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Contents 1 Question 2 GOOF SCIENCE 3 Magma 3.1 Melting processes

[edit] Question

Can we have the composition of lava and magma explained a little more than just saying it is a silicate solution? Explain the basics of what that means, and maybe give a description of the types of molecules and maybe a chart of percentages of different types of elements or compounds? maybe some of this is in the earth's crust article. - Omegatron 20:55, Jun 29, 2004 (UTC)

Edited to include a section on partial melting as the mechanism for magma generation as this was completely lacking. It's not perfect, of course, but at least this now reflects more closely the work which has been done over at Igneous differentiation. Rolinator 09:07, 28 January 2006 (UTC)

Magnetized plasma[1] is a term which pertains to, at best, the nascent solar system and is a conceptual term (see NASA article[2]). Certainly, magma is the absolute and simplest term used to describe molten unerupted rock; there is therefore no need to try to redefine magma because it is already well known what it is. Even laypeople know what magma is.

Which brings me to people putting in the definition earlier on in the article without reading to the next paragraph. Blindness. Rolinator 11:25, 15 October 2006 (UTC)

[edit] GOOF SCIENCE

Articles like this are going to totally destroy Wikipedia's credibility. How about we just delete the article, at least until some boob is found, who wants to claim he can credibly source it? 69.215.151.139 00:27, 14 October 2007 (UTC)

[edit] Magma

[m0001.01] The converse of "all igneous rock is formed from magma" is "all magma is formed from igneous rock", which is false. Your statement here is non-sensical. Dragons flight (talk) 19:53, 21 December 2007 (UTC)

[m0002.01] Sorry, you are wrong. The converse of "all igneous rock is formed from magma", is not "all magma is formed from igneous rock"; the converse of "all igneous rock is formed from magma", is "magma is formed from all igneous rock". Since you based your revert on simply not knowing what "converse" means, I have undone your reversion. Voice of reason993 (talk) 14:46, 22 December 2007 (UTC)

[m0003.01] Actually no, the logical converse of the categorical proposition "All X is Y" is "All Y is X". [3]. At best your statement is unclear about what "converse" is supposed to mean, though personally, I consider it simply to be wrong about what converse means. Dragons flight (talk) 15:17, 22 December 2007 (UTC)

[m0004.01] When I made my edit to the article, I was relying on my fourth-grade education as to what "converse" means, as I wasn't aware that anyone was trying to change the definition of "converse". When I went to school (fourth grade), the converse of "All X is Y", was known to be "Not all Y is X". As I hadn't studied the definition of "converse" since the fourth grade, I clicked on your link [4], and I discovered, lo and behold, that some are asserting that the converse of "All X is Y" is "All Y is X". That is NOT correct. A almost-correct conversion table can be found at [5]. As the converse of "all igneous rock is formed from magma", is not "all magma is formed from igneous rock"; but is, rather, "magma is formed from all igneous rock", I have reverted your revert. Voice of reason993 (talk) 15:40, 23 December 2007 (UTC)

[m0005.01] Confusion?? What "scientific analysis"? No, "magma is formed from all igneous rock" - whether or not it is the trivial converse of the statement, it would be untrue even if so. Please stop edit warring over this semantic nonsense. Vsmith (talk) 16:47, 23 December 2007 (UTC)

[m0006.01] Confusion??? The scientific reasoning process by which it is known that "magma is formed from all igneous rock", is as follows:

[m0007.01] The article defines magma as being molten rock that sometimes forms beneath the surface of the Earth, and tells us, that, by definition, all igneous rock is formed from magma. By the scientific process of deduction, if all igneous rock is formed from magma by definition, then if we turn igneous rock into molten rock by the scientifc process of melting it, and we chemically test it to see that no transmutation of the elements has occurred during the melting process, then by that scientific process just described, in conjunction with the associated definition of magma, it has been scientifically shown that all molten igneous, being of the same composition as magma, as not differing from magma in anyway, is thereby known by scientific process to be what this article defines as being "magma". I can see that you edit lots of science articles, therefore it is reasonable to conclude that you knew that my edit to the article was true, so why did you revert a true statement from the article? Please do not edit-war by deleting true statements from articles, unless you have some other objection, in which case, please state the objection before you revert. Voice of reason993 (talk) 22:46, 23 December 2007 (UTC)

[m0008.01] Igneous rock and sedimentary rock often have the same elemental composition (in part because sedimentary rock often forms from fragments of igneous rock). The difference is one of chemical composition and arrangement, simply having the same elements is insufficient to show they are the same substance. In fact, if you melt sedimentary rock and then cool it you get igneous rock, this doesn't mean that igneous rock and sedimentary rock are the same however. Chemical changes occur during melting and recrystalization. Dragons flight (talk) 00:47, 24 December 2007 (UTC)

[m0008.02] The statement you reverted from the article makes no claim about sedimentary rock, therefore why are you talking about sedimentary rock, and why did you revert my edit? Voice of reason993 (talk) 20:10, 24 December 2007 (UTC)

[m0009.01] My logic textbook would disagree with the Wikipedia page you cite. According to my text the converse of "All X is Y" is "All Y is X" (which is often false). "Some Y is X" is a true logical inference but not the "converse" in the language of my college text. "All X is Y" => "Y is all X" is not any form of named inference and certainly not the "converse". Regardless of what you think "converse" means, you shouldn't be using the term when it clearly doesn't mean the same thing to other people. In addition, Vsmith has a fair point, it is not at all obvious that "magma is formed from all igneous rock" is even true. Dragons flight (talk) 18:33, 23 December 2007 (UTC)

[m0009.02] I can't remember why I watch this article, but I'm tempted to add this to WP:LAME. ccwaters (talk) 18:36, 23 December 2007 (UTC)

[m0009.03] Seems a worthy addition to me. -- Avenue (talk) 00:10, 24 December 2007 (UTC)

[m0010.01] I am really sorry if it is true that they are teaching college students these days that the converse of "All X is Y", is "All Y is X", for that is simply NOT TRUE. The converse of "All X is Y" is "Not all Y is X", i.e., the exact OPPOSITE of what you are claiming you were taught in a college course. The definition of converse in wikipedia as found at [6], defines the converse of "All X is Y", to be "Some Y is X". That is a logical inference from "Not all Y is X". Since my statement is consistent with the wikipedia definition of "converse", and since your definition of "converse" in not consistent with the wikipedia definition of "converse", and is, in fact, "wrong", we really must assume that the reader of the magma article is using a definition of "converse" which is consistent with the defintion of "converse" found in wikipedia at converse. It doesn't matter what either I or you think "converse" means, relative to the inclusion of that term in this article, it only matters what it "actually" means, therefore I put the true statement back into the article. If you have any objections as to its inclusion, putting aside your failure to understand what "converse" means, please state those other objections before removing my true statement from the article. Voice of reason993 (talk) 22:46, 23 December 2007 (UTC)

[m0011.01] The text added to the article is semantic nonsense, as Vsmith said. The converse is simply not relevant, and "by scientific analysis" is too vague to be worth discussing. I'll remove it. -- Avenue (talk) 00:10, 24 December 2007 (UTC)

[m0012.01] Vsmith asked me (at paragraph M0005.01) to describe a specific "scientific process", whereby it could be known (i.e. known by scientific analysis), that magma is formed from all igneous rock. I didn't claim that the presentation in paragraph M0007.01 is the only scientific process whereby the truth of the item which I am calling a "converse" may be known, I only claim(ed) it is at least one. Since I have presented at least one presently undisputed process by which it can be scientifically known that magma is formed from all igneous rock, and since I am using the correct definition of "converse", there has been identified no error in the following statement which you reverted, i.e. " By definition, all igneous rock is formed from magma, however it is by scientific analysis that the converse is known to be true" - semantic or otherwise.

[m0013.01] You cannot merely "say" something is "semantic nonsense", and delete it on that mere basis. You must "show" that something is semantic nonsense before you delete it, otherwise your deletion is arbitrary, and the repeated making of arbitrary deletions is called "revert-warring" in Wikipedia, which wikipedia has policies against.

[m0014.01] Similarly, you cannot revert merely because you "say" something is "not relevant", you must "show" that something is "not relevant", before you delete it, otherwise your deletion is arbitrary, and the making of arbitrary deletions is called "revert-warring" in Wikipedia, which wikipedia has policies against.

[m0015.01] There having been demonstrated no error in the statement "By definition, all igneous rock is formed from magma, however it is by scientific analysis that the converse is known to be true", I have returned the statement to the article. Please do not revert it without DEMONSTRATING an error either in logic, or in the implied meaning of the terms (or lack thereof), or an error of fact, as to do would be "arbitrary", which is prohibited as "edit-warring".

[m0016.01] As to anything which you might consider "too vague to discuss", you certainly don't have to try to discuss anything which you consider "too vague to discuss", and I think most wikipedia editors would appreciate it if, when such is your belief, that you don't even try.Voice of reason993 (talk) 20:10, 24 December 2007 (UTC)

As already stated, "converse" for many people doesn't mean what you think it does. Hence it is poor language to use in Wikipedia. Also, even if it did have an unambiguous meaning, your arguments that "magma is formed from all igneous rock" are dubious and not supported by anything other than your assertions about its obviousness and erroneous assumptions about rock chemistry. As you are the only advocate for this material, I encourage you to stop adding it and try to reach a consensus here rather than edit warring with everyone else. Dragons flight (talk) 20:50, 24 December 2007 (UTC)

[edit] Melting processes

The article needs some details about the processes that actually create the magmas associated with volcanism. Decompression melting is just mentioned once, even though it is the major cause of basaltic melts on Earth. I don't think hydration-induced melting is mentioned at all.

Eroica (talk) 15:02, 5 February 2008 (UTC)