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The Accretionary Wedge #16: Is One Life Enough?

April 7, 2009

TAW #16 (Feb 2009) was hosted at Geotripper — the original (and all the comments) can be found here.

Tuff Cookie plays with lava

Tuff Cookie plays with lava

I am pleased to host February’s Accretionary Wedge Geoblogosphere Carnival! I am impressed and gratified by the contributions; it is wonderful to learn of the fascinating places of our planet, brought to you by those who know and love them.

As you may recall, the mission set forth was as follows:

What are the places and events that you think should all geologists should see and experience before they die? What are the places you know and love that best exemplify geological principles and processes?

It was my hope that there would be a good sampling of international sites and localities (the original list of 100 sites was fairly North America-centric), and I was not disappointed. The pictures in this Wedge are from the contributors unless otherwise noted.

The very first post was from Ikenna, a new geoblogger from Nigeria who offers us the Inselbergs of Nigeria. Check Ikenna’s blog for some nice views of a variety of granite domes that dot the terrain in that region of Africa.

Terry Wright, Professor Emeritus at Sonoma State University, suggests that three places of the world that should be included on our list are:

  • Saline Valley Hot Springs and the Last Chance Thrust (these are in California, in a newly added portion of Death Valley National Park)

  • Victoria Falls-Zambezi River Canyon, Zimbabwe-Zambia
  • Darwins Outcrop-Capetown, South Africa, where he proved the igneous origin of granite.

Renee Aubrey, a high school teacher in New York suggests in an e-mail that Newfoundland is beautiful! She would add to the list two places from there – sunrise at Cape Spear (easternmost point of North America) and a visit to Western Brook Pond (landlocked fjord). She also suggests sunset from the top of Mauna Kea in Hawaii.

Silver Fox at Looking for Detachment suggests three additions to the list:

  • See a metamorphic core complex (her photo is the Snake Range in eastern Nevada, USA; I share her admiration of the landscape. I did some of my field camp work in these mountains)
  • The Tibetan Plateau
  • South China Karst

Check her post for more details
Eric at Dynamic Earth offers up the Wadi Al-Hitan in Egypt (I’m thrilled that we got so many suggestions of sites in Africa). The World Heritage Site is both scenic and full of important fossils. Read about it here.

Geology Happens went and changed the rules (oh, no!) to describe what he would do in one year, with the following choices:

Visit the type area of my favorite formations.
Do a Powell and travel the length of the Grand River system by boat.
See lava coming out of the earth. This need not be a significant event.
Climb in the Himalaya.
See a surging glacier if there are any left.
Calving icebergs
Climb an icefall
Walk a transect of some really interesting geology, coast range of California or the Appalachian mountains
Visit a deep sea trench
Feel an earthquake, again this need not be a major event.
Spend a summer at the INSTAAR field camp.
Climb the walls in Yosemite Valley

If I may editorialize a bit, that would be one heckuva year!

Julian at Harmonic Tremors (only a former music major would take a blog name like that…) suggests that simply listing the San Andreas Fault as a destination doesn’t quite do the feature justice and suggests exploring the entire length from the Salton Sea to Mendocino. Two sites are singled out for special exploration:

The Carrizo Plain National Monument, where the San Andreas is starkly exposed for all to see

The town of Hollister, where streets and buildings are being slowly torn apart by aseismic creep

Ian at Hypo-Theses offers up ten sites in the United Kingdom that ARE NOT the Giant’s Causeway but are far more geologically significant:

The Pembrokeshire Coastline, West Wales (photo below)
The Jurassic Coast
Siccar Point, Berwickshire, Scotland
Eriboll, Sutherland, Scotland
Glen Sligachan, Skye, Scotland
The Ercall, Shropshire, England
Kilve, Somerset, England
Wren’s Nest Dudley, West Midlands, England
Isle of Mull, Scotland
West Runton, Norfolk, England

Excellent descriptions and photographs can be found at his post here. Check them out!

Jessica, at Magma Cum Laude, fleshes out the idea of “visit a volcano”, including seeing an active lava flow (think blast furnace), skiing down a scoria cone, inhaling the delicious aroma of a degassing volcano, and standing on top of a stratovolcano. Check it out here, and also check out one of the things she suggests NOT to do…(that’s her picture at the beginning of the post)

Lockwood at Outside the Interzone was one of several contributors who worked with and modified the original list of 100 places, a notion I strongly support. Check his new list out here. He also added a several new ideas:

Identify an overturned sequence (not have it pointed out to you)
Spend a few minutes mesmerized by a waterfall or lake, and contemplate their ephemeral nature from a geologic perspective
Go on a geologic field trip
Lead a geologic field trip
See fossil fuel leaking from the earth at a natural seep or vent
The Mid-Atlantic Ridge, where it emerges on land in Iceland

Callan Bentley, at NOVA Geoblog responded to the original “100 things” list with a carefully considered rewrite, which he reposted for the wedge (check it out here)

Mel, at Ripples in Sand breaks the rules too (what is it about geologists and rules? But, hey, go for it!) and suggests a comprehensive list of the world’s great deserts. Her idea has the benefit of expanding our list to all of the continents (don’t forget there are polar deserts, too). He also has a nice list of dune fields that he has visited, including White Sands, shown below.

Chris at Highly Allochthonous has an aversion to visiting places just to fulfill a list, and offers us some thoughtful ideas that, in his words, “… identify occasions in my geological journey so far where my perspective has been broadened, and my understanding has been catalysed, by something that I have seen, and generalised from those examples“. His ideas (and wish list)include:
An angular unconformity
The centre of a stable continental craton
Jarring geological contrasts
Nature vs Civilisation
An active fault scarp and raised terraces
Crazy deformation
An active volcano/geothermal field
An eroded, extinct volcanic caldera
The contact aureole of a large igneous intrusion
An igneous intrusion into sediments
Seeing fossils from a Lagerstatten
Diving on a coral reef
The beach
Living stromatolites
Black/white smokers
Antarctica or Greenland (or both)

See his post for some excellent descriptions of his adventures as well as some very nice photos, including Arthur’s Seat and the Salisbury Crags in Edinburgh, Scotland (shown below).

Geotripper: Ironically, I did not spend very long thinking about how I would change the 100 things list, but in the announcement of the Wedge, I had a picture of a deep glacial canyon in the Sierra Nevada of California that was “Not Yosemite”. It is Kings Canyon National Park, and it contains some of the most dramatic and geologically instructive scenery in the entire range. Beautiful vertical exposures of granitic plutons, excellently exposed metamorphic roof pendants, highly deformed metamorphic rocks, marble caverns, glacial moraines, hanging valleys, waterfalls, river-cut gorges, and even the occasional exposure of lava flows. And…it is the second deepest (by a paltry 19 feet) canyon in North America. And despite being perfectly accessible, it has a fraction of the crowds of Yosemite National Park (which I also love, by the way).

Now, click your heels together, because after all our explorations of the big wide world, Kim, at All My Faults Are Stress Related, has one of the great ideas of the wedge this month: to appreciate the uniqueness and beauty, no matter where you live, of the ground beneath your feet. She makes a great argument: every place in the world has a geologic story, and it is almost invariably a fascinating adventure.

It’s been an adventure hosting the Wedge this month, and I deeply appreciate everyone’s contributions. If I have missed any, please let me know and I will add your contributions. You have added a lot of ideas for us to all think about as we map out the arc of the remainder of our lives. Looking over these lists I found myself thinking: Is one life enough?

Thank you very much!


The Accretionary Wedge #15: Pondering the geological future of Earth

February 2, 2009

TAW #15 (Jan 2009) was hosted by Clastic Detritus; the original post can be found here.

First, Michael Welland of the blog Through the Sandglass ponders far into the Earth’s future — 100 million years — and, inspired by Zalasiewicz’s book The Earth After Us, discusses what future geologists/anthropologists might infer from a single layer in the stratigraphic record.

Essentially none of our infrastructure, creations, and artifacts will survive 100 million years of erosion, burial, diagenesis, and tectonics in their original compositional and structural form, and we ourselves, inhabiting the erosional land rather than the depositional marine realms are poor fossil candidates – think of the extent (or lack of it) of the record of our ancestors in the African Rift Valleys.

At the end of his post reviewing and discussing Zalasiewicz’s book, Michael poses a question to the reader:

So, here’s the question, given that our appreciation of plate tectonic processes was a long time coming, difficult, and highly controversial even while their work was going on all around us, in a post plate tectonics world, how would we discern that those processes had ever happened? What would be the evidence revealed to and by geologists of the future that plate motions and plate margin dynamics had sculpted the appearance of our planet? Something to think about as we gaze more closely at other planets?

Head on over to join the discussion.

Next, Hypocentre at the blog Hypo-theses looks at just the next few decades and proclaims that global warming will cause large earthquakes to completely disappear by 2035. Don’t believe it? Well, you better go check out his post.

Silver Fox at the blog Looking For Detachment investigates where, how much, what kind, and under what conditions ore deposits might be explored for in the future:

I recommend drilling for gold in 1 to 5 million years in the Mendocino, CA, area, with 2 to 3 million years being my best estimate of the proper timing. For proper and exact placement of drill rigs, I would wait for the future, when faults and fractures controlling future ore deposits will be identifiable, and when rocks will be available for sampling.

That’s just one of several specific predictions.

MJC Rocks at the blog Geotripper doesn’t pick a certain interval of time in the future, but ponders the basic processes and relationships of processes that both cause and are affected by the evolution of the Earth within the context of Black Mesa in northern Arizona:

I have no doubt that a layer will be discovered that represents a mass extinction event wherein a vast number of organisms disappeared forever, including the mammalian megafauna, and perhaps many oceanic species, especially at the top of the food chain, such as many kinds of sharks and whales. Will we be identified as the cause of the catastrophe? Who knows? Someone or something might figure it out. Or maybe not; it might be another of those mysteries that nag and bother the psyches of those who study the earth and it’s past.

Kevin from the blog The GeoChristian discusses some events and processes that will occur over four orders of temporal magnitude (from 1,000 to 1,000,000 years) and ponders them within the context of his own faith.

Finally, here is my own post that speculates and discusses a million years worth of deposition.

UPDATE: Chris from Highly Allochthonous addresses the question many of ponder about our magnetic field — when will the polarity reverse? And how long does it take? Read the post to learn more.

The Accretionary Wedge #14: Favorite Places for Field Work

December 11, 2008

Dave over at the Geology News blog hosted the November 2008 installment of The Accretionary Wedge geoscience blog carnival. Check it out on his site here.

Apologies for getting the post up late this week. I’ve been quite busy working on a big project for this weekend in San Francisco. Let’s not even talk about how I forgot about the Accretionary Wedge last month…

Source: The Plesiosaur Site

Alright, it’s time for the next installment of the monthly geoblog carnival, known as the Accretionary Wedge. Remember, this is the first of two Accretionary Wedge posts this month. Enjoy!

For this Accretionary Wedge, I asked, “whether you’re a student, researcher, or in the industry, what is your absolute favorite place that you’ve done field work in? Where and why? What were you working on and what made it so great?”

We’ve had some great submissions. Let’s take a look!
View Larger Map


Near the Northumberland Caldera by Silver Fox.

First off, Silver Fox from Looking for Detachment talks about her favorite field area. It’s simple! Wherever she happens to be working at that moment in time. She goes on to explain some more specific areas she particularly remembers:

I spent a lot of time here, first doing some stream-sediment and rock sampling, walking around here and there, mostly from the tops of drainages to the bottoms, looking for high scintillometer readings to indicate the presence of uranium. Later, I spent quite a bit of time mapping parts of the caldera: the northern, central, and southern parts – bits and pieces, here and there, a lot of interesting rocks, formations, faults, ring-fractures, flow-domes, slide blocks, and rocks younger and older than the caldera itself. After that, I was given a fairly large budget for the time, and we started drilling like crazy, at one time having 3 core rigs and 1 or 2 rotary rigs drilling at once (way too many at once, but fortunately 2 were about to leave). That was the first year.

Chris Rowan of Highly Allochthonous shares a similar point of view regarding his favorite places.

So, does this make North Wales my favourite field area? Well, no. Because my fond memories are not so much due to the particular rocks there, as they are due to the pleasure I took in puzzling out, and understanding, the geological stories that they held. It’s been exactly the same in similar instances since; the rocks in New Zealand, or South Africa, may have been pretty cool in themselves, but my best memories are always associated with the spark of insight, the moment of “Oh, I see!” Because of that, I generally find myself looking forward to the place I’m going next, and the next geological puzzle to solve. So, in answer to Dave’s question for the next Accretionary Wedge, I have to say that my favorite field area is the next one. And the one after that, ad infinitum. Or, at least, a darn big finitum.

Big Bend National Park and Glacier National Park

Big Bend National Park by ReBecca.

ReBecca from DinoChick Blogs shares two of her favorite spots in Big Bend National Park and Glacier National Park. Here is an excerpt about her thoughts on Big Bend.

Big Bend is just a wonder – its such an odd place. Every plant there wants to poke, prick or stick you, and with the intention of making you bleed. Its hot. Not just hot. It can be ungodly hot – its awesome. There is really no shade there, so it is all sun, all the time, which is great! It does rain every now and then, that is true. Its remote, which it nice because it keeps your normal human away – you really have to want to go there to go there, because there is really no other reason to be in that part of the world. The general lack of humans can be nice (avoid spring break season however). All of the areas in the park I have worked are nice and off the beaten path so encounters with humans is at a nice all time low, which is always a plus. The geology though of Big Bend is just spectacular! It is everywhere and just so in your face (just like at Glacier). I think that may be one of the things that really caught my heart. Every way you look you just wonder – “now why is that there” or “what does this mean” – it really keeps your mind working IMO.

Colorado Plateau

Sunset at Yellowstone by Garry Hayes
Sunset at Yellowstone by Garry Hayes

Garry Hayes from Geotripper shared a few of his favorite spots for field work on the Colorado Plateau. These include the Cedar Mountain formation, the Grand Tetons, and Yellowstone.

In his series of posts, Garry recounts some interesting tales that happened while in the field.

What happened that particular evening became one of our department legends for the ages. One our students had a knack for fomenting trouble with the powers-that-be in the Universe. On various previous trips he had speculated about what it would be like to get stung by a scorpion, and within a day, he had been (unwillingly) stung by a scorpion. At a stop, he asked if we would see any rattlesnakes. He stepped on one moments later. There was a karma that hung about Craig like a hangman’s noose.

Dolomite Mountains

Dolomite Mountains by David Bressan.

David Bressan of Cryology and Co. gives us a detailed look at his favorite field spot in the Dolomite Mountains.

An approximate bipartition in the eastern Alps is caused by a mayor fault system, the Periadriatic Line, separating the Austroalpine in the North, predominated by metamorphic rocks, from the Southalpine, mainly magmatic and sedimentary rocks. The basement of the Southalpine unit consists predominantly of a monoton succession of quartz phyllites of the Paleozoic era.

Towards the end of the Paleozoic increasing magmatic activity started, one part of the melts remained struck in 12 km depth where it solidified; the other part reached the surface and covered enormous areas with volcanic deposits. This “Permian Athesian Volcanic Group” forms a solid fundament for the Mesozoic sediments that build up the “Pale Mountains”.

Fish Lake Plateau

An outcrop on the Fish Lake Plateau by Tuff Cookie.

Tuff Cookie from Magma Cum Laude shares one of her favorite areas on the Fish Lake Plateau.

I haven’t done a whole lot of research yet, but I always enjoy a good chance to get out in the field. For my undergraduate thesis, this meant spending a few weeks in south-central Utah, on the High Plateaus. The work was part of the 2006 NSF Fish Lake Research Experience for Undergraduates, a joint effort between the College of William & Mary and Coastal Carolina University. The project was in its second year, and had been inspired by past W&M field trips to Fish Lake.

My first visit to Fish Lake was on one of those trips – I had just finished my freshman year, and I was still struggling to learn all the basic skills of field mapping. As I remember, we had a discussion about whether Fish Lake was formed by glacial or tectonic processes (and I was on the glacial side, which ended up being not a great choice). Shortly after that, however, my advisor mentioned that the REU would be doing research there, and (dropping a blatant hint to get me interested) that there might be some volcanology I could work on.

Green River

Green River by Ed Adams.

Ed Adams from Geology Happens shares one of his favorite spots in a course he teaches.

My favorite class I have been teaching is the Geology of the Green River by Canoe through the Colorado School of Mines. Its nothing more than a “teacher enhancement” course meaning that the credit is only good for re-certification of the state teacher license. That said…we do some fun science on the river. The first image shows the river coming around BowKnot Bend. This entrenched meander takes 7 river miles to go less than 1/2 mile of a straight line. For Earth Science teachers who have taught river meanders, oxbow lakes and simple river mechanics in a classroom, the real thing helps them immensely in the next school year.

New Zealand

Dave at the Summit
On top of Mt. Roberts, South Island, New Zealand by Dave Schumaker.

Like many others have said, I have a list of multiple favorite places. Really, I just enjoy being out in the field. However, if I had to pick one place, it would be New Zealand. It is where I did my field camp through Massey University. We looked at a lot of various problems relating to structural geology, tectonic geomorphology, tephra stratigraphy, and glaciology.

I’ve just arrived in the town of Westport, which is on the western coast of the South Island. The last few days have been relatively laid back. We finally left the hippy conclave of Takaka (which admittedly is a nice town) to journey southwards to St. Arnaud… a small ski village located on the shores of Lake Rotoiti. We spent two days in St. Arnaud, looking at various things of geologic significance.

Among the interesting sights we got to experience, was a brisk hike up Mt. Robert yesterday (which was also my birthday), which overlooks Lake Rotoiti. After arriving at the top, we were caught in a short snow flurry, but were able to take cover in a shelter along the trail. The views from the top were quite dramatic and fascinating. However, clouds quickly moved in and it began to rain on our way down. The last few days have actually been rather rainy too, which is somewhat disappointing. I’ve never been to a place where the weather changes so fast though.


Crossing Rio Zamora (photo from JAC via Clastic Detritus.)

Brian Romans of Clastic Detritus brought us an older post on the field area for his PhD thesis, Carro Divasadero in Patagonia, Chile.

The gauchos would drop us and all our gear off and then head back to civilization (i.e., a ranch in the middle of nowhere). For this particular excursion, we were staying for 11 nights. Basically, we set up the date for them to come back and get us … and that’s how it worked (we had a sat phone in case we needed to get out earlier than planned). In the photo above, that’s Chechin and Luis riding off with all the horses … leaving the four of us … in the middle of nowhere … for 12 days.

Finally! We’re there … after 20 hours of flying, a 3 hour drive to Natales, another 3 hour drive to meet the gauchos, and then 3-4 hours on horseback (and a lot of planning before and in between all these steps).


Quartzville Creek from Lockwood DeWitt.

Lockwood DeWitt from Outside the Interzone said his favorite place for field work was Quartzville.

I first visited this area in spring of 1982 with the OSU Geology Club- more of a sight-seeing tour than anything else, but soon afterward I found this field guide (7 Mb PDF) at the library, and returned frequently. The thing that makes the Quartzville area particularly interesting is that a late-stage intrusion (about 18 Ma) emplaced a granodiorite pluton that set up a hydrothermal system. So not only can you see the guts of an arc volcanic system, you can see a range of mineralization from unaltered to complete replacement with quartz. This is not a rich district: 30 years of on-and-off mining in the late 1800’s produced about $200 thousand worth of gold and silver. But that means that no great blocks have been removed or left unsafe to investigate.

Sierra Nevada

Eastern Gem Lake in the Sierra Nevada by Callan Bentley.

Callan Bentley at the NOVA Geoblog says that his favorite spot is the Sierra Nevada in California.

My favorite place to do field work is in California’s “range of light,” the Sierra Nevada.

I did my geology master’s field work in the eastern Sierra, along the Sierra Crest Shear Zone, a major high-strain zone which parallels the eastern edge of the Sierra Nevada Batholith through older meta-sedimentary and meta-volcanic host rocks.

In 2003, I spent the summer out there, starting with my first field area at lovely Gem Lake.

Spanish Pyrenees

The Spanish Pyrenes from Ian Stimpson.

Ian Stimpson from hypo-theses also contributed his favorite place to do field work – The Spanish Pyrenees.

I am extremely lucky having a job that allows me out into the field occasionally, even if at the minute it is just down the road. In my top five I would have to include the Atacama Desert of Chile, Iceland, Colorado and the Alps but at number one has to be the Spanish Pyrenees.

I’ve been many times, as a postgraduate demonstrator and lecturer on undergraduate field courses and twice as a field assistant to a Ph.D. student. However, I’ve not been back in a long time, so apologies in advance for the scans of twenty year old slides.

The Spanish Pyrenees is a classic place to teach geology. The Spanish side (unlike the French side) is arid so there is excellent exposure, and, unlike the Alps, they are not too high and much of the geology is accessible from the roadside (with a suitable loose definition of road).


Middle Mountain from Kim Hannula.

Kim Hannula from All of My Faults Are Stress Related shares one of her favorite field locations in Vermont and remembers some of her experiences there.

love field work. No, really, I do. But when I tell stories about it, they always end up being about running out of food or wrecking vans or collecting samples of giant mosquitoes by slamming a field notebook shut or not being able to find a single sample of high-pressure metamorphic minerals except trapped as inclusions in a garnet. (And that was just my PhD area.) I’ve thrashed through ice-storm-damaged woods, taking an hour to walk a mile, in search of non-existent staurolites. I’ve fallen into streams. I’ve broken a canoe paddle while trying to cross a melt-swollen river. I’ve post-holed through snow banks. I come back from the field covered in mud, sweat, scratches, bruises, and occasionally blood from where my hammer missed the chisel and slammed the back of my hand.

The Accretionary Wedge #13: Geology in Spaaaace!

September 28, 2008

The September 2008 edition of the geoscience blog carnival The Accretionary Wedge, was hosted by The topic is “Geology in Spaaaace!” and the original can be found here.

The unprecedented threat of alien geology must weigh heavy on the minds of human Earth geologists. This month’s Accretionary Wedge (issue 13), opens the alien riddled can of worms that is Geology in Spaaaaace.

Greetings human Earth geologists and geologically interested beings of all kinds. This month’s Accretionary Wedge is dedicated to posts about, from an earthling’s perspective, Geologeeeeeeee in Spaaaaaace. In a manner befitting a species such as homo sapiens, posts will be tackled from a heliocentric perspective, starting with Venus and moving out to the entire universe. Behold the fearful wonder that is Geology in Space!

(note: if you’re reading this in an RSS reader, you’ll probably be missing out on the artwork I did for this post. Make sure you click through to get the full visual experience)


A world of beauty, or a galactic volcano in sediment’s clothing? Only Hypocentre of Hypo-thesis can distil the ancient doom of the Cambrian on Venus!

Something catastrophic may (or may not*) have happened during the Cambrian on Venus.

Maria Brumm of Green Gabbro gives cibophobics another reason to fear cakes, as she compares a plum clafoutis to Venetian impact craters in What Planet is my Clafoutis From?

Like so many moments of culinary inspiration, this plum clafoutis is nothing like what I was thinking of prior to actually wandering into the kitchen to make dinner.


The Earth. A pale blue dot suspended in a sunbeam. The target of jealous and tyrannical alien invaders. And impacts! Geology Happens relays the shocking facts about Impacts from Space!

I am cheating somewhat since my post is about a phenomenon that happens here on earth as well as in space. That is the idea of impact craters.

Tuff Cookie from Magma Cum Laude tells of impactors too in Rocks in from space. Could this be the first wave of yet another alien invasion?

Anyway, spending so much time at the museum – around the meteorites, among other things – was one of the reasons I became a geologist.


The constant, unending invasions from Mars during the 1900s should have been horrifying enough, but now SamStag from cryology and co. makes us quiver in fear at the prospect of Rockglaciers from Mars !!! Will the red menace ever be defeated!?

From all planets and minor objects of the solar system, most similarities to features of periglacial regions on Earth can be found on the red neighbour – Mars.

And if the thought of glacial processes on Mars didn’t send shivers down your spine, Brian from Clastic Detritus informs us of Fluvial Deposits on Mars! Walk for your lives!

High-resolution mapping of planet surfaces (including Earth) from orbiting spacecraft is revealing the beauty and complexity of erosional and depositional landforms.

The Asteroid Belt

The inner Solar System could have bore five terrestrial planets. The smoldering remains of planet 4.5 are what make up the asteroid belt, where material unchanged since the dawn of the Solar System remains. Though there’s no perceived threat of alien attack from the asteroid belt, who can really be sure? Silver Fox of Looking for Detachment discusses Mining the Asteroid Belt, in what can only be described as a preemptive attack to deprive potential invaders of potential resources. Potentially.

But first off, mining in space – in the asteroid belt or anywhere else – is not likely to happen anytime soon, IMO. Numerous people, however, have been looking into it, perhaps at least as long as we have been actively exploring space, beginning with our 1960’s race to the moon.


The gaseous bully of the Solar System offers up intrigue for the bravest of volcanologists. And Dave Schumacher of Geology News gives us the terrifying details of Extraterrestrial Volcanism on Io! Will the space bound geo horrors never cease!?

What is all the lava that erupts on Io composed of? Scientists do not know for certain the composition of the lava, but based on spectrometer data, Io’s surface is covered with a mix of hot, basaltic or ultramafic silicates and a sulfur dioxide frost.


The unfolding story of Titan should surely serve as a warning! Peter Polito over at Geology News regales us with tales of Titan Channels: What we know four and half years later.

One of the most fascinating things about the surface of Titan is that five years ago we knew nothing about it.  But with the arrival of Cassini and Huygens that has all changed.

Lockwood of Outside The Interzone also contemplates the channels of Titan and low temperature freeze-ray geology, as well as details of the moons of Enceladus, Europa and Miranda in A Fine Piece of Ice:

We knew there was a chance a chance of methane/ethane preciptation, we knew there was a chance of liquids on Titan. But the idea that dendritic drainage might form at 178 below zero Celsius never crossed my mind.


Disregarded as a fully qualified planet, could the menace of an atmosphere make Pluto a body of geological interest? Yes! And Chris from Pools and Riffles heralds in the new threat of the Geology of Pluto.

The hardest thing about studying the geology of Pluto is the distance. Pluto is at a minimum 4.28 billion km from earth. A little to far for a rock hammer. At that distance, even satellites have problems.

The Entire Solar System

Cosmochemists (as I could claim to be), like the big picture. The REALLY big picture. Chuck at Lounge of the Lab Lemming tells us of the radioactive horrors that endured when the solar system was dragged kicking and screaming into the galaxy, in Isotope Park.

When’s the last time your non-geological friends told you their 6 year old loves 60Fe?

The Entire Universe

MJC Rocks of Geotripper contemplates scarring the children of today with thought of the universe-sized scorpions and bears, but not as part of some sort of dome, in Done with Domes.

The ancients thought of the cosmos this way, and they made stories to go with the random arrangements of stars that formed bears and hunters and scorpions.

And speaking of space in its entirety:

How long could you survive in the vacuum of space?

You have read it. You cannot unread it. Stay tuned for more exciting geological tales in next month’s Accretionary Wedge. Your very survival could depend on it!

For those wondering, no I didn’t manage to get my thesis in on time. I’ve got a 4 week extension, though, so it’s not far off.

In the title comic book cover, illustrations of the Earth split in twain, the characters floating in space, and the terrifying martian are from various covers of the comic book series Mystery in Space and © DC Comics.

The Accretionary Wedge #12: Geology as a ‘connector’ science

August 26, 2008

The August 2008 edition of The Accretionary Wedge geoscience blog carnival is was hosted at NOVA Geoblog. Go there to check out the original post and comment thread.

When I look back on my four years of undergraduate geology education, the one thing that strikes me as the most important thing I learned is the age of the Earth. It sent my mind reeling to recognize what a huge old planet I was on, and how ephemeral was my own species’ time on it. I was a blip, a temporary arrangement of carbon, hydrogen, oxygen, and a handful of other elements that would last a while, and then disassociate. Material and energy passed into me, and out. This kinetic chemical phenomenon known as me would soon pass, and the Earth would keep turning. The human species would reach its zenith, then collapse (or evolve into something else), and the Earth would keep turning. The continents would rift and crash and the map of the Earth would soon be obselete, and the Earth would keep on turning. Climates change, meteors hit, “rivers shift, oceans fall, and mountains drift” (REM, 1985), and still the planet keeps on spinning, keeps on orbiting, keeps on keeping on.

The day I really realized the age of the Earth wasn’t the day I heard “4.6 billion” in lecture. It was the day I sat there studying and grasped it internally — it clicked that it was immensely, unimaginably old. My temporary human mind was a short-time-scale phenomenon, and it was impossible for this small cerebral system to get a grip on the true scale of the planet’s age. While I would never really know (comprehend/appreciate) the age of my planet, I tapped into something fundamental that day. Looking back on it now, I’m reminded of John Playfair’s words when his pal James Hutton took him to Siccar Point for the first time: “The mind seemed to grow giddy by looking so far into the abyss of time” (1805).

When I made that cognitive leap (by essentially realizing it was impossible for me to fully make the cognitive leap), I got stuck on geology. I connected to the study in a way I hadn’t done before. Suddenly I was subject to a dizzying temporal vertigo, as if a layer of flooring had crumbled away leaving me gazing into a bottomless pit. The realization gave a whole new perspective on things, and it was exhilarating. It felt like one of the conversations when you’re getting to know someone, and realizing that they are both intriguing and yet never completely knowable. It draws you in, connects you. Without getting too gushy, it’s kind of like falling in love. I’ve been a geologist ever since.

As I learned more, both in school and on later peregrinations around the world, I found that geology was a great traveling companion. No matter where I went, geology was there with me, showing me new things, giving me insightful perspective. I was looking at the world through geology-colored glasses, and finding that it had a lot to show me. The world made more sense on an elemental level. Hills made sense; rivers made sense; mountains made sense. While I couldn’t claim to fully understand any of these phenomena, I could claim a connection to them now that wasn’t there before. They were no longer random in my mind; they had a place in the overall system, and it took geology to make me realize it.

So this perspective has stuck with me, and it’s what inspired me to pitch “geology as a connector” as this month’s Accretionary Wedge theme. (Newbies: the Wedge is a semi-monthly geoblogosphere carnival wherein different geobloggers contribute posts organized around a central theme.) I was curious about what I would get, and I didn’t want to restrict my peers’ submissions by specifying what kind of connections should be written about.

Sure enough, different people interpreted connection differently. Tromping around in the mountains doing geologic mapping yields more than insights into local structure and stratigraphy, as BrianR of Clastic Detritus discusses how his field work has connected him to the messy reality that is nature.

Jess at Magma Cum Laude is starting her first semester as a graduate T.A., and is going to employ a teaching technique that connected her to the pervasive nature of geology: everything that the Earth puts out for the purpose of assembling Oreo cookies. Something as simple as an Oreo can be the vehicle through which students realize the manifold ways they depend on the Earth every day.

Where are the boundaries between sciences? Is geology a subset of environmental science, or physics? Or both? How do we define the different parts of Nature that we study? Using a Venn diagram, Hypocentre at Hypo-theses explores the connections between geology and other sciences, particularly in the environmental realm.

Similarly, Mel uses a diagram to explore connections in her post at Ripples in Sand. How does geology connect to paleontology? Join Mel in looking at the taphonomic bridge. (And wish her congratulations on her wedding while you’re at it!)

Joining the crowd in her first Accretionary Wedge post, A Life Long Scholar (at The Musings of a Life-Long Scholar) makes a connection between the very small and the very large. In trying to answer questions about massive tectonic plates, sometimes geologists must turn to little bundles of mass a few micrometers across. Check out her post to see how garnets can reveal the secret histories of the continents.

And then there are the personal connections. In Looking for Detachment, Silver Fox was the first one to submit a post on the “connection” theme with her description of how different members of the mining and exploration community connect to one another over time and space (Nevada, of course). How do Charles Manson, Kevin Bacon, and exploration geologists all fit together? Read her post to find out.

MJC Rocks of the Geotripper blog has contributed a real treat: an exploration of the connection of geologists teaching geologists through time. It turns out that his academic lineage goes all the way back to Agassiz and Cuvier! A pretty impressive consideration which will surely inspire the rest of us to investigate our own geologic pedigrees.

Finally, over at Harmonic Tremors, Julian shares a story of how his knowledge of geology led him to make a personal connection with one of his cinematic idols, director Brad Bird. If you’ve seen the Incredibles, you’re familiar with Bird’s high quality entertainment. When Julian heard that Bird was working on a movie called 1906 about the great San Francisco Earthquake, he wrote a letter to clear up some inconsistencies in the book upon which the movie is based. The talented director took the time to write back to Julian, thanking him for the “seismic tutorial.”

Enjoy the various and sundry posts — follow these digital connections to other geologists in other parts of the world, and feel connected to the larger community of earth scientists. Thanks to everyone who contributed. If I’ve missed anyone or if anyone wants to submit a late post, give me a shout or post a link in the comments.
Playfair, John (1805). Transactions of the Royal Society of Edinburgh, vol. V, pt. III.
REM, (1985). “Feeling Gravity’s Pull,” Fables Of The Reconstruction, IRS records.

The Accretionary Wedge #10: Geology in Art

June 17, 2008

The June 2008 edition of The Accretionary Wedge geoscience blog carnival was hosted by Geological Musings in the Taconic Mountains. Check it out.


Johan Christian Claussen Dahl: Outbreak of the Vesuvius (1826)

Well, depending on your geographic location, you have may have been experiencing similar thunderstorms as those blanketing Vermont – so I’ve stayed away from the computer until it seemed safe again! We had a great turnout and I’m thrilled to write up this summary.

I think a lot of scientists live with the dogma that they aren’t necessarily artistic or creative (i.e. – the whole left versus right brain argument). But geology is a science driven in many cases solely by imagination and creativity, which then leads to an artistic representation or recreation of a time we’ll never visit, a place we’ll never see with our own eyes, or an organism that was only partially preserved. Not only do I believe our science riddled with aesthetic values, but as your submissions indicate, many geologists also yearn to see our science within ‘traditional’ art, literature, music, etc.

Within the genre of paintings/sketches, Hypocentre offers an abstract representation of the Law of Cross-Cutting relationships from Glen Tilt painted by John Clerk for James Hutton, David over at Cryology and Co. provides a link to a fascinating sequence of glacial landscapes and a discussion on the climatic inferences one can make from historical paintings, Silver Fox describes a beautiful McLure’s Magazine cover meant to illicit and capture the life of early prospecting in Montana, Tuff Cookie posted both paintings and photos while discussing the early expedition into Yellowstone and the significance of Thomas Moran’s work in preserving this region (for past and future field camp visits?), Kim offers up a double dose of art with a Chinese painting and poem, one which I think all of us can identify with, EffJot posted a beautiful cross-section, complete with historical context, which is housed in the German Federal Institute for Geosciences and Resources – I wish I had the pleasure of walking by that one every day, and Dr. Ralph Harrington writes with exceptional talent describing Sir William Hamilton’s “Campi Phlegraei: Observations on the Volcanos of the Two Sicilies” and provides a few beautiful examples from this monograph. If I remember correctly, Hamilton is the guy who carried all sorts of materials and objects up Vesuvius to throw into the lava streams just to see “what would happen” – but I might be mistaken. And finally, albeit belatedly, Chris reminds us all that geologic maps are not only informative and fun to make, but art themselves. My undergraduate structure professor once told me that when making your map, if you’re confused about the geology in an area to “color it beautifully” to make up for that fact… This was tongue in cheek of course, but a reference to the aesthetics one should consider in mapping!

Within the genre of geologic materials, Andrew asks us to keep an eye out for anthropomorphic features in outcrop – clearly a fan of The Old Man in the Mountain, Coconino explores the link between geology and architecture in Los Angeles – and made me jealous with her choice in countertops, similarly the Lost Geologist gives us an e-walking-tour exploring Berlin’s building/carving stone origins – this seems to be a topic that is ripe for exploration in almost any city, perhaps the online geocommunity needs to provide such a service for the world? An online repository of virtual building/carving stone tours?

Within the genre of the written, the read, and the sung – Geotripper revels us with a short rendition of Landslide (anyone else care to “chime” in on their favorite geo-song), Harmonic Tremors describes a fascinating relationship between geologic processes, culture, and Javanese music, goodSchist posts a beautifully chilling Maori legend surrounding Mount Taranaki (and manages to sneak the word Emo into the post) and also provides a link to a recent discussion that might be of interest, and finally Brian posts yet another geo-relevant song – Rift by Phish – which conjures up images of topography and should metaphorically elicit a response from any geologist!

It’s a small n I know, but it seems as though geologists are still drawn to the visual – the paintings and sketches that we can interpret through ‘scientific’ eyes. The paintings of Moran, Cole, Turner, Brueghel, Friedrich, Church, etc., are easily appreciated and interpreted by our well-trained eyes. It was a real treat to see where people took this Wedge and I look forward to future posts on the topic, whether individual or whether we choose to tackle a more specific genre (e.g. – geology in music). Finally, there are some wonderful books out there that provide more information on this alternative perspective of our science: Romantic Rocks, Aesthetic Geology, Bedrock: Writers on the Wonder of Geology, and a new release I just saw in GSAToday is Home Ground: Language for an American Landscape. Thanks, this was a blast and very informative!

The Accretionary Wedge #9: Significant Geologic Events

May 26, 2008

The Accretionary Wedge #9 (May 2008) was hosted by Julian at Harmonic Tremors — check out the original post here.


Welcome to the ninth (late night!) edition of the Accretionary Wedge, everybody’s favorite geoblog carnival!

Today, 22 May, is the anniversary of the 1960 magnitude 9.5 Valdivia, Chile earthquake and its associated devastating tsunami, the largest ever recorded. I figured it would be an appropriate anniversary for posting a carnival of entries on significant geologic events, though I intended for the theme to encompass smaller and more personally-significant things in addition to (or, so it seems, in concordance with) the events that changed the world in some way.

What I didn’t know when choosing today for posting was that the the Southern California ShakeOut Scenario, a hypothetical magnitude 7.8 rupture on the southern third of the San Andreas Fault, had today as its release date. This future event – because it is a when rather than an if – is already high on my personal list of most significant events, since fear of precisely this kind of thing got me into reading about things geological when I first moved from Virginia to California, and since that reading showed me why I have always had at least a background interest in the way the Earth works, and since that in turn lead to my whole crazy change of academic directions. This is one of the reasons the 1906 San Francisco quake fascinates me so much – that there will surely be reflections of it in what eventually happens on the southern San Andreas. I know more about the San Andreas now, its pattern of destruction is less mysterious to me than it was in 2006, and it will be a focus in my MS work, but this kind of disaster scenario still scares me. I’m hoping that, if it happens during my lifetime, it will be significant to me because of understanding and survival, not because it’s my last geologic event. Yikes.

But enough about me. There was a prolific response to this theme, with discussions of events long in the past to events personally experienced, precisely the kind of response for which I hoped. Enjoy!

The Lost Geologist understandably has trouble picking a single most significant event, when there are things like meteorite impacts and global glaciations to consider, but he ultimately focuses on the personal realization that Everything is Interconnected.

Callan Bentley of NOVA Geoblog writes a kind of meta-Accretionary-Wedge post, considering two such formations, one west coast and one east. This comparison of California and DC deepened his perspective on his local geology, and highlight the message that Geology Repeats Itself.

Tuff Cookie, of Magma Cum Laude, is also a fan of subduction zones. The subduction of the Farallon Plate is fascinating in and of itself, but is particularly important to Tuff Cookie because it created Utah’s High Plateaus, the stuff of which Senior Theses are made.

Living through a major earthquake, particularly if one came close to not making it through, is a scary kind of significant. Kim, of All My Faults Are Stress Related, has every good reason to reprise her Loma Prieta story from Accretionary Wedge #2.

Andrew Alden also has a chillingly cautionary Loma Prieta story in his Oakland Geology Blog, which describes how the Quake of ’89 permanently changed the city of Oakland, and his personal connection with earthquakes.

Over at Geology Happens, the runoff from the Rockies is both a herald of spring and a show of the power of big water.

Despite her emphatic declaration that she refuses to pick one out of her set of pet geologic events, Green Gabbro‘s Maria focuses on the scouring of Fossil Gorge, a 1993 Mississippi River flood that exposed a 375 million year old ecosystem on the one hand, while engulfing hapless Iowan buildings on the other.

Hypocentre‘s post leaves the Earth itself, though not without taking a chunk of the planet along. He cites the impact that formed the Moon as being key to the development of the Earth’s rotation, core, tides, and tectonics.

Silver Fox, of Looking for Detachment, also had some trouble narrowing the prompt down to a single event, or group of events. In the end, though, she cites the tectonic shaping of the American West, which in turn shaped her geological career and the place she calls home.

On a similar train of thought, Geotripper also had a hard time narrowing things down, but came back to the formation of the Grand Canyon as being an event that shaped a career in addition to a landscape. What a fantastic place for a first ever geology field trip, if I do say so myself!

Brian, of Clastic Detritus, is also taken with the American West, though in its Cretaceous wet stage, rather than its current desert state. He describes the Western Interior Seaway, the paleogeographic puzzle it poses, and the geological epiphany that puzzle-solving was for him.

Ole Nielsen, of Olelog, goes beyond the alteration of an entire city to the near annihilation of the Earth’s entire human population. If the eruption of Mt. Toba had been any bigger, who knows if any of us would have had ancestors enough left to be sure that we would be here blogging today.

And that’s all for this time, folks! Thanks for the excellent entries! Next month’s wedge is, I believe, going to be hosted by John van Hoesen, at Geologic Musings in the Taconic Mountains, so keep an eye peeled over there for the next prompt and deadline!

The Accretionary Wedge #8: Earth Day the Geologist’s Way

April 24, 2008

The April 2008 edition of The Accretionary Wedge geoscience blog carnival was hosted at Andrew Alden’s site here.


Welcome to The Accretionary Wedge, a blog carnival with a geological theme, hosted each month by a different geo-blogger. During the course of Earth Day, I’ll be adding links as the participants submit them, so come back often, and tomorrow too.

I’ll start off. I used to kvetch about Earth Day, calling it “safe as Kleenex.” I said, “Business, environmentalists, and politicians today use science as a shield to avoid consensus, not a tool to explore possibilities.” But fortunately I think that old complaint is getting dated, or maybe my inner softheaded optimist has matured and is bursting through my chest wall. Now my message, and my entry for The Accretionary Wedge, is “Earth Day? How About Earth Life?

Two industrial geologists speak up—first GeologyJoe posts on SlingShot Thought to ask, through a cartoon, whether all the Earth Day hoopla will change anything by 2070, Earth Day 100.

Kenneth Clark, whose blog is The Office of Redundancy Office, has a daughter whose lifetime needs he is contemplating, and his message for Earth Day is simple enough for a child to understand: “clean up after yourself.” Industry can be clean; I’ve seen it myself.

Kim Hannula, of All My Faults Are Stress-Related, takes her cue from her kid too: How to save the planet? “Be a Power Ranger.” But she also wonders, if geologists are newly popular today, “why am I finding it so hard to figure out how to pitch the science to people?

Chris Town over at GoodSchist makes a plea for sustainability starting at the root of the problem. We have met the enemy and he is us, after all.

Julian, of the Harmonic Tremors blog, puts things as simply as a musician-turning-geologist would: Remember the brown part of the Earth, not just the blue and green.

Tuff Cookie, the force behind the Magma Cum Laude blog, prefers to burst into song (“cover your ears!”) with “I Am the Very Model of a Young Environmentalist.”

And just to show that we have our mystical sides, some guy at the Oakland Geology blog submits a meditation on the chthonic vision of Our Lady of Lourdes.

Not to be outdone, Silver Fox posts on Looking for Detachment about looking skyward instead, complete with the best photos in this Wedge (and a plug for Earth Science Week, six months from now).

And Green Gabbro’s Maria Brumm brings us back to Earth again with a practical question that nevertheless calls for some visionary thinking: What green habit of yours would be easier with some help from society?

The Accretionary Wedge #7: Geology/ists in the Movies

March 26, 2008

The Accretionary Wedge #7 was hosted by Tuff Cookie at Magma Cum Laude — see the original post here.


Welcome to the 7th edition of the Accretionary Wedge – and happy birthday to John Wesley Powell, one of geology’s first real action heroes! This month’s scrapings dealt with (depending on how you look at it) one of the biggest sources of headaches or entertainment for the denizens of the Geoblogosphere: Geology/ists in the movies.

Or, as some of the commentary seems to lean toward, “How Hollywood manages to screw up, in movie and/or TV form, the science that it took me multiple years, pints of blood and continuing therapy sessions to learn, and why I can’t be held legally responsible for my reaction when the students in my intro classes spout it back at me on exams.”

Just kidding – but only a little. Geology in the movies seems to bring out both the passionate and the flippant in us. We mark geology movies as points of inspiration in our journey toward our chosen profession; we happily do our best MST3K impressions while tearing apart the shoddy science; we laugh at the absurdities and turn even the worst transgressions into teaching opportunities. Seeing your science represented in film can be both maddening and gratifying, and as a result this month’s posts cover the full spectrum of praise and pugnacity.

I’ll be a little self-indulgent and mention my favorite geology movie (the video of which I’m currently ignoring in favor of writing this), the 1959 version of Journey to the Center of the Earth. I’m fond of all of the characters, even James Mason’s bellowing Professor Lindenbrook, but in my opinion, the real hero – and possibly the best geologist – in the movie is…Gertrude the duck. After all, it is Gertrude who discovers the proper entrance into the bowels of Mount Sneffels, Gertrude who enforces mine safety practices by removing stealing Madam Goteborg’s stays (which could have impeded her breathing), and Gertrude who, by being eaten by Count Sakneussem, leads the group to the Lost City of Atlantis and their volcanic escape route. (Okay, that was a stretch.) And Gertrude aside, Journey is just good campy fun. Giant mushrooms, dimetrodons, phosphorescent pools, lost cities, and singing geologists may be cheesy, but sometimes cheesiness is enjoyable for its own sake.

Had enough previews? Then it’s time for our feature presentation:

Just because you have a deep spiritual connection with volcanoes doesn’t mean you can predict eruptions, according to Chris Rowan of Highly Allocthonous. Hunches are often a good place to start, but unless you back up your gut feeling with a little science, people probably aren’t going to take you seriously. Not even if you’re Pierce Brosnan.

Chris at goodSchist takes us on a tour of the extreme geology to be found on the planet Crematoria in The Chronicles of Riddick. With a name like Crematoria and planet-wide explosive volcanic eruptions ever three hours, this place certainly isn’t going to beat out Cancun as a prime spring break destination – unless you’re a geologist, that is.

MJC Rocks at Geotripper gives us a who’s who of geologists in the movies, bringing together victims of volcanic eruptions, velociraptors, alcoholism, avalanches, and even a few who survive with only minor injuries. (Has Hollywood got a grudge against us or something?) There’s even a reminder that one of the most beloved fictional anthropologists, Indiana Jones, had his roots in a real-life extreme paleontologist.

Here’s something to look forward to – Journey to the Center of the Earth has been remade yet again! In 3D! With giant albino dinosaurs! And Brendan Fraser riding around in a mining cart! What could be better? Mel at Ripples in Sand hopes that the educational campaign accompanying the movie will be slightly more accurate than all that. (She also mentions The Great Warming, which seems to have slipped under the collective radar; I’ll put out a milk carton alert and ask, Have You Seen This Film?)

Some of us are lucky enough to be able to turn snarking into credit hours! John Van Hoesen has a class called “Geology in Film”, and brings to our attention some real classics of geo-cinema. Who knew Paul Newman did disaster flicks?

Not content to stop at a single entry, Dr. Mike at Otago has created an entire blog devoted to “Reel Geology”. Not to be missed is the entry for “Best Use of Mineralogy in a Movie,” awarded to The Monolith Monsters, which apparently features “a water-activated silica-sucking meteorite and ends with the hero saving the town by blowing up a dam conveniently located upstream of a salt mine.” ‘Nuff said.

Steve McQueen as a climate change prophet? Believe it. Callan Bentley at NOVAGeoblog gives us a lovely little tidbit from The Blob that suggests another excellent reason to step up our efforts to slow global warming…

Did you ever wish you could set the filmmakers straight? Well, Jim Repka at Active Margin might have done just that – however briefly. His close encounter with The Core may not have resulted in real science making it into the movie, but at least one anonymous writer now knows the meaning of gigapascal. (He also notes that nuclear weapons may be the next great innovation in seismology. Hmm…)

As a self-admitted Trekkie/Trekker, I was very happy to see the post by Silver Fox at Looking for Detachment about The Devil In The Dark, a Star Trek: TOS episode in which Kirk, McCoy and Spock encounter the galaxy’s first silica-based life form. Being able to mind-meld with a rock would be a fabulous asset for a geologist. Being a geologist on Star Trek, however, would not be so fabulous, as they tend to be relegated to the ranks of the Redshirts. (For those who aren’t familiar with the Original Series, Redshirt = cannon fodder. Sometimes they even manage to kill them before the episode starts.)

Run for your lives – sedimentology is out to get you! Well, not really – but it is out to get Peter Parker in the next Spiderman movie, in the form of the villain Sandman. Thanks to BrianR at Clastic Detritus for the heads-up…and hopefully Imhotep from The Mummy won’t be too jealous.

Laelaps’ multimedia post brings us once again to the exciting world of extreme paleontology, where he explores the declining standards of the Jurassic Park movies; Professor Challenger, the first paleontological action hero in various incarnations of Conan Doyle’s The Lost World; and the likelihood that Cary Grant probably wouldn’t survive a real field camp, despite being Cary Grant. (Frankly, for high odds of survival in a dinosaur-ridden feature, I’d stick with Sam Neill, although he lost a lot of cred with that velociraptor duck-call in the third movie.)

Argus Panoptes at Astronomical Seeing points out why Ross of Friends makes a worse paleontologist than Cary Grant. (He is, indeed, way too well-groomed and lacking proper paleontological attire. One suspects that his field experience is mostly limited to obtaining beer in a crowded bar during a Yankees game, and not obtaining beer while camped in the middle of the Montana desert and trying to hide a secret scotch supply from a pack of ravenous graduate students.)

It’s probably the one and only time a movie featuring a geologist has won any Oscars, let alone multiple ones. There Will Be Blood, featured in ZS’s post at Hindered Settling, takes a look at the oil industry in the early twentieth century. It also explores the less charming side of geologists, and leads us to suspect that the main character may have forgotten his coffee supply, since he at one point looks for oil in a silver mine.

Last, but certainly not least, we have doomsayer Julian from Harmonic Tremors, who warns us that the big one is coming, and there’s nothing we can do about it. Fortunately, it’s not a monster earthquake but a movie about one – an incarnation of the novel 1906 by James Dalessandro, set during the San Francisco earthquake. Though it has its faults (I had to steal that one), including, refreshingly enough, too much science, Julian advises us to put our trust in Brad Bird and Pixar. (And yes, it would be really fun if a bunch of us geobloggers went to see it together – I’m game if you all are!)

Thank you all for your contributions – and for putting up with my own snarking, which has probably grown increasingly less witty and more random, since it’s getting pretty late where I am. Next up among the Accretionary Wedge volunteers is Andrew over at Geology, who’s going to be hosting an Earth Day carnival – don’t forget to check the “Who’s hosting the next Accretionary Wedge” page for updates.

The Accretionary Wedge #6: Geohmms

March 11, 2008

The February 2007 edition of The Accretionary Wedge was hosted at the Lounge of Lab Lemming … check it out here.


Welcome to the 6th thrust-repeated section of the Accretionary Wedge. The theme this time was “Hmm.” Things about our planet that intrigue y’all. Geologists have a tendency to work on all sorts of scales, and this is reflected in this month’s entries. Sadly, though, the smaller scales were conspicuously underrepresented. Nobody is dying to know about crystal defects, space groups, or microinclusions. We are, apparently, macroscale thinkers or larger.

In fact, the smallest scale object that interesting people this month was a word. A recent GSA Today article made a new case for the Anthropocene, and the digital cuttlefish, not merely satisfied with a hmm, wrote an entire poem.

Despite the lack of comments there, the rest of the GBS had plenty to say, and none of it was hmm.
Callan offered a detailed explanation of the paper. BrianS calls it “more of a PR stunt than a rigorous scientific idea.” Andrew quotes Walt Whitman. Greg Laden says no. Chris gives some background and perspective on subdividing geologic time before suggesting that renaming might be premature. Maria calls the Anthropocene unbearably narcissistic, shortly before claiming to be partial to the term. BrianR expressed exasperation that semantics can get everyone is such a tiff. And Tom simply notes the news without comment. Note that Apparent Dip and I, both isotope geochemists, made no comment. After all, ages are properly measured in numbers, not names.

For all the hubbub, you’d think it was a four letter word, not a four syllable one.

Moving on, we scale up from the word to the student. Sciencewoman wonders- and expresses concern (more of a HMm that a hmMm) about the lack of racial diversity in her upper level classes.

Looking at the population as a whole rather than in his class, MJC Rocks wonders why people in general are not fascinated by geology. His post in accompanied by a classic field photo.

And that is it for the language/ people / culture scale hmms. From here, we step back down to the mineral.

Silver Fox wonders about some blue quartz that she remembers from her youth. Unfortunately, her favorite outcrop seems to have been covered by a leach pit.

On the laboratory scale, Maria is curious what, if anything, a neutral buoyancy experiment tells her about real systems.

Now, step up to the outcrop.

Sandstone, Interrupted! has Hypocentre puzzled by the discontinuity of his favorite bed.

Ron is wondering if his fault might swing both ways, but only preserve the medial sandstone on one side.

And the bigger faults are also intriguing. Harmonic Tremors is interested in the pre-periodic period of the Parkwood section of the San Andreas fault. He’s even lucky enough to have gotten a reference in the comments.

On the volcano scale, Chris wonders why Mt. Taranaki is so far west, relative to the rest of New Zealand’s volcanoes. I’ve only seen Taranaki from the plane, and my reaction was more of an Oooo than a Hmm, but I see his point, and suggest that he read up on Japanese volcano locations, as I seem to recall northern Honshu has two rows of volcanoes, and many run-on sentences. While the distance from the subduction zone will in part explain the increased alkalinity (deeper melting zone), it doesn’t explain why there is only one such volcano, nor why it is so pretty.

But I’m not the only one to look out a plane window. Mel said hmm all the way to her ski holiday, while traversing the snow-covered NW United States and SW Canada.

And anonymous Chris wondered about “rivers of stone” reported by Darwin in the Falklands.

Moving up to the plateau scale, Andrew presents new research on the Colorado River prior to the grand canyon formation.

And Chris Rowan wonders about the crinkly microplate style tectonics that happens where plated are grinding past or under each other.

On the hemispherical climate scale, Kim wants to know why an excessively sinuous jet stream is bringing her so much snow, while Callan wonders about global climactic and chemical implications of the hypothetical snowball Earth.

Dropping back down in size by a factor of 2 to a smaller planet, Jeannette is curious about magnetic anomalies on Mars, and what the tectonic implications are. Luckily for her, Chris Rowan blogged about this very topic, back before hmm was a fashionable thing to say.

Finally, on the galactic* scale, I’m curious about what makes our home planet the way it is. And how different planetary formation can be before it produces something completely unrecognizable.

So, there’s the list. Several people have already been lucky enough to get replies in their blogs. So if you are also intrigued by any of these things, wander on over, and see if you can help out a fellow geoblogospheroid.

I think the next installment of this carnival is Geology in the Movies by Magma cum Laude, but we should probably get her to confirm that before we bury her in rants.

[edit: two new late entries added]

*e.g. data-poor.