Talk:Ultramafic rock

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Ultramafic and ultrabasic are actually different terms. Ultramafic is an igneous rock which is composed of greater than 90% mafic minerals, but ultrabasic is an igneous rock which has silica content lower than 45% (weight%). First is mineralogic and second is chemical classification and they should be different articles. Rock can be ultrabasic but it doesn't mean that it should be automatically ultramafic. Siim 20:09, 5 September 2005 (UTC)[reply]

That's fairly pedantic at best. Its like saying a highly mafic-mineral rich granitoid isn't felsic because it has >10% mafic minerals. Anorthosite; since it's got >45% silica due to being >90% plagioclase, and isn't ultramafic because it's >90% 'felsic' minerals...? But it's formed by accumulation from ultramafic magmas? So I disagree with you. Ultramafic rocks are ultrabasic rocks, and arguing specifics ignores the fact that they are all hot, fairly primitive (in a fractional crystallisation sense) rocks.Rolinator 09:48, 24 December 2005 (UTC)[reply]

Ultramafic landscape in Google Street View Here is a link to a GSV looking west from Highway 199 about 6 miles south of Cave Junction, Oregon. Notice the sparse vegetation and the exposed reddish, stony soil (glutted with magnesium but low in other nutrients). On satellite imagery the ultramafic terrain west of the highway appears as gray or reddish; the surrounding non-ultramafic areas are mostly green with dense forest. Tony (talk) 07:46, 11 February 2009 (UTC) http://maps.google.com/?ie=UTF8&t=h&layer=c&cbll=42.095413,-123.682488&panoid=gzzOQ8hQbswG67omfjWMJg&cbp=11,296.15780165686965,,0,5&ll=42.095413,-123.682488&spn=0.114131,0.53627&z=11[reply]