Monday, November 23, 2009

Chaos and Sedimentology

I'm rereading the book "Chaos." Last time I read it I was in 10th grade, but now I've got a little more math background, so the underlying mechanics are easier for me to describe.

A few things have leaped out at me:
  1. The concepts related to chaotic systems, such as the "Butterfly Effect" didn't take long to enter and become part of a "public consciousness" regarding the world around us

  2. I'm not sure if this is because I've not finished rereading the book, or its place as an early summary of the work, but I think they're overselling the concept of "dependence on initial conditions."

  3. One of the more powerful ideas here is in scale independent behavior - especially from a geologic standpoint (see the post in Clastic Detritus regarding sediment plumes in the GoM for an example).

  4. For my own scientific work, I think I may need to change my thinking about chaotic systems and fractals.

I think more attention needs to be paid to the "boundary conditions" controlling chaotic systems. Especially with regards to sediment deposition and transport. While a turbidite displays chaotic behavior, there are often predictable results from these systems - Bouma spent a great deal of time describing the general pattern often seen in turbidite deposits. This holds for other sedimentary systems: you may see all sorts of variation within an eolian deposit, but you're also not likely to see certain things. So while any particular eolianite may display a wide variety of textures and internal structures, there are specific patterns that will usually show up (not every single time, perhaps). The system may be chaotic and display variety of internal features, but you're not likely to produce a diamict, or massive clays as a result of wind-deposition. The mechanics and source of materials form some of these boundary conditions.

Chaos and fractals are fun stuff. But, the concepts are abstract enough that it's easy to misunderstand and apply them. I'll be exploring some of these features in future posts.


  1. I've read 'Chaos' a couple times and always love it. In terms of science books written for a popular audience it is very high on my list ... extremely well-written and thought-provoking.

    In terms of its applicability to sedimentary geology I'd agree that examples of manifestations of chaos and scale invariance (e.g., fractals) are interesting but should be considered w/in context of the fundamental processes and, as you point out, the boundary conditions.

    Just today on my blog I link to a brand new paper by Wolfgang Schlager about orderded hierarchy vs. scale invariance in sequence stratigraphy -- it is a very nice update of these concepts, at least w/r/t stratigraphic theory.

    I find these discussions fascinating ... I look forward to more posts on it!

  2. I'm now working on scale questions in our river models, and how water and sediment work at the mm-cm scale--I was struck by the GoM photo BrianR posted because the turbulent patterns are so similar to what we see in eddies only a few cm across. I look forward to your posts on this as well.