The emplacement of pahoehoe toes; field observations and comparison to laboratory simulations

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doi: 10.1007/s00445-003-0319-5
Authors:Gregg, Tracy K. P.; Keszthelyi, Laszlo P.
Author Affiliations:Primary:
University at Buffalo, Department of Geology, Buffalo, NY, United States
Other:
University of Arizona, Lunar and Planetary Laboratory, United States
Volume Title:Bulletin of Volcanology
Source:for the [Bulletin of Volcanology, 66(5), p.381-391. Publisher: Springer International] International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI), Heidelberg, Federal Republic of Germany. ISSN: 0258-8900
Publication Date:2004
Note:In English. 51 refs.; illus., incl. 1 table
Summary:Studies of emplacement styles of active pahoehoe toes erupted during May-June 1996 at Kilauea, Hawaii, showed that: (1) at lowest effusion rates, velocities and strain rates, smooth-surfaced lobes were emplaced by swelling with new crust forming along an incandescent lip at the lobe front, the rest of the lobe being covered by dark crust. (2) At higher effusion rates, strain rates and velocities, emplacement was by cracking or tearing; the latter was characterised by ripping of the ductile crust near the initial break-out point, most of the lobe surface being incandescent during emplacment. Smooth-surfaced lobes were observed but when an obstacle was encountered the lobes were folded. Cracking was similar but involved breaking a thicker, brittle crust at the break-out point thus required higher flow rates than tearing; typically, ropy folds formed in the centres of lobes and smooth margins. (3) At highest effusion rates the lavas formed open channels with levees. Laboratory simulations, in which polyethylene wax was extruded at constant rates into a cold sucrose solution, produced results similar to natural lavas on the scale of individual lobes but there are disparities between laboratory flows and lava flows on the scale of entire pahoehoe flow fields. Colour photographs of active lobe morphologies and emplacement styles are featured. [J.G.M.]
Sections:Petrology
Subsections:Volcanology
Subjects:Experimental studies; Field studies; Laboratory studies; Landform evolution; Lava; Lava flows; Pahoehoe; Quantitative geomorphology; Velocity; East Pacific Ocean Islands; Hawaii; Hawaii County Hawaii; Hawaii Island; Kilauea; Oceania; Polynesia; United States
Coordinates:N185500 N201600 W1545000 W1560500
Abstract Numbers:04M/3444
Record ID:2010061141
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom, Reference includes data from Geoline, Bundesanstalt fur Geowissenschaften und Rohstoffe
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