12 November 2021

Friday fold: Raven’s Ridge

Happy Friday, all! Two shots today from my friend Joe up in Vermont. He sends these from the Champlain Valley, at a place called Raven’s Ridge.

It looks like an alternating series of sandstones and shales, arched into an anticline, perhaps during the Acadian Orogeny (??). According to the Nature Conservancy’s website, porcupines live in this anticline, which is called “The Oven.” Looks like most of the strata around there are Cambrian in age. If anyone knows more, please clue me in!

A lovely outcrop – thanks for sharing, Joe!

If you have a fold to share for next Friday, beam me a note at [email protected]

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6 November 2021

Revisiting Tinker Creek

While my son takes banjo lessons downtown, I stroll Charlottesville’s walking mall and browse the bookstores. Last week, I dropped $40 at one of the used-book stores, walking away with an armful of volumes. Most were intended for my son (a voracious reader in addition to being banjo-philic), but on the shelf I also saw a trade paperback copy of Pilgrim at Tinker Creek, by Annie Dillard (1974), a book without which I think no naturalist’s library in Virginia is complete. I’ve read it before, but I love it dearly — so I bought it.

Winner of the Pulitzer Prize for general nonfiction in 1975, Pilgrim is a work of wonder at nature and the fact of our existence. Like no other book I’m aware of, it captures the giddiness of the transcendent experience. Dillard has a talent for putting herself in natural settings and being receptive to whatever is offered up.  “I cannot cause light,” she writes. “The most I can do is try to put myself in the path of its beam.” Where that beam shines, it illuminates, and by forming shadows it its absence, the light causes her myriad subjects to pop into relief. Once lit, a landscape or organism is seen in a new way. It means something different by virtue of Dillard’s eye catching those reflections and refractions, by virtue of the way those photons stimulate her mind.

Her language is equally adept at describing the natural world in her Roanoke Valley home and describing her own personal reactions to being out there, receptive to nature’s clockwork and chaos. I think that, at least in this one book, she achieves the most resonant articulation of what it is to be astonished by one’s experiences perceiving natural phenomena. “I had been my whole life a bell, and never knew it until at that moment I was lifted and struck.” It’s a beautiful book that drifts in and out of what you might call ‘nature writing’ and what you might call poetry. There is a substantial infusion of Biblical analogy and mythology, which isn’t my cup of tea, but does frame Dillard’s perspective as distinctive. Her evocations of God serve to emphasize the intense profundity of her experience, and I can relate to that, even if my own experiences lack the spice of belief.

This is my fourth time reading Pilgrim at Tinker Creek, and it still gives me a frisson of astonishment when I read it. It is such a good book.

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25 June 2021

Friday fold: The Blue Ridge Tunnel

On Wednesday of this week, I went for the first time to the newly-opened-to-the-public Blue Ridge Tunnel, a county park in Nelson and Augusta counties, Virginia.

Built in the 1850s to serve as a railway tunnel, it provides a unique perspective on the geology of the Blue Ridge.  The western side is largely bricked-over, but in the middle, about at the Nelson/Augusta County Line, there are a series of extraordinary exposures that Chuck Bailey has dubbed “The Hall of Boudins:

The rocks here are all Catoctin Formation, a Neoproterozoic series of rift-related lava flows and intercalated sedimentary rocks that were metamorphosed during late Paleozoic mountain-building. In the photo above, you can see buff-colored Catoctin greenstone (metamorphosed basalt) with a pronounced east-dipping foliation. Within it are lozenges of green-colored metasandstone. Those pod-shaped blobs are green because they host a lot of epidote in them (a metamorphic mineral that is frequently found in areas of low-grade metamorphism under wet conditions). They are not in their original depositional orientation or shape, however; they have been boudinaged (stretched into asymmetric taffylike segments) as a result of tectonic stresses that shoved Blue Ridge rocks up from the east toward the west.

The kinematics of those same Alleghanian forces can be inferred from not only the asymmetric boudinage, but also asymmetric folds within the same rocks. These folds can be mapped out with careful measurements of bedding and foliation orientations, but sometimes they are more plain, as with this hinge:

There’s also a more subtle Z-fold on the left, above my fingers. The photo also shows well the difference in color between fresh Catoctin (dark) and weathered Catoctin (buff tan).

This is a really cool location to have as a local geologic resource; I look forward to my next visit.

If you visit, first download a geologic guide to the Blue Ridge Tunnel (PDF) by Katie Lang and Chuck Bailey. It calls attention to several subtle things that I missed on my visit this week.

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16 June 2021

Book report

A few more books I’ve read recently….

Why Fish Don’t Exist, by Lulu Miller

An interesting volume by NPR’s Lulu Miller – a philosophical biography of the first president of Stanford University, the fish biologist David Starr Jordan, mainly, but also an autobiography of key moments in Miller’s own life. At first, she looks to Jordan for inspiration – how does this man keep going after a series of awful setbacks to his work? Deaths in his family, the 1906 San Francisco earthquake shattering his jars of preserved holotype fish specimens, etc. Somehow, he takes a lickin’ but keeps on tickin’… What’s the man’s secret to his success? But then it gets darker – Miller lays out the case that Jordan may have engaged in the murder of a key person who might have otherwise undermined his meteoric success. She also shows him to be a virulent proponent of eugenics, promoting the “improvement” of the human gene pool by forced sterilization of individuals he deemed “unfit,” presaging the Nazi’s genocidal campaign by decades. Miller’s journey of exploring Jordan’s legacy takes her from DC to Chicago, and Charlottesville and Lynchburg here in Virginia. Her personal story takes twists and turns but ultimately she finds peace, joining the two narratives with an assessment of what is real in life.

Owls of the Eastern Ice, by Jonathan C. Slaght

An account of a multiyear field research project to document the biology of Blakiston’s fish owl, the world’s largest owl, which lives in eastern Siberia and eats fish from radon-warmed rivers all winter long. There are plenty of mishaps, adventures, and weirdos in the story, which blends a classic travelogue with detailed ecology that will be of interest to birders and biophiles. One of the themes that emerged is the essential value of international collaborations between that very, very small subset of the population who cares passionately about preserving rare and obscure species. Slaght has a collaborator in Siberia who helps make great things happen and smooths over logistical snafus. Another theme that emerges is how incredibly difficult it is to gain basic biological information about species living in such tangled, buggy, wild terrain. This volume documents years and years of difficult work, with precious insights lost when bold ventures fail. A look at the bleeding edge of conservation ornithology, in other words. Very interesting and fun.

Metazoa, by Peter Godfrey-Smith

Where did consciousness come from? In this follow-up to his awesome volume Other Minds, Godfrey-Smith explores key innovations within the animal branch of the great Tree of Life. The author is a philosopher who is an avid scuba diver, and many of the explorations of experimental work are prefaced by anecdotes about creatures he has encountered in the waters around Australia. It’s an exceptionally well-written volume, where complicated and nebulous ideas are presented firmly and tangibly. In fact, if you’re looking for an almost-perfect exemplar of science nonfiction, I’d offer this volume up as “Exhibit A.” Godfrey-Smith makes a strong case that consciousness is widespread though gradational throughout the animal kingdom, and that mind is inherently a function of body. A fascinating pair of tangents toward the end of the book explore the implications of this perspective for artificial intelligence and for the question of what is ethical when it comes to our treatment of other species. Top notch: fascinating & highly recommended.

American Manifesto, by Bob Garfield

Written during the third and final years of the Trump administration (before COVID), this is On The Media’s co-host’s perspective on the American political situation – the degradation of discourse, the polarization of media, the growing lack of willingness to accept experts’ expertise. It’s a dismaying read – the previous four years were a sincerely rough time for my country, and we’re not out of the woods yet. In fact, recent events in Congress suggest the worst may be yet to come, with Trump merely a harbinger of a fatal erosion of our foundational democratic institutions. Bob Garfield is a clever person, and his wit is mostly a joy to behold, striking incisively at a horrible situation with humor and intellect. Occasionally he goes too far, and his analogies make me cringe, but 95% of the time, the writing in American Manifesto made me feel he is a kindred spirit, deeply distressed at the way we’ve come to run our society. Thought-provoking, and perhaps a bit more depressing than Garfield intended it to be.

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14 June 2021

What the Eyes Don’t See, by Mona Hanna-Attisha

I just finished an excellent insider account of the Flint water crisis, written by the pediatrician who brought it to the attention of the wider world.  Mona Hanna-Attisha practices medicine in Flint, has a background in environmental activism, and happened to be good friends with a specialist in the management of municipal water systems. An evening’s conversation between Dr. Mona (her preferred name) and her friend ends up launching her on a path to stop the poisoning of an entire city’s worth of children. She’s the right person in the right place at such a very, very wrong time. The story she tells has many levels – it’s medical and about public health, but it’s a guide to effective strategizing when faced with official government recalcitrance and obfuscation and children’s lives are on the line. Dr. Mona walks us through her decision-making and coalition-building, and the power of key individuals to solve problems or make them worse. It’s also a deeply personal story, where the background saga of the Hanna family’s emigration from Iraq to Michigan is central and relevant. This isn’t just a story of environmental chemistry; it’s a story of unions and past public health crusaders; a story of societal trends and tensions; a story of the power of a key individual to make the world a better place despite harrowing attacks by penny-pinching, racist agents of the status quo. Though written and published prior to the coronavirus pandemic, the book is timely and critical for considering our current spate of public-health challenges, and actions that will tamp down future suffering or exacerbate it. What The Eyes Don’t See is very well written, and the audiobook is perfectly read aloud by the author. Top-notch, worthy of widespread acclaim, and worth your time and attention.

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11 June 2021

Friday fold: inadvertent kink fold analogue model

It’s Friday!

Adam Forte, a geology professor at LSU, posted this image yesterday on Twitter:

It’s a box of sheets of newsprint, stored vertically and ignored for a while, now rotated 90° so we’re looking at a cross-sectional view. To me, this is an excellent example of a physical analogue modelling experiment (albeit inadvertent) that demonstrates the process by which kink folds form. The key parameters to get this distinctive style of folding is (1) a highly mechanically layered material, (2) a substantial confining pressure, and (3) a dominant stress direction is parallel to the orientation of that layering, or close to it. In the case of Adam’s box of paper, the layering comes from the discontinuities between the sheets, the confining pressure comes from the box, and gravity’s pull was the principal stress direction (σ1). In geological examples that I have celebrated on this blog, the layering is usually sedimentary bedding or metamorphic foliation, and compressive tectonic stress is the cause of the kinking, while being buried deep in the crust provides the requisite confining pressure. Compare what you see above to these examples:

Other kink folds, from previous posts:

Dalradian schists, Walls Boundary Fault, Shetland

Harpers Formation phyllite, Harpers Ferry, West Virginia

Dalradian schists, Arran, Scotland

Somewhere else in Arran (not my photo)

Metagraywacke, Billy Goat Trail, Maryland

Playa limestones, Basin & Range

Catoctin Formation greenschist, Thoroughfare Gap, Virginia

Unknown source – kinked phyllite from the GMU teaching collection

Sample on display at Tennessee Tech

St. Ninian’s Isle, Shetland

And one more from Shetland, again of the Dalradian schists adjacent to the Walls Boundary Fault, since they provide the closest visual match to the paper in Adam’s box, but this time as a stone in a rock wall:

Peace be upon you. Enjoy the weekend. Stretch those kinks out, and get some rest.

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29 May 2021

Book report

It’s been a while since I’ve checked in with you on recent reads. I managed to read a few volumes over the course of the disjointed, stressful fall semester. Here are a few of the highlights:

How to be an Antiracist, by Ibram X. Kendi

An important book that explores racism in its many, many forms, structured around Kendi’s reflections on his growth as a person. The “memoir” aspect of the book touches on moments that illuminate some aspect of racism in the United States, including many of a deeply personal nature in the author’s life, and that then leads to more general discussions of capitalism, elitism, or racism within the Black community. One great theme that leaps out of these pages is the inherent racism that exists in all of us, because we have been raised within a racist society. What does “racist” mean in this context? Many things – but in short, it means perpetuating a series of policies that lead to inequality on the basis of race. The second great contribution of How to be an Antiracist is the careful articulation of a series of precise definitions of what it means to be racist in various contexts, and —equally importantly— what it means to be antiracist. Antiracism is a collection of behaviors and policies that lead to increasing equality for all people in our society. I found the rumors about this volume to be true: that it offers a fresh and clarifying interpretation of our societal situation, and by defining terms unambiguously and with compare/contrast examples, shows a way forward toward a better world. Thought-stimulating and recommended.

The Rendezvous, and other stories, by Patrick O’Brian

Patrick O’Brian wrote one of my favorite series of novels of all time, the astounding Aubrey/Maturin adventures. I’ve read several of his other books too, including several other adventure novels and a biography of Joseph Banks. But this is the first time I’ve delved into his short stories. As far as I can tell, this is the only collection of them under a hard cover. I found the stories to be a mixed bag. There were many moments of terrific writing, as you might expect, but overall I think that was outweighed by a pervasive sense of misery and gloom. These stories are almost uniformly about unhappy people in trying circumstances. A lot of them felt like they could have been written by Hemingway, in terms of mood and setting, though not sentence structure. So many focused on fishing, hunting ducks, hunting foxes with dogs. Sometimes this was mixed with the theme of unhappy relationships, sometimes the unhappy relationships were presented on their own. There were many sharp, well-observed details, but none of it really got my serotonin flowing the way an Aubrey/Maturin novel would.

The Invisible Library and The Masked City, by Genevieve Cogman

These are the first two novels in a fun series called “The Invisible Library.” In them, the job of “librarian” is raised to a new level: a spy and an adventurer, traversing alternate realities in search of unique books. The idea is that there is this awesome sounding, multi-square-mile Library that exists in a place out of time and space. Its agents can slip into different versions of the world, fighting against both local bad guys and rogue Library evildoers in a quest to balance chaos, magic, and science. The concept is very fun – visit a Victorian London choked with smog, but with battle alligators, werewolves, and zeppelins piloted by ornery cabbies. Protagonist Irene must mentor a smoldering trainee while sparring with the local detective, the proud culture of humanoid dragons, and a group of Slytherin-esque individuals called Fae. Plus there’s the office politics of the Library itself. The true charm of the series comes not so much from the genre blending of the alternate worlds as from Irene’s thought processes as she figures out her way forward through one crisis after another. The first book is a bit better than the second, but I look forward to seeing where the series leads.

What the Best College Teachers Do, by Ken Bain

This is a follow-up to a volume I read early last year, focused on student behavior. Here, Bain focuses on the approach, preparation, and guiding questions of highly effective professors. He looks at their behavior in terms of their mindset and respect for their students: their focus on learning and growth in their students. I picked up a few new perspectives and ideas from reading it. One is to brainstorm out and articulate all the motivational questions about why a particular course is worthwhile – what major questions does it help the student address? Another, more prosaic, is to make each exam cumulative, and each successive exam score replaces its predecessors, so students are continually motivated to learn and integrate their knowledge. Finally he makes a strong argument against late penalties for assignments that come in after the deadline. Most of the book focuses on broader material, but little of it felt new or uniquely insightful to me. Excellent professors care about their students, prepare thoughtfully, seek feedback, and are self-reflective. None of that struck me as particularly shocking. Also: For what it’s worth, I think the book designers made a mistake with the cover: the back of a silver-haired white man’s head? Come on.

Eating the Sun, by Oliver Morton

Finally, I’ll highlight the third of the great books written by Economist science/climate writer Oliver Morton. This one, from 2008, examines photosynthesis from every angle imaginable, telling a series of stories about scientific insights and the people who produced them in Morton’s characteristic prose: profound, playful, appreciative. To write compelling prose about the Calvin Cycle is a laudable achievement; I’m not sure it has ever been accomplished before! I was really impressed with the discussion of photorespiration and C4 photosynthesis as a response. Morton’s great distinction is his ability to get into the nittiest-grittiest details, while simultaneously retaining a serene sense of poetry about the whole matter. A discussion of entropy, for instance, leads to a comparison between fire and information. “Life,” Morton concludes, “is a flame with a memory.” He knows the right analogies to present to change the reader’s perspective on the matter. Another example, on the subject of the endosymbiosis of a cyanobacterium within an archeal host cell to make the proto-chloroplast: “Because humans are big creatures, it is natural for us to see the story of this symbiosis as starting with an act of ingestion. But from the cyanobacterial pint of view it was much more like a colonization. Photosynthetic bacteria had tackled a number of environments – the open ocean, bacterial mats in tidal flats, lake-bed sediments and many more – before the endosymbiosis. The insides of early eukaryotic cells were just another  new environment, one which, if permitted survival, would be colonized.” I’ve now read three of Morton’s four books, and each has changed the way I think about the planet I live on.

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16 May 2021

A Brief History of Earth, by Andrew H. Knoll

Andy Knoll wrote a masterful, fascinating book in 2003, Life on a Young Planet. Now, 18 long years later, he’s published another popular science volume, an eight-chapter encapsulation of our planet’s story. I don’t know why he’s waited so long (busy doing science, I guess) but he really does have a talent for telling geobiological stories in a full but accessible way. Knoll is a paleontologist, and the great theme he explores in Earth’s biography is the interaction between the nonliving and living portions of the planet. The volume is organized chronologically, starting with 30 pages on the chemical processes that developed in the condensation of the presolar nebula, then moving into the physical processes that organized the planet into layers and triggered motions in some of those layers, into the origins of life, and the rise of oxygen. Animals and plants get a chapter each, which leaves one for a discussion of singular catastrophes (LIPs, extraterrestrial impacts) that interrupt the flow of evolution, and the human influence of natural systems after that. Knoll draws a parallel between the end-Permian mass extinction and the current “Anthropocene” suite of changes in the planet, concluding that the next chapter in the saga is up to us all, collectively, to write.

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7 May 2021

Friday fold: Lynchburg Group

Last weekend, I went to get my second vaccination, and because of the ridiculous quirks of the way the vaccination campaign is (dis)organized, I had to travel to Lynchburg, Virginia, to get the shot. An extra two hours on the road (roundtrip) may sound like a pain, but it was ameliorated by getting to see some cool outcrop along the way.

This is in Riveredge Park in Madison Heights, Virginia, directly across the James River from downtown Lynchburg:

The rock here is Neoproterozoic Lynchburg Group metasediments that were folded and faulted during Appalachian mountain-building. The layering you see is primary sedimentary bedding, and it serves as strain markers for westward-verging asymmetric folds (and tectonic cleavage in the muddier layers).

In the upper right (east), the outcrop features sandy layers that show off more open folding:

Look for the variation in dip across this field of view: essentially vertical in the upper left, moderately left-dipping in the center, and approaching horizontal at the lower right edge:

Small-scale parasitic folds and cleavage are particularly well expressed at this spot:

(I had teased that site on Twitter earlier this week.) Another example of the little crenulations:

Rock fall aficionados will also appreciate this outcrop for its instability. There’s a skin of soil and vegetation stretching across a rock-free chasm at the top of the cliff, and a pile of debris at the bottom. Access to the cliff is fenced off with a “no trespassing” sign posted; a reasonable precaution it seems to me. Still, the debris run-out reached to the edge of the parking area and had broken through one of the fence cross-beams, so maybe they should go further.

It’s also interesting to see the various processes of weathering playing out here. The outcrop was much prettier just two years ago, as this Google Maps Streetview capture shows. Since then, it’s rotted and painted itself with iron oxides and what appears to be travertine:

There are even some little “stalactites” building downward off some of the overhangs:

I collected one sample there; which I intend to turn into a 3D model – Maybe in time for next week’s Friday fold…?

Happy Friday, and Happy End-of-the-Spring-Semester to those who observe!

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16 April 2021

Friday fold: Colorado cluster

Reader Carl Brink laments the lack of robust recent Friday folds, and he’s decided to do something about it!

From Colorado’s Front Range, he sends this image of an intensely folded granite dikelet within Proterozoic biotite schist:

That’s intense. Ptygmatic, sure, but the butterfly-like sense of symmetry to it reminds me of a Rorschach blot.

What a gorgeous fold. Thank you, Carl!

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