Talk:Sima (geology)

Merge into "oceanic crust"?
The word "sial" seems to be merely an alternative name for oceanic crust, not a different concept. I propose to merge the articles, if nobody objects. Jorge Stolfi (talk) 00:53, 28 November 2008 (UTC)
 * See the unified discussion of merging sima (geology) into oceanic crust at Talk:Oceanic crust. The Template:Mergeto used in the article defaults to the "merge to talk page".  --Bejnar (talk) 06:59, 28 November 2008 (UTC)

I just want to say, speaking as a geologist: I have never heard this term before in my life, and "Silica and Magnesium' would give you Enstatite (MgSiO3), though it could just as easilly refer to forsterite (Mg2SiO4), and ultramafic rock. Maybe this is an archaic or foreign term (there are a lot of those in geology), but the mainstream term for "Sima" is "Mafic" (From Magnesium and Iron) and for "Sial" is "Felsic". One of the pages even contains the term. I've even heard mafics called "Basic" and Felsics called "Acidic". Long story short: This should be a redirect to 'Mafic'. — Preceding unsigned comment added by 96.233.61.76 (talk) 15:12, 15 December 2012 (UTC)
 * See Earth Materials and Structure: The Earth's Interior in a current physical geology textbook. --Bejnar (talk) 20:51, 15 December 2012 (UTC)

Sial and sima were terms that were very prevalent in the pre-tectonic plate era of geological thought. If you went to university in the late 1950s or 1960s you would not only have heard of them, they would be basic building blocks for your understanding of earth's near surface structure. These terms are still in use today, see above. Sima is not the same as mafic, nor is Sial the same as felsic. Both terms are broader than the ones you suggest. For example, as noted in the article, both mafic and ultramafic rocks come from the sima. This is not a mineralogy or petrology article, it is about basic crustal structure and geochemistry. The names were created as shorthand and not as chemical or mineralogical formulae. --Bejnar (talk) 20:33, 15 December 2012 (UTC)

Pronunciation?
is it See-ma or Sih-ma or Sih-may? OsamaBinLogin (talk) 19:51, 19 October 2011 (UTC)
 * In American English it is See-ma or See-mah, with the accent on the first syllable. --Bejnar (talk) 20:36, 15 December 2012 (UTC)