science

Such Civil War Is In My Love and Hate

Dana Hunter5 Comments
(This is soooo last minute, so for those breathlessly awaiting another Dojo post, you shall be disappointed until tomorrow.  Forgot all about November ending so soon, didn’t I?  Had to get in my Accretionary Wedge post under deadline, and that means the Dojo gets the boot.  I’m sure you shall all survive.)

Shakespeare fans may note the shout-out to Sonnet XXXV there in the title.  That’s because our lovely hostess Ann has asked, “What Geological features about the area you call ‘home’ do you love? and what do you not like?”  Simple answers to simple questions: love the variety, hate all the damned biology in the way.  Well, I only hate the biology when I’m trying to look at geology and when it’s giving my asthma fits – apart from that, I actually love it quite a lot.

That’s the simple answer.  But nothing’s ever simple, is it?

We’ll discuss Washington State as a whole, though I live very nearly in Seattle.  And I’ll tell you what I love: I love living on a subduction zone.  I love the mountains thrown up by it, and the exotic terranes stuck on any-old-how.  I love the fact I can drive a half-hour from home, and see an old volcanic island floating in a sea of grass:
Mount Si, Snapped by my Intrepid Companion

In the West, we’ve the ocean, with mountains crammed up and jammed up by the North American Plate busily overriding the Juan de Fuca Plate.  We’ve the Sound, dropped low by earthquakes and carved out by Pleistocene glaciers.  We’ve the Cascades, walling us off from the east.  And they’re the reason I’m here: when I visited in 2000, saw Seattle nestled between the Olympics and the Cascades, those snow-capped peaks holding a city in the hollow of their cupped hands, I knew I’d come home.  So what if it took another seven years before I managed to actually move here?

And of course, one of the first books I bought in preparation for the move up was Roadside Geology of Washington. I didn’t think I was moving up for the geology, actually – I’d come because it was where I set my books, and rationalized making the move by listing things like nice city, research purposes, all that rot.  But when it comes down to it, geology brought me here and geology entices me to stay.

I have two things against this state: so much of its interesting geology is completely covered in biology, at least west of the Cascades.  What’s not buried under plants, trees, brambles, ground cover, and other forms of life is usually lost under a deep cover of glacial till, so as far as seeing some of the features we know must be there, forget about it.  Still, things peek out here and there.
Mount Rainier Peeking Through Clouds and All the Damned Biology

The other thing I have against Washington state is that so much of it is terribly young and overwhelmingly volcanic.  Sometimes, I miss the limestones and sandstones of Arizona.  But then I get the opportunity to see what happens to flood basalts that have had the mother of all floods scour them, and I feel much better about matters:
Dry Falls

No one can look at that and say it’s not awesome, and then credibly claim to be moved by natural wonders.  That, my friends, used to be a sea of basalt; millions of years later, Glacial Lake Missoula broke through its ice dam and unleashed the mother of all floods, turning this segment of basalt into a waterfall that dwarfs Niagara – all in the course of a few hours, and for just a few days.  The marks of that flood cover an enormous area of eastern Washington.  You can find traces of it under the Pacific Ocean.  Arizona may be able to lay claim to about 2 billion years of geological history on display, but it ain’t got glacial floods and flood basalts like this.

It doesn’t have mountains like this.
Tarn Near Sunset, Hurricane Hill, Olympic Mountains

This is a complex state with young but fabulously complicated geology.  When it comes right down to it, what I love is far greater than what I don’t.  Even when the rain keeps me off the rocks, encourages more bloody biology, and makes some of the local geology go slip-sliding into the sea.

Such civil war is in my love and hate
That I an accessory needs must be
To that sweet thief which sourly robs from me.

Such Civil War Is In My Love and Hate
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Why Talking to Idiots Gets You Nowhere

Dana Hunter

Finally finished this paper that’s been in my tabs for days: “Irreducible Incoherence and Intelligent Design: A Look into the Conceptual Toolbox of a Pseudoscience.”  Stumbled across it playing on The Panda’s Thumb, and while it took me forever to read because I’ve had the attention span of a spastic on caffeine pills lately, I got quite a lot out of it.  Namely: if one goes about disproving IDiotic blathering about how evolutionary theory can’t explain X, they’d better not be doing it in order to convert the cretins.  May as well spend your time trying to convince me that curling is an exciting and dramatic sport to watch – you’d have better luck making a conversion.  Mind you – I find nearly every sport in the universe dead boring.

No, the only time the IDiots become useful IDiots is when they inspire evolutionary biologists to figure things out and demolish IDiotic arguments from the foundations up – not because any amount of evidence will make these dumbshits realize they’re wrong (none will), but because of the ricochets.  Knocking down an IDiot’s argument is a fantastic way to teach ordinary folk like me about biology.  It makes it more interesting, what with the controversy and the smart people vs. the Dumbskis sorta thing.  It’s also a good idea to have a refutation ready so that innocent bystanders don’t get snookered. 

Besides, it’s fun.  Especially when the poor howling IDiots snivel and have to rush out to move their goalposts.

Anyway.  There’s my thoughts.  It’s an entertaining paper, too, so you lot may enjoy reading it yourselves.  Which you should go do now, because I’m off to watch another Harry Potter film.

Why Talking to Idiots Gets You Nowhere

One of the Most Beautiful Things I Have Ever Seen

Dana Hunter3 Comments

Courtesy of Jessica Ball at Magma Cum Laude:

That’s right – it’s under a waterfall! The flame is sheltered just enough that it doesn’t go out very often (although it’s always a good idea to bring a lighter along if you’re going to visit). Gas wells in this area are generally drilled into the Medina Group (a collection of sandsones and shales, which you can see exposed in the base of Niagara Falls to the north), but the seep itself is in the Hanover Shale, which apparently also has a bit of gas in it.

There’s much more to that post, including some more lovely photographs, so do make sure you go.  And, incidentally, who wants to take a road trip with me?

One of the Most Beautiful Things I Have Ever Seen

Los Links

Dana Hunter

Bored on a holiday weekend, are ye?  Had your fill of turkey, football, annoying relatives, Black Friday, all that rot?  Well, that’s good, because I’ve got lots o’ interesting links I’ve been meaning to do something about but never managed to get round to blogging.

Pour yourselves a glass of something tasty and hopefully strong, and nibble away at some delights, my darlings.

The “Lost Women”: science popularizers and communicators of the 19th century:  We sometimes forget that, even in the days when women were pretty much third-class citizens, a few of them broke out of the barefoot and pregnant mold and managed to make some impressive, not to mention important, contributions to science.  Here’s a start on remembering them.  And, in case that wasn’t enough for ye, here’s my paean to a few of the Unsung Women of Science.

For those who might’ve missed it the first, second, and ten billionth time this got handed round the geoblogosphere, Ole Nielsen has an excellent explanation of How Drumlins Form.

And while we’re on about glaciers, might as well go From end to end: Traversing the Terminal Lines of Long Island.  

Hannah Waters has the definitive post on Developing a scientific worldview: why it’s hard and what we can do.

Remember when we were all supposed to have flying cars?  How about this instead: Trees Infused With Glowing Nanoparticles Could Replace Streetlights.  Pretty damned awesome.

Here’s an excellent read for anyone who loves reading, writing, or understanding how the brain works: This Is Your Brain on Metaphors. 

And, finally, Orac’s got a thought provoking (and snarky) post up: So Al Gore didn’t invent global warming? Who knew?

That should keep you busy enough.  Now if you’ll excuse me, I’m off to watch every single Harry Potter movie filmed to date because that’s the sort of idiotic thing a writer does when they’re blocked…

Los Links

Great Scarp! Seattle Has Faults!

Dana Hunter2 Comments

You know how I promised you a tour of one of Seattle’s most prominent fault scarps a few months ago?  You’d probably given up hope I’d ever get round to it.  But here we are at last, taking a trip through the southern end of the Seattle Fault Zone, and seeing some pretty dramatic evidence of what happens when the ground rips.
Wacky Trees on Ginormous (Presumed) Fault Scarp

We’ll begin with a bit o’ scarp that I’ve been unable to confirm or deny as a fault scarp.  It certainly looks like a fault scarp.  In fact, the only thing that it doesn’t have in common with the known fault scarp at Seward Park is the fact it’s enormous and easily accessible.  There you are, walking the nice, wide, paved path around the boat launch area and Andrews Bay, and all of a sudden the hill gives way to a cliff.  It looks like the end of the drumlin was just sliced right off by a giant’s meat cleaver.  It’s dramatic and a little shocking.

By now, the non-geologists in the audience are probably wailing, “But Dana – what the fuck is a fault scarp?”  It is, quite simply put, what happens when, during an earthquake, one bit of earth either goes zipping up or another goes down (or possibly both at once, I suppose).  Here, you can easily create your own right there at home.  Hold your hands together like you’re praying.  Then aim them like you’re about to shoot somebody.  Let your left hand slide toward the floor a good inch or two, and you will see your right hand become a fault scarp justlikethat.  Neat, huh?

Here’s a nice, simple illustration showing you all the relevant bits:



So, you wanna know why there’s a ginormous fault scarp or two hanging about one of Seattle’s city parks?

I thought so.

Welcome to the Seattle Fault Zone, my darlings.  You can read about my first adventures in it here.  On January 30th, 2009, it gifted us with a 4.5 magnitude earthquake, reminding us that we live in a very tectonically active area.  I mean, practically all of Seattle’s getting crunched and squished and tossed about like a cowboy on the back of a bronco standing on a wild bull standing on the deck of a ship in a hurricane.  People living near the San Andreas Fault don’t know how good they’ve got it.  All they’ve got to deal with is a nasty transverse boundary.  We get a subduction zone, and we’re dealing with no less than three tectonic plates all jockeying for position up here.  It leads to subduction zone earthquakes and volcanoes and tsunamis, oh my.

This enormous fault zone:



means that Seattle’s getting crushed in a north-south vice.  Nobody explains it better than Paul Talbert:

Why is western Washington being compressed? Although the part of the Pacific Ocean that lies offshore from western. Washington rests on the Juan de Fuca Plate, most of the Pacific lies over the Pacific plate, which is slowly moving northwest relative to the North American plate. As the Pacific Plate slides northward along the San Andreas Fault in California, it drags the edge of California northward, rotating western Oregon and squeezing western Washington up against the more stationary rocks of British Columbia. Combined with the northeast movement of the Juan de Fuca Plate, this motion causes compression and thrust -faulting in the Seattle area in the north-south direction.

And that, dear readers, causes things like this:
Probable Fault Scarp Dappled in Sunshine

The Seattle area’s prone to three different types of earthquakes, in fact.  The Big One the teevee yammers about every time they go on about megaquakes in the Pacific Northwest are the subduction zone or interplate earthquakes.  They’re the quakes you get when a subducting plate comes unstuck suddenly and causes a hellacious quake.  They’re called “megathrust” for a reason, and the last one we had hereabouts just over 300 years ago was powerful enough to cause a tsunami in Japan.  Then you’ve got your basic intraplate or Benioff zone earthquake, which occur within the subducting plate.  In this case, it’s the Juan de Fuca plate breaking at depths of around 25-100 kilometers (15-60ish miles).  We’ll discuss those in more detail at some future point, but if you’d like an example of one, look no further than the 2001 Nisqually earthquake that caused so much angst up here.  Locals still love to yammer about that one.

But it’s the third kind o’ quake that concerns us here, your standard-issue shallow crustal earthquake.  These go only skin-deep – roughly down to 30km (18mi), but don’t think shallow means gentle.  Washington State’s largest historic earthquake, the North Cascades earthquake, was probably shallow.  That didn’t stop it from being felt in four states and two Canadian provinces, now, did it?  And, being so close to the surface, they leave quite a mark.
Fault Scarp Looming Over Park-Goers

About 1,100 years ago, something in the Seattle Fault Zone let rip, and sent bits of land careening up by 20 feet.  No less than three substantial tracts of forest went slip-sliding down right into Lake Washington, where they evaded logging for a thousand years before being discovered when the lake got lowered, and enterprising businessmen said, “Oooo, timber!”

I haven’t got pictures of any sunken forests, considering they succumbed to the saw mill, and more importantly, I haven’t got an underwater camera, scuba gear, or any idea how to use any of the above.  But I have got a neat photo of roots growing in the suspected scarp:
Rooted

I have no idea how old these scarps are – they might be from 1,100 years ago, they could be in their mere hundreds.  It’s hard to find specific info on these very scarps.  But I can tell you that they’re on the side of the fault zone that’s going up while the other goes down (which means that bits of Seattle north of the I-90 have
more to worry about than just global warming as far as sea level goes – the northerly bits have dropped 6 miles since the Seattle Fault Zone became active, so the next earthquake could cause parts of the city to become unexpectedly aquatic).  And I can’t tell you much about the formations the scarps are cut in to, but I can show you they have some pretty patterns:
Patterns

There’s some bedrock I’ll babble about in our next installment, and we’ve got a bit on glacial erratics coming up, but for now, I’ll just show you some of what leads me to suspect we’re looking at either glacial deposits or old lahars.  It’s the great big boulders popping out of nowhere:
Boulder with Lichens

Up till now, we’ve dealt with a suspected scarp.  And you’ll see why it’s a good suspect once I show you a known offender:
Undoubted, Indubitable Fault Scarp

Now, the folks who designed the path leading to it weren’t thinking clearly, and planted a whole bunch of vegetation between the old social trail and the new official trail to encourage people to stay put.  The only thing that accomplished was to make the geology nearly impossible to see because of all the damned biology.  But we can catch some good glimpses:
Closer Look

In fact, with a 10x optical zoom, we can practically touch the scarp face:
Even Closer Look

And then we can zoom out to take in the whole scene:
Geology Through the Biology

The thing’s at least 20, maybe 30 feet high.  Now, I have a few things for you to consider: 1. The Seattle Basin is shaped just right for containing seismic waves, ensuring we get shaken harder than one might expect.  2.  A fault crosses the bottom of Lake Washington from Seward Park to Mercer Island.  3.  The above photos show you that a lot of ground can move in a quake round these parts.  And 4. Have I mentioned the fault under Lake Washington yet?  The big, deep, filled-with-lotsa-water lake?  You can see what I’m getting at: those of us in the East Sound who laugh at all those tsunami-prone areas on the coasts should probably stop laughing just about now.  In fact, when that fault under the lake goes, we could be talking waves up to 18 feet high.  And the fact that it’ll technically be a seiche rather than a tsunami is no comfort at all.  We shall get very wet either way.

So.  Fault scarps in city parks, underwater forests, and inland tsunamis – anyone who thinks Seattle is a quiet place to live hasn’t paid attention to geology at all.  That’s why it’s a good idea for everyone to get their arses out to Seward Park, where they can stand dwarfed by a rather imposing example of just what happens when the ground round here lets rip.

And just think, we haven’t even talked about the ice and the implications of exposed bedrock yet….

Great Scarp! Seattle Has Faults!

Explaining Monkeys and Uncles to Christine O'Donnell

Dana Hunter

Yes, I know the election is old news.  Yes, I know Christine O’Donnell lost.  But she speaks for a hefty ignorant chunk of the population when she spouts that snide “Then why are there still monkeys?!” line at the slightest whiff of evolution.

Brian Switek explains a few things about monkeys, uncles, and why your cousins don’t vanish merely because you survived:

In any family tree you care to draw – whether from a broad evolutionary perspective or a narrowed genealogy of close relatives – each point among the branches is going to fall into one of two categories: linear relatives and collateral relatives. Your parents, grandparents, great grandparents, etc. are all linear relatives, while cousins, uncles, and aunts are collateral relatives who are more closely related to you than most other people but are not direct ancestors or descendants. That’s simple enough, and the same sort of logic can be applied to evolutionary relationships.

Read the whole thing, and you’ll be well-prepared the next time some ignoramus thinks he or she has stymied you with the monkey schtick.

Explaining Monkeys and Uncles to Christine O'Donnell

Poisons, Doses, and Ammunition Against Anti-Vaxers

Dana Hunter2 Comments

This has been sitting in my open tabs for far too long.  Kept meaning to blog it, but what with House and the Wheel of Time and the onset of the winter writing season, I never got round to it.  It’s a wonderful post on Neurodynamics entitled Toxicology: the poison and the dose. 

Those of you enamored of mystery novels and/or crime shows may have heard the little phrase, “The poison is the dose.”  All too true – and now you’ll have an actual scientist’s perspective on it.  And you’ll also have a very useful question to ask:

What’s it do?
That’s the first thing I think when I hear someone say something is a toxin. There is no single “toxic” reaction out there. Every toxicologically active chemical entity out there has its own mechanism, its own target. Some are more recoverable than others, some have pretty dire consequences; some we have antidotes for, some not. Some exert an effect quickly, while others can take their time. They can target any physiological system, or multiples.  Cause death, permanent injury, reversible injury, minimal harm, or anywhere in the middle. Locally, regionally, systemically. There are many, many examples of different actions that a given compound could do. The severity of the effects is important to evaluate.

Lob that one at the next idiot who starts going on about toxins.  There are other questions answered there that are equally grenade-like and shall prove quite useful when people babble about all of those awful toxins making all of us sick although they’re only found in vanishingly small quantities, if at all, in our vaccines.

And then remind them of that old crime show/mystery novel truism: the poison is the dose.  Not just any old dose will do.

Poisons, Doses, and Ammunition Against Anti-Vaxers

Oh, Schist! And Other Stories

Dana Hunter3 Comments

Yes, it’s taken me this long to settle on an appropriate deskcrop for this month’s Accretionary Wedge.  In point of fact, I haven’t got any deskcrops.  I haven’t got a desk.  If I did have a desk, I wouldn’t be able to use it, as it would be covered in rocks, books, and the occasional knickknack. 

I have, however, got bookshelves, the bits of which that aren’t filled with books and knickknacks are covered in rocks.  I have also got tables, which are mostly covered in rocks.  Breakfast bar?  I hope you like stone-cold stones for meals, because that’s what’s on the bar.  Little half-wall in the entry way?  Home to more rocks.  And every single rock in this house has some sort of meaning.  Each and every one tells stories.  And they were all hollering “Me! ME! MEEE!” when I attempted to choose just one.  Worse than puppies, they are.

Ultimately, it came down to rocks from home.  And I couldn’t choose only one. 

Some of you may not know this about me, but I have an abiding fondness for schist.  I’m not sure why.  There’s just something about its foliation that I adore.  It may have a lot to do with the fact that it’s a) not volcanic, b) is metamorphic, and c) something I can identify with greater than 89% confidence despite all that.

It wasn’t always like that.  In fact, the first piece of schist I collected, I figured was just an unusual bit of volcanic rock.  It’s the dark one here in this photo:



It’s been with me since the early 2000s, when I grabbed it from the formerly-vacant lot behind my old apartment.  Needed nice, dark, interesting rocks for a mini-Zen garden I was building, didn’t I?  And there it stayed for years, nestled in white sand, and after I moved to Washington it lived in a Ziplock bag, awaiting a day when I had more space for Zen rock gardens.  Then I visited Arizona, picked up that lovely golden piece of mica schist that’s sitting beside it, removed it from its bag to add to the Arizona collection, and went, “Wait a damned minute… Oh, schist!” 

I believe it may even be a bit of Brahma schist.  Not sure.  I mean, it was sitting about 3,000 feet above where it should’ve been, so I know it’s a souvenir rock someone picked up and later discarded.  An anthro-erratic, if you will.  Could’ve come from anywhere.  But I love it anyway.

The mica schist beside it comes from the Mingus Mountains (no, people from Arizona don’t usually refer to them as the Black Hills, at least, not where I came from).  And that other bit there is a very nice little grossular garnet I picked up at the same rock shop.

But I promised you more than schist, and here’s a nice little bit you may enjoy from the same display:



That, my darlings, is a fragment of the nickel-iron meteorite that slammed into Northern Arizona about 50,000 years ago and left us with the enormous hole in the ground known as Barringer Meteor Crater.  They sell bits of it in the gift shop.  I was rather skeptical, so I grabbed a magnet with a bottle opener and a resin-encased scorpion and did a little field test.  Tink!  Yep, it’s magnetic, all right.  So I bought the bits, and a tube of rock flour.  That white powder is pulverized Kaibab limestone.  The meteor hit so hard that it turned major bits of strata right over and turned some into dust so fine that the frontier ladies used it as talcum powder.

So many rocks in that case.  So many stories.  But I shall conclude with this one:



That, my darlings, is a lovely bit of bornite, which I first knew as peacock rock.  Fascinated me as a kid.  I couldn’t care less if it was a copper ore back then – all I knew was, it’s pretty.  And I’d lost my piece.  So one of my major objectives when I went home for a visit was finding a nice specimen.  Where else to go but Gold King Mine, where I’d got my first?  If you ever get a chance, go to Jerome and visit Gold King Mine.  It’s a hoot, and they have lovely rocks and fossils in their shop.

Aside from the fond childhood memories, aside from teaching me more about the copper industry to fueled so much northern Arizona commerce, and aside from the fact it’s pretty, this deskcrop also broke the barriers between me and my newest brother.  You see, my parents had acquired a lavender-point Siamese, whom I hadn’t seen since he was a tiny kitten.  He didn’t remember me.  He wanted nothing to do with me.  I was a Very Scary Intrusion into his settled universe.  He ran from me whenever I came in – until the day I returned from Gold King Mine with a nice set of rocks and fossils.  I’d laid them out on the carpet while I sorted, labeled, and stowed for the journey home.

He inspected the fossils, creeping ever closer, and found the bornite as tasty as I do:



We have been friends ever since.  So, my darlings, remember this: geology not only provides us with knowledge, awe, wonder, and amusement, it can also facilitate better relationships with the important felids in your life.  Trust me, bonding happens.  Especially when you’re doing something fascinating, like trying to build a home for all those lovely samples:



Cats love deskcrops.  Spread the word!

Oh, Schist! And Other Stories

Flu Shot Fears? Read This

Dana Hunter1 Comment

Damn you, Connie Willis!  You made me abandon my readers to finish your damned book.  Stayed up until 7 in the ay-em to finish it, didn’t I?  Now I’m dead on me feet.  I’m too old for this shit!

Makes me wish I’d got my flu shot a few weeks ago, because it takes two weeks to become effective, and right now people at my workplace are passing around all manner of horrible illnesses.  And here I am, exhausted, underfed, and vulnerable!  Not to mention, after having been up until well past bedtime, in no condition to go out and get one just now.  But I shall be doing it soon as I recover, and with this post from Mark Crislip, I won’t be worried a bit.  Those who fear the flu shot should read this post, and take comfort.  Here are your risks, laid out in easy-to-understand comparisons:

The influenza vaccine is safe. Serious side effects are extremely rare and the risks from influenza are much greater. The vaccine is far safer than driving (30,000 deaths a year), taking a bath (450), or standing under a coconut tree (130). 

How can you be afraid of something that’s less risky than a day at a tropical beach?

For those still worried about potential side effects, Mark cites studies that show just how minimal those side effects really are.  For someone like me who’s never thrilled with the idea of someone poking needles into me, it’s a wonderful reassurance that the whole enterprise won’t be as bad as all that – and your risks of side effects go down if you get one every year.  Nice, eh?

All right, so you’ve already got your shot, or you have no fear of the thing at all – so why read the post?  Well, for one, gives you something to point frightened folks back to when they tell you they’re refusing to get their shot because of x, y and z.  If you need to persuade a loved one to protect themselves, it’s handy to have around.  It also explores why it’s important for health care workers to get vaccinated, and why mandatory vaccinations wouldn’t be a bad idea at all. 

And then there’s moments like this:

The Cochrane review, as always with influenza, gets it wrong. While noting that “pooled data from three C-RCTs showed reduced all-cause mortality in individuals >/= 60.”, they go on to say “The key interest is preventing laboratory-proven influenza in individuals >/= 60, pneumonia and deaths from pneumonia, and we cannot draw such conclusions.” No, it is not the key interest. Most deaths from influenza are secondary deaths from exacerbation of underlying medical problems. All-cause mortality is an important endpoint, especially if you are the one dying. [emphasis added]

Here, here!

So, within the next week, I’ll happily be getting my jab.  Just so long as Connie Willis doesn’t ambush me with another book, that is….

Flu Shot Fears? Read This

Wherein I Do Some Geology All By My Lonesome

Dana Hunter2 Comments

Well, actually, my intrepid companion was there, but he paid more attention to the planes.

We’ve been to St. Edwards State Park before.  It’s one of my regular haunts – I try to get there at least once a summer.  Convenient, y’see, and some of the best pebble-hunting grounds around.  There’s a place at the end of the Grotto trail where you come on a nice sandy bit o’ beach, with riprap trapping nice pools of water with pebbles in.  It’s a fantastic place to linger on a summer afternoon.  Little cold for fall, though, which is too bad, because there’s nothing like rolling ye olde pants up to the knee and plunging into the pools in search of pretty pebbles.  Last year, I even found some bits of glorious gray schist washed up, which is rare around Lake Washington.  This time, I found a few calico pebbles and a foliated chunk of something-or-other that I might, someday, be able to identify for certain, lingering close enough to the water’s edge to prevent foot-freeze.

Here’s a view of mah pebbly beach with foamy waves:



But the pebbles weren’t half as exciting as being able to recognize geologic formations all by myself.

Usually, when I write up these missives, I have some sort of guide around.  I’ve got a book or a website that’s discussed the geology in enough detail for me to puzzle things out, and thus sound like I know what the fuck I’m talking about when I babble about them.  Not true in this case!  St. Edwards has too much damned biology hanging about to be a huge geologic draw.  You have to really hunt for areas of exposure.  Luckily, my intrepid companion found one whilst we were searching for a spot where we might be able to see the seaplanes land despite all the damned trees.  There’s a narrow break between the trees, a steep scramble, a little bench of beach, and if you turn around, glory be!  There’s some bare geology:



It’s even got pebbles in!



Okay, so what are we looking at?  Later exploration revealed it’s gotta be some of that yummy Olympia non-glacial stage stuff we talked about when exploring Discovery Park.  How do I know that?  We’ll get to the smoking gun a bit later.  For now, let’s savor the novelty of having actual dirt exposed in western Washington.  This bank has a few items of interest.  Such as these lovely pebbly layers:



Yes!  I finally remembered a quarter for scale!  Good thing I hadn’t spent it on junk food at work.



Isn’t that a pretty bit of white quartz down there in the bottom left?  As for what put the pebbles there, it would take further exploration – and possibly some malicious mischief done to interfering trees – to determine if those are old stream beds or lake shores.  But we do know, from work actual geologists have done, that these sediments were laid down in a flood plain before the glaciers came.  We get lots of sand, lots of pebbles, and some gravel:



And here’s a full view of the bank where all these lovely layers may be found:



I’ve never been so happy to see a plain ol’ dirt bank in my life.  Geology changes things.  It makes the ordinary stuff seem almost ethereal.  Even the drab bits of earth are beautiful when you know they’ve got a story to tell you.  Okay, so they’re having to speak to me in “See Spot deposit some gravel!” language right now, but the point is, I now understand that I’m seeing more than boring old rocks and dirt.

So how can I be sure that this is the famed Olympia non-glacial stage stuff?  Simple.  For one thing, we’re down close to sea level, and that’s where the Olympia etc. deposits are.  Secondly, there’s a ginormous freaking clue up the Seminary trail:



That, my darlings, is a big bare bank of our old friend the Lawton Clay.  And we know the Lawton’s resting above the Olympia etc.  Ergo, Olympia down below.  My intrepid companion just gave me a bemused look when I told him to strike everything I’d said about the previous bank possibly being Esperance Sand.  (I’d gotten my elevations and strata mixed up, until I saw this beautiful exposure.)  Then he watched me get dirty in the name of geology.  Sometimes, I wonder why he puts up with me.

All right, so if I fucked up badly enough to think Olympia etc. was Esperance, how can you trust my word this is the Lawton Clay?  Well, let’s do some field work.  Is it thick?  Check.  Is it gray?  Check.  Is it clay?



Certainly chunks apart like big blocks of wet, nearly-pure clay when it falls, don’t it?  But let’s pick up a chunk to see:



You could make bricks, pots, and little sculptures from this stuff.  It’s smooth and tacky and sticks to your fingers like all that lovely modeling clay you got to mix up and splat your friends with in elementary art classes.  Yup.  That surely do look like clay!

So, if that’s the Lawton, that means we were indeed busily putting quarters all over the Olympia etc. deposits, and further up the hill, we should find…



Could it possibly be…



Yes!  Esperance Sand!  Too bad we came upon it as the trees were busy filtering out very nearly all of the remaining sunlight, but at least Handheld Twilight mode allows us some decent view of things.  Glacial outwash, baby, yeah!



We can even see some pebbles in there.  Fun times!  And a triumphant moment.  Do you know how hard it is to find any exposure of this stuff along the trail?  Up there, where things flatten out, the damned biology has taken over every available space.  There’s just a few spots where a bit of over-steepened bank caves away from the roots, and then a glimpse, a mere glimpse, of glacial outwash goodness.

As for the Vashon Till, it’s still MIA.  Probably buried under 5 billion tons of bark.

So there you have it.  Actual geology, despite the best efforts of the biology to hog the spotlight.

Wherein I Do Some Geology All By My Lonesome