A new week, a new nonfiction geology book by John Dvorak! This one is a biography of Thomas Jaggar, who founded the Hawaiian Volcano Observatory. It was a really interesting portrait of a man driven to spend time with erupting mountains. The book begins with the eruption of Mt. Pelee in Martinique, a harrowing pyroclastic … Read more
So many books have been written about dinosaurs, but this one looks at a deeper history of another important group: our own. Beasts Before Us is “the untold story of mammal origins and evolution.” The Cenozoic is often dubbed “the age of mammals,” but the story of our hairy, milk-guzzling brethren goes much deeper into … Read more
Reader Nancy Weidman (who supplied the Wind River boudinaged basaltic dike images from earlier in the week) sent me this interesting note: Your ichnoanalogue post reminds me of the insect or pillbug tracks I found in Mt. St. Helens ash deposited in Missoula, Montana. At least some of the tracks, if I recall correctly, ended … Read more
Callan documents a geological stroll along the coast of Esterillos Oeste, in central southern Costa Rica, investigating the sequence of sediment in the Punta Judas Formation (Mid-Miocene) exposed there. Fossils, sedimentary structure, diagenetic features, structural deformation, and modern weathering all make prominent appearances.
Got these photos from a reader, showing outcrops in the northern Wind River range (ESE of Island Lake). The question, inevitably, is are these MMEs (microgranular mafic enclaves) or xenoliths? They’re fine grained and mafic… but some lithologies of xenolith could be too! This next set shows what appear to be a bunch of blocks … Read more
Two weeks ago was the annual Virginia Geological Field Conference, which was centered this year on the Goochland Terrane, an interesting block of crust in the Piedmont which shows some similarities to the Blue Ridge geologic province, but also shows some differences that suggest it’s not just a mini-Blue-Ridge. One of the best exposures was … Read more
Inspired by How The Mountains Grew, I ordered the rest of John Dvorak’s oeuvre recently. I read the first over Thanksgiving break – a great nonfiction look at eclipses. The basics of lunar and solar eclipses are dispensed with early on, and Dvorak then spends his time on understanding of eclipses in antiquity, the gradual … Read more
Another glimpse of sand on the beach at Esterillos Oeste, Costa Rica… This time, I offer you a trace of an organism moving through the wet sediment: Note the two parallel lines of tracks laid down by little feet, and the central groove that overprints them. It reminded me very much of this similar arrangement, … Read more
Callan offers reviews of a suite of good reads – some old and some new, some geology and some general science, and some social justice/history.
A fun, if a little musty, compendium of random writings about geology and geologists from a wide variety of sources, excerpted and packed together into a slim paperback volume. It begins with Mark Twain and concludes with Russell Baker, and there are hundreds of entries in between – some poems, some short essays, some clipped … Read more
This is a thoughtful volume on mass extinctions written for the novice. One thing I really liked about this book is that it was written very clearly from the mind of a skeptical scientist who is conscientious about explaining each step in his thinking while explaining fairly complicated, murky stuff for a lay audience. Hallam … Read more
Callan reviews a recently-published book that offers “a new geological history of North America.”
My favorite popularizer of modern geology is Marcia Bjornerud. Her sensibility for what is interesting and important matches very nicely with my own – I feel she is a kindred spirit, though one infinitely more talented with language than I am. Lovers of geology found much to delight them in Reading the Rocks. She took … Read more
The Great Derangement: Climate Change and the Unthinkable, by Amitav Ghosh Marcia Bjornerud put me onto this one. An interesting book that explores the roots and results of our response to climate change. The author, an acclaimed Indian novelist, is particularly interested in the unwillingness of artists and novelists to grapple with climate change, citing … Read more
This weekend, my family and I traveled to a little agrotainment complex north of Harrisonburg, Virginia, a joint called Back Home On The Farm. It featured a corn maze, hayrides, petting zoo, apple cider donuts, and pumpkin picking. All typical fall frolic; good clean fun. But there were also big blocks of limestone everywhere on … Read more
Callan reviews five books, both fiction and non-. In this batch, we get Neal Stephenson’s latest techno-thriller, about geoengineering and its discontents, Barack Obama’s first memoir, a novel by Charles Dickens, a collection of short stories by Andy Weir (author of The Martian), and Bill Bryson’s sole foray into popular science writing.
Happy Saturday! Here are two erratics (glacially transported boulders) that I saw last week in coastal Maine. This one shows prominent subparallel striations: And this one, in the town of Penobscot, next to the greasy spoon called Bagaduce Lunch, shows aligned feldspars that suggest magmatic flow: Nothing like a good erratic to get the weekend … Read more
This volume is a compilation of reporting that author Nathaniel Rich previously published (sometimes in rather different form) in a variety of periodicals, but mainly the New York Times Magazine. The general theme is humanity’s alteration of the natural world, for good or (usually) for ill. The first piece, on West Virginian lawyer Robert Bilott, … Read more
Earlier this summer, I was lucky enough to visit a soapstone quarrying operation in Schuyler, Virginia, right on the Albemarle/Nelson County line. These soapstone bodies are metamorphosed ultramafic intrusions into the Neoproterozoic sedimentary deposits of the Lynchburg Group. The protolith peridotite sill crystallized at ~580 Ma, meaning the host sediments are older than that (but … Read more
