Editing Mount Royal (section)

==Geology==
{{Location map
 |Canada Montreal
 |label=Mount Royal
 |mark=RedMountain.svg
 |lat=45.506389
 |long=-73.588889
 |marksize=20
 |position=left
 |width=300
 |float=right
 |background=
 |caption=[[Location]] of Mount Royal in [[Montreal]].
}}

Mount Royal is the deep extension of a vastly eroded ancient [[Complex volcano|volcanic complex]], which was probably active about 125 million years ago.<ref name="SI">{{cite web|first1=Dan|last1=Scheirer|archive-url=https://web.archive.org/web/20060503173640/http://www.oceanexplorer.noaa.gov/explorations/05stepstones/background/geologic_history/geologic_history.html|title=A Hundred-Million Year History of the Corner Rise and New England Seamounts|access-date=1 August 2007|url=http://www.oceanexplorer.noaa.gov/explorations/05stepstones/background/geologic_history/geologic_history.html|archive-date=3 May 2006|website=Ocean Explorer|publisher=National Oceanic and Atmospheric Administration }}</ref>

The mountain, along with the other mountains of the [[Monteregian Hills]], was formed when the [[North American Plate]] moved westward over the [[New England hotspot]].<ref name="SI"/> By a process known as [[intrusion]], [[magma]] intruded into the [[sedimentary rock]]s underneath the area, producing at least eight igneous stocks. The main rock type is a [[gabbro]] composed of [[pyroxene]], [[olivine]] and variable amounts of [[plagioclase]]. During and after the main stage of intrusion, the gabbros and surrounding rocks were intruded by a series of volcanic [[dike (geology)|dike]]s and [[sill (geology)|sill]]s. Subsequently, the surrounding softer sedimentary rock was [[erosion|eroded]], leaving behind the resistant [[igneous rock]] that forms the mountain.

The mineral montroyalite, discovered in Montreal, is named after the mountain that provided the definition sample.<ref>{{cite web|url=http://webmineral.com/data/Montroyalite.shtml |title=Montroyalite Mineral Data|website=webmineral.com|access-date=12 July 2013}}</ref>