Sunday, March 4, 2012

Geologic Illustrations Galore -- Accretionary Wedge #43

Last fall when I posted my favorite geologic illustration, Ron Schott of the Geology Home Companion Blog suggested I host a blog fest on the topic, hence this month’s Accretionary Wedge.  The results are in and whatever you had planned to do the rest of the day -- forget it, you have lots of diverse and interesting reading ahead.

Historic Illustrations

This project started with an historic illustration, my own favorite:  “Bird’s Eye View of the Black Hills” from the 1875 Newton Jenny expedition.  I came across it shortly after I had moved to the Black Hills, where the geology is interesting and conveniently visible.

Ron Schott -- motivator for AW#43 -- also contributed illustrations from the early days of geology in the American West.  “Ways and Means” features a donkey who took part in the exploration of the Henry Mountains in the 1870s.

Magma Cum Laude submitted “Magnificent Column of Smoke” -- a striking illustration by "Mr. Peter Fabris, a most ingenious and able artist", who witnessed the eruption of Mt. Vesuvius in 1779.  It is geologically accurate in many ways, as MCL explains.

Silver Fox at Looking for Detachment posted an intriguing illustration from Agricola’s De Re Metallica (1556), about prospecting.  Agricola recommended using knowledge instead of luck and magic -- something we take for granted today (well, maybe not always).

Lockwood nominated Clerk of Eldin's 1787 illustration of the Hutton Unconformity at Inchbonny, Jedburgh.  He is mum as to why he chose it, so I will let John Playfair do the talking.  Playfair accompanied Hutton in search of additional exposures of the unconformity, and described the excitement and awe that comes at the moment of realization that one is looking very far into the past:
“On us who saw these phenomenon for the first time the impression will not easily be forgotten...We felt necessarily carried back to a time when the schistus on which we stood was yet at the bottom of the sea, and when the sandstone before us was only beginning to be deposited, in the shape of sand or mud, from the waters of the supercontinent ocean... The mind seemed to grow giddy by looking so far back into the abyss of time; and whilst we listened with earnestness and admiration to the philosopher who was now unfolding to us the order and series of these wonderful events, we became sensible how much further reason may sometimes go than imagination may venture to follow.”
Hutton's Section at Salisbury Crags.
David Bressan at History of Geology chose “Awful Changes”, Sir Henry Thomas De la Beche’s 1830 cartoon lampooning Sir Charles Lyell as “Professor Ichthyosaurus”.  De la Beche didn’t think much of Lyell’s radical ideas, in part because Lyell was a lawyer :)

Ancient Shore posted abouty “The Golden Age of Paleontological Illustration 1: Milne-Edwards and Haime” .  These beautiful illustrations from British Fossil Corals are so realistic -- they appear three-dimensional, almost popping out of the (web)page.


Ann of Ann’s Musings on Geology  & Other Things proves the power of maps with several nice examples -- probably some of the reasons her sons have done so well in geography bees!

Matt Hall of Agile Geoscience submitted “The Map that Changed the Man”, from his independent mapping project.  This is a reminder of those inspirational projects that led us to what we do today -- hopefully still just as inspired.

What Geology Can Teach Us: The Work Endures”, submitted by Cujo359 (who introduced himself as “not a geoblogger”), is about the huge, beautiful and famous “A Delineation of the Strata of England and Wales and part of Scotland” by William Smith.

Metageologist, inspired by Matt Hall’s contribution above, submitted “My Favourite Map” -- another inspirational map from a geologist’s formative years.  This one is from western Ireland, where all kinds of geologic features are packed into a small area.

Cross-sections and Block Diagrams

When Research at a Snail’s Pace encountered the understandable difficulty of choosing a favorite illustration, he decided to submit three:  a cross-section of a convergent plate boundary, a block diagram of sedimentary patterns, and an illustration of a rather scary giant Pleistocene snail!

Aerial Geologist contributed “a geologic cross-section of Minnesota from the Minnesota Geological Survey”, another inspirational illustration for a young geologist.  It provided the realization that "Geology is closer than you think, it's right beneath you, all around you, is not all the same and tells a fascinating story".

Callan Bentley shared a block diagram rightly called “A work of art”.  “Check out how much information is infused into this one diagram” of the structural geology of the Scottish highlands.

My geology mentor, Nip Mears, would have submitted one of the memorable and beloved block diagrams of Samuel H. Knight, perhaps this one of the Medicine Bow Mountains and Laramie Basin (Wyoming) during the Pliocene showing exhumation of earlier landscapes following regional uplift.  Drawings of fauna also by Doc Knight.  Click to view.
From:  Knight, Samuel H.  1990.  Illustrated geologic history of the Medicine Bow Mountains and adjacent areas, Wyoming.  Memoir 4.  Department of Geology and Geophysics, University of Wyoming.

Other Diagrams

Sandatlas posted a “QAPF diagram” for classification of plutonic rocks.  It is quite elegant, especially given its crystalline shape, and makes rock classification look very clearcut.  But surely there must be difficulties, or is nature unusually cooperative here?  I enjoyed Siim’s discussion of classification, something we struggle with all the time.

En Tequila Es Verdad provided “Proof that Geology Diagrams aren’t Boring” with a metamorphic facies diagram.  Not only are they not boring, there are times when they are much more effective than words, as Dana explains.  So are we still obligated to write explanations?  I’ve often wondered about this ...

Erik Klemetti of Eruptions submitted “Bubbles, Fragmentation and Explosive Eruptions”.  This is another example of elegant clear explanation via illustration, in this case a schematic of how bubble growth in magma leads to explosive eruptions.

Fun with Chemographic Projections” comes from Meagan Pollock at Wooster Geologists.  I hesitate to try explain this post ... but I love it!  The cartoons are wonderful, and I do feel sorry for poor garnet -- I believe he was turned into a chlorite pseudomorph due to the retrograde garnet-out reaction (I have a lot to learn).

Beautiful hand-drawn micrographs illustrating progressive metamorphism are included in “pen & ink petrographic drawings” from Life in Plane Light.  Elli Goeke notes that drawing helps us “see what’s going on so much better".  This reminded me of Vincent Van Gogh’s observation:  “When I draw I see clearly”.  And I feel the same about writing (hopefully).

And there’s more!

Geology Happens posted about “wearable illustrations” including a stratigraphic column, cross-section and fault map.  I’m surprised more people didn’t think of this! ... perhaps a subject for a future Accretionary Wedge.

Matt at Geosphere submitted “The Art of Geology” with several illustrations, including the only dynamic contribution.  I won’t give it away -- check it out.

"The Art of Geology" ... why not "The Music of Geology"?  Geosphere’s post reminded me of this video, which Chris Rowan called “The soundtrack of our unquiet Earth”.  Hold onto your seats -- the Tohuku earthquake made me jump even though I knew it was coming! (at ca 1:50)


  1. Thanks for the mention of my article. I need to correct a misapprehension, though. My Internet handle is "Cujo359". Slobber And Spittle is the name of my blog. So, to be correct, the introduction should perhaps read:

    - “What Geology Can Teach Us: The Work Endures”, submitted by Cujo359 (who introduced himself as “not a geoblogger”)

  2. yeah, I tend to use blog name and user name interchangeably because some folks don't use the latter. I'll fix it. Thanks for the contribution.

  3. Replies
    1. thanks for the thanks :) In spite of the volume, it truly was a pleasure -- and wow, did I learn a lot!