Editing Absaroka Range (section)

===Absaroka Volcanic Province===
[[Igneous rock]]s of the Absaroka Volcanic Province cover an area of approximately {{convert|23000|km2|sqmi ha|abbr=on}} in southwestern [[Montana]] and northwestern [[Wyoming]], including roughly one third of [[Yellowstone National Park]]. These [[extrusive]] rocks were erupted during the [[Eocene]]  [[Epoch (geology)|Epoch]] of the [[Paleogene]] [[Period (geology)|Period]]. [[Radiometric dating]] has shown that eruptive activity lasted from about {{ma|53|43.7|million years ago}}. The eroded remnants of many large [[stratovolcano]]es are found in the area. The dissection of these long [[extinct volcano]]es by [[erosion]] allows [[geologist]]s to see volcanic structures that are impossible to see in [[active volcano]]es. Many terms now widely used in [[volcanology]] originated in nineteenth century field studies of these ancient volcanoes.<ref>{{cite journal|last1=Hiza|first1=Margaret M.|title=The Geologic History of the Absaroka Volcanic Province|journal=Yellowstone Science|date=Spring 1998|volume=6|issue=2|page=2|url=http://www.nps.gov/yell/learn/upload/YS_6_2_sm.pdf| access-date=28 July 2015}}</ref>