Diameter of basalt columns derived from fracture mechanics bifurcation analysis

Abstract

The diameter of columnar joints forming in cooling basalt and drying starch increases with decreasing growth rate. This observation can be reproduced with a linear-elastic three-dimensional fracture mechanics bifurcation analysis, which has been done for a periodic array of hexagonal columnar joints by considering a bifurcation mode compatible with observations on drying starch. In order to be applicable to basalt columns, the analysis has been carried out with simplified stationary temperature fields. The critical diameter differs from the one derived with a two-dimensional model by a mere factor of 1/2. By taking into account the latent heat released at the solidification front, the results agree fairly well with observed column diameters.

Hydrovolcanic features on Mars: Preliminary observations from the first Mars year of HiRISE imaging

“…To produce the parallel fractures of columnar jointing, an additional cooling mechanism is required. Penetration of water along growing fractures is the most geologically plausible process to provide this additional cooling deep within the flow (e.g., Milazzo et al, 2003;Bahr et al, 2009). Applying previous numerical studies of the cooling of lava flows (i.e., Long and Wood, 1986), Milazzo et al (2009) estimate that the liquid water was intermittently present for a few months to a few years.…”

Drying colloidal systems: Laboratory models for a wide range of applications

“…The work of Müller [84,111,112], however, began the modern interest in analogue experiments with starch. Over the past few years, there has been a rigorous series of experiments involving potato starch [85,113] and, more commonly, corn starch [86,87,[113][114][115][116][117][118][119]. A typical experiment consists of mixing a few hundred grams of commercial starch powder with an equal mass of water, and some antiseptic such as a tablespoon of household bleach.…”

Melt migration in basalt columns driven by crystallization-induced pressure gradients

“…Spectacular arrangements of columns have fascinated observers for centuries, and numerous hypotheses on their origin have been proposed [1][2][3][4][5][6][7][8][9] . Diffuse semi-circular structures occurring inside basalt columns have previously been described by several authors 5,7 , with suggestions that these internal features could be formed by constitutional supercooling 4,5 .…”