science

Fossil Freeway Redux

Dana Hunter

So last year, remember, one of the first adventures we engaged in was a little jaunt along the Fossil Freeway.  What?  You don’t?  You don’t recall every single word I’ve ever written?

Sigh.

Well, go read that post, then.  And then click this link and listen to the song “I Am A Paleobotanist,”  because yea, verily, it is teh awesome, and you all deserve a chance to get your science geek on with rock and roll.

And for extra science singing madness, if you haven’t already, don’t miss Christie Wilcox singing “Extinction’s a Bitch.”  Then immediately go follow her on Twitter, because if she hits 2,000 followers by May, we’ll get more songs!

(Tip o’ the shot glass to @Laelaps.)

(And yes, for those who were wondering, I don’t expect you to recall every single word I’ve ever written.  It’s just that the opportunity for melodrama was knocking, and I answered the door thinking it was Jehovah’s Witnesses.  There I was, expecting entertainment… le sigh.)
Fossil Freeway Redux
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It's the Apocalypse, Isn't It?

Dana Hunter6 Comments

Sorry, but under the circumstances, Los Links shall have to wait until tomorrow.  Allow me to ‘splain.  Or sum up.  After all, it’s the apocalypse, and we haven’t got much time.

The Gnus among you are probably already aware of Chris Mooney and his history of, how to put it nicely, being an utter fucktard when it comes to all matters framing and his habit of so rabidly hating the Gnus that he happily falls head-over-heels for lying, sockpuppeting sociopaths who tell him what he wants to hear.  And then spends most of his time deleting comments on his blog that a) would’ve shattered his dream or b) were the least bit critical of him.  And when forced to admit he’s a dupe, snivels he couldn’t possibly have known, even though all he had to do was listen to a few folks who were telling him that he’s a dupe.  And that coming after a long history of blacklisting people (yes, plural) and being an utter fucktard.  I’d already written him off after the Great Frame Wars of 2009; the Unscientific America debacle just put paid to the whole thing, because here we had a man who obviously couldn’t get a clue even when hit simultaneously by dozens of clue-by-fours, so by the time he’d got dicked by Tom Johnson, I’d been conditioned by his own actions to merely point and laugh when Chris Mooney appeared on the scene.

In fact, it took me years to unfreeze toward Sheril Kirshenbaum because she’d been so tainted by that whole affair.  Chris Mooney, though, never displayed any reason why I should give half a tug on a dead dog’s dick about a single thing he said.  He’d killed his credibility a dozen times over and done bugger-all to get it back.  If I clicked on an unknown link and ended up on one of his posts, I’d experience physical revulsion, compounded after reading a few paragraphs. It got to the point that I couldn’t stand to see his smarmy, smiling face, so I blocked him on Twitter just so his Colgate grin wouldn’t show up in retweets and put me off my grub.

(And for those who think I’m being too harsh, just click a small selection of the links above and tell me where the rat bastard’s ever proven himself trustworthy.  Criticism is fine, but deceit, blacklisting and endless whining, plus taking forever to make even a minor course-correction after being taken in by a con, all the while proclaiming Gnus the Enemy of All because they told him he can stick his framing where the sun don’t shine – no.)

This has been a rather long introduction to the apocalypse.  You see, not five minutes after I’d become so fed up with seeing Chris Mooney’s mug plastered all over my Twitter feed by the people who still, for reasons unknown to me, sometimes take him seriously, blocked his butt, here was this tweet from Bora:

I was waiting for this schism for years – Mooney leaving Nisbett behind: http://bit.ly/gvrmgW Good for Chris.

I couldn’t help myself.  A schism between Tweedle Dee and Tweedle Dum?  I had to see!  And, to my horror, I found myself cheering Chris Mooney on.  Because while I have no respect for Chris Mooney, I actively despise Matt Nisbett.  And Chris dispatches a particularly idiotic bit of Nisbettian dumbfuckery with aplomb.


Credit where it’s due and all.  I decided I’d grab it for Los Links.  Look, just because I think a man is a shit-for-brains doesn’t mean I can’t appreciate a small spark of intelligence when it manifests.


But that is not why I believe it’s the apocalypse.  This is:

Psych Evidence that Supports New Atheism http://bit.ly/esNCVw Mooney is really on a roll today, isn’t he?

Oh, how that must have hurt him!  To have to admit, after so long kicking and screaming and howling that those evil, evil New Atheists would ruin absolutely everything ever, that he was actually not correct in this assumption.  Of course I had to click through to his bloody blog twice in one day.


You can tell it pains him.  He clings to his final remaining shred of plausible deniability, trying very hard to believe (without adequate evidence) that we are still icky and wrong, even though he was wrong:

In general, I believe what we know about human psychology runs contrary to the New Atheist approach and strategy. However, I do my best to follow the data, and here’s a study that suggest at least one aspect of their approach may work. The tactic finding support here is not necessarily being confrontational–that would tend to prompt negative emotional reactions, and thus defensiveness and inflexibility towards New Atheist arguments–but rather, making it more widely known that you’re actually there–as “out” atheists try to do…

Oh, Chris.  Chris, Chris, Chris, Chris, Chris.  Gather your crow recipes while ye may, because you shall be forced to eat a banquet’s worth of it one day, and you have proven today might be man enough to swallow it.  After, of course, kicking and screaming and refusing to do so for too many years, but still.  At least there’s the possibility you’ll hold your nose and do it.  Bravo, sir.  Bravo.

But, despite this minute concession, he still misses the point by a country mile.  We must be forgiving, he’s always had terrible aim.  But there’s the fact that, for a subset of people, being confrontational does go a long way toward snapping them out of religion.  I’m sure some clever dick (or vagina) will do a study someday – perhaps already have done, for all I know, considering I’m not as well-read in the psychological literature as I should be – and prove even to Chris’s satisfaction that he’s full of shit.  But even saying he’s not.  Let us be generous and grant him the conceit that shouting the truth at religious people without sparing their feelings never, ever works and only makes them dig their Sunday-shoed heels in.  He still misses the fucking point, even so.

Because, you see, New Atheism isn’t about bringing the true believers into the bright light of reason.  It’s about telling the damned truth without sugar-coating.  It’s about breaking the spell.  And you do not, cannot, do that by treating religion with respect and deference.  If you treat religion as a thing to be respected, you end up with religion still thinking it’s a thing that is entitled to respect.  And what does religion do when it and everyone around it believes it is entitled to respect?  It demands respect, it attempts to force itself on the masses, it insists all to bow and scrape to it, it bullies people and sullies science, science education, and secular government, and it basically runs around believing it owns the place.  Non-believers are treated as something nasty to be scraped off society’s shoe.  And people who don’t believe or don’t believe all that much end up silent and cowed, because no one has told them in no uncertain terms that religion deserves no such respect, is due no such deference, and moreover needs to be ushered firmly out of the public square. 

We have no problem with doing so politely, but if it kicks up a fuss, we reserve the right to boot it in the arse.  And religion has a distressing tendency to kick up fusses.  Ergo, we apply the judicious toe to the nether regions.

There’s also the bystander effect.  This atheist, for instance, would not be an out-and-proud atheist without the New Atheists.  I wouldn’t be here in love with science and defending it against fundie fuckwits if it weren’t for those evil, evil gnus.  I wouldn’t even have understood there was a problem.  So no, standing up and shouting in believers’ faces may not work directly on them all the time, but it sure as shit can be effective with people like me.

There’s room for gnus and for the softer, fluffier, make nicey-nice with the believers sorts in the battle to keep creationist hands off our science.  Nothing in the rules says we can’t use all of the tactics at our disposal.  And if the accommodationists would just stop sniping at gnus long enough, they might come to see the value in a good-cop-bad-cop strategy.

I will know that the apocalypse has truly come the day Chris Mooney realizes all that and apologizes for being such a massive shite to his fellow atheists.  Not holding my breath on that one.  I want to live.

But it’s nice to see him take the first step on the long road.  We’ll see how far he gets before he decides it’s too far to walk.

It's the Apocalypse, Isn't It?

Liesegang Banding: Automatic Art

Dana Hunter3 Comments

So this one day, on Twitter, Callan Bentley posted this: 

The best Liesegang banding you will see today is here http://bit.ly/fgzbBO and here http://bit.ly/gFjQja.

Had no earthly idea what Liesegang banding was, but if Callan says it’s the best, you know it’s something good.  So I clicked through.  Do it.  Go on.

Amazing, isn’t it just?  Made little lights go flash for me, because it turns out I’ve spent a lot of time surrounded by Liesegang banding.  It’s all over the sandstones in northern Arizona, and we used to sell bits of it in our bookstore, coasters and bookends and such.  It’s marketed as “picture sandstone.” The patterns are gorgeous.  When I saw stacks of coasters at the rock shop near Gingko Petrified Forest State Park, I had an acute onset of terminal nostalgia and bought some.  Lovely!
One o’ mah coasters.  Just look at that Liesegang Banding!

And now I know what caused those incredible patterns.  Well, sort of.  We haven’t quite figured out the processes that cause Liesegang banding.  And by “we,” I don’t mean me and my cat, although the two of us don’t quite understand it.  No, the whole scientific community is still scratching its collective head over the particulars.  But we’ve got some broad understanding.  It’s not a complete mystery, just one of those mysteries that keep scientists happy and busy.


In the meantime, we get to look at the pretty results.  Imagine my delight when, in a Google search for Liesegang banding, I got led to none other than Brian Romans’s very own blog, and this gorgeous field photo:
Liesegang banding, Valley of Fire State Park, Nevada (© 2009 clasticdetritus.com)

I spent my teen years galloping over rocks very like those, magnificent Jurassic sandstones formed from ancient dunes.  I thought the pretty stripey colors, all of the yellows and mauves and reds and deep dark browns, happened at the beginning.  But no!  That came later.  First, you had your dunes, then you had your sandstone, and then along came groundwater, dissolving all those lovely iron-rich minerals like hematite, and precipitating it out.  


Then, after a great many years and a general dry-out, you get wildly-patterned formations like the above, and some bugger comes along to quarry them for things like this:
Mah other coaster.  I like the way the Liesegang banding resembles the dune fields the sandstone formed from.

It’s not just sandstone that gets your Liesegang bands.  It can happen to tuff, too, and even man-made things like lime mortar (but only the Roman recipe stuff that’s aged 14 years and similar).  All that’s required is something suitably porous.  The phenomenon was first noticed in blotting paper by a man named Frederic Ferdinand Runge in 1855 – he was so taken by his “self-painting pictures” that he wrote the book on them.  But he failed to take the world by storm, so it was left to Raphael Liesegang, futzing around with photographic chemicals forty-one years later, to rediscover them.  In one of those wonderful scientific accidents that leads to discovery, he dropped a crystal of silver nitrate onto his gels and saw concentric rings form.  Instead of throwing the mess out, he wrote papers about it.


In nature, things aren’t so neat as his concentric rings.  Liesegang bands appear as, of course, bands, but also rings, spirals, and spheres, oriented in various directions, with younger sets cutting across and sometimes dissolving older ones.


One of the most fascinating things about these bands is that they’re formed by a self-organizing process: they don’t need a template for their patterns.  They’re not directed by something living.  They just happen.  All of that beautiful, artistic complexity is the result of simple, mindless processes.  I find that enthralling.  The power of physics, chemistry and geology to combine and form such patterns is amazing.


Wonderful ol’ world, innit?

Liesegang Banding: Automatic Art

Living With Geology

Dana Hunter3 Comments

John Van Hoesen of Geologic Musings in the Taconic Mountains asks a good question for this month’s Accretionary Wedge: “How much or what kind of ‘geology, have you incorporated into you home / living space?”

If I had my druthers, this house o’ mine would be slathered in stone.  Floors, counters, patio, all stone, of all sorts of varieties.  Sometimes, I stand in the aisles of Home Depot and just dream.  Travertine?  Slate?  Granite?  Gabbro?  Something more exotic?  I love it all.

However.  This is an apartment, and the complex might not take too kindly to me ripping various and sundry bits up and replacing them with a riot of rock.  So I’ve had to make do with hand samples.  They’re everywhere!
Mah not-so-grand entrance

If it’s flat, it’ll fit a rock.  That’s my philosophy.
Richmond Beach rocks

Here’s some lovely bits I collected from Richmond Beach, a sandstone sort of thing in a gorgeous mauve color.  You can see the old mudcracks.  I loves them!  There’s just something about an ordinary moment in time captured forever in stone that way.
Mah table

This is my constant companion, the table I sit by whilst writing.  On it, you’ll find some of my most-treasured treasures.  My spessartine garnet, my garnet schist, my carbonundum.  There’s some petrified wood, and odd unidentified bits I’ve picked up on walks along the area, including a chunk of what I’m nearly certain is marble.  Pretty pebbles, some beautiful pieces of local schist, all gathered from beaches.  A few polished stones from Arizona.  The hematite bracelet my mother got me for Christmas, which showed me she really had been listening to all my geobabble.  And a bit of limestone from Lord Hill.  Limestone’s rare around here, so I treasure it.
Zen garden.  Yes, I made the whole thing, including the building.  Look upon my works, ye mighty, and weep!

I love Zen gardens.  If I could have a yard, I’d have a Zen garden in it.  Have to content myself with Zen in miniature for the moment.  The dark rocks in it are bits of basalt picked up around my home in Flagstaff.  They’re from my childhood stomping grounds, so I treasure them.
Arizona Collection and extras

Here’s my rock collection from my Arizona trip.  You can read about the making of it in Arts and Cats I, II, and III, and a treatise on the finished product here.  Beside it, you’ll see some lovely bits of granite picked up in a Grand Coulee road cut.  Granite’s rare round there, so I treasure it.

You begin to see a theme, I’m sure.

On the other side, various bits and pieces picked up around beaches in the Olympics.  Just cuz.
Breakfast Bar

When I moved in here, I was a little overwhelmed by the white.  Decided early on I’d have to do something about that.  I began with some brown marble tiles from the Home Depot across the road, and rounded out with leftover bits of gabbro countertop that Lockwood kindly saved for me.  And atop those, some beauties gathered on adventures near Mount Rainier.
Richmond Beach collection

Okay, so I went a little nuts on the rock collecting at Richmond Beach.  Look, all sorts of awesome stuff had washed up on the beaches.  And there were endless delights in the railway embankment.  And when it comes to rocks, I haven’t got any willpower at all.
Oregon box

This is stuff I collected when out traveling with Lockwood last September.  I just haven’t got round to deciding where to put it yet.  But the dining table’s nearly empty….
Nightstand fountain

This is where it all began, this little fountain.  Nearly every rock on it is something special I bought: a bit of amethyst from Mount St. Helens, various baubles found in rock shops and gift shops around Seattle, Arizona, and other places.  Believe it or not, that tiny little fountain used to represent most of the rocks I owned.
Olympics collection
Closeup of the best sample

These were all collected during our trip to the Olympics.  Eventually, I’ll have them displayed properly.  They’ve got stories of subduction zones and orogenies to tell.  They’re the last thing I see before I go to sleep.  Well, other than my Lord of the Rings posters, anyway.  One of which has some really interesting fantasy geology in it…

Come back after this summer’s adventuring season, and I’m sure you’ll see plenty more.  Now you know why I’m afraid to ever move.  Between the books and the rocks, it’ll probably cost me a gajillion dollars.  But they’re worth it.

Living With Geology

Local Geology Kicks Project's Arse

Dana Hunter4 Comments

Confession: this post is mostly an excuse to post my super-awesome front loader and dump truck photo:
Check out the dirt-dumping action!

How awesome is that?  I’ve never had so much fun photographing a dump truck before.  Comes to that, I don’t think I’ve ever photographed a dump truck before.  But when Cujo and I were out walkies, looking for nice cherry blossoms, we passed by the site of this mysterious building project that’s been going on for half of forever.  Usually, it’s hidden behind walls, but the wall has come down, and the whole thing is revealed!  Also, there’s a sign we never noticed before:
Sooper-seekrit projeckt revealed!  Image credit Cujo.

Ah-ha!  ‘Tis a wastewater treatment facility.  And if you’ll direct your attention to the lower left of the photo, you’ll see there’s this tunnel they’re excavating that goes out to the Sound.  This tunnel is where the problems begin.

Cujo sent me this article in the Seattle Times that shows what happens when you drive a tunnel through gobs and oodles of glacial sediments: sinkholes.  And how.  Check this out:
Kenmore Sinkhole, image credit and copyright TunnelTalk

Allow me to direct your attention to a paragraph in the article describing that incident, from which the above photo was filched:

Neither the owner nor the contractor would discuss the focus of their investigations, but these will likely look at several possible causes, including the experience of the slurry machine operator with the closed slurry system making it difficult to judge the amount of material being excavated during a shove. Another possible cause might be the presence of a large boulder in the face that stalled penetration without slowing extraction of material and caused over-excavation. A third possibility is the meeting of high artesian water pressure and its influence on the excavation cycle. [emphasis added]

All of you geotypes are probably shouting, “Glacial erratic!” about now.  Seattle’s got lots, random boulders dropped by the Cordilleran Ice Sheet during its stay.  According to the articles I found, the tunnel-boring machine’s been encountering quite a bit of sandy soil, which it sometimes proceeds to remove too much of.  Not to mention running in to boulders.  Tunneling through all of that glacial outwash, till, and random erractics has got to be an absolute nightmare, and goes a long way toward explaining why the project’s run over on both time and money. 

TunnelTalk has a nice, simplified geologic cross-section showing what the excavators are dealing with here:
Image courtesy and copyright TunnelTalk

You’ll notice there’s not much clay it gets a chance to run through.  That means it’s grinding itself up against sand and gravel.  According to TunnelTalk, this means more frequent cutter replacements – only trying to get down there to replace a cutter when you’re not in a nice, stable bit of clay is difficult.  And then there’s the propensity for sinkholes.

This is something ordinary folk don’t usually think about when contemplating infrastructure, when they contemplate it at all.  But geology’s critical when it comes to deciding where and how you’re going to dig your tunnels things like wastewater lines.  We don’t have a lot of good choices here.  The bedrock’s down too deep in most places, the water table’s high, and glacial deposits are difficult to deal with.  Planners need to understand and deal with those issues so that the needs of the metropolis can be served.  And this is a good dry run for the gargantuan tunnel they want to replace the Alaskan Way Viaduct with: without this, they may not have been alerted to the true scope of the problems they’re going to face in sending a highway underground.

Oh, Seattle!  You are beautiful, but when it comes to infrastructure, you’re a right pain in the arse.

Local Geology Kicks Project's Arse

Oregon Geology Bonus Features: Geologic Core

Dana Hunter5 Comments

There’s a little something wonderful buried deep under the ground at Portland’s Washington Park.  If you go to the MAX light rail station:
MAX Light Rail Station

And step into the elevator:
Not the TARDIS, but it’ll do as a time machine

You’ll notice that you’re traveling into the past.  Deep into the past.  Millions and millions of years, in fact.

We don’t often think about that, when we’re going underground.  But dig down below the soil, into the rock, and you’re on your way to another age.  Here, two hundred and seventy feet of vertical travel takes you sixteen million years into the past, back to the time when the Columbia River basalts were busy paving vast portions of Washington and Oregon.  Its a world that bears little resemblance to our own.  And it’s all laid out for you to see.

All that history, mounted in tubes on the wall between platforms:
Core East
Core West

All of this would have been much better if my mad photography skillz hadn’t been downright rude at the time, but it’ll do for a journey into a tumultuous past. Quite a few cores were bored through the Tualatin Mountains in preparation for boring the three mile long rail tunnel; this one is the most complete.  Displaying it for the public was a stroke of genius.  It’s time people saw the geology beneath their feet and celebrated a little science.
Allow the Core Sample Timeline to introduce itself

Let’s begin at the beginning, nearly sixteen million years ago.  As you begin walking the timeline (see slideshow below for the full experience), you’re following the Winter Water Member of the Grande Ronde basalt formation.  This is the oldest bit of the Grande Ronde on display, and it’s thick – goes on along the wall for at least 15 feet.  Something interesting about the Winter Water Member: it’s one of the few you can recognize on sight.  It, unlike other bits of the Columbia River Basalt Group, has plagioclase phenocrysts visible to the naked eye.  I wish I’d known that when I was there, because then I might have found some in the core sample.

Following that, you’ll come upon the contact between the Winter Water and Sentinel Bluffs Members of the Grande Ronde.  Keep walking.  You’ve got nearly thirty feet worth of basalt to go before anything else happens.  And one thing that should be impressing itself upon you by now: that’s a fuck of a lot of basalt.  And it ain’t even half over yet.  Portland wouldn’t have been the most comfortable city to live in for a while there.

But then, there was an interval.  The Grande Ronde stopped flowing.  All silent on the volcanic front.
Closeup of the Vantage Horizon

You’ve reached the Vantage Horizon.  About 15.6 million years ago, three hundred thousand years of peace reigned.  Soils had time to form.  Plants, trees and animals thrived.  Humans might have found it a nice place to live, except for the fact they hadn’t evolved yet. 

Seeing those sudden paleosols after so much basalt is a shock and a delight.  But don’t get too used to it.  Take a step, and bang! you’re back in basalt.  We’re in the Wanapum Formation now.  Wave goodbye to palesols and hello to nature’s pavement.  Flow after flow after flow of flood basalts spilled over this site.  You are doomed to walk among it FOREVER!  Okay, only for about forty feet or so, but still.  That’s a hell of a lot of basalt, and we’re talking about almost a million years of molten rock.  If your mind hasn’t boggled, you’ve either spent too much time in deep time or you haven’t got an imagination.
Closeup of Wanapum Basalt

Then, after all that nearly-endless basalt, the Wanapum Basalt comes smack up against the Portland Hills Silt.
Portland Hills Silt

There was a very long period of erosion before the Portland Hills Silt was deposited.  We left the Wanapum Basalt about 14 million years ago.  Now we’re standing in front of something that, at its oldest, is around 700,000 years.  That’s the thing with geology: periods of high excitement are followed by big blanks.  It’s like Mother Nature delights in ripping pages out of the history book.  So here we are, and all we can really say by looking at this core sample is that there was basalt, then ?, then loess.
More loess or loess is more?

Lots and lots of loess.  Lots.  Apparently, there were glaciers, and winds sweeping over outwash plains, and the loess accumulated to enormous depths.  You’ll walk along about thirty feet of loess before anything else happens.  Then you’ll see that the place heats up a bit.
Contact between Boring Lava and Portland Hills Silt

Don’t be fooled by the name.  The Boring Volcanic Field is anything but.  Starting about 2 million years ago, tectonic stresses started pulling the Portland Basin apart, and the lava came: shield volcanoes and cinder cones, mostly, with some eruptions salting the area with ash.  So things had gotten a bit exciting again, and still could today, considering no one’s quite sure whether the Boring Volcanic Field’s truly extinct or not.

The absolute neate
st thing about it, though, is that reversals in the polarity of the earth’s magnetic field are clearly marked on the core:
Reverse the polarity!

I’m sorry if this makes me a total geek, but that just delights me to no end.  I mean, the bloody magnetic field flipped, north became south, and we can see it recorded in the rock!  Okay, we need instruments to see it, but still.  It’s bloody freaking awesome is what it is.

And you can see bits where the Portland Hills Silt and the Boring Volcanic Field battled it out for supremacy.
Portland Hills Silt with a bit o’ Boring Volcanic Field rock.  Nice vesticles!

Ice!  Silt!  Volcanoes!  Fight!

And then, and then (and this is my favorite thing outside of the polarity reversals), the Floods came:
Missoula Floods closeup

Oh, yeah.  Right there.  Right there, you can see where the floods came roaring through, wall after wall of water, burying this region of Oregon up to 400 feet deep in roiling, icy, sediment-laden, gargantuan jökulhlaup.  Brilliant.
Moi et Missoula

 After that, lots more silt, etc.

It really is amazing to see so much geology in a tube like that, displayed with such loving artistry.  If you get the chance, you should go see it for yourself.  The scale of the thing can’t be captured by a camera.  But I’ve done my best, and here present you with a slide show of the whole thing, start to finish.

You’ve just walked nearly sixteen million years.  How amazing is that?

Here endeth Oregon Geology Phase I.  Never fear.  Phase II cometh, after an interval in which we enjoy Mount Rainier, the Olympics, and quite possibly some Arizona geology.  Believe me, I have no shortage of wonderful sights to show you.  Stay tuned!

Oregon Geology Bonus Features: Geologic Core

Geology in Odd Places: Insurance Building

Dana Hunter4 Comments

When I stopped off to pick up my insurance check, I noticed something odd about the floor tiles.  They were all sort of shiny and wrinkly and lumpy.  I paused for a closer look, and very nearly shouted out two words in a paroxysm of glee: “Garnet schist!“
Garnet schist tiles

I’m a sucker for schist.  And garnets are near and dear to my heart, being my birthstone and all.  Put the two together, stick them in an unexpected place, and what you’ve got is a very happy Dana indeed.  One who goes back to the insurance building toting a camera and begging the staff not to think her insane for photographing floor tiles.

Here they are in context:
Tile strip

How awesome is that?  I didn’t even know such things existed, but they indubitably do.

So that led me to start asking what, exactly, is garnet schist all about?  I know it’s a metamorphic rock, and I know it’s pretty.  That about sums up my knowledge.  So I threw the question out on Twitter, and got this reply from our own Ron Schott:



That sound you heard just then, rather like a blimp with a catastrophic failure in its air tanks roaring past at Mach 10, was nearly everything he’d said flying right over my head.  There were words there I recognized.  Problem was, I’d never seen them strung together like that.  And Elli Goeke was off at a conference, so this really wasn’t the time to turn to her and say, “Hey, Elli – my ignorance is total.  Halp!”

This is one of those moments when one frantically turns to Google.  Search “garnet schist,” and you get bugger-all.  Search something like “greenschist to amphibolite facies,” and suddenly you’re cooking with Sterno.  Or possibly with vast tectonic forces.

I found Barrovian metamorphism.

I’ll leave it to that link to explain in clear, succinct detail just what the hell that is.  Basically, if you’ve got major tectonic excitement like a volcanic arc or an orogeny, you’ve got Barrovian metamorphism going on.  In the context of our delightful garnet schist tiles, this gives us a recipe for their formation.

Let us begin with the garnets.  What sort of garnets are we dealing with here?  The Hudson Valley Geologist can point the way with this wonderful post on garnets.  He says, “Almandine is the most common type of garnet and typically the garnet found in garnet schists.”  Almandine ’tis, then: we’ll work on an assumption since the insurance company might get a tad upset if I dig up a tile to haul off to the lab.  What’s almandine, then?  It’s Fe3Al2(SiO4)3.   So we’ve got iron, aluminum, silicon, and oxygen.

Right, then.  Let us begin with a shale containing said elements.  Maybe our tiles began life on a nice, quiet continental shelf, as clay particles and quartz and all that other stuff gently settled out of suspension and got compacted.  It’s nothing particularly special.  Not yet.

Then, let there be an orogeny.  Continents collide!  Squish!  Squeeze!  Temperature and pressure rising!  And something interesting begins to happen:
From shale to gneiss

As our continents collide and our mountains build, our perfectly ordinary shale starts to change.  We’re at greenschist facies: 700-900 degrees F (400-500 degrees C) and 5-31 miles down (8-50km).  If our poor shale had stopped feeling the ol’ squeeze-and-burn right round there, it might have been fated to be a blackboard, or maybe a nice slate roof.  It might have ended up an unremarkable phyllite, at the farther end of that scale.

So what’s happening?  All that pressure-cooking is changing its mineral composition.  At greenschist facies, the index mineral formed is chlorite.  That mineral, in the absence of others formed under conditions of great heat and pressure, tells us just what sort of metamorphism our rocks have been subjected to.  So far, so not schist.  Until we increase the heat.

Now we’re entering amphibolite facies territory.  And things get very interesting indeed.  We’re cooking our former shale at temperatures of around 950-1200 degrees F (500-700 degrees C), and maybe we’ve buried it bit deeper.  Our index mineral becomes amphibole.  Here be schist – and possibly garnets.
Detail of garnet schist tile

What do those garnets tell us?  Well, it was hot.  We’re dealing with regional metamorphism on a convergent plate boundary, most likely.  Think the Alps, or the Himalayas.  Way down beneath the bulk of the mountains, the former phyllite was busy cooking into schist.  Minerals were lining up in a nice, platy structure, leading to future foliation.  You can rather see that in the tiles, all those lovely linear streaks there.  And deep in that hot, ductile rock, iron, aluminum, silicon and oxygen were busy forming garnets.  These beautiful crystals grow from microscopic dimensions up to something that can be centimeters (and, believe it or not, if conditions are just right, up to meters) across. 

The ones in these tiles are fairly small.  Look, I’ve even remembered to put a nickel in for scale!
Garnet schist tile, nickel for scale.  I iz fotograffing domestick geology rite!

They look a little like raisins in a pastry, don’t they just?  But if you could move a mountain and pluck out the schist underneath while it’s forming (here’s hoping you’re wearing the best oven mitts in the known universe), you wouldn’t be pulling out a sticky, tacky, half-baked and malleable rock.  This stuff can deform, but not on a human time scale.  You know how stained glass “flows” over hundreds of years, eventually bulging a bit at the bottom, over a time frame so long we never saw it moving?*  It’s an Olympic-caliber sprinter compared to this rock.  And the pressure it’s under is like nothing we’ve ever experienced.  Lockwood put it like this: “This truck weighs 60 tons. Imagine one parked on every square inch of [your] body. Not something I can picture.”

Yeah.  Yeow. 


On top of that, only some of the minerals will act plastic.  Some will remain brittle.  But if you add water to the equation, you might get some melting at upper amphibolite facies.  How exactly all that behaves under such extreme conditions is a question I’ll have to leave to experts like Elli.  

Whatever the details, ultimately, the rock’s “soft” enough that those lovely little garnets don’t get their style cramped as they form their faces.  They laugh at the pressure.  They bask in the thousand-degree heat.  And, after millions of years of high-quality pressure cooking, you end up with something like my pride and joy, a gorgeous garnet embedded in schist:
Mah beautiful garnet in schist!

But you’d probably like to see the full context, wouldn’t you?  Here she is, in all her glory:
So glad she didn’t end her life as a floor tile

So, there we are.  An orogeny’s cooked up a nice batch of garnet schist, but it’s just down there, miles and miles under the earth, where it can’t show off.  Until erosion removes the mountains.  And then it’s bold and beautiful and just waiting for some enterprising bugger to quarry it, where it will spend the next phase of its life prettifying the floors in a Seattle-area insurance company office.
Garnet schist tile with one thin dime for scale

There’s just something incredible about this.  You don’t walk into an office building expecting to see dozens of millions of years laid out ready to tell a story.  But I guess it’s appropriate.  This stuff formed in a continental collision, and they pay out claims for collisions of a different sort.

Remarkable.

As a special added bonus, here’s another garnet I’ve got.  In rhyolite, in fact.
Pretty in pink rhyolite

Yes, garnets are opportunistic little buggers who believe an eruption’s as good as an orogeny. But that’s a story for another day…

(With special thanks to Lockwood and Ron, without whom I wouldn’t have got a start and would have later ended up embarrassing myself.  I’m still likely to have spectacularly screwed up somewhere along the way.  Mistakes, misrepresentations, misunderstands, and general mis-es are my sole responsibility.  You metamorphic petrologists in the audience are welcome to kick my arse, and corrections shall be made as necessary.)

*Okay, so nevermind.  Let this be a lesson in the perils of not fact-checking the stuff you learned in grade school.

Geology in Odd Places: Insurance Building

I'll Take Wonder and Awe Over Mystery, Thanks

Dana Hunter1 Comment

Seems it’s time to talk about science and beauty again.  You see, several people tweeted this XKCD:



And then, on the same day, Eric MacDonald has this post up:

This morning, in the The Independent, Michael McCarthy has an article entitled “Mere Science cannot account for beauty.” And while it may be true that mere science cannot account for beauty — there may be no strictly scientific account in terms of chemistry or physics of why we respond as we do to things that we find beautiful — I wonder why he felt the need to say it. Science has, in fact, revealed many beautiful things. Some of the pictures that Jerry Coyne or PZ Myers have put up from time to time on their blogs — close-up pictures of insects, the amazing variety of squids and octopuses, eagles’ nests, and eaglets — or the pictures of stars and galaxies and supernovae that Carl Sagan included in his books — show that scientists, far from negating beauty or awe at the wonder of nature, celebrate and revel in such things. The deeper they probe, the more they study and come to know, the more wonderful and beautiful nature seems.

Motion carried.

I used to be one of those woo-woo idjits swanning around mourning the fact that science takes the mystery out of things.  I also used to be one of those woo-woo idjits swanning around perplexed by the fact that an ostensibly benevolent universal consciousness took such delight in creating really ugly shit.  Inordinate fondness for beetles is only the tip of it.  Tended to ignore the ugly stuff, then, in favor of pretty things.  Oh, and I really wanted to believe in magic and faeries.

There had, I told myself, to be something more to this universe than just plain boring ol’ matter.  And why were those meanie scientists so intent on taking the mystery and magic out of life?  Sure, some of what they did was made of awesome, but did they have to be such bastards about it?  Did they have to make it impossible for me to believe in faeries?

For a while, I had this weird split-personality.  One side of myself read and reveled in Carl Sagan’s The Demon-Haunted World while the other gobbled up books on Celtic magic.  I thought the world wouldn’t be quite so pretty without the possibility of mysteries beyond science’s ken.  I still liked watching science spank assorted silly people, like UFO conspiracists and fundies, but hands off my faeries, damn it.

Then, somewhere along the line, I grew up. 

And I found out something.

Science solves mysteries, yeah, but mysteries aren’t half as much fun unsolved as they are when they’re being solved.  That thrilling sense of mystery was nothing, absolutely nothing, compared to the numinous sensation of gazing upon a mystery solved.  What I mean by that is, having things explained didn’t lessen them a bit.  I mean, let’s go back to Eric’s post, where he demonstrates Mr. McCarthy wanking about butterflies:

With science, McCarthy tells us, he can explain that

it was an insect; that it belonged to the butterfly family Pieridae, the whites; that it had overwintered as an adult, one of only four British butterfly species to do so (the others pass the winter variously as eggs, or caterpillars, or pupae); that in its caterpillar stage it had fed on the plants buckthorn or alder buckthorn; and that it had hibernated disguised as a leaf, probably in an ivy clump, until the first warm day in March woke it up.

But that, he says, just “doesn’t remotely get it.”

Dude, McCarthy, you don’t remotely get it.  What has science told us about that butterfly?  Without science, we have a wee pretty little insect fluttering around, yes, okay, “like a piece of sunlight that had been loosed from the sun’s rays and was free to wander, announcing the spring.”  I get that, it’s very nice.  You can throw a bit of animism in there if you like, and talk about butterfly spirits if you’re feeling particularly frisky.  Whatever melts your butter (or flutters your butterfly).  But you, O wanker who recites some science facts whilst totally missing the point, aren’t seeing the real majesty here: science tells us that we and that butterfly are related.

That’s right.  Not closely related, mind.  The butterfly might not get invited were we to throw a family reunion, but trace the family tree back enough, and you’ll see that little brimstone butterfly and ourselves share a common ancestor.  We’re kin.  That may not be mysterious, but that leaves my jaw hanging, that does.  That gets me all giddy inside.  And we never would have known that if it wasn’t for boring ol’ science out there solving mysteries and banishing ghosts, gods, and all sorts of nature spirits.

Here’s another thing you might see, looking at that little butterfly: it’s made of star-stuff.  Literally.  All of the atoms in it got cooked up in stars or supernovae at some point in the universe’s history.  It’s not just that we need sunlight to survive: we needed gigantic exploding stars to make this planet possible in the first place.

If the two above facts do not induce a sense of awe and wonder in you, then you are bloody well hopeless.

Mysteries are nice, yeah, but they’re too easily ignored when they can’t be solved.  What really gets the awe and wonder going, what leaves me stumbling round in slack-jawed amazement, occasionally bursting into gales of giddy laughter, is the sheer magnitude of what science has revealed about the workings of the world.  It makes everything huge.  Back when I thought goddidit, I could just shrug stuff off.  ‘Course it’s pretty, God made it that way, or the faeries or the spirits or whoever.  But you can’t shrug off the beauty of the natural world so easily.  Not when it comes down to the intricate interplay of physics and chemistry and geology and biology, some or all of them combining in any one moment to unconsciously create something of extraordinary beauty.  It’s like a really good magician’s trick, the kind where seeing how it was done only makes you appreciate the illusion more.

Oh, and did I mention how science makes ugly things lovely?  Even slime molds that look like dog barf.

You woo-woo lot can go into agonies of ecstasy over the first butterfly in spring.  I shall sing odes to the slime mold, and the mud flat that could tell me a once and future story about its birth in the heart of a star, its wander through space until it became part of a primordial planet, its journey through the Hadean earth and its incarnations as, perhaps, a bit of magma or a solid bit of shell before erosion weathered it away to become what it is now, a home for the oysters, on its way to an eventual date with lithification once more, cycling ever onward.

I'll Take Wonder and Awe Over Mystery, Thanks

Oregon Geology Bonus Features: Geologic Art Interlude

Dana Hunter3 Comments

Did I say last week it was the end of Oregon Geology?  Well, consider this the DVD collection, complete with extras!

We stopped over at Washington Park the morning we were in Portland, and found some delicious geologic art. 

Les AuCoin Plaza

One of the most striking is Les AuCoin Plaza, near the MAX station.  You like light rail, thank former Rep. AuCoin, who was instrumental in making it happen.  This plaza does him total justice.  It’s beautiful, for one thing.  The enormous columns of basalt (say high to our old friend the CRB!) are just wonderfully worked in.  You can really get up-close and personal, inspect them, get a feel for how massive they are.

And there’s so much more.

Here’s another view of columns, above the Plaza:
Columns and Benches

This is in a sandy sort of amphitheater.  You can sit on the stone flag benches, or on the columns, and just feel the solidity of the rock around you.  Definitely recommended for a geology buff.  There’s nothing quite like sitting with solid geology in an urban setting.  And those of you who fell prey to the columns meme will adore them.

Down by the World Forestry Center, across the way from the MAX rail station, you’ll find some enormous chunks of petrified wood.  I mean huge.  It’s hard to tell because I didn’t bloody put anything in there for scale, but these things are at least waist high.  Here’s the biggest:
Enormous Hunk o’ Petrified Wood

And a closeup:
Delicious Ancient Wood!

I love the colors.  It’s like a sunset captured in stone that used to be a tree.  Amazing stuff, that.

There’s another one there that isn’t so much about color as texture:
Looks Like a Crocodile

Wish I knew what it was, but I love that it looks so much like crocodile skin. 

And, of course, this being the Northwest, there’s plants growing in it:
Ivy and Ancient Tree

Stuff like this really delights my synapses, especially when it’s unexpected.  We’d only gone down there to see the geologic core.  We had no idea we’d be running into geologic art at every turn.  Really, really beautiful stuff.

Right, then.  There’s that.  And if I can tear myself away from Doctor Who and fiction writing long enough this week, I’ll get my research done for the next installment, in which you’ll finally get to see the reason why we were at Washington Park in the first place: the geologic core displayed at the MAX rail station.  You’re going to go “Squee!”  I guarantee it.

Oregon Geology Bonus Features: Geologic Art Interlude