Thursday, October 6, 2011

So Many Field Trips!

Where did September go? It seems like I just got back into town, and now it's October. Every weekend in September I was away on field trips, taking advantage of the good weather before the rain sets in. The first weekend I went to Washington State with my Quaternary Geology class for four days, followed by a Igneous and Metamorphic Petrology trip to South-Western Vancouver Island, and then another trip to Sooke for Paleobiology. Needless to say, I have been putting out fires on the homework front, and stockpiling photos to put up on here, but I do have some great photos and some great geology to share when I can write up all about Washington, which will probably happen tomorrow evening (Friday) or Saturday.

But until then, I have a bit of a puzzle. I'm not sure if there IS an answer out for my question, but anyways...

(For scale, there are some rock climbers on the right hand side at the base of the columns)

In Washington State, we were looking at some columnar basalts that have some interesting kinks in them. These columns appear to have waves in them that carry beyond each column into a wavy pattern that is visible across the outcrop (as seen in above photo). The wavey bits are due to the column having different thicknesses, but it's just strange how they seem to line up. We asked our profs on our trip, and they didn't really know why they would do that, so I thought I'd ask around and find out if anyone had any good ideas or explanations.


  1. The only (and I mean only) reference I could find looks at the same outcrop, and it doesn't say much. Something about an "oscillatory instability" in the crack formation.

  2. Prof (Ed Taylor) once commented that phenomenon was "not well-understood" (Do geo-types have a lock on that phrase or what?) but that it was characteristic of particular flows. Once you learn to note it, he claimed, you could reliably recognize that particular flow across a wide area. He'd spent a lot of time in the CRB, so I presume he knew what he was talking about, but I've never heard this from anyone else.

    I've seen lots of examples of this, but never at that odd angle oblique to the columns... generally perpendicular.

  3. my contribution to science is that I think it looks neat :D