Order and disorder in columnar joints

Abstract

Columnar joints are three-dimensional fracture networks that form in cooling basalt and several other media. The network organizes itself into ordered, mostly hexagonal columns. The same pattern can be observed on a smaller scale in desiccating starch. We show how surface boundary conditions in the desiccation of starch affect the formation of columnar joints. Under constant drying power conditions, we find a power law dependence of columnar cross-sectional area with depth, while under constant drying rate conditions this coarsening is eventually halted. Discontinuous transitions in pattern scale can be observed under constant external conditions, which may prompt a reinterpretation of similar transitions found in basalt. Starch patterns are statistically similar to those found in basalt, suggesting that mature columnar jointing patterns contain inherent residual disorder, but are statistically scale invariant.

7 pages, 5 figures, will appear in Europhys. Lett. This arXiv version has smaller, somewhat blurrier figures. For a sharper version, see http://www.physics.utoronto.ca/nonlinear

References in corpus (2)

• Stable propagation of an ordered array of cracks during directional drying
• On maturation of crack patterns

Cited by in corpus (10)

• Evolving fracture patterns: columnar joints, mud cracks, and polygonal terrain
• An Experimental Investigation of the Scaling of Columnar Joints
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• Universal Scaling of Polygonal Desiccation Crack Patterns
• Drying and cracking mechanisms in a starch slurry
• Origin of crack pattern in the deposition from drying colloidal suspension
• Numerical study of drying process and columnar fracture process in granules-water mixtures
• Morphometric analysis of polygonal cracking patterns in desiccated starch slurries
• Star shaped patterns caused by colloidal aggregation during the spreading process of a droplet
• Experimental investigations on the nonequilibrium dynamics of pattern formation in fluid and granular systems