GeoCo Rocks » igneous http://www.geocoinfestslc.com Wed, 20 Jul 2011 08:33:40 +0000 en hourly 1 http://wordpress.org/?v=3.3.1 What igneous rock types form in a mount. belt? Why are these rocks diff from those formed at the oceanic ridge http://www.geocoinfestslc.com/what-igneous-rock-types-form-in-a-mount-belt-why-are-these-rocks-diff-from-those-formed-at-the-oceanic-ridge/ http://www.geocoinfestslc.com/what-igneous-rock-types-form-in-a-mount-belt-why-are-these-rocks-diff-from-those-formed-at-the-oceanic-ridge/#comments Sat, 29 May 2010 20:34:28 +0000 http://www.geocoinfestslc.com/what-igneous-rock-types-form-in-a-mount-belt-why-are-these-rocks-diff-from-those-formed-at-the-oceanic-ridge/ http://www.geocoinfestslc.com/what-igneous-rock-types-form-in-a-mount-belt-why-are-these-rocks-diff-from-those-formed-at-the-oceanic-ridge/feed/ 2 What types of intrusive igneous rocks are formed by metamorphic rocks melting into magma? http://www.geocoinfestslc.com/what-types-of-intrusive-igneous-rocks-are-formed-by-metamorphic-rocks-melting-into-magma/ http://www.geocoinfestslc.com/what-types-of-intrusive-igneous-rocks-are-formed-by-metamorphic-rocks-melting-into-magma/#comments Thu, 25 Mar 2010 08:34:08 +0000 http://www.geocoinfestslc.com/what-types-of-intrusive-igneous-rocks-are-formed-by-metamorphic-rocks-melting-into-magma/ So when a metamorphic rock is pushed into the earth’s surface, what kinds of intrusive igneous rocks can be formed when the metamorphic rock melts into magma?

]]> http://www.geocoinfestslc.com/what-types-of-intrusive-igneous-rocks-are-formed-by-metamorphic-rocks-melting-into-magma/feed/ 1 What criteria is generally used to distinguish extrusive from intrusive igneous rocks? http://www.geocoinfestslc.com/what-criteria-is-generally-used-to-distinguish-extrusive-from-intrusive-igneous-rocks/ http://www.geocoinfestslc.com/what-criteria-is-generally-used-to-distinguish-extrusive-from-intrusive-igneous-rocks/#comments Sun, 07 Mar 2010 08:37:08 +0000 http://www.geocoinfestslc.com/what-criteria-is-generally-used-to-distinguish-extrusive-from-intrusive-igneous-rocks/ The color of the rocks. Intrusive rocks are generally much darker in color than the extrusive rocks.

Visual acuity. If you can see the crystals with the unaided eye it is considered intrusive.

Their composition. Extrusive igneous rocks are richer in Si, Al, K and Na.

Xenoliths, if an igneous rocks contains xenoliths it is considered to be intrusive.

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