Slickrock

I spent four years on top of a type section, and I never knew it.

Moi avec Page Sandstone, many years ago

I lived on Manson Mesa, in Page, AZ, where the type section for the Page Sandstone is located (pdf).  I knew it was sandstone.  I thought it had been laid down in a sandy sea during the dinosaur years, and there my geologic awareness ceased.

My geological knowledge back then suffered from, let’s be generous and call them deficiencies.  I wish I’d known then what I know now, because then I would’ve taken about ten trillion photographs of the place and gotten a lot more out of living there.  Still.  That landscape did settle into my soul.  Slickrock country settled into my soul.

It’s stark, sand-scoured, barren but beautiful.  I’d walk up the road from our house and along a dirt track, topping a rise on the mesa, and then partially descend the other side.  That’s when it would hit: the most profound silence I’d ever heard.  I’d stand there looking out over Lake Powell and just soak in the silence.  It couldn’t have been all that much quieter back in the Jurassic, when the Page Sandstone was nothing but coastal dunes marching along for miles.  They rested atop even older dunes, which are now the Navajo Sandstone.  Sandy then and sandy now.  You go to Page, you’ll become intimately acquainted with sand, both lithified and windblown.

Stand here, with me, on the sandy side of the hill.  Look over the lake.  Do you see that arm of the Colorado, meandering through the side canyons it’s carved into the ancient dunes?

The Colorado River, or at least parts thereof

You can play games with it, here, shift your perspective and spell things out.  Just there, from that vantage, it’s a J.  Move a few yards, and it’s a T.  Walking back in time.  Jurassic-Triassic.  There may even be some Triassic rocks around here – I’ll find out next time I go, now that I know more, now that I can love it for what it was and not just what it is.

Back then, I’d just stand and stare at the sapphire-blue lake incongruous in the pale red desert, and wonder how the fuck anyone could possibly call a rock surrounded by nothing but rock “Lone Rock.”

View of Lake Powell from Manson Mesa.  Lone Rock is that rock in the middle ground on the right.

On the other side of Manson Mesa, the wind has swept the stone clean, and you understand why it’s called slickrock.  It’s smooth, almost slippery, although the grains of windblown sand locked in their matrix do a pretty good job providing traction, if you know how to work it.  And I worked it.  In slick-soled boots, on dunes turned rock that weathered into rounded tops and tiny ledges on steep slopes before becoming sheer drops.  I’d run, flat-out, on ledges no more than a few inches wide, with nothing more than a few hundred feet of air on one side and high, rounded stone on the other, and I never once feared I’d fall.  The slickrock wasn’t so slick for me.  It gripped me, assured me it wouldn’t let me go.  I could trust it implicitly, even the crumbly bits where erosion was returning the stone to its original sand.  We understood each other, this sandstone and me.  We knew each others’ limits.

There was a place on the edge of the mesa where flash-floods had carved a gully between rock walls, and those stood high above the desert floor like castle turrets.  They were my citadel.  When I was up there, I was queen in my castle.  I could stand at the top of a turret and gaze over my treeless domain.

And it was treeless.  Sagebrush, a few straggling junipers, and some unidentified bushes growing along the washes were about the limit.  This is a stark, startling place, to someone who’d left an alpine paradise behind.  No mountains, no ponderosa pines reaching for the sky.  Just rock and sand with a desperate bit of biology barely clinging on, far as the eye could seen.

There used to be trees up there, legend says.  This is a landscape for legends.  You can believe nearly any wild tale you’re told, up there.  You can believe the trailer park built to house the folks building Glen Canyon Dam exploded at midnight on Halloween night in 1959.  You can believe skinwalkers stalk the darkness.  Just listen to the way the coyotes’ howls echo off those stone walls, refract and reflect and become something supernatural.  You know where those legends arise, now.  You know why, when people tell this story, you can believe it:

Back in the 1800s, a cowboy was passing near Manson Mesa on his way to Lee’s Ferry with a Navajo guide.  No lake there, then, and precious few ways to cross the Colorado, which had been cutting its way down into the Plateau for millions of years.  But there was this mesa, and the cowboy wanted to go up there and have a look.  The Navajo guiding him refused to take him up.  The cowboy demanded, the Navajo steadfastly refused.  The cowboy finally demanded to know why.

“The top of that mesa used to be covered with trees,” the guide said.  “There used to be a forest.  But something evil came to the mesa.  It scared the trees to death.”

The cowboy scoffed, went up alone, and never came back down.

Something so evil it scares trees to death.  Yes, sometimes, that’s what you feel up there.  But only close to the city.  On the side of the mesa, where it’s still wild, you may keep a weather eye out for skinwalkers, and you may feel like a very tiny thing lost in the vastness of the desert, but lean back against the slickrock and absorb the silence and you’re suddenly more at peace than you ever thought you could be. 

Besides, if you’re a geologist, you’d probably like to find that evil thing and thank it profusely for getting rid of all that pesky biology in the way of the rocks.

There’s another place, and another way, to see the rocks round there.  Down by Glen Canyon Dam, you can hop in a raft and run the river.  I never did, but my mother did, and thanks to her, we have some views that only a few people ever see.

My mother, with Glen Canyon and Glen Canyon Dam as her backdrop

I believe that canyon is cut from the older, far more extensive Navajo Sandstone, but you’d be doing me an unkindness by holding me to it.

Still.  Go up on the bridge over the dam.  There’s a walkway for pedestrians, and you can look down down down into a chasm where the Colorado flows, through sandstone walls painted dark with desert varnish.  You’ll get deliciously dizzy, standing there with a vertical drop and vertical walls.  If you’re very lucky, you’ll be there on one of those days when clouds are scudding across the sky, and you can watch sun and shadows play spectacularly artistic games on the ancient stone.  You can watch them release water from Lake Powell, keeping the Colorado flowing and the power generating, and see how wild the river can be.

The Colorado roaring down Glen Canyon

There are some places you have to leave to love.  For me, Page is that place.  All I ever wanted or needed while I lived there was to get the hell away.  Now, I’m older and wiser and miss it quite a lot.  My beautiful, barren, bewildering slickrock country, I’ll come home soon.  Just for a while. 

And I’ll come away with a piece of you, just so I can waggle it at visitors and say, “Ha!  Look at this, bitches – a piece of the type section of the Page Sandstone!”  Because there are few things in this world that a geology buff could love doing more.

Slickrock
{advertisement}

The Big Ba-Boom

It’s that time o’ year again.  31 years ago, Mt. St. Helens blew herself nearly in half and changed America’s consciousness of volcanoes for generations.  Up till then, I think a good majority of us believed that ginormous esplodey eruptions were things that happened to other countries’ mainlands.  Yeah, we’d had eruptions in Alaska and Hawaii, but, y’know, they were Alaska and Hawaii.  Always the odd states out.  (Apologies to my Alaskan and Hawaiian readers, but face facts: your states are awesomely exotic to us grubby lower 48thers).

She seared herself into my consciousness 31 years ago, at a very tender young age, and has stayed with me ever since.  One of the most exciting things about moving up here was getting to see her face-to-crater. 

I won’t go on about it – did a bit of that in my 30th anniversary post and its addendum.  Someday soon, I hope, I’ll get back out there with a proper camera and a better understanding of the landscapes created and do her up properly.  She’s just a day-trip away, now.  In the meantime, I wanted to share this post full of incredible photos that popped up via someone in my Twitter feed, I wish I remembered who.  Thanks, whoever it was!  Some of the particulars in the captions are spectacularly wrong, but the photos are still gorgeous.

Some of them I’d never seen before, like this eruption at sunset:

USGS Photo #11 taken on July 22, 1980, by Rick Hoblitt

And a perfect demonstration of why I’ll never become a vulcanologist:

Photo #21 Date 17 April 1980 by taken from USGS helicopter

If you look above the 17, just over a third of the way to the top, you’ll see a very tiny human being climbing up the slopes of a violently active volcano.  That is David Johnston, USGS vulcanologist, whose last words I’ll never forget: “Vancouver!  Vancouver!  This is it!”  They bring tears to my eyes even now.  He embodied everything it means to be a geologist studying volcanoes: excitement, discovery, and devotion to science despite the danger. 

There’s a memorial at Johnston Ridge Observatory dedicated to the victims of the blast.  Take a moment to remember them today: the visitors, the residents, the reporters, the workers, and the scientists who became a part of the mountain’s history forever.

Memorial – David Johnston’s name is one row down to the left of the rose
The Big Ba-Boom

Summer Interview Series: Who Wants to be Famous?

So I’ve got this idea: I’d like to interview a bunch of you and run those interviews throughout the summer.  You all deserve some loving attention.  First question: would anybody be interested in perusing such a series?

On the assumption the answer to that is “yes, please, Dana!” we shall move on to the next one: who’s up for answering pesky questions about their work and/or their blogging?  Alert me either in comments or at my Yahoo home, which is dhunterauthor.

Third question: what sorts of questions should I be asking, then?  We’ll start with the basics:

What… is your name?
What… is your quest?
What… is the air-speed velocity of an unladen swallow? 

(Monty Python fans are grinning about now.  Non-fans are tsked at and asked to watch Monty Python and the Holy Grail forthwith.)

All right, so those aren’t really the questions I’ll ask.  Thought, actually, I’d leave that up to you, dear readers.  What sorts of things do you want to know about working scientists and full-time writers and science bloggers?  Is there an interview question you think should be asked at every interview, but never is?  Put on your Nosy Bugger cap and get thinking.

Interviews will be conducted via email, of course.  I’d love to meet each and every one of you in person, take you out for a drink and that sort of thing, but I’ve got a limited budget and an elderly cat who will get a bit annoyed if I start jet-setting at this time of her life.

Right?  Right.  We’ll get started just as soon as we’ve got some victims experimental subjects volunteers.

Summer Interview Series: Who Wants to be Famous?

Moenkopi

Flagstaff isn’t known as red rock country.  But there’s one place, just a bit to the north, where the world changes in an instant.  Drive past Sunset Crater, and you’ll suddenly leave the black basalts and the towering ponderosa pines; the volcanics abruptly change to sediments, the Painted Desert appears on the horizon, and low, rolling hills broken by bones of rock appear.  At first, everything appears to be a subtle shade of rusty tan, nearly hidden beneath tawny bunch grasses and sage and occasional pinons and junipers.  But you reach Wupatki, and sudden, vivid red-orange rocks leap from the land.

Moenkopi Formation

The low ridges and hills crumble in slabs, broken along bedding planes.  It’s a completely different world from the ones you just left.  In parts of Flagstaff, the Kaibab speaks of shallow tropical seas.  Young volcanics, looking as if they erupted only recently (and, geologically, it happened just a moment ago), speak of fire.  But here, in this place, you’re on a tidal flat.  Rivers ran a lazy course to the western sea; worms burrowed in the mud.  This is the Moenkopi Formation, an expanse of sandstones and shales that remind you that this place, once, was on the edge of the sea.  You’re on a coastal plain in the high desert.  It feels like a different time and place; you can’t believe you drove for only twenty minutes, that the volcano you just left is only a few miles away.  But:

View Larger Map

There it is.

The Sinagua found the Moenkopi a very friendly formation indeed.  It splits off in flat bits absolutely perfect for building a stone mansion.  Enormous blocks of it that hadn’t weathered so conveniently merely got incorporated into the design, forming solid and rather artistic walls:

 
   
Building Before Bulldozers

I wonder if any of those ancient pueblo peoples wondered.  They could see cross-bedding, where the tides stirred the sediments.  They could see ripple marks and mud cracks.  They probably found fossils when they split larger slabs into smaller.  Did any of them pause and ponder?  I’m certain they admired.  The way they incorporated the monoliths into their walls doesn’t seem merely a matter of necessity, but one of aesthetics.  There are places where they seem proud to show off the attributes of the stone they used to build their big house.

The sedimentary rocks here look out on the upstart young cinder cones with some indulgence. 

Wild weathering and young volcanics

It’s almost as if the Moenkopi knows it will be there long after the cinders have eroded away.  Yes, wind and water wear down those ancient tidal flats and coastal plains, but it started its life as mud and sand.  What does it matter to the Moenkopi that it will become mud and sand again?  Someday, conditions will change, and loose sediments will be compacted into firm stone once again.  Millions of years from now, new pairs of hands may choose out pieces to put into a wall.  It might be darker then, having incorporated basaltic sands.  It might be formed from eolian dunes rather than fluvial processes.  But it will always have the echoes of the coast in it. 

This is one of the finest places in the world to just sit.  Look at the ancient coastal plain lapping up against the baby volcanics.  Sit here where the desert and pine country weave together.  Listen to the wind blow over fantastically eroded rocks.  Absorb the colors: the red and the black and the brave traces of green.  Remember the people who built their stone houses here. 

It’s a fine place to be.

Moenkopi

Kaibab

I feel like waxing sentimental about sediments again.  And one word, just one, is all it takes to put me in an altered state:

Kaibab.

Just say it: kye-bab.  Short.  Slightly exotic.  Maybe it doesn’t roll off your tongue.  Maybe it sounds a bit hard, truncated, abrupt.  It’s a Paiute word that means “mountain lying down” or “mountain inside-out.”  It’s a good name, appropriate for a formation from which you can see a mountain that blew itself inside-out.

In a land of black volcanics, red beds, and tan dirt, it’s a dramatic snowy-white in certain light, shading to a pale golden beige.  It was my first experience with the ocean.  It’s astonishingly beautiful.

Promontory of Kaibab Limestone, with ruins in the distance

Here we are, at Lomaki Ruin.  Look at the crumbling Kaibab.  Long, long ago, this area was submerged under a shallow tropical sea.  Two hundred and fifty million years later, Sunset Crater laid down a sea of cinders, which you can see lapping against the promontory.  The limestone shrugged off the young volcanic upstart here.  The Sinauga used it to build their homes, perched on cliffs of it.

Box Canyon Ruin, San Francisco Peaks, and the Box Canyon

You can see its bedding planes here in the canyon walls, with the San Francisco Peaks forming the backdrop.  Fishes swam here once.  Brachiopods, mollusks, sea lilies, and corals went about their lives in shallow warm waters, generations of them.  There was a time when oceanfront property in Arizona wasn’t a joke.  Depending on how you view matters, it still isn’t.  The ancient peoples who lived here probably never knew it, but they had ocean views.

Lomaki Ruins, with the Painted Desert in the distance

Look at that bright line of rock, far in the distance.  That’s the Painted Desert.  You can sit on the Kaibab here and look over ages, laid out in delicate, sweeping colors in the far distance.  That’s the kind of land this is.  Everywhere you turn, there’s a new scene.  And I didn’t know it as a young college student, reading about karst landscapes for the first time, it turned out I’d been living in one all along.  My old house backed onto a forest filled with limestone cliffs.  Just down the road from here is an enormous sinkhole, which we shall visit sometime soon.  The land beneath us is riddled with caverns, and in one utterly magical place, the wind blows from underground.

It was in a shallow pond at the bottom of a Kaibab canyon that I caught my first tadpoles.  The first (and only) time I shot a rifle, I was standing on a ledge of the Kaibab, aiming at a fallen log across that self-same canyon.  Hit it, too, which pissed off the boys I was shooting with – they who couldn’t hit the damned thing to safe their lives.  The shot echoed off the ancient sea walls, and a little puff of dust went up from the log, and the boys gasped and then grumbled, because a girl had just outgunned them.  They got over it.

Later, we’d ride our horses down those blocky limestone walls, finding a sure path down.  Lichen grew in shades of gray-green and brilliant orange and delicate yellow on the old stones.  Sometimes, you’d come across a surface many people had walked over, and it gleamed, polished and smooth and cool to the touch.  We had an old white-and-gray boulder of it in the middle of our yard.  It had defeated my dad, who’d had delusions of neat and tidy landscaping.  When he mowed down the weeds, he’d have to leave a little island around that boulder, which in turns became my own personal mountain to climb or a throne to perch upon, depending on what imagination required that day.  And if you turned over bits of it, you might find a nest of spiders or some really brilliant velvet ants, which would scream a squeaky sound like “help!” if you flipped them gently onto their backs with a stick.  Those were amazing creatures, black with their furry abdomens in bright shades of scarlet or orange.  They stood out like little drops of fire against the serene cream stone.

The Kaibab provided a solid foundation for excellent childhood memories.  And so you can understand why I grinned so widely, coming across a spectacular outcrop of it at the Grand Canyon:

Mi con Kaibab, snapped by my intrepid companion

Beautiful stuff.  And now that I’m older, and while perhaps not wiser but at least more well-read, I can sit upon it, gaze out over the rolling hills toward distant mountains, and dream of wine-dark seas.

Kaibab

Accretionary Wedge #34: Call for Posts

And this time, it’s gonna get weird.

Not just because I’m hosting, although that’s weird enough.  But we’re talking about Weird Geology.

Let’s face facts, people.  Geology can be strange.  Outrageous.  Bizarre.  I’m sure you’ve all run into formations and landscapes and concepts that have left you scratching your head.  Maybe they got less weird later.  Maybe they stayed strange.  But however transient or permanent that weirdness was, it got weird.

So tell us about it.  Hit us with the strangest stuff you’ve got.

And then throw me a link in comments here, or at the main Accretionary Wedge site.  Let’s say, oh, by May 27th, so that I can have us all weirded out by the 29th.

Accretionary Wedge #34: Call for Posts

Sedimentary Sentiments

Right.  So, Callan Bentley’s pointed out that we in the geoblogosphere haven’t had a good meme in a while.  My Doc Holliday instincts kicked in.  “I’m your huckleberry.  That’s just my game.”  So let’s have a meme.  Love and sediments.  Give me a sedimentary rock or structure you’re sentimental about.

I’ll begin:

Sedona in miniature

That rock there is a microcosm of Sedona.  I’m not sure what formation it came from.  Could be the Schnebly Hill Formation, or a fragment of sandstone from the Supai Group.  I picked it out of a creek bed during that memorable physical geography field trip many years ago.  It delighted me because it looked like the contact between the deep red rocks of the Schnebly Hill Formation and the blazing white of the Coconino Sandstone.  More likely, that white bit at the top just represents a long soak in the creek, but still, a girl can dream.

It’s a piece of my history.  It represents scientific discovery, and childhood, and ancient worlds.  Just a tiny thing, fits in the palm of your hand, but it stands for something enormous.

This is the place I once called home:

My Valley

If you look to the left, down in the dip, you’ll see the red tile roof peeking through the trees.  That’s my old house on Mountain Shadows Drive.  We didn’t have much of a view down there, but if you walk up the hill a bit, opposite the steep bit where my idiot dog slept in the road one night and ended up at our friend the vet’s office with my dad and the vet sewing her up while drinking beer (true story), you’ll find yourself facing a panorama that has made many a photographer scream for joy.

That little round mound in the foreground is Sugarloaf, a lump of the Schnebly Hill Formation that looks a bit like a flying saucer landed in the middle of the West Sedona suburbs.  UFOs are big in Sedona, but for some reason, the UFO freaks didn’t hang round Sugarloaf.  They all thought the aliens lived in Bell Rock instead.

The enormous mass on the left is Grayback, imaginatively named because the back of it is mostly gray, or so I’ve been told – I’ve never actually seen the back of it.  To the right is Coffee Pot Rock, which looks remarkably like one of those old coffee percolators.  I spent a good amount of my time in the shadow of those rocks, scrabbling around at the base of Sugarloaf, sliding down the loose and crumbly walls of a deep gully cut in the shales and mudstones of the Hermit Formation, upon which Sedona is built.  Where I’d grown up, in Flagstaff, dirt was tan or brown.  Down here, it was a deep, dark red, so very red that it could stain white clothes rust.  I’d come home coated in the stuff.

Those rocks were the only solid thing in my world back then.  We’d just moved down from Flagstaff, where I’d spent the vast majority of my young life.  My parents had almost gotten divorced, and while we were there, my mom had her first bouts with bipolar disorder.  I had very few friends.  I was surrounded by people even stranger than my mother (at least she had the excuse of an actual psychiatric disorder).  Little wonder, then, that I spent so much time alone in the wilderness, sometimes with my friend Crystal in tow, exploring every nook and cranny of those old red rocks with their white Coconino Sandstone hats.

They were alien to me, in a way: I identified with the volcanic peaks of the San Francisco Volcanic Field, where I’d spent the happiest years of my life to that date.  There was something almost too beautiful, too surreal, about those magnificent red rocks.  I didn’t know what they were back then.  Didn’t know I was surrounded by ancient beaches and dune fields and floodplains.  But I knew they were something special.  Sometimes, they were even friendly.  Their texture, slightly rough, gave my sneakers good purchase as I scrambled up steep cliffs on impossibly narrow ledges.  Some of the finer-grained sandstones made for good nail files in the field, for those times when I broke a fingernail climbing.

Those red rocks loomed.  They were solid, stolid, and steady, and yet could change in an instant: in the angle of the sun, in a passing cloud, in a dusting of snow or a soaking of rain.  Their colors shifted through a million shades.  I don’t know how to describe the intensity of that color, how it’s never quite the same from one moment to the next.  It doesn’t feel like a human setting.  It’s something primal and almost painful.  You are this drab little thing among it, until the colors soak in to you, and it makes you a part of it, some little wild thing scurrying in the shadow of monoliths.

Some people got interested in geology, living there.  Some people turned to crystal magic.  And some got obsessed with UFOs.  It can be hard to tell whether the local business folk are laughing at or with the UFO nuts, but they do take full advantage:

Moi avec UFO fountain at the diner

Holding that little lump of stone in my hand brings it all back: the taste of Permian dust in my mouth, gritty on my skin.  The deep red earth, in turns silty-soft and sandy.  The ancient-world smell of wet slickrock after a high desert rain.  So many long drives down from the Rim, watching as gray basalts turn to cream-colored sandstones and finally, dramatically, to rusty-hued sand and siltstones.  The coolness of that crack in the earth, tracing the Oak Creek fault, as the creek ran alongside the road, soft sound of wind and water through the open window, and the scent of all that boisterous green life – something you don’t get in many places in Arizona.  Blackberry brambles and sycamores and ferns, earthy and sweet, demanding you fill your lungs to the bursting again, again, again.  And under it all, the slightly-sharp, hot, impossibly old smell of lithified landscapes.

Sentimental?  Yes, I should think so.  How could I not be?

There’s one word for landscapes like this, and it’s the name of
a road in Sedona:

Inspirational Drive

Those are some of the sediments that I love.  What are yours?

Sedimentary Sentiments

Not For Wise Readers Only

I’ve got the outline for ye olde geology book posted for Wise Readers only.  If you’re regretting your decision not to be a Wise Reader about now, there’s still time!  Just send a request to dhunterauthor via Yahoo. 

Even if you don’t take that plunge, though, you’ve still got a chance to shape the book.  Isn’t that exciting?  And all you have to do is let me pick your brain.

I’ve got questions, you see.

Geology professionals and students: 

What are words used commonly in geology that trip laypeople up?  What terms do you find yourself having to explain (or at least sum up) every time you discuss this stuff with a layperson?  What are terms, phrases and words you believe the public at large should be aware of?  What words do you find laypeople misunderstanding because their common usage is completely different from the way they’re used in geology or science in general?  What stumped you when you first started studying geology?  Favorite geology words?  That sort of thing.

Interested laypeople:

What scientific or geologic words really throw you off?  Confuse, confound or otherwise baffle you?  Are there words you’ve heard that you don’t quite know the meaning of, but would like to?  If scientific language is a stumbling block for you, why?  Don’t be shy about admitting it – believe me, I’m among those interested laypeople who stop dead at certain words and says, “What the fuck is that supposed to mean?”

Half the fun is in finding out.  Hence, this book. 

Right, then.  Hit me.

Not For Wise Readers Only

Seattle Area Folks: Come to Science!

Friend and fellow Pharyngulite Andy McMillan is giving a talk this Wednesday night at UW.  It’s called “Shining a Light on Protein Shapes,” and is bound to be enthralling:

Proteins are responsible for most biological functions, and understanding their shape can tell about how they work (or don’t work in the case of illnesses). A common way of studying proteins is to look at changes in fluorescence from the protein when it changes shape, but the reason why this fluorescence is affected is not always obvious. I am using a combination of experiments and computer simulations to try and understand how changes in a protein could result in changes in fluorescence. 

You know howI know it’s gonna be enthralling?  Because when we went to Blind Guardian last year, Andy was talking about his work.  Had to shout out the details over some very loud heavy metal, and I almost didn’t want Blind Guardian to come on until he’d finished, even though I could only hear about half of what he said and understood about a quarter of it.  People: he made fluorescing proteins more interesting than my favorite metal band

Okay?

So I’m gonna go see him, and if you’re in the Seattle area, you should do it, too. 6:45pm.  Johnson Hall, Room 102.  Be there or be sad you weren’t.

Seattle Area Folks: Come to Science!

Accretionary Wedge #33: Now Available!

Okay, well, it has been for days now, and I’m only just getting to announcing it.  But just in case you hadn’t heard, Accretionary Wedge #33: Geology and the Built Environment: Past, Present, Future is up at Geological Musings in the Taconic Mountains.  Excellent stuff.  Get over there and get your geo build on!

Accretionary Wedge #33: Now Available!