal but that, from the point of view of our elders the rocks, are flashes of the moment, easily checked and reversed, as they have been in the past, throwing us in directions from which no amount of cleverness can really save us. As we gum up the great chemical pathways that make life as we know it liveable, there is perhaps still time to determine where we want ourselves to go by heeding where our planet as been, what paths it has tried, and what it has learned along the way, stories there in abundance for the hearing, as long as we have people like Bjornerud around to translate the words for us.
FURTHER READING: Bjornerud’s two books are must-reads for anybody looking to fill in unconscious gaps in their scientific literacy, as well as people who want to cultivate the habit of larger scale thinking when considering what direction we need to head as a species. She also has a neat book, Geopedia, which is part of a series of pocket encyclopedias about different aspects of the natural world that I am now addicted to collecting. I asked her what, beside her own books, she would recommend to somebody interested in deepening their geological literacy, and she highly recommended both Robert Hazen’s The Story of Earth and Merlin Sheldrake’s Entangled Life.
Images: Courtesy of Marcia Bjornerud for publishing here on Women You Should Know
Want to know more awesome Women in Science? Check out my WYSK column archive and my books: A History of Women in Medicine and Medical Research – Exploring the Trailblazers of STEM (December 2022, pre-order), and Illustrated Women in Science – Volume 1, Volume 2 and Volume 3.
