Talk:Volcanic plug

Latest comment: 3 years ago by Kent G. Budge in topic Devils Tower, USA
Volcanic plug
TypeGeological formation
Location
CountryAfrica, Europe, North America, the Carribean, New Zealand, Australia

Devils Tower, USA

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Is the Devils Tower a volcanic plug? The National Park Service of the U.S. Department of the Interior wrote here:

Other theories have suggested that Devils Tower is a volcanic plug or that it is the neck of an extinct volcano (an unlikely theory, for there is no evidence of volcanic activity - volcanic ash, lava flows, or volcanic debris - anywhere in the surrounding countryside)!

Jan D. Berends (talk) 22:37, 5 February 2008 (UTC)Reply

The feature is almost certainly a laccolith-the remains of an ancient intrusive flow of magma into the earth's crust millions of years ago.The surrounding rock is all sedimaentary and at one time would have been higher than the Tower. Erosion was caused by -almost certainly -at the end of the last ice age which released a mammoth flood of melt water through modern central USA-the central plains. The old intrusive flow is much harder and resisted rapid erosion thus standing up above the modern landscape. There are many of these features in the USA. — Preceding unsigned comment added by 222.152.198.245 (talk) 22:28, 1 November 2011 (UTC)Reply
Its mode of emplacement remains uncertain. A recent speculation (2015) is that it was a lava dome emplaced in a maar. Whether this should be regarded as a kind of volcanic neck seems to me to be a matter of semantics. --Kent G. Budge (talk) 14:21, 21 July 2021 (UTC)Reply
Závada, P.; Dědeček, P.; Lexa, J.; Keller, G.R. (April 2015). "Devils Tower (Wyoming, USA): A lava coulée emplaced into a maar-diatreme volcano?". Geosphere. 11 (2): 354–375. doi:10.1130/GES01166.1.

Reference footnotes for Sigiriya paragraph not working.

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I couldn't figure out the formatting used by the editor, and so could not fix them.

Sigiriya

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"Sigiriya, or the Lion's Rock or the Lion's Mountain, is a hardened magma volcanic plug formed from an extinct and long-eroded volcano."

I've seen this being repeated on several places in the internet, but there is no primary source to back up this claim. For example this paper on the geology of Sri Lankan archaeological sites (including a section on Sigiriya) does not mention an extinct volcano or a volcanic plug.

Uvants (talk) 03:25, 30 October 2013 (UTC)Reply

Removed it from the list and the image from the gallery per the solid pdf you link above. Vsmith (talk) 13:15, 28 February 2014 (UTC)Reply

The Nut

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I notice there has been some back-and-forth editing on whether to include The Nut, a geologic feature of Tasmania, as an example of a volcanic plug. In hopes of settling the issue: This presumptively reliable source identifies The Nut as a laccolith, not a plug.

Goto, Yoshihiko; McPhie, Jocelyn (February 2004). "Morphology and propagation styles of Miocene submarine basanite lavas at Stanley, northwestern Tasmania, Australia". Journal of Volcanology and Geothermal Research. 130 (3–4): 307–328. doi:10.1016/S0377-0273(03)00311-1.