21 November 2016

GIGAmacro sample preparation: 3 techniques

Here are three pairs of GIGAmacro images to illustrate a few techniques I’ve used in preparing the samples and the images. The image pairs here illustrate the effects of transparent acrylic coatings, pressure-washing, and post-imaging clean-up in Photoshop.

Let’s begin with a meta-ignimbrite of the Catoctin Formation, cut with a rock saw and polished using a handheld grinding wheel with diamond grit pads, and then with one of the two sides, the second one in this set, sprayed with a layer of clear acrylic “paint.”
Link GIGAmacro by Callan Bentley

Link GIGAmacro by Callan Bentley

Here’s a mylonite, before and after being pressure-washed:
Link GIGAmacro by Callan Bentley

Link GIGAmacro by Callan Bentley

Here’s a pair to show the effects of digital clean-up in Photoshop after the image has been stitched together. Both show a set of three fossils (Khufus, Turitella, and Dentalium) from the Sunken Meadow Member of the Yorktown Formation in Virginia’s Coastal Plain. In the first, a layer called the “alpha channel” exists, automatically generated by the image stitching software I used, Kolor AutoPano Giga, producing the irregular white mess at the top of the image. In the second, I’ve deleted the alpha channel and also deleted many of the white scraps of shell debris lying on the black velvet backdrop.
Link GIGAmacro by Callan Bentley

Link GIGAmacro by Callan Bentley

I’d be happy to answer any questions you might have about any of these techniques. I’d also be eager to read your feedback on the merits of the different ‘treatments.’

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18 November 2016

Friday fold: Lewisian gneiss near Tarbet

I tried something new this morning, and polled Twitter for their choice of Friday fold:

As of the time of this posting, the first choice, “Lewisian gneiss @ Tarbet” won out with 7 / 10 votes.

The people have spoken, and this time I like the result of their voting!

So here you go, enjoy some lovely folds in the gneissic banding of the Lewisian basement on the coast of Scotland near Tarbet, in the North-West Highlands:



Happy Friday!

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17 November 2016

A pocketful of podcasts

podcastsI listen to a few podcasts, and I’ve been meaning for a long time to write down some thoughts about them to share, in the same spirit in which I review books, or less frequently movies or television programs.

First, a general comment: I really, really like podcasts. This is a medium that is unique (aside from radio) in its ability to get you to think while you’re doing something else. And we all have a lot else to do. When that other activity doesn’t require my word-generating or word-understanding brain centers, I go for a podcast. For me, this means working in the yard, driving to and from campus, editing photos or making visual art, or sitting on the porch with a cup of tea. Podcast consumption isn’t compatible with reading or writing or teaching or parenting or even anything noisy, like doing the dishes. Just the same, I find I have a lot of time where I can reasonably tune in, and I do. I would estimate I consume about six hours of podcasts in a typical week, more in some weeks.

Lexicon Valley

A podcast about language. This has historically been one of my favorite podcasts. It explores the quirks of language, mainly the English language. There have been episodes of this show that have changed the way I think about words I’ve been uttering my entire life. That said, the show has changed formats, and I preferred the old format better. It used to be conversation-based between two, and sometimes three, articulate hosts. Now it’s mainly monologues from one (different from the earlier three) host. All are smart and have interesting material to share, but I liked the repartee that characterized the show’s initial incarnation (prior to the past summer), in particular the profane precision of (ex-?)host Bob Garfield. Every two weeks.

Point of Inquiry

This is the podcast of the Center for Inquiry, an organization dedicated to promoting a secular society based on science, reason, freedom of inquiry, and humanist values. It has two excellent hosts, Lindsay Beyerstein and Josh Zepps, and they take turns hosting the show. In each episode either Josh or Lindsay interviews someone about their work or experience. Sometimes this is an author of a new book, and sometimes it’s someone who has a unique perspective on a current event, and sometimes it’s a Big Name in the world of skeptical activism or secularism. Weekly.

We The People Live

Zepps (mentioned above) is a former “HuffPost Live” host at the Huffington Post, with a distinct voice and a passion for social justice and secularlism. He’s a political junkie, too. I see him as a rising star among public intellectuals in our country, despite his Australian heritage (obvious as soon as you hear him talk). He hosts a podcast based on discussions between bright minds on the critical topics of the day, often live at a bar in Brooklyn, and sometimes in a studio. Recent episodes I’ve appreciated: discussions of the Trump phenomenon, discussions of the rise in Jihadi terrorism, and how to have difficult conversations – high level conversations on difficult, almost-certainly-inflammatory topics. He’s whip-smart and articulate and he shares my values, so I like listening to him talk about important stuff. Irregularly published, on average twice a week.

Waking Up

Detailed, high-level conversations and commentary from Sam Harris, author of The End of Faith, The Moral Landscape, and several other books. This podcast was launched as a companion to his book Waking Up, but like Jerry Coyne’s blog Why Evolution Is True, it’s persisted long since its original purpose of book promotion has ceased. Sam Harris is a very precise thinker whose work doesn’t often translate into the modern expectation of soundbites and Twitter blips. The podcast is an ideal format to explore the ideas he’s interested in, since there’s no time limits, he can fully articulate the issues in question. The format varies – sometimes it’s interviews and discussions (some good, others exemplars of intractable conversational messes), sometimes it’s Harris discoursing on a particular topic (like the day after the election, which is an excellent listen – the episode is called “The Most Powerful Clown”) and sometimes it’s a “Ask Me Anything” format, wherein he answers audience questions. It’s a thoughtful body of work, and I’m forced to think about a suite of interesting issues from a new perspective as a result of listening to it. Irregularly published, on average a few times per month.

The Skeptic’s Guide to the Universe

This is one of the longest-running science podcasts, and one that’s been a staple of mine for years. The format is a long (1+ hour) discussion between the same set of panelists called “rogues.” There are probably better ways of describing them, but I think a newcomer to the show will be struck that the distribution of their genes is anomalous: the rogues consist of three Novella brothers, one non-Novella male, and one non-Novella female. The fact that three of the rogues are men from the same nuclear family is a bit bizarre, but it works anyhow. In my opinion, Steve Novella, the show’s host, is a delight to listen to, as is Cara Santa Maria, the newest rogue and the lone female voice on the show. (The show’s loss of Rebecca Watson weakened it substantially, but Cara has filled Rebecca’s shoes admirably and made the spot her own.) By way of criticism, i would say the other two Novella brothers (Bob and Jay) are not as strong in terms of the content they present or the comments they make, but you could argue that this makes the show’s dialogue work better, as sometimes their statements become jumping-off points for lessons in skepticism or understanding the scientific method. The truly great thing about this show is its consistency. Week after week, they offer a reliable format that has become as familiar to me as the All Things Considered theme song. If I were to run a podcast, I would be wise to model it after this one. One final caveat: I’m often frustrated at the shallowness of their geology coverage, but I’ve learned a ton about astrophysics and neuroscience from the show. Weekly.

Science… sort of

A rotating cast of panelists (“rogues”?) discuss science, but also beer and also whatever else comes into their minds. I met a few of the folks behind this podcast at the annual GSA meeting in Denver this year, and enjoyed talking to them. They seem to enjoy talking to each other, and some (like Ryan Haupt) have that awesome blend of articulate speech and arcane knowledge that makes for fascinating conversational partners. I have a feeling I’d really enjoy drinking beer around a campfire with these folks. However, I’m not sure it works perfectly for a podcast. Many times while listening to Science… sort of, I wish they would wrap up a given topic and move on to the next one. I guess the Skeptic’s Guide has trained me to expect relative “tightness” with the amount of time spent on a given topic, and my sometimes my expectations of time economically spent aren’t exactly met when it comes to this show. Still, they have strong geoscience content, and they appear to be doing it solely because they want to (not to make money at it), which is laudable. Weekly.


A groundbreaking radio program from WNYC, hosted by by Jad Abumrad and Robert Krulwich, an ideal pairing of personalities. Their inquiries are playful and enthusiastic and hip, and they tell the stories of scientific insight and hapless misadventure in a way that was clearly inspired by This American Life, but has branched off to become its own thing. Probably most of my readers will already be familiar with Radiolab, but if on some odd chance you’re not, I highly recommend it. Every two weeks.

More Perfect

A Radiolab spinoff about the Supreme Court. Only a handful of episodes, the most recent published in July. It’s good stuff, and it would be pertinent in the dark years to come to continue the series. Every two weeks, but apparently on indefinite hiatus.

Wait Wait, Don’t Tell Me!

This is nothing more than the popular NPR news quiz show, rendered in podcast form. It’s the same thing you would hear on the radio, but since I never listen to the radio, I prefer to get it this way, since I can listen to it via podcast whenever I want. Smart, funny commentary on the week’s news with a rotating panel of smart smart alecs, plus host Peter Sagal. Weekly.

Brains On!

This is a podcast for kids, and I have it on my iPad in case I’m driving with my son. It’s a podcast for his four-year-old mind that’s also interesting enough for me to listen to. It’s also spawned from public radio, and has the same feel or production value as a Mini-Me Radiolab. Every two weeks.

There is no reliable podcast focused on geology. I’m considering starting one. If I were to do that, what sort of material / features / characteristics would you want to hear?

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16 November 2016

Cobble diversity of Fetlar’s beaches

Now that we’ve examined the geology of the outcrops at Funzie Bay on the island of Fetlar in northeast Shetland, let’s stroll along two beaches. Here we have cobbles from Funzie Beach and a small beach eroded from serpentenite and metaharzburgite of the island’s ophiolite complex.

Compare. Contrast. Rejoice.

Link GigaPan by Callan Bentley

Link GigaPan by Callan Bentley

Both of these were handheld panoramas of ~60 photos apiece. It’s interesting to me that overall both panoramas show the same shape – relatively crisp right edge, and relatively ragged left edge, with the upper left corner underrepresented. Weird – I guess that has something to do with me being right-handed or something.

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15 November 2016

Hate trumps love; Ideology trumps science

It’s been a week since Donald Trump defeated Hillary Clinton in the race for the President of the United States.

I’ve been processing the news, and I’m not happy about it. I’ve been on “radio silence” for a week, mourning, ruminating, fretting. From my perspective, this is one of the most disturbing developments in the history of my country since the Civil War, since the McCarthy hearings, and since the 9/11 attacks. I’m not being hyperbolic: Trump worries me fundamentally on multiple levels. I was astonished that he won, given his awful behavior (bullying coarseness, sexism, xenophobia), his near-constant lying on almost every topic imaginable, his lack of tractable policy prescriptions while campaigning, his dismissal of climate science, and his embrace of racism. There is no President in the history of our country (though Andrew Jackson comes closest) who more fully embodies despicable behavior, recklessness, and malevolence relative to the standards of their day.

I feel like I have to get a few things off my chest here – and recall that I speak only for myself, not on behalf of any institution, including the one that hosts my blog or the one that employs me.

Why did Clinton lose?

  1. Clinton was a lame candidate. The fact that her obvious experience, tact, and even keel could not overcome Trump’s litany of failings is astonishing. Any one of Trump’s lies or gaffes should have been the death knell of his campaign, but every time, he bounced back. Meanwhile, Clinton slogged through the muck of near-constant speculation about her stupid emails. She never shook that off to lead. She certainly got my vote, but really it was mainly because the alternatives were so much worse. Her apparent sense of caution was a liability as well as an asset. I found her uninspiring, which is awful, considering that the first female candidate for the highest office in the country should be — should have been — an absolutely inspirational figure. I wish she had inspired me as more than just “the only sane alternative to Trump.”
  2. It’s a shame that many people judged Clinton in light of her husband’s failings (in particular his philandering). Bill Clinton’s baggage weighed down his wife’s prospects.
  3. I think it was a mistake for President Obama to not work harder at filling the empty seat on the Supreme Court. Obviously, filling it isn’t up to him alone – The Senate’s deliberate obstructionism of Merrick Garland’s nomination is an abominable dereliction of their duty. But given that situation, I feel as though Obama should have pulled out all the stops to force their hand. Perhaps he should have used a recess appointment or sued Mitch McConnell. He should not have let the topic rest, but spoken about it continuously and constantly, motivating the American people to force their representatives to do their jobs. Instead, Obama effectively acquiesced, rolled over and accepted the GOP’s power play. The fact that seat remained tantalizingly open was a clear draw for any conservative voter. They may have been put off by Donald Trump’s numerous failings as a Bona Fide Conservative, but the prospect of a conservative-leaning high court was a palliative to mask their distaste of the man who might deliver that court to them. In other words, failing to resolve the Supreme Court vacancy was a strategic miscalculation on the part of the Democratic ticket’s advocates in the Obama administration.
  4. The flaws of Obamacare are more glaring with each passing year. Rising insurance premiums hurt, and this is something I heard from conservative friends and family. I appreciate that perspective, as it is quantifiable – it now costs more to get health care. You can counter that with the rosier picture from the national perspective that more people have health insurance than there used to be, but from the individual’s perspective, the wallet is demonstrably thinner than it was. This was a second major factor that played into voters’ decisions. The blame for the Affordable Care Act’s many failings is not exclusively Democratic, as the bill was an imperfect, overly-complicated Frankenstein’s monster that was seen as the only thing that would pass Congress when it was cobbled together early in Obama’s tenure. But regardless of the fact that the bill isn’t ideal from either party’s perspective, its downsides were prominent in the minds of some voters I spoke with.

Why does Trump’s ascendancy concern me?

  1. Temperamentally, Trump is not fit to be President of my left pinkie toe, much less one of the most powerful countries on Earth. His thin-skinned vindictiveness will not mesh well with the responsibilities of the office to which he’s been elected. That Americans elected such a volatile narcissist regardless of this obvious flaw is nothing short of shocking.
  2. Trump is an exceedingly poor example for our young people to emulate. His cheating, lying, denigrating behavior make him an undesirable role model. The job of President doesn’t have “being a perfect person” as a prerequisite, but I can think of many people more fit to serve as exemplars for our children, and I can think of only a few who would be worse. Trump’s awful behavior was vindicated by his election. Predictably, this has triggered a series of ugly incidents of racist vandalism and sexual assault. I worry that when the Top Dog is such a cad, our youth will calibrate their actions to match.
  3. The new media angle is a valid consideration for everyone to think about. Trump mastered Twitter, and relied on that for his means of outreach, caring little for the fact that almost every newspaper in the country endorsed his opponent. The unhappy evidence we must now contemplate is this: strongly-worded, well-reasoned opinion pieces and newspaper endorsements no longer carry any weight. Further, I witnessed Facebook devolve into an unpleasant morass of political posts, repetitive at the very least, delinquent in many cases, and outright false in others. Facebook has been criticized in the aftermath of the election for their willingness to host “fake news” stories – fodder for their clients’ numerous independent echo chambers. I’ve taken a week off of all social media, including this blog, Twitter, and Facebook, and I’m not sure I can bring myself to return to the latter. What should be a venue for pictures of peoples’ kids and travel photos has curdled into a putrescent mass of vitriol and misinformation. That nest is fouled – perhaps irreparably.
  4. I worry about Trump’s effect on the culture of our country. His candidacy has emboldened racists in a way I’ve never before witnessed. Doubtless older readers will recall similar nastiness in the 1960s, but that’s before my time. My jaw dropped many times during the campaign as he cultivated and embraced white supremacist support. I am aghast at the outbreak of racist incidents in the aftermath of the election, and absolutely stunned that Trump would select Steve Bannon as his closest advisor in the White House. I see Bannon as a modern equivalent of Joseph Goebbels, especially now that he’s ensconced directly at the right hand of the President-elect. He is a facilitator of hateful propaganda, and he has absolutely no place anywhere near any decent president.
  5. This administration is going to be the worst thing for science in a very long time. Vice President-elect Mike Pence denies evolution and has even made statements that suggest he doubts the relationship between smoking tobacco and deadly disease. Trump’s rumored selection for the Secretary of Education is Ben Carson, a climate change denier and young-Earth creationist who intimated last year that he would use the Department of Education to deny federal funding to any university or college that exhibits politics he disagrees with – which I guess could include any research in biology or Earth system science (depending on how he defines “politics”). This is an astounding, horrific prospect with potentially catastrophic consequences for human health and ecological function. And of course, there’s the selection of Myron Ebell, a long-time outspoken climate change denialist for the job of head of the Environmental Protection Agency. To say that the fox will be in charge of the henhouse is putting it mildly. Not only are the hens doomed, don’t bet on the henhouse to survive either. This may be the longest-lasting damage that results from Trump’s election. Obama and Bush before him and Clinton before him have all been delinquent in grappling with climate change in any substantive way, but putting Ebell at the helm of the EPA flies flagrantly in the face of all we know about the way the Earth system works. It breaks my heart.

In summary, there is an unprecedented list of reasons to view a prospective Trump administration with pessimism and horror. I don’t see any positive aspects to the situation. I’m not being a “sore loser” here – I accepted the loss of Al Gore to George Bush, of John Kerry to George Bush, and I would have accepted McCain or Romney, had they been elected over Obama. But Trump is cut from a different cloth. This apparently constitutes much of his appeal to many of his supporters. But I think he represents an unprecedented threat to our republic.

So what am I to do? What are thinking people to do, faced with this unholy prospect?

I have no clue. I’m utterly disheartened. After a week of cogitation, I find that I cannot rally my emotions and look for a silver lining. I can’t steel myself to work harder at truth-telling and standing up for science in the Era of Trump. I am flabbergasted at the suggestion that we should just Give Him a Chance To Be The Best President He Can Be, a suggestion that even President Obama seems to be taking.

The situation appears to me to be wholly and completely awful.

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8 November 2016



Link GigaPan by Callan Bentley

… That’s the Bay of Funzie on the east side of the island of Fetlar, in northern Shetland. You may be struck by the beautiful scene, but what catches my eye are the rocks in the foreground. That is a stretched-pebble metaconglomerate. Originally a conglomerate, its pebbles and cobbles were smeared out by ductile deformation, changing their shape. This bay is the first place that the Flinn diagram was ever used.

I made a structural geology pilgrimage there in July. Driving in with my guide, Allen Fraser of Shetland GeoTours, we passed this informational rock wall showing an artistic rendering of the island’s geology:


Here it is in GigaPan form. The light colored blob on the right is the Funzie metaconglomerate.
Link GigaPan by Callan Bentley

The conglomerate itself looks like this:



Link GigaPan by Callan Bentley

How best to quantitatively describe the “fabric” of this body of rock?

This was the problem Derek Flinn (University of Liverpool) faced when he was figuring out the geology of Shetland. In 1962, he published the first rendition of an elegant diagram that allowed a quantitatively-based visual display of the shape of the strain ellipsoid. Here’s a version of it:


That image was modified (by me) from an original (in Hungarian) on this page by Konrád Gyula of the University of Pécs in Hungary.

The key thing to note is that the shape of a deformed object of known (or assumed) original dimensions can be quantified in terms of the lengths of three mutually-perpendicular axes, X (the longest), Y (intermediate), and Z (the shortest). The hemi-axes in these orientations are respectively designated S1, S2, and S3. (So S1 = ½X, etc.)

If X and Y are about equal to one another, but are larger than Z, then you have a shape like a pancake, an example of ‘flattening strain.’ Rocks with a fabric defined by lots of these “oblate” strain ellipsoids are called S-tectonites. Think of a messy pile of papers lying more or less parallel to one another on a desk top.

If X is far and away much longer than Y and Z, which are more or less equal to each other, then you have a shape like a cigar, an example of ‘constrictional strain.’ Rocks with a fabric defined by lots of these “prolate” strain ellipsoids are called L-tectonites. Think of a handful of pencils clutched in fist.

Assuming all the values of X, Y, and Z start off as “1,” the situation where X is greater than Y, which shows no strain, which is greater than Z, is ‘plane strain.’ All the strain has taken place within a single plane. As Z is shortened, X grows, but Y doesn’t change. That’s the situation along the 45° line running up the middle of the Flinn diagram. Think of a school of fish swimming in the same direction.

The Flinn diagram is well-nigh ubiquitous as a clean, easy way of stating the strain state of a body of rock with good strain markers. I used it in my thesis, for instance, on deformed ignimbrites in the Sierra Nevada Shear Zone system. But Funzie (prounced “Finney”) Bay is where it was first developed. Feast your eyes on its rocks:





It was a treat to go to a place like this, see these inspirational rocks. For me, it was like a scholar of American history might feel on walking into Independence Hall in Philadelphia for the first time.




Link GigaPan by Callan Bentley



Certain outcrops really showed the role of pressure solution in attaining this shape:


(See how the grain boundary of the greenish clast totally gets into the personal space of the larger white clast?)


Bonus: a small fault, looking alogn strike to the east and then to the west:



I call this next one, “Cobble of cobbles, with cobbles” :


Long ones:




Now for a trio of GigaPans of the same outcrop imaging three mutually-perpendicular perspectives on the rock fabric: the XZ plane, the XY plane, and the YZ plane:


LinkGigaPan by Callan Bentley


Link GigaPan by Callan Bentley


Link GigaPan by Callan Bentley

This beautiful metaconglomerate spurred the development of the Flinn diagram. I’m glad I got to visit it in person.

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7 November 2016

Coastal colluvium + coal contest in context

Here’s the answer to the contest:


This is an outcrop on the beach at Funzie Bay, Fetlar, Shetland, U.K.

The modern beach sediment is the lightest-colored, rounded cobbles at both the top and bottom of the photo. Poking out in between is a layer of light-gray colluvium (angular fragments) overlain by dark peat, now perhaps approaching lignite. Because peat in Shetland cloaks the hillsides but is unlikely to grow a couple meters above sea level where the pounding waves of winter storms can reach, this combination suggests a lower sea level for Shetland at some point in the past. In other words, the modern beach deposits overlap older hillside deposits.

And the implication is that sea level was lower in the past.

Another line of evidence for this is geomorphic: all over Shetland, you’ll find voes, like this one:


A voe is a local term (Shetland + Orkney) for an ocean-flooded valley. So a fjord (ocean-flooded glacial valley) would be a special kind of voe. But most of Shetland’s voes are fluvial rather than glacial in origin. [I suppose, by this definition, the Chesapeake Bay could be considered a voe, since that estuary was formed as sea level rose and flooded the former valley of the Susquehanna River.]

Anyhow, look at Shetland! Explore it in this embedded Google Map – you’ll see all sorts of skinny little coves reaching in from the sea like the tentacles of a cephalopod. Almost all of these are voes, though there’s at least one fjord among them, too.

Streams only cut valleys if they’re flowing downhill (i.e., toward the sea), which means that all these places that are today below sea level used to be above it.

Thanks to those who participated in the contest. Among them, Simon Wellings and Bill Burton came closest to the mark – got it right, even, though I used it as a springboard to this sea level discussion.

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6 November 2016

Contest: interpret this outcrop

img_0816Lens cap for scale.

Correctly tell me what’s going on here, and you get A Big Prize!

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5 November 2016

Travels in Siberia, by Ian Frazier

siberia I’ve let my subscription to the New Yorker lapse, but before I did, I was pleased to read each week its diverse suite of authors on a diverse suite of topics. This has been a source of surprising delight on several occasions, and has allowed me to discover not only topics I never thought to be interested in, but also authorial voices I never would have otherwise read. I’m reminded of how, two decades ago, reading John McPhee’s geology books with sesquipedalian glee led me down the warren of rabbit holes of his other books – oranges, blimps, birchbark canoes, how UPS ships lobsters – with delight and wonder. The fact that many of these books started off as pieces for the New Yorker is not a coincidence. Anyhow, Ian Frazier is another staff writer for the magazine, and I enjoyed the pieces he published in the magazine about traveling in Siberia. Recently, these were published along with much more in a hefty book simply titled, Travels in Siberia. I recently listened to the audiobook version of it, read by the author. If you’re into travel literature, you might like it. It’s cut from the same cloth as many of Paul Theroux’s books in that genre. The difference, and I think it’s a notable one, is that Frazier is a Russophile, and has been for decades. He’s taken many trips to different parts of Siberia, by multiple means of transport, with different traveling companions, in different seasons. That’s one of the strengths of this book – each trip is its own thing, though some are relatively brief and others are multiweek expeditions. There’s a diversity of flavors that results. It stands in contrast to something like Theroux’s book about taking the train across Asia (including Siberia), The Great Railway Bazaar. That said, most of the book is centered on a single trip, a big one, by car, east to west across Siberia. That’s the trunk, with branches coming off to detail earlier forays and later jaunts. There are discussions of Russian literature, culture, and history, but most of Travels in Siberia is about personal experience, detailing daily routines and key anecdotes, moments of misery and sublime insight. It’s a traditional piece of travel literature on that mark, and I wouldn’t consider it exemplary in any way. It’s well written, as you’d expect, and I enjoyed listening to it, but I doubt I’d ever go back to it for a second read, nor am I inspired to visit Siberia on account of reading it. Frazier’s driving Russophilia does not appear to be contagious.

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4 November 2016

Friday fold: orogeny in a cobble

Happy Friday. Thank goodness it’s the last one before this horrible election season finally concludes.

Let’s celebrate with two cobbles from the beach at Papil Water, Fetlar, Shetland. They show small-scale folds in metasedimentary and metavolcanic rocks of Ordovician or Silurian age, part of the ophiolite complex that makes up most of Fetlar.



Each is a nice little sliver of mountain-building, small enough to hold in a hand. “Time in a bottle?” …Give me orogeny in a cobble!

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