Marcia Bjornerud on the Profound Wisdom of Rocks

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TRANSCRIPT

SPENCER BAILEY: Hi, Marcia. Welcome to Time Sensitive.

MARCIA BJORNERUD: Hello, Spencer. Thanks for having me here.

SB: The obvious place to start, I feel like—if I’m speaking to a geologist—would be Deep Time, and you’ve described Deep Time, aptly, as a “radical rewriting of Earth’s past.” So I guess—not to sound like a shrink or anything—but I was hoping we could begin with you just telling me a bit about your relationship, as a geologist, with Deep Time.

MB: Well, at this point in my career, I’ve spent a lot of time in the company of rocks. And they really have shaped my worldview as a human being. Although I don’t think any of us can really understand what a million years or a billion years is, after listening to rocks and understanding their experiences, you begin to have a sense of the Earth’s timescales, and I think that has shaped my own small experience as a human.

It gives me a sense of durability, continuity, that is reassuring in some fundamental way. It’s not diminishing. I think too many people when they think of Deep Time feel that it’s a diminishment of us, but I think the better way to interpret it is that we’re part of a continuum in time and there’s as deep a geologic future as there is a past.

SB: You’ve written that fathoming Deep Time is arguably geology’s single greatest contribution to humanity. That’s pretty profound.

MB: Well, I think so. I think geologists really do think of Deep Time, which is John McPhee’s phrase, we should mention, in a kind of spatial way, and in a sense, the geologic timescale is mapping Deep Time. It is extraordinary that we can in such detail reconstruct the many, many versions of the world that have existed over the past four billion years.

At four billion, we kind of lose the thread. Earth is four and a half billion [years old], but for four billion years we have a remarkably continuous rock record and we’ve managed to read much of that. There’s still much of it to be decoded, but it is an extraordinary intellectual achievement of humankind.

SB: I guess it should be said here, and I don’t think most people or humans, or as you would call them, “earthlings,” [laughs] that we’ve been here for 0.007 percent of Earth’s lifespan. That is astounding when you think about how short a time us mere humans, or earthlings, have been here.

MB: That is true, but again, we’re connected to that whole, long chain of earthlings that have come before, and to me that’s the more important message, that we’re among kin. All of the previous lineages of life are still with us—it’s not as if they’ve been left behind. The archaea and the bacteria who were the early ones are still here and in fact probably still in charge of everything, and that’s the way that we should conceive of ourselves as sharing the Earth with this rich, old family.

SB: Well, yeah, the microbes were here long before us; they’ll be here long after us.

MB: Probably. [Laughs]

SB: I was fascinated to learn in your new book, the memoir Turning to Stone, about “residence time,” which is this time that carbon spends in plants, soils, and rocks. Could you provide a quick lesson on this for the listeners? What is it and why does residence time matter?

MB: Yeah, this is a really important and pretty simple idea that applies not only to carbon, but to any entity that cycles, so the carbon cycle is a good way to think about it. We could think of the carbon cycle as having reservoirs or places where carbon is stored for some period of time, like in a tree or in the soil or in the ocean, and then flows or fluxes, which are the rates of inflow or outflow. In a balanced system, those rates would be the same. As much carbon is coming in as is going in and out of any reservoir.

The residence time is the ratio of the size of the reservoir, say, the ocean, divided by the inflow or outflow. The units come out in time, so it’s the average length of time that, say, an atom of carbon would stay in the biosphere or the ocean. So, it’s a way of just kind of quantifying the inertia in a system, how rapidly things are cycling.

When we think of the carbon cycle in particular, there are two kinds of timescales. There’s what’s usually called the fast carbon cycle, which is what we think of with plants photosynthesizing, fixing carbon, dropping their leaves, decomposing—and that is playing out typically with residence times on the order of, say, years to centuries.

Then there’s the slow carbon cycle that includes rocks and the solid earth itself, and in particular the formation of limestone, which is made of calcium carbonate—fixing carbon dioxide in mineral form. The residence time for carbon in limestone is more like a hundred fifty million years [laughs], and so that is the long-term carbon sequestration scheme for the earth. These long and slow carbon cycles are linked subtly, but that idea of residence time is key. It’s understanding that gives us some glimpse of the processing time that the earth needs for these different biogeochemical cycles.

SB: Yeah, and I guess I should specify here, you’re a structural geologist, so your work really deals with this, this idea of process. We often talk about the flow of time in our human lives. I’m curious how you think about time flow from a rock perspective. [Laughs] Obviously it’s a slower kind of flow, but a flow nonetheless.

MB: Oh, absolutely. In my field of structural geology, it has to do with mountain-building, so we think of mountains as something that grow [laughs] and as rocks that literally flow. In my work I model rock deformation as if rocks were very, very viscous fluids. Not liquid, but flowing—in that sense, fluid—in the solid state.

So you do have to kind of just change your mindset about what is malleable, what is flexible, but I would also say that the earth actually has many different characteristic timescales. In the main, for example, mountains grow slowly, but sometimes they grow in quantum leaps that we call earthquakes, and we don’t like that. We expect the Earth to only be changing in tiny increments, and if it moves too fast, we call that a catastrophe, but that’s equally characteristic of the planet. It’s not only slow. [Laughs]

SB: Right. You’ve pointed out that the planet doesn’t think in natural disasters [laughs]—that’s a human construction.

MB: Yeah, and tragically—and I’m not making light of the suffering that can result—but it’s a fact that the Earth is dynamic and these things are just part of the way the planet works, and it’s our own fault for not learning to live well on a very sometimes mercurial planet that lurches and changes suddenly.

SB: Yeah. On the time front, I’d also like to ask you about your field itself. How, because of new instruments, computational power, systems thinking, recent decades have completely transformed your field from when you were a student. Could you talk about this? This is not just in geology; this is also geoscience, this is really what you’ve called “a golden time” for the field. Astonishing to think that in 1955, that was only when we were finally discovering the age of the Earth. So much of what has transpired, this is just a few decades of work. Tell me a little bit about that and the significance.

MB: Yeah, that’s absolutely right. I think the public perception of the geosciences, unfortunately, lags behind what they are today. We are in this golden age where we finally have the conceptual frameworks, the analytical tools, the computational capacity to really see the planet top-down over time. We didn’t know the age of the earth until 1955, plate tectonics was only really figured out in the mid-1960s, and even when I was an undergraduate starting in the late seventies, there were plenty of faculty members who were reluctantly joining that paradigm. [Laughs]

That’s the way the solid earth works. It explains everything—like vulcanism, seismicity, why mountains grow, the topography of the earth—and yet that’s within living memory for me. The whole field of climate science really did not emerge until the 1980s, when we began to have the drilling technology to get ice core records from Antarctica and Greenland. Again, the computational capacity to crunch all that data and make sense of it over time. And the whole field of biogeochemistry really did not exist at the time that I was in university.

So yeah, we are in this amazing moment where, scientifically, we really do understand the idiom of the planet in ways that we never have before, but we’re not somehow fully communicating that to the average earthling.

SB: What have been some recent discoveries, say, from the last year or two that stand out to you?

MB: Well, in my own field, I think there’s been an interesting change in thinking about the earth as we’ve discovered all these exoplanets out beyond our solar system. We don’t have real granular, detailed information about them, but we generally can make a guess at their composition based on their masses and things like this. So there’s been interest in thinking about how many Earth-like planets there might be, and whether they would ever have developed the habit of plate tectonics, for example.

So people are looking at, really, what it has taken for Earth to develop this habit of recycling the crust through subduction, which is really the signature of earth tectonics and realizing it’s a very peculiar thing. It requires a combination of variables that is kind of unlikely even for a rocky planet to have maintained, especially for billions of years. So to me, that’s a really interesting new perspective that’s coming as we look at Earth from the outside, a kind of reverence for this planet that perhaps we didn’t have before.

SB: Yeah, it almost takes going outside to look back in.

MB: Leaving home and feeling a little homesick. [Laughter]

SB: Yeah. Astronauts have called that the “overview effect,” so yeah.

MB: Exactly, yeah.

SB: Since this is a podcast about time, I definitely have to touch on Timefulness, this great book from 2018 that you wrote. I love this word, timefulness, which brings to mind many things including mindfulness, which you effectively define as, “an acute consciousness of how the world is made by—indeed made of—time.” Share a bit about how you came to this word, timefulness, which I think before your book was not widely used or referenced much, if at all.

MB: Well, it is a deliberate play both on mindfulness, which is a sort of trendy thing. I’m not against it—

SB: [Laughs]

MB: The Western read on mindfulness, though, is kind of a preoccupation with being in the now, in the present. I think traditionally in some Eastern meditative traditions, it was really something more akin to the memory of the future or memory of the present, kind of being present in multiple nows.

So, it was partly to push back a little bit against what I think already is kind of a pathology of being preoccupied with now in our society, but also against timelessness, which we think we would like things to stay the same, but it’s an impossible and, I would argue, sterile aspiration. That if things never change, there is no development, there’s no growth, there’s no story arc—only dead and inert things are timeless. In fact, the joy in all of our lives comes from the motion and the timefulness, so it was a deliberate effort to get people to think a little bit about both mindfulness and timelessness.

[Laughter]

SB: Well, and rocks. I think the cliché is almost, you look at a rock and there’s the assumption that it’s static or timeless, but actually it’s timeful.

MB: Exactly. It remembers another version of the world, and it’s interacting with the present day as well. It’s soaking up yesterday’s rain or today’s oxygen and is very responsive in some ways.

SB: In this book, Timefulness, you write about “temporal proportion,” which obviously, again, if we’re talking time and geology, we have to talk about. This is, as you put it, “the durations of the great chapters in Earth’s history, the rates of change during previous intervals of environmental instability, the intrinsic timescales of ‘natural capital’ like groundwater systems.”

This is a very different way of thinking about time than I think most people are used to, and you’ve pointed out that, at least in the West, we live in this system of chronophobia or time denial, and in effect we are time illiterate or even time blind. It’s seemingly primitive, our relationship with time [laughs], as if we’re living in this total hyperreality, time-wise, from what we should be thinking about. So I guess a long-winded way of saying, or asking, what are some ways, in your mind, that we could begin to get more people to think at a geological timescale?

MB: It’s a big charge [laughs], and this chronophobia emerges from so many different sources, ranging from understandable personal fear of mortality and sadness at losing people and the versions of the world that we prefer, to some religious traditions that don’t choose to embrace the idea of Deep Time, to the failure of our educational systems to expose people to, again, basic geologic concepts. So there are many different fronts that we need to work on.

I think that starting with familiar landscapes that one already knows the topography of a place, has some sense of its human history, and then, delving deeper, can help one get a sense for how you read Deep Time from familiar ground. There’s, these days, plenty of resources from state geological surveys, local libraries and historical societies that will take people gently into the logic of geology.

Then reading landscapes as palimpsests—this is a word I’ve borrowed from my colleagues in medieval studies—to see landscapes as these documents that are written and then partly erased and then written over. Just getting into that habit of mind of seeing time, not seeing things as mere, “This is just a hill.” This hill is here, this is telling us something. It came to be as it is now, and it’s this overwritten document.

So I think geology, more than anything, is a collection of cognitive habits of seeing things in four dimensions, including time, of learning to zoom in and out of both spatial and temporal timescales, knowing what you can infer from a single place about a larger region. That is not simple. It takes some practice, it takes some guidance, but I think with some mentorship, anybody can acquire that habit of mind without having had to immerse themselves in the geosciences.

SB: As you were saying that, I was realizing that I’ve never thought about how the term geological has “logic” wedged right inside of it.

[Laughter]

MB: Yes. Geologic logic.

SB: Yeah. Yeah, there is something, I think, very logical about thinking geologically about time [laughs]. What would you say a time-literate society would actually look like? If we could imagine or dream that up, what do you think would result if, say, early education included time literacy?

MB: Utopia. [Laughter] Well, first of all, let me maybe slightly snidely say we would not have people asserting, for example, that we could colonize Mars and possibly turn it into a habitable planet in anything like human timescales. That sort of assertion reflects Deep Time illiteracy, complete disrespect for and ignorance of the intrinsic time that it takes to develop a habitable planet.

But if we could rewind the clock to say the mid-twentieth century, we would not have had all of the climate denial going on. If the average Earth citizen really understood the carbon cycle, for example, and the consequences of doubling CO2 in the atmosphere in a matter of a hundred years, we would never have cavalierly burned fossil fuels at the rate that we did. There would’ve been outrage at that…

SB: Yeah, I mean, I think we can’t talk about this short-view thinking without talking about the climate crisis and, to a certain extent, the Anthropocene, which you’ve described as “the emergence of humans as a geologic force.” When you put the Anthropocene in that way, it really shifts your thinking about it, or at least when I read that it did for me.

So I wanted to ask, I guess, do you view the climate crisis and the Anthropocene in some ways as an extension of time-blindness? Is there a direct link from the way we view time to what is happening to the planet right now in terms of the destruction of climate?

MB: Yes. I am nodding emphatically over here. [Laughter] Yes, absolutely. It’s this insouciance, this idea that the planet won’t notice what we’re doing and not understanding the almost obscene acceleration of rates of change that we are imposing on the planet. 

It’s not that the planet has not changed in the past, but some of the things that we are accelerating, particularly carbon dioxide emissions to the atmosphere, phosphorus release into both fresh and ocean water—these things are so out of proportion relative to the rates of change of the past, that yes, they reflect Deep Time ignorance.

SB: Yeah. Well, and you’ve pointed out that part of this issue is the economic decision-making that we exist in, a sort of society culture economy of fiscal quarters [laughs], not so much thinking about decades or centuries.

MB: Yeah, all of the reward systems in capitalism are short-term. Likewise in our political system. There’s no benefit to politicians for thinking on decadal or century timescales; they have to be looking to the next election. So the entire incentive structure is completely out of sync with what we actually need to persist and thrive as a society on the planet, and that’s a tragedy. We need to be thinking of ways to align those two things.

SB: There’s this one sentence you wrote from Timefulness that really got me. You write, “While the need for long-range vision grows more acute, our attention spans are shrinking, as we text and tweet in a hermetic, narcissistic Now.” You wrote this around six years ago or so. Certainly true then, but even more true now, and I don’t know about you, but I have felt this profound shift in the past two years, more or less, since getting out of the Covid lockdowns in which time has reached a certain hyperspeed that’s even beyond where time was at pre-Covid. Attention spans seem to have shrunk even more than where they were at when you wrote that sentence.

Often it feels like we’re living by the millisecond, which sounds absurd, but also sort of true. There are op-eds being written. I was reading one this morning in The New York Times by a professor at Southern Methodist University saying he doesn’t teach books anymore, because his students don’t read. [Laughs] I’m like, “Wait, that happened in a decade?” It just seems like such a profound shift, and I don’t really have a question other than maybe, how are you thinking about that sentence now?

MB: Yeah, sadly, I agree. My experience with students is the same. It’s really hard to get people to sit down for sustained attention, and there’s nothing more analog than rocks, highly unsexy. [Laughter] But when they do, when I kind of insist, Okay, no phones out here, we’re going to be just listening to the landscape for an hour and a half, I think that appetite can be rekindled. But it’s like any kind of bad habit, like too much sugar. Yeah, but it sadly is now a societal level affliction, and many people don’t even know and don’t realize what’s happened, and to me, that’s the most insidious thing, that it’s become normalized.

SB: We’re not even twenty years into the iPhone, and I feel like that’s the device that wound its way into all of our pockets and has completely transformed that relationship to time, that attention span. It’s not to decry—I don’t want to sound like a Luddite here. I love my iPhone, I use it all the time, but I think there is this innate human desire to, or at least I feel this way, to try to limit that usage, but I think it’s almost not being tended to, in a way. It’s not being even looked at as something we need to try to control, and that’s where the issue becomes….

On both sides of the aisle in the U.S. and worldwide, the one thing that all politicians seem to be able to agree on is that social media is toxic, but I don’t know what to do about that. Actually, what’s sort of interesting here—now that we’re just talking geology, rocks and technology—rocks are the very thing that allow us to have this tool, right? It is the modern-day Paleolithic hand axe. It is rocks that resulted in the metals that allow us to live this way, so there is this sort of… It’s not irony, but it’s profound coincidence that rocks are the thing that could slow us down, but also the thing that have sped us up.

MB: So many thoughts.

SB: [Laughs]

MB: First of all, another irony about our time is the increasing rate of obsolescence of phones and digital devices, which again, stones are a good antidote to that. A billion-year-old rock still functions perfectly well [laughs], but yeah, we’re still in the Stone Age. Everything we manufacture is essentially coming out of the earth, and that’s a pragmatic reason why more people should understand rocks and minerals.

Unfortunately, I think even the green technology revolution, which I’m all for—anything to wean us away from fossil fuels is a good thing—but it’s going to require mining of new elements on a scale that we haven’t seen before. That’s something that I think the environmental movement hasn’t always wanted to acknowledge, trying to get people on board.

SB: Yeah, where did the battery metals come from?

MB: Yeah.

SB: Terrestrial mining, we’re running out. We’re going deeper and wider for lower quality ores. Where do you go?

MB: Yeah. There’s this illusion that the digital age is just being conjured out of nothing, but it’s coming out of the earth.

SB: Let’s talk Indigenous thinking here, because that’s another way of reframing this conversation a little bit. There’s the Seventh Generation Principle; you’ve written about ancestral rituals and how they could play a role in reforming our relationship with time. You’ve also written about art as a tool for shifting conceptions of time—I think that’s a really powerful one. You’ve advocated for both a deeper understanding of time, not only through geology, but also through spirituality.

Could you share a little bit about this thinking, how art, spirituality, ancestry, Indigenous thinking, these can become tools and how they relate to rocks, actually? Because they do.

MB: Well, I think that our current delusion that we’ve outgrown the Earth or it’s not relevant is quite recent, and so there are many traditions, Native American traditions, but even Western European pre-Christian traditions that were based in reality. People lived very close to nature, understood that nature was fully in charge, tried to make sense in their own ways of the logic of nature—and these were pre-scientific ideas, and yet in some ways far more enlightened than our own.

I have a friend and colleague at my university who’s a medieval-art historian, and she did take me to task for a sentence or two that I wrote in Timefulness, using medieval as a pejorative term [laughs], and has made the point, and I’m now fully convinced, and I regret that, that the medieval worldview was in fact a very much more unified worldview, that people had a sense of their place.

Of course, the church loomed large over that in Western Europe, but there was also this sense of harmonious relationship with nature and a spirit of reverence and gratitude, that, again, looking back, sounds quite enlightened to me. So, I think there are many paths back through some of these older traditions.

We used to have some kind of relationship with stone. One of the most interesting news articles of this year to me was the discovery that the altar stone at Stonehenge had come from Orkney off the north coast of Scotland, all the way to the Salisbury Plain, somehow, probably by boat. Those people really, really, really wanted that stone in this sacred place—it meant something to them.

SB: Yeah, yeah.

MB: I would love to know what it was. So we can find our way back, I think, without being Luddites, but it’s really a cultural revolution more than anything that needs to happen, and those are the slowest of all.

SB: So, when it comes to establishing what we could call long-view leadership or a more polytemporal way of looking at the world, rocks, I do think, provide pretty much the ultimate compass. It sounds cheesy to say to a geologist maybe [laughs]. But I wanted to ask, having spent so much time with and around rocks, what is it about them that you think is so enduring and powerful, comforting, or actually as you put it earlier, reassuring?

MB: I often use text metaphors. I can’t walk down the street, even here, I notice paving stones, I notice the stones that are preventing people from driving onto sidewalks. They’re bits and pieces of text, they’re full of information at different scales, so they almost demand reading. In that sense, you have the feeling that you’re communicating with some larger, wilder, more ancient wisdom [laughs], so that’s comforting to me.

I would be terrified if the human story were all that is. If we’re the whole thing, oof, that’s more existentially terrifying to me than having a deeply mysterious ancient world that is partly still with us, still changing with us, that makes me feel embedded in something grander.

SB: Let’s go back to your upbringing. You grew up in rural Wisconsin in the seventies, and in Turning to Stone, your new book, you describe your childhood self as “an odd and awkward girl who found trees and stones to be good companions.” [Laughs] Your father was a woodworker; your mother taught English at high school in a town on the edge of this large Ojibwe reservation. You had an adopted sister actually born in Chicago to a teenage Ojibwe mother who had given her up at birth.

So within this tapestry of an upbringing, could you share some of your early memories with rocks? What are some of the maybe more profound things rock-wise that occurred in your childhood?

MB: Well, I grew up in a part of Wisconsin that has these beautiful honey-colored sandstones, and each chapter in Turning to Stone is about a rock type that I either lived on or was obsessed with later in my life as a geologist, so the first chapter is about this sandstone. One thing I vividly do remember about it are the fantastic icicles that would come out of the creek banks and the sandstone. It’s a very good aquifer or groundwater-carrying layer, and so in the winter the groundwater stays liquid underground, but then when it meets the cold Wisconsin winter air it will freeze. So in the creek bank below our house, these sandstone banks would become monstrous creatures with great tusks hanging down.

But at the time I was growing up, I never had anyone say, “That’s geoscience. People study these phenomena, these great tusks of ice coming out of the earth.” [Laughs] But I think I was noticing things in a kind of naïve way, and it would just take many years until I realized, that’s a science; we could study that.

SB: Right. It was when you enrolled at the University of Minnesota, you thought you’d study language or become a translator, but a geology class changed all that, and you went on to graduate at age 20 and then finish your Ph.D. by age 24. I mean, the rest is history. Not really. I mean, obviously a lot happened and you write so beautifully about it in this book, but I think it’s worth noting here that, in a way, you did become a translator after all. You are exploring rocks as geologic texts, and these are records of ancient worlds that can be and are translated by you and your colleagues.

So, I was wondering if you could just speak to this relationship between rocks, language, words, translation? Because that, it seems to me, is your work: How do you translate this thing that is highly animate that so many people think is inanimate? It’s not just geology as science—what you’re doing is geology as translation, poetry, philosophy, literature. Share a little bit about that.

MB: Yeah, thank you. Very perceptive. [Laughs] When I first started college, I really was a humanities-oriented person, had no sense that I could be a scientist. I remember quite vividly in the first couple of weeks of the Intro Geo class that I was taking strictly to get a lab science requirement out of the way, just being fascinated by the eclectic lexicon of geology. The rock and mineral names, landscape feature names that are just— They can be off-putting to people, because they’re just overwhelming, but to me, I loved how unsystematic they were. Unlike the names of chemical compounds that are neologisms from Greek and Latin roots, geology is just this kind of magpie discipline. It takes old names, some new names.

Anyway, so I was fascinated just at the language of geology, but then I started realizing that the rocks themselves were encrypted messages and themselves had etymologies. I sometimes say that the worldview of geology is like understanding the etymology of the world. It explains how things are the way they are. And to me, there is joy in that. That’s like, okay, that is not just an arbitrary thing out there, it has a backstory, it makes sense. It was this and it slowly evolved into that, and now it’s becoming that.

SB: Yeah, rocks are verbs. [Laughs]

MB: Exactly. Yeah, so there is, I think, a through line that I recognize, retroactively, to that early, very naïve idea that I could be a translator.

SB: I have to bring up Norway here, specifically Svalbard, but maybe you have more to share about Norway generally. Svalbard is where you did your graduate school fieldwork, and you’ve returned many times throughout your career.

In Svalbard, famously—I think we’ve even talked about it on this show previously—there is no official time, it is, in a sense, out of time. Could you talk about that, both the notion of time in Svalbard, but also your time there, how you think about it in retrospect?

MB: Yeah, Svalbard is a special place to me. I did my graduate fieldwork there, and this was initially in the eighties, and it really was a very remote and wild place at the time. We would be dropped off from a research vessel, usually carried to land by a helicopter for two months and really see no one else, maybe a group of three to five people in a pretty remote place that was not otherwise accessible. These days you can get to Svalbard on a cruise ship, and there are limited ports where tourists are allowed, but it’s still a—

SB: Yeah, in the eighties, how did you get to Svalbard from Minnesota? [Laughs]

MB: Well, yeah, flew to Oslo, usually took a long train ride to North Norway and then boarded a research vessel with the Norwegian Polar Institute that would take a very long time to get to Svalbard doing oceanographic measurements, so three days later we’d finally be taken off the boat—very seasick—on to land by helicopter with all of our gear slung beneath the helicopter dangerously in a net bag, and then wave goodbye to the ship and be picked up two months later.

Being in that really elemental landscape in such a place that has a minimal human footprint really deeply affected my psyche as a young adult, and I feel very fortunate to have been there at that time. But I’ve also seen that landscape, which seems timeless, change radically in the intervening thirty or thirty-five years. It’s really viscerally depressing to me to see the state of the glaciers and the central ice cap in Svalbard. Everything has become just kind of a grimy residue of ice. Even in the eighties, you could see beautiful white advancing glaciers, but they’ve retreated dramatically.

So, I use this idea that Svalbard has no official time officially. It’s a political thing, because the Norwegians and the Russians can’t agree which time zone Svalbard should be in. But as a kind of counterpoint, it does seem a timeless place until you start listening to the landscape and seeing how it can change even on human timescales—it’s not exempt from time either.

SB: In Svalbard, you befriended this man I’m fascinated to learn about, and I wanted to ask you about—the late Japanese geologist, Yoshihide Ohta, who was also an artist and an epicure and a philosopher, and he became this important mentor to you. So I guess, looking back now, how do you think about your time with him? What was it about him that had such a profound impact on you?

MB: I’m so glad you asked about Ohta-san. [Laughs] He really was perhaps the most important intellectual mentor to me. My own graduate advisor was a kind person, but I would say not a tremendous intellect, very conservative in his science. Ohta saw the world impressionistically, almost, and had a bifocal vision as scientist and artist.

So, he had worked for the Norwegian Polar Institute for most of his career. He came, I think, to Oslo initially as a postdoc, and he then stayed, and he was involved with some of the first mapping of the bedrock in Svalbard through the lens of plate tectonics. So, one of the first people to really try to unravel the pretty complicated story that Svalbard’s rocks tell—using a more modern lens, and he covered huge terrain.

You can’t get obsessed with one little area, you have to just keep moving on, make some critical observations, and, little by little, try to put those together into a larger framework. I think he taught me to be observant and also more confident about a quick impression [laughs], and to just be a more joyful scientist in a way, not worrying whether other people were going to second-guess my conclusions.

So yeah, I think I learned joy in fieldwork from Ohta. He was very emphatic that we should eat well in the field. We should not think that we have to just be miserable the whole time. He insisted that rice be cooked properly. [Laughter] So yeah, he showed that you can do serious science, but you can also really live well even under rather extreme conditions.

SB: Yeah, and you found yourself in quite a few extreme conditions with him. [Laughs]

MB: Wild storms, bad fog, polar bear encounters, yes. [Laughs]

SB: Yeah. Yeah, there are more polar bears than people in Svalbard, right?

MB: Yeah, and ironically, although they’re not doing well, you are more likely to encounter them on land these days than in the past, because the sea ice has really diminished. Normally in the summertime they’d be hanging out on the sea ice looking for seals to grab, but as the sea ice has begun to melt back earlier and earlier, they start coming onto land and they can smell unwashed geologists from a couple miles away.

[Laughter]

SB: Another place I wanted to bring up was Italy. You spent considerable time there thinking about stones as well, and in 2016, you wrote a piece for The New Yorker that I thought I would quote from, just because it speaks so much to the relationship between geologic time and human time, and how we have these very mixed perceptions of what’s actually old. [Laughs]

So, you write, “To live in Italy is to wander constantly back and forth in time. Etruscan, Celtic, Greek, and Roman place names are jammed together on the map; off-kilter medieval houses stand incongruously next to brash, rectilinear postwar buildings; stones quarried a millennium ago are repurposed for modern construction. But if the country seems ancient from the viewpoint of human habitation, it is among the youngest geologically.”

Tell me about the geology of Italy, because it’s so fascinating—this place that we think culturally of as so old is actually so young geologically speaking.

MB: Yeah, absolutely. Twenty million years ago, maybe even just fifteen million years ago—blink of the eye geologically—Italy did not exist. It was the continental shelf off the coast of Africa, an area that is now geologically called Adria, the Adria plate. Then it’s only been in the last twenty or fifteen million years that subduction in the Adriatic Sea has crumpled the rocks of that ancient continental shelf into mountains that stick up above sea level and are now the Apennines of Italy.

So for someone, I live in the Great Lakes region—I’m used to looking at rocks that are up to three billion years old—Italy seems just like this very juvenile Johnny-come-lately place. [Laughter] I mean, it’s a fascinating place and the mountains are still growing and changing, and there are earthquakes that happen there, but yeah, it’s very, very recent and still in progress.

SB: We have to talk about some of the time you’ve spent there. There was this extraordinary experience you had with your sons where you experienced an earthquake in Italy. Tell me about that.

MB: Yeah, it was the Amatrice earthquake of 2016 that sadly something like three hundred people died in [Editor’s note: According to The New York Times, at least 241 people died in the earthquake]. We were about thirty miles from the epicenter. It wasn’t a huge earthquake, I think it was 6.5 on the magnitude scale, but that’s enough to shake old stone buildings that have not been reinforced, and sadly there was significant loss of life [Editor’s note: The earthquake had a preliminary magnitude of 6.2].

But I actually study earthquakes as part of what I do as a structural geologist, and experiencing that event was a strange bifurcation of my brain that I…. It happened at 3:30 in the morning. I was in a pretty deep sleep, but I was awakened by what I recognized right away as the P waves, which are the first waves to arrive. They’re pressure waves like sound waves are, they’re not the ones that really cause a lot of destruction.

But in a fraction of a second, I was awake and knew that I probably needed to get to the door before the next waves, the S waves, the sheer waves, which are more…. They have a higher amplitude and they really deform the ground more. I could experience it both intellectually in that time and from a purely human—

SB: As a mother, right? Yeah.

MB: ….and as a mother, my kids were in the next little villa. They were visiting. I was teaching at a field school in Italy, and they had all three come at that time to visit, and I just thought, “Oh, my God.” But luckily our area did not have as much damage, but it was an interesting case. I could feel terror and also intellectualize exactly what was happening. [Laughs]

SB: Wow. So if Italy is young, geologically speaking, tell me about some of the older or oldest places on earth. I know Australia and Canada are home to some of the oldest rocks. Share a bit about the oldest rock formations that we know of on Earth.

MB: So all of the continents do have these ancient shield areas that have pretty old rocks, and I think on every continent, including Antarctica, there are rocks as old as about three billion years, but the really, really old, old ones are in the Canadian Shield that clock back to about four billion years, and, depending on the dating methods we use, maybe 4.2 billion.

Most of those are not rocks that formed at the surface. They’re gneisses, they’re highly deformed, so they’re not telling us about surface conditions at that time; they’re telling us something about the solid earth, the thermal budget of the early earth. The oldest rocks that have memories of what was happening at the surface are about 3.8 billion, so there’s a bit of a gap between the oldest rocks and the oldest rocks that formed at the surface.

Those ancient ones remain enigmatic. There are just a few here and there, but they do point to an earth that was probably quite different, probably did not have plate tectonics. There might have been plates moving around, but they were softer and squishier, because the planet was hotter, probably did not have subduction. One of the big issues in structural geology these days is when did plate tectonics in the modern sense really begin? We’re not entirely sure. I think the consensus is converging around three billion years ago.

SB: To finish, let’s talk about metamorphic rocks, which you’ve described as “the wisest, most interesting mentors in the pantheon of stones,” calling them “seasoned travelers” and “exemplars of versatility.” I’d love it if you could just talk a bit about these metamorphic rocks from a time perspective, and what exactly makes them the wisest.

MB: Yeah, metamorphic rocks are my favorite—don’t tell the others—

SB: [Laughs]

MB: Because they have had experiences and they have some kind of observations to make. Actually, I’ve been thinking about this again in the context of what we’re discovering about other planets, both in our solar system and beyond, probably metamorphism is unique to the earth for a couple of reasons.

Metamorphism is the recrystallization in the solid state of rocks that happens when they move to new environments. To move to new environments, you have to have a planet that’s shuttling rocks around, causing them to be deeply buried into the subsurface. Then, equally strange, if people are going to find them, they have to find their way back to the surface again. So even having metamorphism is probably not going to happen on a planet that doesn’t have some kind of tectonic system, because rocks will be formed and they’ll just stay where they are. So on earth, rocks have the opportunity to travel, to study abroad, and then to come back.

We have now geochemical and isotopic ways to read that whole journey, both if, say, a rock began as a mudstone on the seafloor, and then found itself in the guts of a mountain belt and recrystallized to a beautiful garnet schist and then came up again. Many parts of that journey, little bits can be recorded in subtle geochemical clues, minerals that developed along the way, and then that also changed or recrystallized on the way back to the surface. We call these pressure-temperature time paths. We can really read the itinerary that the rocks took.

And those, especially the deepest—the metamorphic rocks that record the highest pressures, the deepest depths—are the only way we have any information of significant depths in the subsurface. The deepest drill hole that’s ever been made, in a crazy Cold War competition between NATO and the USSR, went down like twelve kilometers, so that would be eight miles, something like that [Editor’s note: According to the BBC, the hole was 12.2 kilometers deep, or 7.6 miles]. Below that, we don’t have any physical samples. We have indirect ways of making inferences, but only metamorphic rocks are the physical samples that we can consult to know what’s going on at greater depths.

So to me, they’re the richest texts. Maybe, if we use our literary analogues again, they’re like marginalia written in books. They have multiple stories to tell, and they just seem more seasoned and interesting than rocks that have spent all their lives in one place.

SB: Just to bring it back to the literary thing, it really makes me think of how many authors have used this theme of metamorphosis to great ends. Ovid, to name an obvious one. There’s one line from Turning to Stone I’d like to leave all the listeners with, which is, “Rocks, whether one ever thinks about them or not, ultimately define reality for everyone who lives on this rocky planet.” [Laughs]

MB: Hear, hear.

SB: Marcia, thank you so much.

MB: Thank you, Spencer.

This interview was recorded in The Slowdown’s New York City studio on October 25, 2024. The transcript has been slightly condensed and edited for clarity. The episode was produced by Ramon Broza, Emily Jiang, Mimi Hannon, Emma Leigh Macdonald, and Johnny Simon. Illustration by Diego Mallo based on a photograph by Elizabeth Boutelle.