Editing Mount Garibaldi (section)

===Structure===
[[File:Atwell Peak 1.jpg|thumb|right|alt=A rocky pyramid-shaped mountain peak with forested lower slopes.|Atwell Peak from the south]]
Mount Garibaldi is a moderately eroded stratovolcano overlooking the town of Squamish at the head of [[Howe Sound]] north of Vancouver.<ref name="GVP"/><ref name="HLK"/><ref>{{cite book|last1=Knight|first1=J.|last2=Harrison|first2=S.|title=Periglacial and Paraglacial Processes and Environments|publisher=[[Geological Society of London]]|year=2009|page=222|isbn=978-1-86239-281-6}}</ref> It is one of the three Cascade Arc volcanoes made exclusively of dacite, the other two being [[Glacier Peak]] and Mount Cayley. [[Rhyodacite]] is also a common volcanic rock at Mount Garibaldi and Mount Cayley, although high-[[silica]] rhyolite is uniquely present at Mount Garibaldi. Subordinate [[andesite]] erupted at all three volcanoes relatively early in their histories. At Mount Garibaldi, the total volume of volcanic rocks amount to {{Convert|16|to|20|km3|mi3|abbr=off}} and represent many episodes of activity spanning from about 670,000&nbsp;years ago to the [[Holocene]]. Andesite-dacite lavas and their [[Pyroclastic rock|pyroclastic]] accompaniments from several vents initially filled [[paleovalley]]s glacially incised into the [[Coast Plutonic Complex]] [[Basement (geology)|basement]]. Several dacitic domes and derivative pyroclastic material then built the main volcanic edifice starting about 260,000&nbsp;years ago.<ref name="FG">{{cite book|last=Hildreth|first=Wes|url=https://pubs.usgs.gov/pp/pp1744/|title=Quaternary Magmatism in the Cascades—Geologic Perspectives|publisher=[[United States Geological Survey]]|pages=7, 8, 10, 11|year=2007|isbn=978-1-4113-1945-5}}</ref> Much of the volcano was rebuilt in the last 50,000&nbsp;years by a series of violent eruptions similar in character to the [[1902 eruption of Mount Pelée]].<ref name="KE">{{cite web|last=Edwards|first=Ben|title=Mt. Garibaldi, SW British Columbia, Canada|work=VolcanoWorld|publisher=[[Oregon State University]]|year=2000|url=http://volcano.oregonstate.edu/vwdocs/volc_images/north_america/canada/Final-Gar.html|access-date=2008-05-10|url-status=dead|archive-url=https://web.archive.org/web/20100731224109/http://volcano.oregonstate.edu/vwdocs/volc_images/north_america/canada/Final-Gar.html|archive-date=2010-07-31}}</ref> The modern {{Convert|6.5|km3|mi3|adj=mid|abbr=off}} volcanic edifice is a [[Wiktionary:supraglacial|supraglacial]] volcano, having been partially constructed over glacial ice during the [[Pleistocene]] epoch.<ref name="HLK"/><ref name="HY"/>

[[File:MtGaribaldi-NorthFace-TheTable.jpg|thumb|left|alt=A prominent, glaciated mountain rising over a flat-topped, rocky mountain and a turquoise-coloured alpine lake in the foreground.|Mount Garibaldi and The Table]]
Like many other stratovolcanoes in the Cascade Volcanic Arc, Mount Garibaldi stands out by itself above the surrounding landscape. This is in contrast to most other volcanoes in the Coast Mountains, which are hidden within higher subranges.<ref name="JC"/> The mountain has a proximal relief{{efn|According to Hildreth's definitions, proximal relief refers to the difference between the summit elevation and the highest exposure of old rocks under the main edifice.<ref name="FG"/>}} of {{Convert|1300|m|ft|abbr=off}}, a draping relief{{efn|According to Hildreth's definitions, draping relief marks the difference between the summit elevation and the edifice's lowest distal lava flows (excluding pyroclastic and debris flows).<ref name="FG"/>}} of {{Convert|2375|m|ft|abbr=off}}, an elevation of {{Convert|2678|m|ft|abbr=off}} and a height of {{Convert|700|m|ft|abbr=off}}.<ref name="HLK"/><ref name="FG"/> With a length of {{Convert|3|km|mi|abbr=off}} and a width of {{Convert|5|km|mi|abbr=off}}, Mount Garibaldi is one of the larger volcanoes in the Garibaldi Volcanic Belt.<ref name="HLK"/> The western side of the mountain contains a {{Convert|600|m|ft|adj=mid|-high|abbr=off}} [[escarpment|scarp]] exposing its internal structure.<ref name="HLK"/><ref name="JV"/> This scarp formed as a result of collapse of the western flank which produced a debris flow deposit in the Squamish Valley called the [[Cheekye Fan]].<ref name="JV"/><ref name="LR">{{cite journal|last1=Fath|first1=Jared|last2=Clague|first2=John J.|last3=Friele|first3=Pierre|title=Influence of a Large Debris Flow Fan on the Late Holocene Evolution of Squamish River, Southwest British Columbia, Canada|journal=[[Canadian Journal of Earth Sciences]]|publisher=[[NRC Research Press]]|volume=55|page=333|year=2018|issue=4 |issn=1480-3313|doi=10.1139/cjes-2017-0150|bibcode=2018CaJES..55..331F |hdl=1807/82572 |hdl-access=free}}</ref> At the time of its formation, the Cheekye Fan extended across Howe Sound, resulting in the impoundment of a freshwater lake upstream of the fan. The Squamish River subsequently built a [[River delta|delta]] into this lake during the Holocene. It then filled in the lake with sediment over the last 3,300&nbsp;years to create the Squamish River [[floodplain]].<ref name="LR"/>

Mount Garibaldi is bounded by Brohm Ridge on the northwest and by Alice Ridge on the southwest.<ref>{{cite bcgnis|id=1120|name=Brohm Ridge|archive-url=https://web.archive.org/web/20220109100930/https://apps.gov.bc.ca/pub/bcgnws/names/1120.html|archive-date=2022-01-09|access-date=2022-06-18}}</ref><ref>{{cite bcgnis|id=1008|name=Alice Ridge|access-date=2022-06-18}}</ref> Extending from the southern flank of Mount Garibaldi is the unusually long Ring Creek lava flow. It is dacitic in composition, attains a length of approximately {{Convert|15|km|mi|abbr=off}} and contains well-defined levees{{efn|Levees are natural embankments that form as a result of periodic overflow of lava or as molten lava pushes cooled lava over the edge of a lava flow.<ref>{{cite web|title=Kīlauea Volcano — Lava Levees|publisher=[[United States Geological Survey]]|date=2018-07-05|url=https://www.usgs.gov/media/images/k-lauea-volcano-lava-levees|access-date=2022-08-22|url-status=live|archive-url=https://web.archive.org/web/20211025074931/https://www.usgs.gov/media/images/k-lauea-volcano-lava-levees|archive-date=2021-10-25}}</ref>}} along its margins.<ref name="KE"/> The emplacement of the Ring Creek lava flow altered drainage patterns along a valley bottom downstream, causing Skookum Creek and the Mamquam River to follow the southern margin of the lava flow and Ring Creek to follow along the northern margin. Sediments eroded from the Ring Creek lava flow form an [[alluvial fan]] at the Mamquam River and Skookum Creek confluence.<ref name="KA">{{cite journal|last1=Brooks|first1=Gregory R.|last2=Friele|first2=Pierre|title=Bracketing Ages for the Formation of the Ring Creek Lava Flow, Mount Garibaldi Volcanic Field, Southwestern British Columbia|journal=[[Canadian Journal of Earth Sciences]]|publisher=[[NRC Research Press]]|volume=29|pages=2425, 2426|year=1992|issue=11 |issn=1480-3313|doi=10.1139/e92-190|bibcode=1992CaJES..29.2425B }}</ref> The western slopes of Mount Garibaldi are underlain by [[Shear zone|sheared]] and altered [[quartz diorite]], which has undergone stream and glacial erosion to form rugged [[topography]] with relief up to {{Convert|1800|m|ft|abbr=off}}.<ref name="HLK"/>