Granitoid
Grus sand and granitoid (upper left)
A granitoid or granitic rock is a variety of coarse grained plutonic rock similar to granite which mineralogically is composed predominantly of feldspar and quartz.[1] Examples of granitoid rocks include granite, quartz monzonite, quartz diorite, syenite, granodiorite, tonalite and trondhjemite. Many are created by continental volcanic arc subduction or the collision of sialic masses. Volcanic rocks are common with granitoids and typically have the same origins. However, they are normally worn away after years of erosion.
While many granitoid rocks are located in areas that have experienced crustal thickening during orogenies, others known as anorogenic granitoids are unrelated to convergent boundaries or subduction zones.[1] These anorogenic granitoids may represent the deep sources for rift volcanism exposed where erosion has removed the volcanic rocks and other evidence of rifting. These A-type granitoids may have been produced by hotspots or mantle plumes.[1]
References
^ abc Blatt, Harvey and Robert J. Tracy, Petrology, Freeman, 2nd Ed., 1996 .mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"""""""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
ISBN 0-7167-2438-3
 | This article related to petrology is a stub. You can help Wikipedia by expanding it. |
