To outsiders, geology can seem so boring, with a lexicon just as opaque, but to insiders it is a boundless source of wonder. Different authors have used different tools to crack open the dull exterior of geology to show non-geologists the sparkling wonders within: Robert Hazen used color; Jan Zalasiewicz used a pebble; and Richard Fortey, for example, took advantage of a train journey.
Marcia Bjornerud uses words to unravel the mysteries of geology like a video game can use gems to unlock a new level to explore. Her new book is a buffet of bite-sized chapters that are perfect for popping in and out, read in any order. Geopedics is structured like an encyclopedia to the extent that the topics are arranged alphabetically, but it is written for fun rather than a mere reference to facts.
Bjornerud keeps the reading light even when serving expansive time and space, and she follows each geological “dish” with a chase of references to other items that may be related, if only tangentially. For example, after ‘Amethyst’, she suggests ‘Kimberlite’, a diamond ore, and ‘Pedogenesis’, the process by which earth is made.
Geological buffet
Each chapter has its own tasting menu. Under “Amethyst” I learned that ancient Greeks believed that Amethyst crystals protected wearers from getting drunk. From there, Bjornerud jumps to the definition of a mineral, to limestone containing atmospheric CO. lock up2, and on atomic impurities that give color to crystals; she jumps from subject to subject like a geological Mario jumping between platforms in a video game.
The “Tully Monster” (a real creature from 310 million years ago) brings us via Star Wars Episode IV‘s “cantina scene” created ongoing controversy over where it fits in the animal kingdom. “Oklo” links a 2 billion-year-old meltdown to the rise of oxygen in Earth’s atmosphere (your granite countertops are slightly radioactive, Bjornerud casually mentions).
The topics span the topics I’d expect (like Anthropocene, Unconformity, Moho, etc.), but Bjornerud did her best to include the odd (Geophagy, anyone?) and curiosities like salt glaciers and mud volcanoes. She has also unearthed words that are unclear even to geologists (until Geopedics, I thought a Yazoo was an 80s synth pop group).
Nibbles of big ideas
The book could easily have been a frothy collection of trivia, but Bjornerud expertly feeds the reader with morsels of geology’s meatier concepts, such as deep time, plate tectonics, and the co-evolution of life and our planet. Topics that could become technical are illuminated by everyday analogies (for example, brittle failure compared to a ‘run-in stockings’ or uranium precipitating ‘like a busload of passengers being forced to disembark’).
She also maintains a human connection. In ‘Geodynamo’ we learn how Danish geophysicist Inge Lehman (then a rare woman in the field) identified the Earth’s inner core in 1936 thanks to a major earthquake in New Zealand. Explaining the Earth’s magnetic field, Bjornerud notes that while there’s no clear evidence that magnetic field reversals cause extinction, one today would be “debilitating” for humans. In another example, she describes a 1929 earthquake off the coast of Newfoundland that caused an immense undersea landslide, resulting in a tsunami that killed 28 people. Cut undersea communications cables alerted us to this invisible danger and provided an explanation for hitherto unexplained sediments called “turbidites.”
Quirky Gem
the tone of Geopedics is quirky – I never expected to go from “Karst” to WWII mass executions or from “Snowball Earth” to the Norse myth of Ymir and his rock licking cow. It can be whimsical at times, like when Bjornerud portrays Earth’s oldest rocks as a matriarch she calls “Old Acasta.”
Haley Hagerman’s black-and-white drawings complement that idiosyncratic tone. On one page you will find a view of a thin section of a microscope that resembles an abstract composition; on another there is a polar bear with a sign that reads “North Pole was here.” An intricate display of Amethyst crystals is followed by a dog with a bubbly basalt body.
The collaboration between Bjornerud and Hagerman revisits their 2018 book Timeliness: How Thinking Like a Geologist Can Help Save the World, who was shortlisted for the Phi Beta Kappa Award in Science and a finalist for the 2019 Los Angeles Times Book Prize in Science & Technology; it also won the PROSE Award 2019 in Popular Science & Popular Mathematics, among other awards. Geopedics seems destined for similar praise.
Its pocket-sized format makes it perfect as a travel companion, and the short chapters suit our exhausted attention spans, making it a fun alternative to nighttime doom scrolling or heavier non-fiction. It doesn’t matter if you’re a rock-hard rockhound or a geological outsider, you’ll get something valuable from this gem of a book.
Howard Lee is a freelance science writer who focuses on geology and climate change in the distant past. He has a B.Sc. in Geology and M.Sc. in Remote Sensing, both from the University of London, UK. When he’s not writing, he’s probably gardening, hiking, or kayaking near his home in rural Massachusetts.
