Viscoelastic thermal stress in cooling basalt flows

Lore, J.; Gao, H. W.; Aydin, Atilla

doi:10.1029/2000jb900226

Cited by 48 publications

(34 citation statements)

References 40 publications

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“…As the lava rapidly cools against the ice and water to form glass, the rate of heat transfer slows, the glacier resists further melting, and the flow becomes confined against its margin (Lescinsky and Sisson 1998). Fractures form when the tensile strength of a lava flow is exceeded due to thermal contraction (Lore et al 2000) and propagate perpendicular to the maximum thermal gradient, i.e. away from the cooling surface (DeGraff and Aydin 1987).…”

Section: Evidence For Lava-ice Interaction At Ruapehumentioning

confidence: 98%

Lava-ice interaction on a large composite volcano: a case study from Ruapehu, New Zealand

et al. 2015

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Ice exerts a first-order control over the distribution and preservation of eruptive products on glaciated volcanoes. Defining the temporal and spatial distributions of ice-marginal lava flows provides valuable constraints on past glacial extents and is crucial for understanding the eruptive histories of such settings. Ice-marginal lava flows are well displayed on Ruapehu, a glaciated andesite-dacite composite cone in the southern Taupo Volcanic Zone, New Zealand. Flow morphology, fracture characteristics and 40 Ar/ 39 Ar geochronological data indicate that lavas erupted between~51 and 15 ka interacted with large valley glaciers on Ruapehu. Icemarginal lava flows exhibit grossly overthickened margins adjacent to glaciated valleys, are intercalated with glacial deposits, display fine-scale fracture networks indicative of chilling against ice, and are commonly ridge-capping due to their exclusion from valleys by glaciers. New and existing 40 Ar/ 39 Ar eruption ages for ice-marginal lava flows indicate that glaciers descending to 1300 m above sea level were present on Ruapehu between~51-41 and~27-15 ka. Younger lava flows located within valleys are characterised by blocky flow morphologies and fracture networks indicative of only localised and minor interaction with ice and/or snow, mainly in their upper reaches at elevations of~2600-2400 m. An 40 Ar/ 39 Ar eruption age of 9±3 ka (2σ error) determined for a valley-filling flow on the northern flank of Ruapehu indicates that glaciers had retreated to near-historical extents by the time of emplacement for this lava flow. The applicability of 40 Ar/ 39 Ar dating to ice-marginal flows on glaciated andesitedacite composite volcanoes makes this technique an additional proxy for paleoclimate reconstructions.

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Section: Evidence For Lava-ice Interaction At Ruapehumentioning

confidence: 98%

Lava-ice interaction on a large composite volcano: a case study from Ruapehu, New Zealand

et al. 2015

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“…At a given stress level, higher tensile stress will yield fewer fractures per unit distance and will therefore cause larger columns. Published values of unfractured basalt range from 8.6 to 14.5±3.3 MPa, but these studies do not address potential variations as a function of temperature, pressure or composition (Lore et al 2000;Schultz 1995).…”

Section: Assessment Of the Main Controlling Factorsmentioning

confidence: 99%

“…The currently most widely accepted view for columnar jointing is contractional cooling, first proposed by Raspe (1776), which states that the network of fractures forming the column boundaries develops due to mechanical stress buildup while the lava cools and contracts. This idea stands at the origin of numerous papers with different investigation methods, including in situ observation of columnar jointing formation (Peck and Minakami 1968), numerical models using thermal and/or mechanical equations (Jaeger 1961;Long and Wood 1986;DeGraff et al 1989;Budkewitsch and Robin 1994;Lore et al 2000Lore et al , 2001Kattenhorn and Schaefer 2008) and analogue experiments with starch desiccation (Müller 1998;Toramaru and Matsumoto 2004;Goehring and Morris 2005;Goehring et al 2006Goehring et al , 2009.…”

Section: Columnar Joint Formationmentioning

confidence: 99%

Scales of columnar jointing in igneous rocks: field measurements and controlling factors

et al. 2011

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“…Ryan and Sammis 1978;Aydin and DeGraff 1988;DeGraff and Aydin 1993;Grossenbacher and McDuffie 1995;Lescinsky and Fink 2000;Lore et al 2000). Because the secondary fractures are always perpendicular to the primary fractures, it is suggested that they were not affected by shear stresses within the lava body and were most likely formed during a later stage of cooling once the stress fields within the lava had become stable.…”

Section: Fracture Generationmentioning

confidence: 98%

“…Ryan and Sammis 1978;Lore et al 2000). Steam is then thought to have penetrated into the fractures at the flow base, and caused rapid chilling of the fracture surfaces.…”

Section: Fracture Generationmentioning

confidence: 98%

Snow-contact volcanic facies and their use in determining past eruptive environments at Nevados de Chillán volcano, Chile

2005

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Studies of the eruptive products from volcanoes with variable ice and snow cover and a long history of activity enable reconstruction of erupted palaeoenvironments, as well as highlighting the hazards associated with meltwater production, such as jökulhlaups and magmawater interaction. Existing difficulties include estimation of ice/snow thicknesses and discrimination between iceand snow-contact lithofacies. We present field evidence from the Cerro Blanco subcomplex of Nevados de Chillán stratovolcano, central Chile, which has erupted numerous times in glacial and non-glacial periods and most recently produced andesitic lava flows in the 1861-1865 eruption from the Santa Gertrudis cone on the northwest flank of the volcano. The main period of lava effusion occurred during the winter of 1861 when the upper flanks of the volcano were reportedly covered in snow and ice. The bases and margins of the first lava flows produced are cut by arcuate fractures, which are interpreted as snow-contact features formed when steam generated from the melting of snow entered tensional fractures at the flow base. In contrast, the interiors and upper parts of these flows, as well as the overlying flow units, have autobrecciated and blocky textures typical of subaerial conditions, due to insulation by the underlying lava. Similar textures found in a lava flow dated at 90.0±0.6 ka that was emplaced on the northwest flank of Cerro Blanco, are also inferred to be ice and snowcontact features. These textures have been used to infer that a small valley glacier, overlain by snow, existed in the Santa Gertrudis Valley at the time of the eruption. Such reconstructions are important for determining the long-term evolution of the volcano as well as assessing future hazards at seasonally snow-covered volcanoes.

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Viscoelastic thermal stress in cooling basalt flows

Cited by 48 publications

References 40 publications

Lava-ice interaction on a large composite volcano: a case study from Ruapehu, New Zealand

Lava-ice interaction on a large composite volcano: a case study from Ruapehu, New Zealand

Scales of columnar jointing in igneous rocks: field measurements and controlling factors

Snow-contact volcanic facies and their use in determining past eruptive environments at Nevados de Chillán volcano, Chile

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