Monday, February 25, 2013

Field Injuries (Accretionary Wedge #55)

This month's Accretionary Wedge is at Maitri's VatulBlog; the topic is geo-injuries.  I’ve not had any memorable ones, even after 35 years.  But I can’t say the same for my vehicles ...

My first field vehicle was a 1968 Volkswagen squareback, also known as the Type 3, the 1600 Variant, and, near the end of our relationship, the Antichrist (as in The Gods Must be Crazy).  I bought it for $400.  It had electronic fuel injection and a computer (!), but no front breaks as the calipers had been pulled off.  A friend replaced them.
During my three field seasons as a grad student, the Variant was terrific.  It had fairly high clearance, and was surprisingly able on bad roads, probably because the engine sat over the back axle.  All problems were minor and easily fixed in situ.  In 1985 I overhauled the engine, thanks to that amazing masterpiece for Compleat Idiots titled “How to Keep your Volkswagen Alive” by the patron saint of backyard VW mechanics, John Muir.  The Variant was happy, and ran beautifully.
Next I got a real job, a dream job really -- as botanist and sole employee of the Wyoming Natural Diversity Database, appropriately acronymmed “WYNDD”.  But it was a shoe-string budget -- no motels, no restaurants, no field vehicle.  I kept driving the Variant, to the far corners of Wyoming.
The old car held up well in spite of its years.  All problems continued to be minor and easily fixed.  But then ...
... there were two major breakdowns, both in Lonetree, Wyoming, both on projects involving the rare Uinta greenthread.  (ok ... these weren’t geo-injuries, they were phyto-injuries.)
The Uinta greenthread, Thelesperma pubescens.
WYNDD; photo by author.
The Unita greenthread grows on the summit margins of several flat-topped "mountains" -- remnants of mid-Tertiary alluvial fans that sloped down from the high Uinta Mountains to the south.  Wind blows all fine material away leaving gravel, cobbles and boulders.
Rim of Cedar Mountain.  Cushions with yellow flowers are the Uinta greenthread, growing on rocky soils derived from the Bishop conglomerate.  WYNDD; photo by author.
The first incident was not terminal.  Near the end of field survey, the engine periodically lost power but still ran. The problem became consistent and I drove 300 miles back to Laramie via every side road available.  But sometimes I couldn’t avoid driving uphill on Interstate 80 at 30 mph.  Fortunately, I was never pulled over.
I consulted with John Muir who suggested the points driving the fuel injectors were bad.  The local mechanic thought probably not, but sold me a used set which fixed the problem.  It was true ... the Variant had made it all the way home on two cylinders!
The next episode did not have a happy ending.  In Lonetree once again, the engine refused to run even though it turned over ... and over and over.  We pushed, we towed ... no luck.  It stayed in Lonetree, I took the Greyhound bus to Laramie, borrowed a pickup, rented a dolly, drove back to Lonetree, and towed the Antichrist home.

John Muir advised checking the electronics of the fuel delivery system -- sensors, wiring, computer, etc.  I tested.  I replaced.  I even tried a different computer.  I gave up when I found a 1978 Datsun pickup for sale for $900.  It only broke down once.

When I think back on those adventuresome days, I miss my Variant a little and even get a bit misty-eyed.  It served me so well.  But in truth, I’m happy not to be dealing with an ancient electronic-fuel-injected air-cooled engine anymore.
The Variant's last incarnation, as Antichrist, was not all bad.  It was the inspiration for my first web publication, at Car Talk Haiku:

Hot hot sun beats down.
Ancient air-cooled engine stops.
Dead VW.

Friday, February 22, 2013

Still Life with Mysterious Rock

“still life photography does not have to be of fruit and flowers!” says Photo Tuts+.
Continuing our tour of notable but mysterious rocks in the kitchen, we move next to several reminiscent of abstract sculptures.  They don't attract as much attention as the heavy green rock from the upper mantle.  Still, when visitors do see them, their bizarre forms always elicit comments:   “they were made by a volcano”, “they must be meteorite fragments”, “are these left over from D’s latest welding project?”, and so forth.
These rocks aren’t all that mysterious.  In fact, I know what they are.  Do you?  (tiles are 12” x 12”)
I’ve been reading about still-life photography, and was eager to try it.  My goal was to compose an artsy shot of the curious rocks, with typical still life objects of similar color and texture in the background.  These would be slightly out of focus.  The results were very clear in my head, but I didn’t quite get there.
Playing with perspective ... larger objects in distance, smaller object up close.
A large aperture is required for a shallow depth of field, so that only the rock in the foreground is in focus.  With my Canon Powershot A720 IS in Av mode, I chose the lowest value, f/2.8, i.e. largest aperture, and moved the auto-focus frame to center it on the rock in the bottom of the picture.  This is all quite doable with the Powershot, even for someone who hates reading instructions.  However I never could get the degree of blurring in the background that I wanted.  I need to figure out how to make the depth of field even more shallow, if that’s possible.

Turning to light:  “The soft, flat light produced when the sky is overcast and cloudy may be frustrating when shooting outdoors, but it’s perfect for shooting still lifes at home” according to Digital Camera World in a post on still life photography using window light.  With a snow storm outside, it was a good day to try it.
Every now and then the sun came out, changing the game.  With the window directly in front, objects are fully lit but that can be boring.  Side light provides a mix of light and shadow to play with.  Also, it’s easier to keep the photographer’s shadow out of the mix.
Supplemental light can be helpful or interesting.  An incandescent bulb added warmth -- interesting maybe, but I didn’t pursue it.
Light from a flash often gives a flat boring photo with unwanted highlights and reflections.  But not always.  Sometimes it works nicely, here revealing the interior of the old cup.
On to composition:  the “compositional element of your still life work is an absolutely crucial part of ensuring that your work is engaging” (Photo Tuts+).  This is good, as composition has always fascinated me and it’s something I play with naturally.  Shooting still lifes indoors allows for a lot of control in composition -- over color, pattern, texture, and light and shadow, as well as choice and arrangement of objects.  I found the grout lines to be useful additions.  They add interest without taking away from the subject, and can direct the eye of the viewer.
I like photos with something a bit different, unexpected.  Here’s a regular pattern but a rock is missing it seems.
Finally, post-processing (iPhoto):  I did some straightening when grout lines were unintentionally askew, and some cropping of course.  With the day’s light and somewhat-reflective tiles, I often had to reduce highlights.  I also lightened shadows a bit.

As always, I took lots of shots ... very easy as still lifes don’t move.
Old and rusty -- this is a hint!
As to the mysterious rocks -- here's one in situ, not yet weathered out ...
... and its home:
Where on Google Earth?  Right here (click photo for a better view):

UPDATE:  For more on the Navajo sandstone and iron concretions, see the sequel to this post:  The largest erg on earth ... ever!

Tuesday, February 19, 2013

Plant Blogging

[This post is based on an article I wrote for the newsletters of the Wyoming Native Plant Society and the Great Plains Native Plant Society, in hopes of recruiting more local botanists into the phytoblogosphere.]
blog |bläg| (orig. web log) noun:  website where a person or group regularly posts news, information, opinions, photos, etc.;  verb: to add new material to a blog. blogosphere: the collective community of blogs. phytoblogosphere: that part of the blogosphere inhabited by plant bloggers.
I’ve come to love the blogosphere.  Most mornings over coffee I peruse the latest posts to see what my fellow nature lovers are doing, thinking, dreaming and puzzling over.  They write of their latest adventures, research or cool things they’ve stumbled upon.  Styles range from literary to academic, short to lengthy.  There are travel journals, photo galleries, the latest science news, nature stories, educational articles, and sometimes just random encounters and thoughts.

Blogging is yet another embodiment of democratization provided by the internet.  It’s a way we common folk can experience the satisfaction of publishing, of expressing ourselves, of sharing our interests and excitement with like-minded people all over the world.  The pool of potential readers and writers is enormous.  With a little effort, we can find just the right audience for our posts, just the right bloggers to follow, and just the right part of the blogosphere to inhabit.  You might consider joining us, if you haven’t already.
Lucy of Loose and Leafy kindly keeps a tree-following page.
You might consider joining, it’s fun!  Used with permission.
Setting up a blog is easy.  The popular platforms, Blogger, TypePad and, provide guidance and templates.  You don’t need to know HTML, and adding photos, videos and locations is simple.  It also is very easy to create a bad blog.  Fortunately there’s excellent advice available, including blogs about blogging.  Blogging Basics 101 has good posts for beginners, starting with How Do I Start a Blog?  If you have fame and fortune in mind, see the Blogging Starter Checklist (be prepared for lots of shameless self-promotion).

There is so much more to consider.  What is your niche?  What do you want to write about and in what style? long? short? humorous? serious? photo-rich? creatively-written?  The best way to decide is by reading lots of blogs (see list below).  Scan the ones they recommend.  Figure out why you like the ones you do.  Don’t be afraid to experiment, and don’t hesitate to change your blog when new ideas come to mind.
As Blogger says “Your blog is whatever you want it to be ... there are no real rules.”  Be creative.  Notes of Nature came up with a cool Five Fact Friday series.  Used with permission.
I stumbled into the blogosphere several years ago while planning a vacation.  With Google’s help, I found terrific blog posts about areas of interest, filled with descriptions, recommendations, photos, maps and links.
While planning a trip to the San Rafael Swell, I discovered Written in Stone, a great resource for nature-geeks.  Photo of San Rafael Reef by Jack Share, used with permission.
After happily wandering through the blogosphere for several days, I thought “I can do this too!” and started my own blog, In the Company of Plants and Rocks.  It accommodates my diverse natural history interests, as reflected in the header:  subalpine wildflowers in Precambrian stromatolites in the Medicine Bow Mountains of southeast Wyoming.

At first I was all alone, casting my creations out into the vast space of the blogosphere where it seemed they couldn’t possibly be found, but eventually, amazingly, they were.  There were more and more hits, some from far corners of the earth.  I signed up to follow blogs of interest, and commented on posts I especially liked.  My circle grew.  And then I discovered blog carnivals.
blog carnival: a collection of blog posts on a specific topic; hosted by an inhabitant of that part of the blogosphere.
Carnivals are one of the great joys of the blogosphere.  I attend two regularly:  Accretionary Wedge, a geocarnival, and Berry Go Round, a phytocarnival.  Each month, the host compiles a list of posts based on readers’ submissions and other sources, and publishes them in a summary post.  Carnivals are very good places to find blogs to follow, and to get your posts out for others to read.
I hosted Accretionary Wedge #43, the topic was My Favorite Geological Illustration.  Mine is a "Bird’s Eye View of the Black Hills" from 1875.  Click illustration to view details, including birds.
“Have you posted anything related to plant science lately?
Then your post is probably suitable for Berry Go Round.”
Blogging is a great way to share what’s going on in your botanical life, and I highly recommend giving it a try.  Are you already a phytoblogger in the Rockies or Great Plains?  If so, please add a link to your site as a Comment below.  And consider joining a Berry Go Round carnival (go here for details).  I’m the host for March and would love to include botanical news from our region.
The highlight of a recent vacation was communing with bristlecone pines in the White Mountains of eastern California -- ancient plants on ancient rocks.

Some plant blogs I read, in no particular order:

The Artful Amoeba, a favorite, occasionally posts about plants, e.g. The surprising world of cyads (especially their sperm).

A local (South Dakota) botanist writes about North America’s Native Plants at Suite 101, not exactly a blog but close.

Teton Plants is a brand new blog, by the Teton Chapter of the Wyoming Native Plant Society.  It features walks, hikes, lectures and other plant news from the Grand Teton area.

Get Your Botany On! recently has been blogging about Green in Winter, featuring plants peeking through snow.

A Digital Botanic Garden has beautiful photos, as does Beyond the Human Eye, his microscopy blog.

Moss Plants and More is a good resource for all things bryological, e.g. Why are moss plants so short?

See No seeds, no fruits, no flowers: no problem for adventures in fern biology.

Cornell Mushroom Blog recently featured “Zap! Lightning, Gods, and Mushrooms” and “I ate fungus slime, and it made my breath minty fresh” (that would be your mouthwash).

Seeds Aside.  “Plant gossips… are almost cotton!”, a curious title and interesting blog.

AoB Blog  User-friendly posts on a variety of topics from The Annals of Botany and AoB Plants.

Plantwise  Blog of the Plantwise initiative to improve food security and lives of the rural poor by reducing crop losses.

Notes of Nature offers a nice diversity of plant posts, including the Five Fact Friday series.

Catalog of Organisms sometimes features plants (encourage him!), e.g. When Ferns Don’t Look Like Ferns.

The Daily Plant is always interesting, “A surprising look at the plants around us and how they've influenced our world.”

Agricultural Biodiversity Weblog is “anything we find ... that relates somehow to the notion of agricultural biodiversity ... a big tent but one that the whole of humanity shelters beneath.”

Alien Plantation “Plants and people change, evolve, together.  We take advantage of them ... And they take advantage of us.”

At Loose and Leafy you can join Lucy on virtual excursions around coastal Dorset.  She also has a tree-following page.

Foothills Fancies  The subtitle tells it all:  Small Wonders and Natural Moments; Life and Nature in the Colorado Front Range. is “a forest of arboreal links” leading to tree- and forest-related content from around the world.

California Wildflower Hikes (and some outside the state) ... how cool is this?!  We need one for our part of North America.


Nature Blog Network is a large collection of blogs ranked by number of page views.  Search on “flora” for plant posts.

scienceblogging is an aggregate of aggregates! -- testimony to blogging’s rapid growth.

Need still more plant reading?  Check out these sites:  Top 50 Botany Blogs and Top 100 Botany Blogs.

And don't rule out Facebook!  The Wyoming Native Plant Society has a Facebook page where you can find out about events, hikes, and more.  See what members are doing, and consider adding photos and commentary of your own.

Thursday, February 14, 2013

Lovesick? here’s a cure (maybe)

Being a god isn’t all that easy.  For one thing, repeatedly falling in love with maidens and virgins takes its toll, in the form of addiction to phenylethylamine.  Perhaps that’s why meso-American gods drank elixirs of kakaw, also known as chocolatl.
Cacao pod, food of the gods; from Köhler's Medizinal-Pflanzen.
Theobroma cacao L., the chocolate tree, is native to the New World.  In the 16th century, returning Spanish explorers introduced it to Europe where it became quite popular among those who could afford it.  Carl Linnaeus, in his pioneering Systema Naturae, named it theobroma, "food of the gods”.
Theobroma cacao L.;  from Köhler's Medizinal-Pflanzen.
Chocolate soon developed a reputation as an aphrodisiac, which continues to this day even though conclusive evidence is lacking.  Cacao contains theobromine and caffeine; both are stimulants capable of enhancing attraction and arousal.  The actual culprit, if there is one, may be the alkaloid phenylethylamine, a mammalian neurotransmitter.  Levels increase when Cupid strikes, along with fight-or-flight hormones, and they drop precipitously with rejection.  Phenylethylamine also is found in chocolate -- the basis for the “Chocolate Theory of Love”.  Might chocolate help with the pitfalls of love?  Unfortunately, it appears that phenylethylamine is quickly metabolized and little if any reaches the brain.
Phenylethylamine, a seemingly-simple but mischievously-useful drug (vintage card).
Chocolate can be dangerous if frequently consumed in large quantities, as theobromine is a heart stimulant, even stronger than caffeine.  Not every creature can eat chocolate.  Dogs are among the animals that process theobromine so slowly that it is dangerous even in smaller amounts.  However, it isn’t quite as bad as I once thought.  Toxic amounts are on the order of 50 g for small and 400 g for average-sized dogs, which explains why Cleo didn’t die after eating the freshly-baked chocolate cake off the kitchen table.  But of course, dogs don’t need chocolate like we do, so there’s no reason to share.
Sparky loves everybody, no extra chemicals needed.  "Happy Valentine's Day!"

Monday, February 11, 2013

Mysterious Green Rock, continued

Last week, I posted about a curious rock from the Santa Maria River (California) that I suspected was one of the unusual rock types on the Central Coast, products of subduction back when the North American plate was overriding the Pacific plate.  Readers’ comments and further investigation have made the whole business even more interesting.

My first thought was serpentinite -- mantle material squeezed up during subduction and metamorphosed in the process.  Serpentinite starts out as peridotite, a common igneous rock in the upper mantle, composed mainly of olivine and pyroxene.  These minerals are unstable in the face of weathering, and by the time they reach the upper crust and surface, they usually have been altered to serpentine, producing serpentinite (serpentinite is a rock, serpentine is a mineral; even so, the State Rock of California is called serpentine).  Several readers agreed serpentinite is a strong candidate.

Others suggested harzburgite (also here), a variety of peridotite and in fact the most common one in these types of subduction zones.  Part of the logic for this choice is that serpentinite may not be tough enough to survive a rough trip down the Santa Maria River from its headwaters to where I found the rock.  But harzburgite is a peridotite, with those unstable minerals often altered to serpentine -- is it possible to find chunks of harzburgite at the surface?

How about partially-metamorphosed harzburgite/serpentinite?  It seems there could be various degrees of metamorphism, with intermediates.  So I was really excited to find this thin-section of “serpentinized harzburgite” at Evelyn Mervine’s website, Georneys ...
Serpentinized harzburgite in thin section, plane polarized light.  Used with permission.
... and this photo of “Serpentinite; Harzburgite with Asbestos” (source; no size given)
It looks like the mystery rock also has asbestos veins and veinlets (below, click to view).
Serpentinite sometimes contains the mineral chrysotile, which in fibrous form is a type of asbestos.  In fact, serpentinite was declared the State Rock of California in 1965 in part to promote the asbestos industry.  But times changed.  In 2010, a bill was introduced to strip serpentine of its title because “California should not designate a rock known to be toxic to the health of its residents.”  Californians once again were confusing a mineral with the rock that contains it (sometimes).  Fortunately the bill failed.  See Geotripper’s posts here and here for an interesting and inspiring account of the bill and its defeat.
The South Hills Natural Reserve in San Luis Obispo, California, features hiking trails through beautiful outcrops of serpentin(it)e, still the State Rock.
The California coast ca 100 million years ago, with subducting oceanic crust and serpentinite (lavender).  Courtesy National Park Service, Presidio of San Francisco (geology).
One term led to another, and in the process of reading about various mantle-derived rocks, a clearer picture emerged of how all these things fit together on the Central Coast.  The massive moving plates of the earth’s surface consist of crust and the upper part of the mantle -- mainly peridotite.  Thus oceanic plates are peridotite topped by rocks from marine environments.  During subduction, pieces of oceanic plates sometimes are plastered onto the continental margin rather than subducting.  These are ophiolites, which typically consist of “peridotite plus associated rocks such as gabbro, pillow basalt, diabase sill-and-dike complexes, and red chert”.  As it turns out, California’s Central Coast is well-known for ophiolites, and in fact the Coast Range ophiolite is recognized as an example rich in harzburgite ... another piece of evidence for the puzzle.

Now when friends ask about the striking green rock on the kitchen counter, maybe I will tell them it’s serpentinized harzburgite (wow!).  But without some kind of destructive analysis, I probably can't be sure.  More likely I'll just say it’s mantle rock ... a mysterious traveler from the depths of the Earth.
© 2008 Jack Mueller, from Whacking the Punchline.  Used with permission.

Monday, February 4, 2013

A Notable and Mysterious Rock

© 2008 Jack Mueller, from Whacking the Punchline.  Used with permission.
The rock below is the most notable in the kitchen, the only one that consistently draws attention, maybe because of its size.  Friends routinely pick it up, shift it in their hands, ask “why is it so heavy?”  [It weighs 12 lb (5.4 kg).]
The shape is interesting, “it’s like a brain!”  [It’s a bit bigger -- 20 cm long, and 12-15 cm wide and high -- and a lot heavier than a human brain, which weighs 3 lb (1.4 kg).]
It arrived in the kitchen several years ago, having been transported by car from the Santa Maria River on the west coast of North America to the interior.  But what is it?
I’m just an amateur geologist, with almost no training in rock id, but I do know it isn’t right to ask for identification of a rock out of context, ex situ.  Unfortunately, this rock was already ex situ when I found it ... a traveler.  It was sitting amidst coarse deposits in a broad sandy river bottom.  It appears to have traveled quite a ways, as it’s well-rounded, smoothed by bumping and grinding.  In my many walks down the Santa Maria River, I've seen only a few green rocks, and none so nicely shaped.
Here's another pretty green rock in the sandy river bed; width of view is roughly 25 cm.
The Santa Maria River is dry most of the year, but can rage during winter storms.  The bed is wide, sometimes almost a quarter mile across, with willow stands and braided deposits of sand and coarser debris.  By the end of spring, it often is covered with a healthy crop of annuals and biennials.
Santa Maria River, from Santa Maria to the sea; click photo to view details.
Such a curious rock -- large, round, an unusual and appealing color.  I decided to take it home.  A few minutes later I heard yelling in the vicinity of a willow thicket.  Sparky (dog) had met up with a man pushing a bicycle across the river.  “¡Hola, hola, buenos días!”  “Buenos días” I replied, “piedra verde grande” (large green rock).  “¡Sí, sí!” he agreed.

Maybe there are clues upstream.  The Santa Maria River is formed by the confluence of the Cuyama and Sisquoc Rivers, which drain the Coast and Transverse Ranges to the east and southeast.  The geology of these mountains is complex and hard to figure.  The area is famous today for earthquakes along the San Andreas Fault, where crustal plates jerkily slide past each other.  But before this lateral (transform) motion started ca 30 million years ago, this was a subduction zone where the North American plate overrode the Pacific plate.  The result is a “grand mess” that keeps geologists thinking and theorizing.  Today’s exposed deformed rocks include spectacular banded deep sea sediments (cherts), sediments from shallower offshore waters, volcanic rocks (metamorphosed and not), pieces of oceanic crust, and even mantle rock that was pushed up during all the crazy activity.  These are lumped together and called the Franciscan Assemblage or mélange, a very puzzling collection of rocks.
“If all rocks resembled the Franciscan Complex, no science of bedrock geology could have emerged.” (Alt and Hyndman 2000).
Look at what was going on along the coast of California 100 million years ago!
Courtesy National Park Service, Presidio of San Francisco (geology).
Among the fascinating and even awe-inspiring features of the Franciscan mélange are rocks not usually found at the surface.  I was suspicious, in fact hopeful, that this rock had come from deep in the earth.  Might it be the state rock of California, serpentine, which is part of the mélange?  (Technically, serpentine is a mineral; the rock is serpentinite.)  The serpentinite masses exposed along the Central Coast are thought to have been squeezed up from the mantle during subduction.  I had explored outcrops in nearby San Luis Obispo just a few days before.  Those exposures are greenish to bluish, and quite smooth, not really like my kitchen rock.  And is serpentinite tough enough to survive a trip down a river?
Poppies and serpentine -- California State Flower and State Rock.
Another possibility is eclogite, an uncommon rock sometimes found in association with serpentinite outcrops in the Coast Ranges.  It forms through metamorphosis of igneous rocks carried down to regions of high temperature and pressure during subduction.  One of my California geology guides (Alt and Hyndman 2000) describes eclogite as “notably dense in the hand ... surprisingly hard to break with a hammer, the quality geologists call toughness”, i.e. tough enough to survive a trip down a river.  This seems a more likely candidate.  A google search for images of eclogite didn’t rule it out, but didn’t produce anything convincing either.  Generally, the rocks in the images were green but more sparkly than mine, with visible crystals of red garnet.

My final candidate is another tough rock, greenstone, suggested by this photo from Shell Beach in northern California.  These rocks are intriguingly similar, though too far away to say for sure.
Greenstone from Shell Beach, northern California.
The chunk of greenstone below, from San Benito County in the Coast Ranges to the north, has white patches and veins like the rock in my kitchen (source; size not given).

So the rock remains a mystery for now ...  or do you know what it is?

Update:  More information and ideas about this rock can be found in this follow-up post.

Sources (in addition to links in post)

Alt, D. & Hyndman, D.W.  2000.  Roadside geology of northern and central California. Missoula MT:  Mountain Press.

Mueller, Jack.  2008.  Whacking the Punchline; Compression Sketches.  The Lithic Press,
1391 19 Road, Fruita, Colorado 81521.