Another work of art
I found this image the other day on Geoff Lloyd's research homepage:
A couple of weeks back, I showed you another image depicting structural geology in the British Isles: the gorgeous hand-drawn diagram by Voll (1960). There are some differences between these two similar diagrams. As an exercise in thinking about how to depict rock structures on the two-dimensional space of paper or computer screens, I think they are worth taking a few moments to examine. Let's compare and contrast...
Similarities:
I'd like to point out that some other informative sketches have been popping up elseswhere in the geoblogosphere lately: See (in chronological order): here, here, here, here, here and here.
A couple of weeks back, I showed you another image depicting structural geology in the British Isles: the gorgeous hand-drawn diagram by Voll (1960). There are some differences between these two similar diagrams. As an exercise in thinking about how to depict rock structures on the two-dimensional space of paper or computer screens, I think they are worth taking a few moments to examine. Let's compare and contrast...
Similarities:
- Similar perspective (block diagram with the "front" at lower-left).
- Diagram is drawn with the short end along the strike of the structures, and the bulk of the diagram across strike.
- Both depict structurally complex rocks that vary across strike.
- Both use landmarks to give the reader perspective on where on the land's surface these subterranean structures are changing from one motif to another.
- Both are isometric, with the horizontal scale of the block being equal to the vertical scale.
Differences:
- This one was drawn by computer; Voll's was by hand.
- This one is in color; Voll's was in black and white.
- Voll's was generalized to show variations in rock fabric over a large distance; this one is reflective of specific localized data. (I like how it even side-steps a short distance where it apparently wasn't physically possible to go completely perpendicular to strike; see for instance the short jump at the Maer Anticline, and another larger jump at marker 0740 on the scale.) Voll's diagram, in contrast, smooths out those particular rough spots in the data to produce a seamless "summary."
- Voll's was one long wedge; the one is even longer, and as a result has been split into three separate views that are graphically stacked but connected with dotted line, so you can display them in a square- or retangular-shaped space, but can follow along with the overall story from "front" to "back." I think this is a good compromise, graphically speaking.
- Voll's showed the upper and side-facing-us views of the rock units; while this one shows the lower and side-facing-away-from-us views of the rock units, with occasional structures projected out into space between them to show their three-dimensional shapes.
I'd like to point out that some other informative sketches have been popping up elseswhere in the geoblogosphere lately: See (in chronological order): here, here, here, here, here and here.
2 Comments:
Really interesting, and this raises all kinds of fascinating and important issues. The display of three (and, of course four) dimensional information is one of the greatest challenges that geological communication faces. A couple of further comments - Lloyd's illustration has equal horizontal and vertical scales, which, in my humble view, should be the default case wherever possible. And his use of colour is clearly considered - there are so many examples of illustrations where the power of colour (to mislead as well as inform)is ignored (but then I have endless things to say about colour use and visual cognition - it's just a soapbox of mine).
Do you know the fantastic books by Edward Tufte? e.g., "The Visual Display of Quantitative Information" and "Envisioning Information." Plus, "The Cognitive Style of Powerpoint" should be required reading for anyone who uses that brilliant but routinely-abused piece of software.
I find the original block diagram style easier to interpret or read, possibly just because I'm used to that style - where the top is on top, and the side is towards the viewer.
The new, computer version appears to show more real data or information, and the coloring is useful. I think it will be used more and more commonly and become a standard format.
I still wish more emphasis was being placed on geologists actually being able to draw, the way it was when I was in field camp - it's true that some are better at it than others, but it used to be partly a matter of training and practice, both in drawing and in detailed observation. You can take a picture in the field, but if you can't draw the lines on a photo in the field or in your notebook or on a digital field sketchbook, you might have a hard time making sense of the photo later.
FWIW, I have a couple simple drawings/sketches here and here. Both are drawings based on photos
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