Focusing on S-C fabrics

Today’s geology word (according to Evelyn) is “fabric.” I spent a little time this afternoon playing with my ultra-cool Nikon microcamera, and decided to photograph the S-C fabric in one of the rock samples I collected in Turkey.

Because the microcamera is powerful, its plane of focus is very fine. As a consequence, slightly higher “elevation” parts of the rock sample are in focus at one notch, and slightly lower at the next notch. So I shot a bunch, changing the focal depth slightly for each snapshot, and then I stitched them together into this animated GIF…

Pretty cool effect, right?

“C” surfaces are more or less oriented to the horizontal edge of this image. “S” surfaces dip from upper left towards lower right. Sense of shear would be sinistral (top to the left).

What uses can you think of for animated GIFs like this in geology? I’ve got some ideas, but I’d love to hear what you think.

UPDATE: Here’s a slower version:

0 thoughts on “Focusing on S-C fabrics”

  1. I think the thing I’ve been most impressed with re. gif animations is their ability to illustrate a third dimension- either in time or space. Your illustration above is an interesting variant- a third dimension of space illustrated by a changing focal plane. The way I’ve most often seen 3-D in gifs is with changing angles; my own experiments have had varying degrees of success, but I learn a little more each time I mess around. Here’s an example with someone else’s photos from nearly a year ago.

    Reply
  2. Are you going to make some thing sections of the rocks to see if the quartz’s have aligned c-axes or not? I will admit that I almost always think, “gee, I wonder what it will look like with a microscope” 🙂

    Reply
    • I’d love to. The weird thing about my situation though is that I occasionally have funding from the college for big-ticket equipment purchases, but have no research budget where I can commission thin sections whenever I feel like it. If any thin-section-making company wants some free press on this blog in exchange for a couple of thin sections every month, let’s talk…

      Reply
  3. I passed your blog post on to Scott at Wagner Petrographic. Don’t know if he would be interested, but I have been very satisfied with their work in the past.

    Reply

Leave a Comment