Editing Mount Baker (section)

====Modern craters and cone====
[[File:Baker Fumarole.jpg|thumb|right|Sampling [[fumarole]] gas at [[Sherman Crater]] in 1981]]
Mount Baker was built from stacks of [[lava]] and [[volcanic breccia]] prior to the end of the [[last glacial period]], which ended about 15,000&nbsp;years ago. Two craters are on the mountain. Ice-filled Carmelo Crater is under the summit ice dome.<ref name="Hildreth03"/> This crater is the source for the last cone-building eruptions<ref name=Scott03b>{{cite journal |last1=Scott |first1=K.M. |author-link1=Kevin M. Scott |last2=Tucker |first2=D.S. |author-link2=Dave Tucker (geologist)|last3=McGeehin |first3=J.P. |date=2003 |title=Island of Fire in a Sea of Ice — The Growth of Mount Baker volcano and the Fraser Glaciation in the North Cascades |journal=XVI INQUA Congress Program with Abstracts |page=51 |url=http://www.mbvo.wwu.edu/abstracts/abstractText.php?id=18 |access-date=2009-03-31 |archive-date=2010-07-02 |archive-url=https://web.archive.org/web/20100702051932/http://www.mbvo.wwu.edu/abstracts/abstractText.php?id=18 |url-status=dead }}</ref><ref name="Tucker04">{{cite journal |last1=Tucker |first1=D.S. |last2=Scott |first2=K.M. |author-link1=Dave Tucker (geologist) |author-link2=Kevin M. Scott |date=2004 |title=Boulder Creek assemblage, Mount Baker, Washington: a record of the latest cone building eruptions |journal=GSA Abstracts with Programs |volume=36 |issue=4 |url=http://www.mbvrc.wwu.edu/5abstracts/abstractText.php?id=20 |access-date=2009-03-31 }}{{Dead link|date=August 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>
The highest point of Mount Baker, Grant Peak, is on the exposed southeast rim of Carmelo Crater, which is a small pile of [[andesitic]] [[scoria]] lying on top of a stack of [[lava flow]]s just below. Carmelo Crater is deeply dissected on its south side by the younger Sherman Crater. This crater is south of the summit, and its ice-covered floor is {{convert|1000|ft|m|abbr=on}} below the summit ice dome. This crater is the site of all Holocene eruptive activity.<ref name="Scott03"/> Hundreds of [[fumarole]]s vent gases, primarily {{chem|H|2|O|link=water}}, {{chem|C|O|2|link=carbon dioxide}}, and {{chem|H|2|S|link=hydrogen sulfide}}.<ref name="mbvrc"/><ref>{{cite journal |last1=Werner |first1=C. |last2=Evans |first2=W.C. |last3=McGee |first3=K.A. |last4=Doukas |first4=M.P. |last5=Tucker |first5=D.S. |author-link5=Dave Tucker (geologist) |last6=Bergfeld |first6=D. |last7=Poland |first7=M.P. |last8=Crider |first8=J.G. |date=2007 |title=Quiescent degassing of Mount Baker, Washington |journal=GSA Abstracts with Programs |volume=39 |issue=4 |url=http://www.mbvrc.wwu.edu/abstracts/abstractText.php?id=45 |page=65 |access-date=2009-03-31 |archive-date=2011-07-20 |archive-url=https://web.archive.org/web/20110720122425/http://www.mbvrc.wwu.edu/abstracts/abstractText.php?id=45 |url-status=dead }}</ref>
[[File:7487 copy Sherman Crater from Grant Peak 8-1-04.jpg|thumb|left|View south into Sherman Crater from Grant Peak, {{convert|10781|ft|m||abbr=on}} in 2004. Sherman Peak, {{convert|10140|ft|m|abbr=on}} at left; fumaroles of west rim at right.]]
Lava flows from the summit vent erupted between 30,000 and 10,000&nbsp;years ago, and during the final stages of edifice construction, blocky [[pyroclastic flow]]s entered the volcano's southeastern drainages.<ref name="Tucker04"/> An eruption from Sherman Crater 6,600&nbsp;years ago erupted a blanket of ash that extended more than {{convert|40|mi|km|abbr=on}} to the east.<ref name="Tucker07"/> Today, sulfurous gases reach the surface via two fumarole pathways: Dorr Fumarole, northeast of the summit, and [[Sherman Crater]], south of the summit. Both are sites of [[hydrothermal alteration]], converting lavas to weak, white-to-yellow [[clay]]s; [[sulfur]] is a common mineral around these fumaroles. At Sherman Crater, collapses of this weakened rock generated lahars in the 1840s.<ref name="Scott03"/><ref>{{cite journal |last1=Warren |first1=S.N. |last2=Watters |first2=R.J. |last3=Tucker |first3=D.S. |author-link3=Dave Tucker (geologist) |date=2006 |title=Future Edifice Collapse as a Result of Active Hydrothermal Alteration and Geologic Structure at Mt. Baker, Washington |journal=Eos Trans. AGU |volume=87 |page=Fall Meet. Suppl., Abstract V53A–1746 |issue=52 |bibcode=2006EOSTr..87...53Z |doi=10.1029/2006EO050009 |doi-access=free }}</ref>