Talk:Ductility (Earth science)

Brittle/ductile transition
It is not true that the brittle/ductile transition is a hard boundary. The position of the transition changes with strain rate, orientation of stress, pH2O (for rocks) and lots of other factors.

geological transition
"The transition zone occurs at the point where brittle strength exceeds ductile strength."

This sentence is only correct if the observer is transitioning from deep to shallow. If the reader has drilling or mining in mind, the "the point" descending then the statement is technically speaking false. There is no direction stated or implied from the contest.

At a minimum, I suggest replacing this sentence with "The transition zone occurs at the point where brittle strength equals ductile strength."

IMHO the Geology section needs a conceptual edit.u —Preceding unsigned comment added by 72.209.11.238 (talk) 09:40, 21 April 2011 (UTC)


 * The original text was just moved from the general ductility article, so came without context. I've made a minor move to improving that. I've adopted your wording using 'equals' - thanks. Mikenorton (talk) 18:27, 27 January 2013 (UTC)

Content
Currently this article covers the same ground as brittle-ductile transition zone, but in less detail and is an obvious candidate for deletion. I will attempt to expand it and change its emphasis to cover ductile processes in the Earth in a much more comprehensive way. This should include deformation in the Asthenosphere as plates move, ductile deformation in the lower part of the crust and deformation of rock salt in the top few kilometres as a minimum. There should also be something on the deformation behaviour of the main rock-forming minerals. This is likely to take me some time, so I would welcome a nudge if nothing has changed here in a few months time. Mikenorton (talk) 17:32, 22 October 2011 (UTC)


 * There were no nudges, but I've got around to a slight expansion - lots more to do. Mikenorton (talk) 18:11, 27 January 2013 (UTC)

ductile strength decreases with increasing temperature
I do not understand this sentence and would like some clarification. From what I understand, ductile strength is the ability of an object to deform easily or bend (without breaking). Wouldn't an increase in temperature mean an increase in the ability of the object to deform (just think about anything close to its melting point) and hence higher ductile strength? — Preceding unsigned comment added by 97.92.94.10 (talk) 02:50, 2 November 2011 (UTC)
 * The strength is the stress required to make it deform - the higher the temperature, the lower that stress needs to be to achieve the same deformation, hence a lower strength. Mikenorton (talk) 18:25, 27 January 2013 (UTC)