O.G. (Original Geochronologist) R.J. Strutt

Blogger's Note - Today we are digging into the archives of Apparent Dip. I am working on my AGU poster and not up for a brand new post, so I thought I'd re-post one of my earliest entries. My audience has grown since I first put this up (1/16/2007), and it is one of my favorites. So enjoy.

As much as I like the idea of being a field geologist, anyone who knows me also knows that the bulk of my graduate (and most likely post-graduate) geology career took place in a lab. Not just any lab, mind you, but a noble gas thermochronology lab. I primarily worked on (U-Th)/He thermochronology. In the past decade, (U-Th)/He thermochronology has exploded in popularity and has become a relatively common and useful thermochronologic tool. Of course, the more we learn the more potential problems and pitfalls we see, which is good, because that means there are plenty of papers left to write. To show you how the techqnique has really taken off, below is a chart showing the number of georef hits for (U-Th)/He by year. (I compiled this data myself rather quickly, so I am sure I am missing some relevant papers.)



In many ways, (U-Th)/He thermochronology is a cutting edge technique. But, it is also the first radiometric geochronometer. As far back as 1905, super-scientists like Ernest Rutherford and R.J. Strutt were estimating the age of rocks and minerals based on their measurements of U, Th, and He. I'd like to focus on one of these papers today, the one that I am most amazed with. It was written by R.J. Strutt in 1910:

Strutt, R.J., 1910, Measurements of the Rate at Which Helium is Produced in Thorianite and Pitchblende, with a Minimum Estimate of their Antiquity: Proceedings of the Royal Society of London, Series A, Containing Papers of a Mathematical and Physical Character, Vol. 84, n. 571, pp. 379-388

I found this paper on JStor, which most academic libraries have access to. Reading this paper and those it references I am first blown away that they could measure U, Th, or He in the first place, especially He. I spent months and months with very fancy equipment trying to accurately measure the amount of He trapped in apatite crystals. Of course, I was trying to measure much smaller quantities with much higher precision, but I am still astounded by the ingenuity with which these labs were built. For example, to meaure the rate at which He was produced, Strutt first dissolved the material in various liquids (usually combinations of acids), and placed the solutions in this contraption


The solution was allowed to sit for some period of time for the helium to accumulate. Then, the helium was gently boiled off and collected in a test tube inverted into a pool of mercury. (I'd love to try to get this experiment approved by the Health and Safety folks at the University nowadays). The collected helium was transferred into this set up



Here, the helium, in the test tube on the left. The gas would be let into the apparatus (evacuated with a mercury pump), and then the tubing would be filled up with more mercury, pushing the helium along until it was confined to area c, which is a cooled charcoal trap used to clean up the gas (an idea still used today in He thermochronology thanks to nifty devices like this



from Janis Cryogenics). After a while the helium is "drawn" into part "d" (not sure how that is done), and part "d" is filled with even more mercury, pushing the helium into the capillary "g" where the volume of helium can be measured using the length of tube the gas occupies and the pressure of mercury that is pushing it up there. As someone who regularly complains about high-tech devices that dare to come without GPIB ports or LabView drivers, this is slightly humbling. So, amazing fact #1 is that they could actually accurately measure helium in the first place.

Amazing fact #2 is that they could measure helium production rates from both U and Th with decent reproducibility.

Amazing fact #3 is that they all didn't die from Mercury poisoning (curiously, however, the lab assistants are never named)

But, the most amazing fact, that would be #4, is that the ages Strutt calculated, and most importantly the conditions he applied to interpreting that age, are really pretty good.

Below are his results from that paper

Strutt refers to these as "minimum ages," according to him "...because helium leaks out from the mineral, to what extent it is impossible to say"

In earlier papers, specifically one called Leakage of Helium from Radio-Active Minerals (Same journal as above, v. 82, n. 553, pp. 166-169), Strutt discusses some of the reasons helium "leaks" out of geologic materials, spending significant time talking about temperature. Thermally activated helium diffusion is of course now the basis for He thermochronology, something he alluded to in 1909.

So, he realizes that these are minimum ages, and his reasons make perfect sense. But his minimum ages are really not that bad. Realistically they are all good minimum ages for the time period they represent (8.4 Ma for a minimum age for the Oligocene, 31.0 Ma for the Eocene, 150 Ma for the Carboniferous, and 710 Ma for the Archean). This both blows me away and makes me wonder why it took me so long to get a lab running! It also makes me thankful that there are now good alternatives to mercury filled McLeod gauges and mercury pumps.

So, tonight I raise a toast to the O.G.'s of this world, the Original Geochronologists. I'll put another plug in for JStor, they have so many of these early papers there for the downloading.

Brett Favre Shrimp Dip

And other search terms Apparent Dip is the #1 Google hit for:

brett favre shrimp dip

electric triscuit disaggregation

severely emotionally disturbed thermochronology

extraneous Ar reservoir

urlacher apparent moses

I found the "brett favre shrimp dip" one from looking at my StatCounter, the rest I came up with sitting here.

Predicting Science News

Andrew over at About.com (the geology page) posted his fantastic idea for the upcoming Fall AGU meeting. Prior to the meeting he tries to predict what ten research projects presented at AGU would get the most print. That is, which talks or posters would show up in newspapers, magazines, and on-line. He batted an astonishing .900 last meeting (see this for his write-up on the process.) Both the prediction and the post-meeting media analysis can serve as good starting off points for science and society discussion. If I were in a position where I had students, I could also see this as a good way to make the connection between current research and the science page of their local paper.

Andrew is soliciting entries to either be posted on his blog, or linked to from his About.com page. Links are above or in my sidebar.

As a note, I know that most of you when compiling your lists will search through the abstracts for exciting terms like "thermochronology," "k-feldspar MDD modelling," or "apatite (U-Th)/He." For some unknown reason, print media has been slow to pick up on the Thermo-craze, so while I know that those are the stories you all think SHOULD be reported on the most, I'd suggest trying other themes. Someday print media will understand what the rest of the earth science community already knows (low-temperature thermochronology is hot), but for now, things like earthquakes, hazards, and climate change get all the ink.

Deskcrop #3 - Ventifacts

Today's deskcrop is a ventifact. A ventifact is a rock that has been abraded by the windblown particles: sandblasted if you will. They typically have a heavily grooved or polished surface. Large ventifacts can have the grooves aligned with the prevailing wind direction. Small ventifacts, like mine, appear to not remain stationary, and therefore can develop a "brainy" texture. Ventifacts are not all that common, reflecting the relatively small importance of wind erosion. Water (both solid and liquid) is far and away the most powerful erosive agent around; wind is much less significant. In order to see well developed ventifacts, it helps to look in places where the wind is absurdly strong, there are abundant loose and abrasive particles (i.e. sand), erosion from water is relatively minor, and you don't have to worry about plants or soil covering things up. My samples are from Ventifact Ridge, in Death Valley National Park. (legal note, these were collected by someone who had the proper permit to take a few chunks). The rock itself is a basalt, Pliocene in age I believe (but cannot confirm right now).


Besides general interest, ventifacts and other eolian-erosion related features are the best earth analogs we have for many of the images sent back from the different martian landers. Below are images taken by the Viking and Pathfinder landers thought to represent Martian ventifacts (from Greeley et al., 2002.) Greeley et al., is an interesting paper that compares images sent back from the Martian landers to eolian features in the Mojave Desert and in Iceland.


In addition to dry environments, ventifacts need time to form. I haven't found any references for the average amounts of time needed to create well-developed ventifacts, but I imagine it is strongly dependent upon wind speed, lithology, and the type of particulate matter being thrown through the air. References would of course be appreciated.

Greeley, R., Bridges, N.T., Kuzmin, R.O, and Laity, J.E., 2002, Terrestrial analogs to wind-related features at the Viking and Pathfinder landing sites on Mars. Journal of Geophysical Research, v. 107, n. E1, 10.1029/2000JE001481.

AGU Meeting Planner

I spent some time this morning searching the schedule for the upcoming American Geophysical Union meeting in San Francisco, and decided to vent. The on-line abstract searcher and meeting planner could be the most user-unfriendly and time-wasting internet tools around. I don't think AGU has updated their online searching in years, and as far as I can tell you can only export your selected itinerary as a poorly formatted email, damn near impossible to import into anything useful or make easier to read in any way. I move that AGU pays one of its computer savvy members to redesign the meeting website for next year, this time with a focus on being user friendly. Seriously, I'd be thrilled for a tab-delimited text file right about now. As it is I have about 13 printed pages of session names, posters, and talks. I think the style is properly called "dot matrix, circa 1991." I feel like printing it out on that wide green-striped paper we used when I worked for the Department of Fish and Game.

Deskcrop (?) #2 - Mantle Xenoliths

As pointed out by Ron and Kim, the next samples from my rock collection for posting are my mantle xenoliths. Xenoliths are pieces of a pre-existing rock that get incorporated into a magma but for any variety of reasons, do not melt. When the magma crystallizes the xenoliths appear as distinct bodies and are usually pretty recognizable. You find xenoliths in all sorts of igneous rocks: basalts, granites, andesites....really almost anything. Somtimes the xenoliths are pretty local in origin. This summer while sampling granites, for example, we found xenoliths a few kilometers from the pluton-country rock contact that were easily identifiable as pieces of one of the wall rock units.

Magmas that rise through the crust relatively quickly can incorporate pieces of all of the rocks they pass through. Magmas with deep origins, therefore, can bring up pieces of the lower crust, or in some cases, even the mantle.

The mantle xenoliths I have in my office are from Kilbourne Hole, a maar in New Mexico that is part of the Pleistocene Potrillo Volcanic field. Maars are explosive volcanoes that form when magma flash heats groundwater. In the case of Kilbourne Hole, a basaltic magma carrying pieces of the lower crust and mantle erupted sometime between 80 and 17 thousand years ago. The xenoliths are medium to coarse grained peridotites, with P-T-ometery suggesting origin depths up to 67 km (Thompson et al., 2005). One of the things I always think about with chunks of the mantle is how odd our perspective is as geologists. I like to show these rocks off, even to non-geologists, because they are odd-looking and distinct. But, if you assume that some flavor of peridotite (or related olivine- and pyroxene-rich ultramafic rocks) makes up the entire mantle, then this is volumetrically the most abundant lithology on earth. Most of us make our living studying the dynamics of the outermost scum of the planet. The lithologies we regard as common, ones that I wouldn't even bother displaying on my window ledge, are really some of the rarest. It is just our limited surficial perspective that makes mantle rocks seem rare, and granites or shales seem abundant. There are of course good reasons for this, but it always sticks in my head.

First, a field map (taken from Thompson et al., 2005.) I collected these rocks on a field trip in 1996 while in college. We spent two weeks going up and down the Rio Grande Rift. Kilbourne Hole is on the west side of the rift, where the obvious rift features start to give way to the Basin and Range province. The xenoliths occur as volcanic bombs, often with thin basalt crusts. Collecting the xenoliths is pretty simple, you basically walk around on the rim of the crater, picking up bomb shaped items, and cracking them open. Well worth the drive if you are in the area.


And a google maps view, you can see Kilbourne Hole as the bluish splotch in the middle of the field of view. The Potrillo Volcanic field includes the big pockmarked region to the west of Kilbourne Hole. Las Cruces is the city in the northeast part of the view, at the intersection of the interstates. Las Cruces is the home of the Whole Enchilada Fiesta. Man, I miss mexican food.

Now the mantle peridotite xenoliths!

Thompson, R.N., Ottley, C.J., Smith, P.M, Pearson, D.G., Dickin, A.P, Morrison, M.A., Leat, P.T., and Gibson, S.A., 2005, Source of the Quaternary Alkalic Basalts, Picrites and Basanites of the Potrillo Volcanic Field, New Mexico, USA: Lithosphere or Convecting Mantle? Journal of Petrology, v. 46, n. 8, pp. 1603-1643; doi:10.1093/petrology/egi028. Available here.

The outcrop I've been carting around Part 1

For the past year I've been living in the academic equivalent of the penthouse apartment. I was the sole inhabitant of a two-room office; the outer room has two enormous windows looking out over the campus. It is a first floor office, but elevated enough that I have an excellent view. This past week, the postdoc population of my group, and consequently my office, doubled. This is an excellent development on a lot of different levels, one of which is that I actually tend to work better with someone else in the office (well, I am sure there are exceptions to that, but in general it is true.)

So when I moved into the office, I had way more space than I needed. Consequently my crap kind of exploded all over the place. My rock collection was no exception. I ended up having them all piled on the heating grate under the window. This served double duty, not only was it a place to pile the rocks but it also helped regulate the air, which in the winter is set at "Thermochronic total fusion", and in the summer "Cryogenic cold trap."

So I had to rearrange all of the crap in my office, including the rocks. I've decided to photograph and post about some of my favorites.

First, I want to draw a distinction between my rock collection and my sample collection. I've been collecting rocks since my first Introductory Geology field trip (heh, some of those first Wisconsin Ordovician dolomites and glacial erratics are still in a bucket in my parent's garage.) Rocks in my collection were all picked up on field trips, during field work, while hiking, plus a few gifts. I rarely took very good notes on the samples when I picked them up, or if I did the notes are long gone. This was especially a problem early in my career as a geologist, I've been trying to work on it, but the end result is I have a lot of rocks with vague pedigrees.

Samples, on the other hand, I could take back to their place of origin and more than likely put them exactly where they came from. Samples all have GPS coordinates, they are marked on maps, and I have pictures of the outcrops before and after sampling. Why I can't replicate that for random rocks I pick up I have no idea.

So I moved all of my collection over to my side of the window, it is a little more compact, but I think it still works. Notice how I am covering up about a third of the air vent.



Today's sample is one of my personal favorites. It is something I picked up during my first year in graduate school, when I was a field assistant for my office-mate. Incidentally, Clastic Detritus provided the original inspiration for putting this rock on a post. (And, as a general inspiration, Loose Baggy Monsters recent post about her desk also inspired me to both clean and post a general shot of my workspace. Unlike her post, however, you can actually see my desk in these pictures.) As far as I remember, it is an Early Cambrian shale that I collected along the Transcanadian Highway in eastern British Columbia, just east of Golden B.C., and about as close to the Burgess Shale as you can get on the highway. I remember my office mate telling me we were actually in a late Pre-Cambrian unit, but perusing as many geologic maps as I can find makes me think we were firmly in the Cambrian. I'll hunt some more, but we'll see. Anyways, these are burrow trails in a really old shale. A trace fossil! Our ancestors!



This has always been one of my favorites to show off. Whenever I've participated in people's practice qualifying exams I use this as one of the test rocks. It is amazing how many people want to call it a metamorphic rock, staurolite schist or something.

So more to come, some with better explanations. But I bet that most professional geologists reading this blog have similar piles in their office. Show them off! Let me know and I'll link in this post.

Also, there are outcrops and roadcrops.... so what are these called? Deskcrops? Workcrops? Any suggestions? I am trying to play with the word diamictite, but it is just not working right now.

Amory Lovins and Technology

I had a chance recently to see Amory Lovins speak. Lovins (not McLovins, as I found myself saying) has a rather impressive resume, but he is bet known as the co-founder, chairman, and chief scientist of the Rocky Mountain Institute (RMI), a "think and do tank" that specializes in profitable "green" technologies. Early in his talk, Lovins drove home what seems to be his central philosphy: the profit or the environment dichotomy is entirely false. In fact, switching to energy saving technologies is extremely profitable, and any business that expects to survive and compete needs to realize that. He has countless examples or instances where the RMI has partnered with companies to help them retrofit factories, redesign systems, and adopt new materials and technologies that both save energy and dramatically increase profit. He also focuses on what he calls "breaking barriers." This means designing with efficiency in mind, and optimizing efficiency so standard items that are both expensive and inefficient are unnecessary. One of the examples Lovins uses is his own home, high in the Rocky Mountains, 16 miles west of Aspen, sitting at a beautiful 7100 feet. Even though the home is in an area that can get frost yeear-round, and will dip well below 0°F in the winter, the home does not have a furnace. Want to be more impressed? Well, the home also has a high-falootin' greenhouse, where they grown a great deal of fruits and vegetables, including bananas. Yes, growing bananas at 7100 feet in Colorado with no furnace. And, Lovins insists that the technology and engineering used to make the home so efficient is actually fairly cheap. Cheap enough that the initial costs are minimal, and the long term costs are much lower than if he had built a conventional home.

Far and away the focus of his talk was on cars. Specifically, the advances that RMI has helped to develop that can make cars lighter, safer, more efficient, and...wait for it....cheaper. The main advance is a composite carbon-fiber body with more crash absorbing power than steel, but at a fraction of the weight. The carbon-fiber is so light that even modern hybrid engines can give you excellent acceleration and towing power. They are more aerodynamic, so they are safe from big rig wind gusts, and because of a reduction in tire width, have as much traction as your standard WMD, err, sorry, I mean SUV.

OK, that part was great, yay technology! But at it's core I felt his argument was this: Efficiency is profitable, the technology is already there, so if we spread the gospel of the RMI and it's associated advancements things like CO₂ emissions and Peak Oil become irrelevant, they will just get fixed. He actually went so far as to say that Peak Oil didn't really matter.

This comes awfully close to the "technology will save us" argument, which I particularly get annoyed with. On some levels it makes sense, but realistically I feel it pays little attention to history.

The point, especially in regards to Peak Oil, is not whether or not we will run out of oil in the future. That is a certainty, at some point, non-renewable resources will become exhausted. That is why they are called non-renewable. What is worrisome is the path we will take to get there. Throughout human history, too many wars have been fought over scarce resources for me to put my faith entirely into the market and technology. One can make the argument that we are at a special point in human history where technology can bypass the nastiness that seems to accompany different groups of people fighting over dwindling supplies of some necessary good, but that is still not all that comforting to me.

I also am suspect of arguments like the one Lovins made. The idea that every company can make a big profit and, perhaps more importantly, position themselves as a leader in their industry while saving energy. I am sure there is inertia in all industries, but I find it hard to believe that there are all of these companies passing up profitable ventures. If it is such a no-brainer, as Lovins suggests, then why hasn't it been adopted wholesale?

In truth I was very excited about most of the talk, and most of my critiques stem from three "party fouls." First, Lovins was at our University as part of a University-wide speaker series in honor of a geologist who passed away 3 years ago. Yet he was at best dismissive of the use of the earth sciences in addressing global environmental problems. I thought that was bad form. I have heard that Lovins is a big proponent of "speaking to your audience," or using the correct message for your particular group of listeners. This talk would have been right for a group of people who's primary concern is how much they have to spend on gas for their next SUV, not for a group of academics with a heavy showing of earth scientists, in honor of a well-known geologist who worked on climate change!

Second, PowerPointless. Lovins used the kind of PowerPoint presentation I have been trained for years to avoid. Text text text, in random colors, tiny print, the works. Graphs with unreadable axes that he did not bother to explain. Stats and numbers and profit margins without any reference or discussion of where the data comes from, or what other forces may have contributed to the trends. If he was a student in my class I would have told him he should have spent more time preparing the presentation. My guess is that he gives this one, or some variant on it, dozens of times a year. He should hire a second year graduate student to smooth it out.

And finally, much of the talk focused on potential energy savings from transportation. Let me rephrase that, much of the talk focused on making more fuel efficient cars. That is a good goal, but not once did he mention applications of these technologies to public transportation, or RMI's position on creating well designed high-density housing integrated with business and commercial properties, you know, cities. As much as I love the idea of living in a sustainable home at 7100 feet in the Rockies, I also believe that any calculation of the amount of energy required by the house must take into account transportation to and from the house. You know, to the grocery store, hardware store, soccer practice, work.....These things weren't mentioned once. Again, maybe he was "talking to his audience," but I felt it a glaring omission. It actually reminded me of a recent trip to Washington D.C. to visit metcaffeination. We went to the National Building Museum, and ended up looking through the Green House Exhibit. Although I thought some of the displays and materials were interesting, almost all of the example homes were in the fricking middle of nowhere! Oh look, I have to drive 30 miles to get to my house but when I am there I can do my laundry with 33% less water. Well, why not put those things in city homes? Near public transport? Within walking distance to work?

OK, a little bit of a diatribe. In general I was impressed by his talk, the examples he gave of profitable and energy saving innovations were really interesting. But, I left the talk in general feeling very disappointed. Lovins missed the mark with me. RMI is doing good things, don't get me wrong, and Lovins has done a lot of impressive things. Anyone else have similar experiences? I'd be interested to know.

While thermal models run.....

I owe him little thermochronology and less love.

Which work of Shakespeare was the original quote from?

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....I mess around online

Cry 'Havoc!', and let slip the thermochronology of war.

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Never was a story of more woe
Than this of Juliet, and her Thermochronology.

Which work of Shakespeare was the original quote from?

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Come not between the thermochronology and his wrath.

Which work of Shakespeare was the original quote from?

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O thermochronology! O gentle thermochronology!
Nature's soft nurse, how I have frighted thee.

Which work of Shakespeare was the original quote from?

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and finally, for when I get the ICPMS results back and calculate the ages for my (U-Th)/He samples

Presume not that I am the apatite I was.

Which work of Shakespeare was the original quote from?

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This could go on forever, I must now stop, head upstairs, and check the feldspar MDD models.


UPDATE!
Ha! This will never grow old!

Friends, Romans, countrymen, lend me your thermochronologist.

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Beware the geologist of March.

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Red Rock Canyon State Park

Red Rock Canyon State Park, in southern California, is usually the first stop on the Death Valley field trip my graduate department used to run over spring break. I had the chance to TA this trip once, and went on the trip a few other times. These pictures are from the apring of 2006, the last time I went on the trip, and the last time I've been in the area.

The Red Rock area has some spectacular exposures of Miocene fluvial sandstones, eroded in many areas into badlands style topography. During the Miocene, basin and range style extension was active all throughout western North America, eventually creating the corrugated morphology we see today. As I mentioned in this post, as the crust was stretched apart, it was broken into upflited ranges and downdropped basins.

The ranges are beautifully exposed, from California to Utah. Many geologists have made their careers understanding the ranges. The basins though, are buried, and therefore much more difficult to study. There are a few places where the basins have been dissected or are otherwise well exposed, and Red Rock Canyon is one of them.

The pictures are various views of the area, showing the Ricardo Formation dipping to the west. The beds have variable dips, reflecting their deposition during basin formation. In the first picture, I am standing on one of the interbedded basalt flows. In the background of the image you can see a more gently dipping surface.




And a close-up of the actual rocks

The Ricardo Formation is famous for it's fossils. This page is dedicated to the paleontology of Red Rocks, and includes boatloads of images of some of the finds. And to finish, some scenery from near the Ricardo campground.

A Joshua Tree

And a student on his way back to camp.

Mineral Separations Part 2

So I was really interested in all of the comments I got for my first mineral separation post (here). So I decided I'd try to make a list of the various steps people seem to use. This may be a little repetitive considering my last post, but it's been in my head, so if you are tired of mineral separations, go read one of the other fine blogs in my sidebar.

Separating minerals has the end goal of pure piles of individual minerals. You are often searching for relatively small and not all that abundant. Mineral separation techniques are equivalent to burning the haystack to find the needle; taking advantage of various properties that remove minerals you don't want, and leave what you do.

The first step is almost always turning your rock sample into a pile of individual minerals. There are two primary ways people do this.

1. Crushing and grinding. Jaw crushers (like the Bico Chipmunk) reduce fist sized rock chunks into small pellets. Disc mills, or pulverizers (like the Bico UA Pulverizer) break these small pellets into sand. The hope is that the minerals preferentially break along grain boundaries, but themselves stay realtively intact. Realistically it is difficult to tell what percentage of the desired minerals are broken beyond recognition (a real problem in the (U-Th)/He world, as I blogged about here and here), but I would not be surprised if the total yield from a standard pulverizer was 50%. As far as the actual machines go, there really aren't that many options when it comes to the jaw crusher, you can buy large ones and small ones, but they operate in the same way. With the pulverizers, there are two main options in style; you can have them belt-driven or direct-drive. Unfortunately Bico no longer makes the direct drive model, and if anyone knows of another supplier, please let me know. The belt drive models are OK, but much less powerful and much more difficult to set up. Pulverizers work by grinding your sample between two metal plates, and the quality of your grind depends on how far apart the two plates are set. Belt drive plates tend to drift during grinding, whereas the direct drive plates stay set. Think of coffee, you want a standard drip grind, but the belt drives give you some drip, some espresso, and some french press. The other option with pulverizers is the material the grinding plates are made of. You can get various steel alloys, iron, and even ceramic. I have recently started using the super expensive Mo-steel plates and have now become a complete convert. Iron plates leave filings in your sample, which have to then be removed. The Mo-steel plates do not "shed" and consequently do not wear down as fast. Again, I'd be interested in other other experiences.
2. Electric Pulse Disaggregation (EPD). EPD machines are now commercially available, although they are still pretty pricey. They were originally developed for use on lunar samples, where the waste generated during standard crushing and grinding would have just been unacceptable. The company marketing them now is called SelFrag. They have a pretty good website (complete with downloadable video), but don't show enough examples of separated crystals. EPD works by sending an enormous pulse of electricity through your sample, causing it to fall apart along grain boundaries. EPD separates whole crystals, even preserving delicate surface features. Bernhardt Saini-Eidukat at North Dakota State University has a nice page showing images of EPD separated minerals, I think made using a home made device.

Once your rock sample has been turned into a pile of sand, the order of the steps becomes somewhat arbitrary. It depends on preference, what mineral you are aiming to separate, rock type, and sample size. So I'll present the options in the order I tend to do them. The next step, for me, is to concentrate the dense minerals (namely zircon and apatite, but monazite and sphene also count). This is typically done hydrodynamically, using machines that are basically big gold pans. Gemeni tables and Wilfley tables work on the same principle: your sample is slowly introduced onto a sloped and vibrating grooved table that has a constant stream of water running over it. The "heavy minerals" are preferentially caught in the grooves, while the "light minerals" get washed away. You then collect the heavy and light fraction in buckets, and can effectively reduce your pile of sand from a big bucket to a small beaker. At one point in grad school I collected and separated some of the Fish Canyon Tuff. I was unimpressed with the total amount of apatite and zircon I ended up with, and decided to go back to the light fraction from the gemeni table and see if I had missed some substantial amount of apatite. I tried everything and ended up discovering that there was absolutely no apatite or zircon in the gemeni light fraction; they are pretty efficient machines.

I've also heard rumors of skilled geologists using actual gold pans to separate minerals. I am terrible at gold panning, and have never tried it with anything but river sand.

After hydrodynamic separation, some samples may need to be cleaned and/or washed. For granitoids, this means just time in an ultrasonic and rinsings with ultra-pure water. But you may also want to soak in acetic acid (to get rid of carbonate cements), hydrogen peroxide (do dissolve organics), or some other chemical (again, I'd love to hear more examples).

Two of the primary minerals geochronologists are interested in are non-magnetic (apatite and zircon). Minerals have slightly different magnetic properties, so the next step in separations is to take your cleaned heavy fraction from the gemeni table and run it through a Franz magnetic separator. Using a Franz is simple, your sand is slowly let into a vibrating metal channel that runs through a large electromaget. The magnetic field acts on the grains as they move down the channel, pushing the "magnetc" fraction to one side of the channel. You end up with two different streams of mineral grains, the magnetic and the non-magnetic, which can easily be collected once they exit the magnet. You can vary the power of the magnet, and really skilled users can effectively separate out very pure piles of magnetic minerals, including monazite, sphene (yes, I still call it sphene), different micas, amphiboles, etc... When you are done with all of the magnet powers, you are left with the non-magnetic fraction. This is hopefully mainly apatite and zircon, but is usually contaminated with quartz and feldspar that made it through the gemeni table. That means, time for the heavy liquids.

In my last post I mentioned a lot of heavy liquids, but I realized afterwards I should be more systematic in my presentation. So I'll try. First with a list of the heavy liquids I know about, then a brief discussion of the different ways to use them. All heavy liquids separate minerals by floating things less dense than the liquid, and letting the rest sink.

Heavy liquids I know about (most available from GeoLiquids or Sometu):

1. The Tungstates: Sodium polytungstate (SPT), lithium polytungstate (LST of FastFloat) and lithium metatungstate (LMT now discontinued) : ρ=2.5-3.1 g/cm³. These liquids have the distinct advantage over all other products in the fact that they are non-toxic. Many of the other liquids I'll mention are nasty things, but the tungstates don't even require a fume hood. Their only downside is their relatively high viscosity, which means it takes a while for your heavy minerals to sink, and filtering the liquid is kind of a pain. But I don't care, the safety and freedom from the hood is well worth it. SPT, LPT, and LMT will float quartz and feldspar, and sink apatite, zircon, and pyrite (argh, pyrite).
   
2. Tribromomethane or Bromoform : ρ=2.85 g/cm³. Bromoform is not pleasant to work with; it is very toxic and you have to avoid both skin contact and inhalation. It can be especially bad for your liver and kidneys, oh, and even better news, it might be a carcinogen. Bromoform has the same use as the tungstates, which begs the question, why does anyone buy bromoform?
3. Thallium foimate or Clerici Solution : ρ=4.32 g/cm³. I've only heard of this in legend, well, and I've seen a locked cabinet with a "Warning, Clerici Solution" on it. I am guessing you use it to sink zircon and float apatite. Or you use it to destroy your enemies, I am not sure. I think I'd rather hand pick apatites from a pile of sand than use it. From the MSDS "May be fatal if swallowed. May be fatal if absorbed through the skin. Causes respiratory tract irritation. Causes eye and skin irritation. May cause digestive tract irritation. May cause central nervous system effects. May cause liver and kidney damage. May cause cardiac disturbances."
4. Acetylene Tetrabromide or Tetrabromoethane (TBE) : ρ=2.96 g/cm³. TBE, by the way, is also called Muthmann's Liquid, I like that name, had never heard it before tonight, and thought I'd mention it. (could diet coke be called Thermochronic's Solution?) TBE is nasty, but allegedly less nasty than Bromoform, but is dangerous in similar ways, it attacks organs, is an inhalation hazard, and can be easily absorbed through the skin. TBE has the same general uses as Bromoform and the tungstates (separating apatite and zircon from quartz and feldspar). I've used TBE to make "feldspar juice" ρ=2.58 g/cm³, which lets you float k-feldspar and separate them from quartz and plagioclase feldspar. I've been able to get very pure feldspar separates, some of that data I'll be showing later.
   
5. Methylene Iodide or Diiodomethane (MEI) : ρ=3.32 g/cm³. MEI is also nasty, but it has a really low viscosity and you typically don't need to work with large volumes, thereby decreasing the hazard. MEI will float apatite and let zircon sink, which is what it is mainly used for. Using MEI isn't too bad, the real danger is that you wash it with acetone, and the mixture of MEI and acetone is very flammable. If it catches on fire you would rather not be in the vicinity. But that is easy to avoid.

So as far as I can tell there are three primary ways people use the heavy liquids. I have only tried two of them, but here we go:

1. Separatory funnels. These are straightforward to use, the have a valve at the bottom, you fill them with the liquid, dump in your sample, and let things settle. You can then open the valve, let out the dense minerals that have sunk to the bottom, but leaving the light minerals in the funnel. Separatory funnels have the advantage of being simple and easy to buy, but they use a large amount of liquid (50 - 100 mL), and because of their design can often leak. In addition, many are made with plastic valves, which get abraded and can actually have lots of little mineral grains stuck in them, that are almost impossible to clean.
2. Constriction tubes and knitting needles. If you've never tried this, check out the classic paper Dumitru, T.A. and Stockli, D.F., 1998, A Better Way to Separate Apatite From Zircon Using Constriction Tubes, in P. van den Haute and F. De Corte (eds) Advances in Fission-Track Geochronology, p.325-330. These allow you to separate small samples using only a few mL of liquid. Check out the article for a description, and when the web resource describing the technique become available I'll post a link. Any description I try to do will just be confusing.
3. Liquid Nitrogen. I've never tried this, but Ain't From Around Here says she's going to try it, so I am eagerly awaiting the results. The idea is that you put your sample and the liquid in a tube. Some people then centrifuge the tube, but even if you don't, you give things time to settle and separate. You then stick the bottom in liquid nitrogen, freezing the bottom liquid and effectively trapping the heavy fraction. The light fraction is then poured off, and you then just have to wait for the frozen liquid to thaw, and then pour off the heavies. Allegedly the liquids are not damaged by the freezing.

After this you are left with piles of pretty pure individual minerals. Some phases are easier to separate than others, but this is at least a good place to start. Each technique you use, at least for geochronology, has more steps, but they all begin with pure separates. If I missed something please comment or email. Mineral separation is really an amazing thing to watch. Parts of it are a pain, but some of the steps are just incredible. My favorites are the Franz and using MEI. In both of those you immediately see the separation....very gratifying.

The Art of Mineral Separation

UPDATE - My next post is a more complete discussion of mineral separation.

When many people in the geochronology/thermochronology community talk about new gadgets and gizmos on their wishlist they seem to focus almost entirely on the sample analysis side of things; particularly multi-collector noble gas mass spectrometers and various high end lasers. I'll admit, these machines are impressive and could be potentially very exciting, but if I had a pot of money to spend to increase the quality and quantity of the data my labs produce, they would not be the first thing I'd look into.

In a broad sense, doing meaningful thermochronology requires 4 basic techniques.

1. You must be able to identify tectonic and/or geochemical problems that can be be at least partly addressed thermochronologically. This starts with the big picture, but includes consideration of available lithologies and access to the necessary samples.

2. You then need to collect and process the samples. This means turning a 5 kg sack of rocks collected carefully in a very specific location to individual mineral separates ready for your lab.

3. Once you have mineral separates, you need to analyze them in a lab. Although actually collecting data in a lab is fairly trivial, running a lab well enough to insure that your data actually means something is not.

4. Once you have the data, you need to interpret it, again in order to answer the original tectonic and/or geochemical problem you set out to solve in the first place.

Steps 1 and 4 are probably the most complex, and in my opinion are the hardest skills to develop. To design and interpret good projects you need a strong background in basic geology and need to consult all of the experts that relate to the study. In my own work I need enough background to understand what the petrologists, sedimentologists, geophysicists, geomorphologists, structural geologists, and geochemists think. This requirement is not unique to thermochronologists. I'd argue that any geologist who considers tectonic questions is necessarily broad in scope. So steps 1 and 4 I see as general considerations for any earth science study.

Step 3 receives a great deal of attention. I've been a thermchronologist for less than a decade, but even in that time the number of new and expensive machines and techniques has ballooned. I've been involved with building and maintaining labs, and therefore have paid a lot of attention to these advances. As I've gone on in my career, I've started maying more attention to who gets what lab upgrade funded, or what people get with their start-up packages, or what they negotiate for when they have leverage. Right now the flavor of the day seems to be multi-collector noble gas magnetic sector mass spectrometers; these allow for the simultaneous measurement of all of the different isotopes you need to measure for whatever technique you are involved in, thereby cutting down the uncertainty and time lags of changing magnet power, yada yada yada. I won't get started on that.

What I do want to talk about is step 2, sample collection and preparation. In particular I want to talk about turning a rock into an individual mineral, a process called mineral separation. Mineral separation fascinates me, but what really amazes me is how many people either ignore or do not understand the process.

Here is the problem: for almost all analyses you need to analyze pure mineral samples. Techniques which work on small single crystals (fission-track, (U-Th)/He, U-Pb) typically require minerals that are small (100-200 microns in length) and not overly abundant in the average granite (maybe form a 5 kg sample I'll get a few milligrams of apatite). Techniques that work on multiple crystals (biotite, muscovite, and k-spar Ar/Ar), typically require a few milligrams of very pure separates. They both, therefore, require methods of separating a rock into piles of individual minerals. Mineral separation is a blanket term that describes the various ways to turn a rock into a sample. The first step is almost always reducing the rock into individual mineral grains. This is typically done by crushing and grinding the sample, trying to get the minerals to break apart along grain boundaries.

In my experience, the next step is to run your sample over a rogers or gemeni table. These are basically large gold pans that concentrate the denser minerals (apatite and zircon in particular) into a smaller pile. This is then washed and dried, and run through a magnetic separator, basically a large magnet where you can vary the power and separate minerals based on their magnetic susceptibility. This is done is a series of steps, and a skilled mineral separator can obtain almost pure concentrates of the various "magnetic minerals" such as biotite, hornblende, and monazite. When you are done, you are left with a pile of non-magnetic mineral grains, including apatite and zircon.

If you need to get apatite and zircon, you must then enter the world of heavy liquids. Heavy liquids are exactly what they sound like, liquids with very high densities, anywhere from water (1.0 g/cm³) to 4.4 g/cm³. Because minerals have fairly specific densities, they will either sink or float in different heavy liquids. Zircon is very dense (4.6-4.7 g/cm³), and will sink in a liquid like MEI (Methylene Iodide density=3.33 g/cm³), while apatite (density 3.2 g/cm³) will float. Heavy liquids have been used in geology for a long time, but the particular liquids and their methods of use have changed significantly. Many of these liquids are toxic, and therefore kind of a pain to work with. Two of the nastier liquids I have fortunately never worked with, those are Clerici's Solution (Thallium Malonate density=4.36 g/cm³) and Bromoform (Tribromoethane, density=2.89 g/cm³). Clerici's Solution and Bromoform are not all that common anymore, mainly because there are now less toxic alternatives. TBE (tetrabromoethane density=2.95 g/cm³) is also fairly nasty, but is still in use in many labs, primarily because it has a lower viscosity than its non toxic alternatives SPT or LMT (Sodium Polytungstate or Lithium Metatungstate, density 2.85 g/cm³).

I was lucky in my graduate education to learn from one of the masters of mineral separation. While many people have used the same techniques and materials they learned on decades ago, my min sep teacher has continually improved and refined his techniques, trying as best as possible to increase cleanliness, and efficiency, and reduce unnecessary exposure to toxic liquids. He tells me he will soon have a web resource of his methods available, which will be advertised heavily on this blog. I am presently trying to implement some of his methods in my new lab. This is the first time I have had to work with TBE, or with large quantities of MEI, both of which, in my opinion, are completely avoidable.

But what fascinates me is how little attention this necessary step in thermochronology, or geochronology, typically receives. Would anyone dream of asking NSF Facilities for money to upgrade a mineral separation lab? The amount of time and money wasted in mineral separtion is really astonishing. I think though, that one of the reasons these facilities rarely receive the attention they deserve has to do with the hierarchy of the average thermochronology lab. One of the first jobs you delegate with increasing seniority is mineral separation. Right now we have a fleet of undergrads working for us helping crush, grind, and separate minerals. The drive to streamline the procedures is reduced when those of us in charge no longer have to do them. My main reason for trying to improve the set up is primarily because I don't like the idea of an 18 or 19 year old handling liters of TBE on my behalf, especially when there are good alternatives. Although old ways die hard, I think I have convinced a critical mass to support my efforts, and was even able to put in an order with our glassblower this week.

Aside from heavy liquids, I think the most exciting (albeit expensive) recent advancement in the art of mineral separations is the introduction of commercially available electric pulse disaggregators (EPD's). Instead of physically crushing and grinding rocks, EPD's send a pulse of electricity through your rock, which causes minerals to break apart along grain boundaries. The technique has the advantage of retrieving the crystals from the rock intact, that is, you don't run the risk of physically breaking them apart (a huge advantage for separating apatite.) The method was developed originally to work with small and relatively expensive lunar samples, but is amazing in what it can retrieve from a rock. The link above includes a movie showing how quick and easy the process can be. Although it would increase the quality and throughput of samples, they right now are pretty pricey (well, from a geologists point of view, from a college athletics perspective it would cost about 0.33 D1 college football coach yearly salaries, and in my current situation would have only 2 fewer wins.)

I believe wholeheartedly in the garbage in, garbage out philosophy. This is one reason that I think a great deal about mineral separation. I think when it comes to bang for the buck, this could be one of the best ways to improve lab productivity. I'd be interested in other people's experiences with mineral separation, especially if you have used something safer or less toxic that the heavy liquids I described.

Fighting Pseudo-Science, Prime Time Edition

Unfortunately I did not write my contribution to the Accretionary Wedge #2 (How the Earth Can Kill You). I am going to post this thought though. although I understand it is a poor replacement. Read the Accretionary Wedge first, there are some excellent contributions this time around, then you can come back here.

During an ad break in a football game Sunday I overheard a promotion for a new show on NBC, called Phenomenon, which is allegedly in search of the world's new "mentalist". The show is starring Chris Angel (who had a magic, err, excuse me, mentalism show called MindFreak where he entertained with a "distinct blend of magic, mentalism, and dazzling pyrotechnic effects") and Uri Geller. That's right, wanna-be magician, swindler, liar, and all around jackass Uri Geller is trying to make a comeback. For those of you who don't know who Uri Geller is, (or why he is always standnig around with an ED-afflicted spoon) he came to fame in the 70's with his claims of psychic abilities, including his most famous illusion, bending a spoon with his "mind." The folks over at the Denialism Blog have a nice summary and two exceptional videos showing 1) Geller getting debunked live on the Tonight Show thanks to tips from skeptic and debunker-of-BS James Randi, and 2) One of Geller's "secrets" getting caught on camera.

Even though Geller was before my time, I know of him primarily through my brother, who became a big fan of Randi's when we were young. My parents also took us to a live show where James Randi was the main speaker (and where my brother got to be the person who held the magic spoon as it was bent and broken by Randi's "mind"). I have no problem at all with illusionists, I think they can be entertaining, but whenever anyone tries to pass off their tricks as proof of supernatural abilities, well, that's just too much. People like Geller (or even worse Peter Popov, also featured in the videos I linked to) often use their tricks and personality to swindle people. Although these are two extremes, I think these characters and their techniques speak volumes about our role as scientists in society. We do not know everything, we aren't always right, and science has been used for plenty of bad reasons, but one of our duties, I believe, is to single out and call Shenanigans (or BS) when applicable. Although many things we see are not as blatant as Geller or Popov, they can be much more dangerous. Most pseudoscience is really just a slight variation on their themes, misdirection and manipulation. We see it with the ID crowd, the young-earth crowd, the "CO₂ is life" crowd, it's really the same idea, misdirect and make it so there appears to be only one possible answer. I think the use of the term "irreproducible complexity" (a Beheism) is a direct analog to the "mentalist" illusion; It must be ESP/Supernatural Forces, what other explanation is there?!?!?

What is most baffling to me is this: Geller's whole spoon thing is completely debunked, so how does he get away with it? Maybe that is his real magic trick, convincing people to continue to believe his BS even when he's been outed a thousand times. Popov at least went bankrupt, but now Geller gets a new show?

And finally, am I the only one who is convinced that Uri Geller was the inspiration for Gob Bluth from Arrested Development, perhaps the funniest American television show of the last 5 years? You be the judge, can you guess who is who?



And just in case the video link from the Denialism Blog isn't working, here is one of the videos I mentioned

The Barton Garnet Mine and Fall in the Adirondacks

This Saturday I was able to tag along on a mineralogy field trip to Gore Mountain, in the Adirondack Highlands, home of the Barton Garnet Mine. I was especially excited about this, even as far back as my mineralogy course (12 years ago?) I remember seeing samples of these garnets. First a little background.

The Barton Garnet Mine is an open pit garnet mine that operated for more than 100 years (1878-1983). The mining level is now below the water table, so to avoid the costs of pumping water out of the pit the operational mine has moved about 4 miles away. What is left at the original mine is now open to the public. The biggest part of the tourist attraction is the first pit (shown below), where you can search for gem-quality chunks of garnet. The garnets themselves can be enormous (10cm or so), but small chips of them, especially some of the darker red chips, are gem quality, can be cut, and are therefore potentially valuable. That is the main draw it seems, you can keep whatever you find (well, at $1 a pound, but that is almost nothing for chips of garnet).

The picture above is from the main pit, where you can collect the chips. You can see it was a superb fall afternoon. The mine is at about 2600 feet, and with the wind made it pretty chilly, but that just kept other folks away.

The garnets are entirely hosted by a hornblende-rich garnet amphibolite unit that is itself in fault contact with a meta-syenite to the south, and grades into an olivine meta-gabbro to the north. The garnets can be enormous, up to 35cm in diamter, even though the modal percent of garnet is not all that unusual for the Adirondacks (5-20%). I think the most impressive thing about these garnets is how the are often mantled with thick haloes of hornblende (shown below). The larger the garnet, the larger the hornblende halo. The garnets are largely pyrope (Mg-garnet 37-43%) and almandine (Fe-garnet 40-49%)

Although it is pretty and would make an exceptional counter top and/or stone fireplace, the primary reason this garnet is mined is as an industrial abrasive. Garnet is hard (8 or so on Mohs scale, although according to our guide this particular garnet can top out over 9), and because garnet does not have any cleavage (which means it is a self-sharpening abrasive, every time it breaks it is a conchoidal fracture, which creates a new sharp edge), garnet is a very good abrasive. Most sandpaper is made with garnet, the polishes used on the lens of the Hubble telescope were garnet based, most sandblasting is done with garnet, the list is endless. And (again according to our guide), 95% of the world's industrial garnet comes from this mine. The founder of the mine (Henry Hudson Barton) was actually a jeweler who married into a wood-working family, and used his knowledge of minerals to pioneer the use of garnet as the abrasive in sand paper.

Aside from the garnets it was a great day outside. Fall has arrived in the Adirondacks, and the colors were exceptional. Just some pictures from right near the visitor's center at the mine.
To finish with the pictures of fall, I'm just going to end with this. Fall colors always remind me of this poem, and in particular of cruising down M street on the back of my Dad's bike on my way to school.

October's Party by George Cooper

October gave a party;
The leaves by hundreds came-
The Chestnuts, Oaks, and Maples,
And leaves of every name.
The Sunshine spread a carpet,
And everything was grand,
Miss Weather led the dancing,
Professor Wind the band.

The Chestnuts came in yellow,
The Oaks in crimson dressed;
The lovely Misses Maple
In scarlet looked their best;
All balanced to their partners,
And gaily fluttered by;
The sight was like a rainbow
New fallen from the sky.

Then, in the rustic hollow,
At hide-and-seek they played,
The party closed at sundown,
And everybody stayed.
Professor Wind played louder;
They flew along the ground;
And then the party ended
In jolly "hands around."

Quick Advertisement

I've been meaning to advertise this blog for a while, but todays post finally reminded me at a time when I was at my computer. It is not a geoblog, but a good chemistry based science one. The long posts are usually pretty informative and worth reading. It is A Man, A Plan, A Trash Can, check it out.

Tomorrow I am heading on a short field trip, hopefully pics will follow!

Congratulations IPCC

Just wanted to send a blogospheric congratulations bouquet to the folks at the UN's Intergovernmental Panel on Climate Change (IPCC) for receiving the 2007 Nobel Peace Prize. The IPCC has been a reliable source of climate related information for quite a while. I am especially interested in the connection the Nobel folks made between natural and environmental forces and human quality of living and interaction. It appears as if news stories will be dominated by the other co-winner of the Peace Prize this year (and congratulations to him), so I thought it appropriate to focus on the "et al" part of the news coverage.

Oh, and I shared an office in graduate school with someone who now works for the IPCC, which means I am somehow on the "in" with a Nobel Laureate. Go me.

Tambora, Frankenstein, and Darkness

One of the things I've been most impressed with in my new department is the number and quality of invited speakers we have. Almost every week we have a new person visit for two days, culminating in at least one talk (sometimes 2 and on rare occasions more), and plenty of time to visit.

The talks this week were especially interesting. I am still undecided about whether or not I want to blog about the main topics the speaker covered, but one thing has been stuck in my head and I haven't been able to stop thinking about it.

The first lecture dealt a great deal with paleoclimate, and in particular the effect that the solid earth has on climate. When I say solid earth I mean tectonic processes, as opposed to things like weathering rates, space dust clouds, Milankivic cycles, and the like. As an example, the speaker talked about the effects of the Mount Tambora eruptions in April of 1815. It was a massive eruption of a stratovolcano, which most likely would have injected enormous amounts of SO₂ into the stratosphere. ****Interesting aside, I had always assumed it was the ash from volcanoes that affected weather, turns out the SO₂ has a much longer residence time in the stratoshpere and ends up significantly increasing the earth's albedo for much longer.**** Tombora led to a reduction in average global temperature by ~3° C, and resulted in 1816 being referred to as "the year without a summer." The cold of 1816 led to all kinds of distasters, crops failures and mass starvation in particular. ****Another interesting aside, the effect of enormous volcanic eruptions is similar to what we might expect from a nuclear winter.****

That same summer, a 19 year old Mary Shelley (among others) was visiting Lord Byron in Switzerland. The weather was so miserable that most of the normal summery outdoor activities had to be put on hold. Shelley took to a challenge from Lord Byron to write a scary story, allegedly to fit the mood of the weather. What she produced, of course, is one of the most memorable and famous stories of all time, Frankenstein. First I need to get past the fact that at 19 I spent most of a summer cataloging my CD collection and deciding what the best mix tape for heading back to college would be (almost as productive as Shelley). Frankenstein is full of weather related imagery, not the least of which is the fact that it is set in part in the Arctic. That weather was the direct result of geologic phenomena, which is in itself interesting. But what I am even more interested in is the potential of literature (and art in general) to provide insight into how humans will respond to some of these "extreme" geologic events.

Byron himself was also effected by the terrible weather, and I don't think it is too much of a stretch to say it is obvious in the first few lines of his poem Darkness

I had a dream, which was not all a dream.
The bright sun was extinguished, and the stars
Did wander darkling in the eternal space,
Rayless, and pathless, and the icy earth
Swung blind and blackening in the moonless air;
Morn came and went -and came, and brought no day,
And men forgot their passions in the dread
Of this their desolation; and all hearts
Were chilled into a selfish prayer for light;

Uplifting, I know, like a Morrissey song. The poem goes on to even mention volcanoes! The influence on weather on art and literature was the subject of an NPR story you can listen to here. For now, I have decided to try to collect as many artistic and literary references to geologic phenomena as possible. Loose Baggy Monster informs me that many authors dealt heavily with emerging geologic theories back in the day, now I just have to find them! Any ideas, please email or comment.

The Geobola Virus

I complained in this recent post that geology does not get enough respect as an exciting, relevant, and important science. I wondered why that was, and today learned at least one of the causes. That is, the geobola virus. The geobola virus manifests itself as members of the geoscience community who do not appear to care at all about geology, or in it's most virulent forms downright do not like geology. Infection can devastate a department, and may take years to recover from.

Things I heard professional geoscience educators say today:

"I mean, we spend so much time on all the rocks and minerals and it is just so boring!"

"They ask me 'when are we ever going to need to know any of this rock and mineral stuff' and I tell them the truth is you never will, it's really just not relevant!"

The geobola virus eats departments from within, beware! It is contagious! Mortality rates are high!

The Omnivore's Dilemma - Review

Michael Pollan's The Omnivore's Dilemma is a book about food. That might sound simple, but when I say "about food" I mean about all aspects of food: production, consumption, evolution, emotion, health, community, enviroment, and philosophy. What Pollan set out to do was to describe the creation of 4 different meals. This would take him to restaurants, grocery stores, feedlots, farms, and hidden mushroom gathering sites in the Sierra Nevada, all the while discussing the importance of the food gathering activity in social, economic, political, and environmental terms. His four meals all centered around different aspects of American food culture, and can be thought of as:

1. Industrial - A fast food dinner bought in a drive through and eaten while cruising in a car.
2. Industrial Organic - Organic food bought at a local Whole Paycheck and cooked at home, with ingredients from all over the world, but each grown "organically."
3. Local - After a week's stay at a farm in Virginia, Pollan cooked another meal using only local ingredients (things grown and produced within a defined geographic area).
4. Hunted and Gathered - A meal, once again cooked by Pollan, with food he hunted and gathered within a days drive of his home in Berkeley, California.

If you don't want to read the whole post, in short, it is an excellent book, is now in paperback, and will be thought provoking to anyone who eats food on a regular basis.

Before I go on much further, in the interest of full disclosure, I must admit that I am a vegetarian. I have been for about 13 years now, and started reading the book with more than a decade's worth of thought on food (specifically meat and meat production) swirling in my head. Just so you don't think I am a completely unreliable food critic, however, I must also admit that I am a vegetarian who thinks many other vegetarians are incredibly annoying (almost as bad as the people who try to convince me to eat meat or otherwise say idiotic and derogatory things about veggos.) I believe there are a lot of excellent reasons to be a vegetarian, and I get annoyed by people who make up completely new (and usually groundless and/or non-sensical) reasons. For example, claims that meat is inherently unhealthy or that humans cannot properly digest meat really burn me up. Add that to how inundated vegetarian grocery stores and magazines are with all kinds of shark-cartilage-plant-extract-dietary-supplement-snake-oil-nonsense and you can see why anyone might get a little ticked off. Why make up B.S? Why not just stick to the obvious and well proven facts? Why not have an intelligent discussion about the pros and cons of all aspects of food production and consumption? A-Ha! You thought I was digressing, but I just brought us right back to Dilemma.

The first meal Pollan describes is the ultimate in modern industrial fast food. To see where the food comes from, Pollan visits a feedlot where a calf he "bought" is spending it's last days getting fattened up on corn and antibiotics. He also visits some large scale industrial farms in the lower midwest. A large part of the first part of the book deals with the central role that corn plays in our modern industrial food production. Corn, or some corn byproduct, has worked it's way into almost every processed food item that we eat, including most of the beef sold in the US. This last fact is no small feat, especially considering that cows don't naturally eat corn, and in fact cannot digest corn well without help. Corn has the advantage of getting cows fat quickly and adding "marbling" to the beef, but only with the help of drugs and vets. Most feedlot stays are relatively short, so the goal seems to be to pump them full of anything that can get them to the slaughterhouse fat. ****This by the way has stuck in my head. You always hear about "corn-fed" beef like it is some mark of authenticity. Cows don't eat corn! They eat grass! Corn-fed beef is a relatively new invention that requires a veterinary staff armed with drugs to implement. Why did that surprise me?****As one could expect, there aren't many positive sides to the industrial meal, the production and consumption of the food is filled with huge wastes of money and energy, disgraceful animal living conditions, exploitation of labor, absurd government subsidy structures, and consumers inhaling unhealthy food with little connection at all to it's source.

The first part of the book was really not clicking with me. These were arguments I have read and heard many times, and were some of the reasons I swore off meat in the first place. I am beyond the time in my life where I want to read affirmations of my own thoughts, and put the book down for a while. Fortunately I picked it up again, because the stories surrounding the last three meals are fascinating. One aspect of the first section I do want to mention though is his discussion of "reductionist nutrition." Basically, the idea that we know all of the essential fundamentals we need to eat, and if we synthetically fortify foods with these basic building blocks then we will have healthy diets. This is a dangerous way to think, every year there are new things we never knew we couldn't live without, lycopene, antioxidants, omega-3 fatty acids, the list goes on. The antithesis to reductionist nutrition is eating a variety of fresh foods, what we have evolved eating. I think this discussion especially struck a chord with me because I was also reading (at the time) Apsley Cherry-Garrard's amazing The Worst Journey in the World, a chronicle of Robert Falcon Scott's fatal attempt to reach the south pole. This relates because Cherry-Garrard spends a lot of time on the various diets they experimented with for polar travel, all different combinations of fat, sugar, and protein. This was well before people knew about the importance of vitamins, let alone omega-3 fatty acids. Anyone who thinks they've nailed down what a healthy diet needs (in a reductionist sense) should read these accounts and gain some perspective. These explorers, at the time, were on the cutting edge of understanding what a body needs to survive, and they were missing huge parts (with deadly consequences.) Back to the book...

The second meal, industrial organic, deals a great deal with the arguments for and against organic food. For example, is it better to eat a "conventional" apple from a farm down the road, or an organic one flown in from New Zealand? And just what is "organic," or "free range" anyhow? This section of the book really made me scratch my head. I don't want to just repeat his points, but man, "organic" farms sure can look a lot like conventional farms....

The third meal was the most interesting to read about. Pollan spent a week working on Polyface Farm, a self contained grass farm run by a man named Joe Salatin that raises cows, chickens, pigs, turkeys, rabbits....and I think that is it..... The idea is that instead of importing nutrients in the form of chemical fertilizers (or corn grown with said petrochemicals), Salatin uses a very well planned and intricate system of animal rotation to raise everything using only his own forest and pasture land. This system fascinated me; allegedly grass grows better if it is nibbled on (but not overgrazed), and with this system Salatin (and his father) have turned an overgrazed wasteland of a farm into a very efficient and productive plot of pasture and forest. Salatin's system is absolutely fascinating, and I'd recommend the book just based on this section alone. It has even made me hunt down a local grass farmer who I know by my eggs from (saturday farmers market). I think what got me thinking the most in this section was the interplay of meat, vegetarianism, organic, and local food. My default preference has always been organic vegetarian, but is that always the "best choice." All organic produce requires animal derived fertilizer, and after the industrial organic section I am now putting more favor on local food. Anyways, those are my dilemnas, the point is that the workings of Polyface Farms and the whole grass farmer idea has made me think more about food and farming than anything I've read in the past decade. No, it hasn't converted me, I'm just saying, it's worth the read.

The final meal was about as close as one could come to the who hunter-gatherer model. Pollan hunted mushrooms, wild pigs, and random greens and fruits to make a dinner focused on things that he "found" himself. I wasn't expecting much from this meal, but once again Pollan does an excellent job of integrating so many aspects of the experience, hunting, foraging, etc., that you get sucked in.

What I ended up really liking about this book was Pollan's sense of even-handedness. When he talks about killing animals, either in a slaughterhouse, on Salatin's farm (he participated in the processing of the chickens), or in the forest of northern California, he uses intelligence without sounding removed, and emotion without sounding sappy. That is a tough balance to strike, and it is easy to slip down either side (either to reaffirm your choice to not eat meat or convince yourself it is OK to). He even nailed on the head one of the hardest parts of being a vegetarian, that is feeling like an inconvenience when friends invite you for meals, feeling like a constant problem, or just a rude and unappreciative guest. When he discussed organic versus local there wasn't always a clear winner, there are pros and cons. In the end, the book isn't so much about what you should do, but more about how you should think about food. I think it has something to offer everyone, and I can't recommend it enough. As a warning, the first part where he keeps talking about corn, that can get a little repetitive, but power on through and trust me it is worth it.

Pollan is an excellent writer, and I just want to end this with a few quotes. First, some of his thoughts on the meals he hunted and foraged:

Perhaps the perfect meal is one that's been fully paid for, that leaves no debt outstanding. This is almost impossible ever to do, which is why I said there was nothing very realistic or applicable about this meal. But as a sometimes thing, as a kind of ritual, a meal that is eaten in full consciousness of what it took to make it is worth preparing every now and again, if only as a way to remind us of the true costs of the things we take for granted. The reason I didn't open a can of stock was because stock doesn't come from a can; it comes from the bones of animals. As the yeast that leavens our bread comes not from a packet but from the air we breathe. The meal was more ritual than realistic because it dwelled on such things, reminding us how very much nature offers to the omnivore, the forests as much as the fields, the oceans as the meadows. If I had to give this dinner a name, it would have to be the Omnivore's Thanksgiving. (pp. 409-410)

And finally to wrap things up

This is not the way I want to eat every day. I like to be able to open a can of stock and I like to talk about politics, or the movies, at the dinner table sometimes instead of food. But imagine for a moment if we once again knew, strictly as a manner of course, these few unremarkable things: What it is we're eating. Where it came from. How it found its way to our table. And what, in a true accounting, it really cost. We could then talk about some other things at dinner. For we would no longer need any reminding that however we chose to feed ourselves, we eat by the grace of nature, not industry, and what we're eating is never anything more or less than the body of the world. (pg. 411)