Miniature columnar jointing...

cooked up in the lab by colleague SK and her students using corn starch (click to enlarge). Not only are the vertical columns nicely developed but the polygonal jointing on the upper surface is similarly well represented.

Here are the details about how to conduct this experiment from a previous post.

What's that cookin' in the sed lab?

I'm very slowly heating a cornstarch/water solution in an 600 ml beaker in a drying oven in order to hasten dessication and simulate the formation of columnar jointing in basalt. This technical paper on Order and Disorder in Columnar Joints describes an experiment that successfully duplicated the structure in the laboratory and inspired my effort. I'll be sure to post some pictures of the outcome of my tinkering, which is likely to take at least a week or two.

Hey, if you can't get out in the field during the winter there's always the laboratory.

Columnar jointing...

spotted in high resolution images of a crater wall on Mars (click to enlarge.) A recent technical paper describes the discovery of these volcanically-generated structures that result from the cooling of ponded lava. These structures are very common in the Miocene-age flood basalts on the Columbia Plateau in eastern Washington. Moreover, the suspected pillow structures seen in the image strongly suggests the presence of water coeval with the extrusion of the lava flow.

I tweaked the image a bit by rotating it so that the downslope direction is to the lower right, and by making slight adjustments to brightness/contrast. The annotations in red are also mine. HiRISE image PSP_005917_2020 courtesy NASA/JPL.

Wanna see Mars? It's as close as a short drive to the Grand Coulee.