The formation of columnar joints produced by cooling in basalt at Staffa, Scotland

Abstract

(2013) 'The formation of columnar joints produced by cooling in basalt at Staa, Scotland.', Bulletin of volcanology., 75 (6). p. 715.Further information on publisher's website:http://dx.doi.org/10.1007/s00445-013-0715-4Publisher's copyright statement:The nal publication is available at Springer via http://dx.doi.org/10.1007/s00445-013-0715-4.Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details.

Disclosing the temperature of columnar jointing in lavas

“…Their presence in the rock record has long represented one of the most awe-inspiring geological features 3 and their regular geometry has challenged our understanding of pattern ordering during thermal contraction 4 . To date, the temperature of their formation has remained unconstrained, although it holds thermo-mechanical information key to resolving the cooling history of volcanic rocks 5 , 6 and intrusive magma bodies 7 . Columnar joints are permeable structures that play an important role in fluid circulation in the crust, exerting controls on heat transfer 7 , 8 , resource transport and ore deposition 9 , geothermal and hydrothermal reservoirs 10 as well as rock alteration, and degradation of rock mechanical properties 11 .…”

Instantaneous record of the geomagnetic field direction of various facies from pyroclastic flow deposits: Tests for consistency in paleomagnetic directions

“…All mean directions from this type of lithofacies were interpreted in situ, despite the fact that site 74 apparently dips at an angle of $30°. Site 74 is located within a structure of slanted columnar joints with a width (side length, Phillips et al, 2013) of about 30 cm and an average plane perpendicular to the direction of the columns that dips 31°t oward 37°E. If we perform a tilt correction on the direction of site 74 using this plane, the direction appears apart from those of the other sites, which results in a large uncertainty of the mean direction for all four sites (D = 11.0°, I = 75.1°with a 95 = 17.3°, 4 sites) and in a negative fold test at the 95% confidence level (McFadden, 1990).…”

Scale selection in columnar jointing: Insights from experiments on cooling stearic acid and numerical simulations

“…The columns are commonly polygonal shaped, with the diameter being approximately constant over a significant fraction of their height. The observed diameters range from a few centimeters up to 3 m while the column height can be up to 30 m. The regular columns tend to have five, six, or seven sides, although three‐, four‐, and eight‐sided columns exist as well [ Hetényi et al , ; Phillips et al , ; Spry , ]. As illustrated in Figure b, the regular columns can be intersected by a highly disorganized region with smaller curvy columns.…”

“…Here we have neglected the latent heat, but the result from including latent heat is qualitatively identical. While an increase in striae height has been observed within a few meters from the cooling surfaces [ Ryan and Sammis , ; Degraff and Aydin , ], columnar jointed igneous rock commonly has a constant striae height over much of the column height [ Goehring and Morris , ; Phillips et al , ]. The constant stria height could be explained if the system had one fixed length scale.…”

“…Basalt columns typically have a constant column diameter over most of their height [ Peck and Minakami , ; Goehring and Morris , ; Phillips et al , ]. The speed of the temperature front, which is proportional to the cooling rate, is widely considered the governing quantity of the column diameter [ Budkewitsch , ; Grossenbacher and McDuffie , ], with faster cooling leading to slenderer columns.…”