Disclosing the temperature of columnar jointing in lavas

Lamur, Anthony, Lavallee, Yan, Iddon, Fiona E, Hornby, Adrian J, Kendrick, Jackie E, von Aulock, Felix W and Wadsworth, Fabian B (2018) Disclosing the temperature of columnar jointing in lavas. NATURE COMMUNICATIONS, 9 (1). 1432-.

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Abstract

Columnar joints form by cracking during cooling-induced contraction of lava, allowing hydrothermal fluid circulation. A lack of direct observations of their formation has led to ambiguity about the temperature window of jointing and its impact on fluid flow. Here we develop a novel thermo-mechanical experiment to disclose the temperature of columnar jointing in lavas. Using basalts from Eyjafjallajökull volcano (Iceland) we show that contraction during cooling induces stress build-up below the solidus temperature (980 °C), resulting in localised macroscopic failure between 890 and 840 °C. This temperature window for incipient columnar jointing is supported by modelling informed by mechanical testing and thermal expansivity measurements. We demonstrate that columnar jointing takes place well within the solid state of volcanic rocks, and is followed by a nonlinear increase in system permeability of <9 orders of magnitude during cooling. Columnar jointing may promote advective cooling in magmatic-hydrothermal environments and fluid loss during geothermal drilling and thermal stimulation.

Item Type:	Article
Uncontrolled Keywords:	37 Earth Sciences, 3703 Geochemistry, 3705 Geology, 3706 Geophysics
Depositing User:	Symplectic Admin
Date Deposited:	27 Apr 2018 09:38
Last Modified:	22 Jun 2024 07:54
DOI:	10.1038/s41467-018-03842-4
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3020648