Elysium (volcanic province)

The southeastern portion of the province is geochemically distinct from the northwest.{{Cite journal|last1=Susko|first1=David|last2=Karunatillake|first2=Suniti|last3=Kodikara|first3=Gayantha|last4=Skok|first4=J. R.|last5=Wray|first5=James|last6=Heldmann|first6=Jennifer|last7=Cousin|first7=Agnes|last8=Judice|first8=Taylor|date=2017-02-24|title=A record of igneous evolution in Elysium, a major martian volcanic province|journal=Scientific Reports|language=en|volume=7|issue=1|pages=43177|doi=10.1038/srep43177|pmid=28233797|pmc=5324095|bibcode=2017NatSR...743177S|issn=2045-2322|doi-access=free}} The southeast is composed of sedimentary and porous rocks.{{Cite journal|last1=Morgan|first1=Gareth A.|last2=Campbell|first2=Bruce A.|last3=Carter|first3=Lynn M.|last4=Plaut|first4=Jeffrey J.|date=2015|title=Evidence for the episodic erosion of the Medusae Fossae Formation preserved within the youngest volcanic province on Mars|journal=Geophysical Research Letters|language=en|volume=42|issue=18|pages=7336–7342|doi=10.1002/2015GL065017|bibcode=2015GeoRL..42.7336M|issn=1944-8007|doi-access=free}} The majority of the southeastern portion is made up of Amazonian-Hesperian volcanic units. Most of the remaining southeastern volcanic units are late Amazonian in nature. In recent history, there were significant groundwater deposits in the region.{{Cite journal|last1=Burr|first1=Devon M.|last2=Grier|first2=Jennifer A.|author2-link=JA Grier|last3=McEwen|first3=Alfred S.|last4=Keszthelyi|first4=Laszlo P.|date=2002-09-01|title=Repeated Aqueous Flooding from the Cerberus Fossae: Evidence for Very Recently Extant, Deep Groundwater on Mars|url=https://www.sciencedirect.com/science/article/pii/S0019103502969216|journal=Icarus|language=en|volume=159|issue=1|pages=53–73|doi=10.1006/icar.2002.6921|bibcode=2002Icar..159...53B|issn=0019-1035}}

It has been hard to study the composition of this province, due to the layer of dust that sits on top of the crust. Investigations in relatively dust-free regions indicate that it is made primarily of high-calcium pyroxene and olivine.{{Cite journal|last1=Viviano|first1=Christina E.|last2=Murchie|first2=Scott L.|last3=Daubar|first3=Ingrid J.|last4=Morgan|first4=M. Frank|last5=Seelos|first5=Frank P.|last6=Plescia|first6=Jeffrey B.|date=2019-08-01|title=Composition of Amazonian volcanic materials in Tharsis and Elysium, Mars, from MRO/CRISM reflectance spectra|url=https://www.sciencedirect.com/science/article/pii/S0019103518303853|journal=Icarus|language=en|volume=328|pages=274–286|doi=10.1016/j.icarus.2019.03.001|bibcode=2019Icar..328..274V|s2cid=127155512|issn=0019-1035}} To a lesser degree, the province is made up of hematite and hydrated silica, among other things. There are no strong magnetic fields in the region.{{Cite journal|date=2020-03-01|title=Crust stratigraphy and heterogeneities of the first kilometers at the dichotomy boundary in western Elysium Planitia and implications for InSight lander|journal=Icarus|language=en|volume=338|pages=113511|doi=10.1016/j.icarus.2019.113511|issn=0019-1035|doi-access=free|last1=Pan|first1=Lu|last2=Quantin-Nataf|first2=Cathy|last3=Tauzin|first3=Benoit|last4=Michaut|first4=Chloé|last5=Golombek|first5=Matt|last6=Lognonné|first6=Phillipe|last7=Grindrod|first7=Peter|last8=Langlais|first8=Benoit|last9=Gudkova|first9=Tamara|last10=Stepanova|first10=Inna|last11=Rodriguez|first11=Sébastien|last12=Lucas|first12=Antoine|bibcode=2020Icar..33813511P|hdl=1885/222099|hdl-access=free}} There are some extant near-surface glacial deposits in the caldera of Hecates Tholus, a volcano in the province.{{Cite journal|last1=Hauber|first1=Ernst|last2=van Gasselt|first2=Stephan|last3=Ivanov|first3=Boris|last4=Werner|first4=Stephanie|last5=Head|first5=James W.|last6=Neukum|first6=Gerhard|last7=Jaumann|first7=Ralf|last8=Greeley|first8=Ronald|last9=Mitchell|first9=Karl L.|last10=Muller|first10=Peter|date=March 2005|title=Discovery of a flank caldera and very young glacial activity at Hecates Tholus, Mars|url=https://www.nature.com/articles/nature03423|journal=Nature|language=en|volume=434|issue=7031|pages=356–361|doi=10.1038/nature03423|pmid=15772654|bibcode=2005Natur.434..356H|s2cid=4427179|issn=1476-4687}}

The southeastern portion of the province is approximately 0.85 billion years younger than the northwestern. The region as a whole has been volcanically active for at least 3.9 billion years, with a peak 2.2 billion years ago, although activity has decreased considerably in the last billion years.{{Cite journal|last1=Platz|first1=Thomas|last2=Michael|first2=Gregory|date=2011-12-01|title=Eruption history of the Elysium Volcanic Province, Mars|url=https://www.sciencedirect.com/science/article/pii/S0012821X11005887|journal=Earth and Planetary Science Letters|language=en|volume=312|issue=1|pages=140–151|doi=10.1016/j.epsl.2011.10.001|bibcode=2011E&PSL.312..140P|issn=0012-821X}} Crater counting done on the lava flows in the southern region show low cratering rates, which would indicate younger volcanic activity, as recent as 10 Myr.{{Cite journal|last1=Hartmann|first1=William K.|last2=Berman|first2=Daniel C.|date=2000|title=Elysium Planitia lava flows: Crater count chronology and geological implications|journal=Journal of Geophysical Research: Planets|language=en|volume=105|issue=E6|pages=15011–15025|doi=10.1029/1999JE001189|bibcode=2000JGR...10515011H|issn=2156-2202|doi-access=free}} The most recent volcanic activity dates to 2 million years ago. The southeastern portion overlaps with Cerberus Fossae; features in this region are thought to have formed due to volcanic and water-related processes, such as phreatomagmatism, relict ice flows, and interactions between lava and water. In general, many flow units in Elysium Planitia (such as Rahway Valles and Marte Vallis) are thought to have their origins in lava originating from this region.{{Cite journal|last1=Voigt|first1=Joana R. C.|last2=Hamilton|first2=Christopher W.|date=2018-07-15|title=Investigating the volcanic versus aqueous origin of the surficial deposits in Eastern Elysium Planitia, Mars|url=https://www.sciencedirect.com/science/article/pii/S001910351730831X|journal=Icarus|language=en|volume=309|pages=389–410|doi=10.1016/j.icarus.2018.03.009|bibcode=2018Icar..309..389V|s2cid=125918565|issn=0019-1035}}

Hecates Tholus erupted ~350 million years ago, with glacial deposits in the resulting caldera dating between 5 and 24 million years ago. Craters in the region are not generally typical of impacts; rather, they are thought to have formed due to explosive volcanism or collapse due to subsurface lava withdrawal.

Elysium contains numerous lava flow units with variable histories as well as volcanic and fluvial channels.{{Cite journal|last1=Mouginis-Mark|first1=Peter J.|last2=Wilson|first2=Lionel|last3=Head|first3=James W.|last4=Brown|first4=Steven H.|last5=Lynn Hall|first5=J.|last6=Sullivan|first6=Kathryn D.|date=1984-04-01|title=Elysium planitia, mars: Regional geology, volcanology, and evidence for volcano-ground ice interactions|url=https://doi.org/10.1007/BF00114309|journal=Earth, Moon, and Planets|language=en|volume=30|issue=2|pages=149–173|doi=10.1007/BF00114309|bibcode=1984EM&P...30..149M|s2cid=120632318|issn=1573-0794}} The three major volcanoes of the region sit on top of a 1700 x 2400 km broad dome. The summit of Hecates Tholus shows evidence of pyroclastic activity. Martian volcanism has been dominated by effusive eruption styles and there is limited evidence to support widespread explosive or pyroclastic volcanic eruptions on Mars.{{Cite journal|last1=Whelley|first1=Patrick|last2=Novak|first2=Alexandra Matiella|last3=Richardson|first3=Jacob|last4=Bleacher|first4=Jacob|last5=Mach|first5=Kelsey|last6=Smith|first6=Reagan N.|date=2021|title=Stratigraphic Evidence for Early Martian Explosive Volcanism in Arabia Terra|journal=Geophysical Research Letters|language=en|volume=48|issue=15|pages=e2021GL094109|doi=10.1029/2021GL094109|bibcode=2021GeoRL..4894109W|s2cid=237689743|issn=1944-8007|doi-access=free}}

Elysium Mons is approximately 1.5 times as steep as any other Martian volcano at approximately 7-7.5°.{{Cite journal|last1=Wilson|first1=Lionel|last2=Mouginis-Mark|first2=Peter J.|date=2001|title=Estimation of volcanic eruption conditions for a large flank event on Elysium Mons, Mars|journal=Journal of Geophysical Research: Planets|language=en|volume=106|issue=E9|pages=20621–20628|doi=10.1029/2000JE001420|bibcode=2001JGR...10620621W|issn=2156-2202|doi-access=free}}{{Cite journal|last1=Kallianpur|first1=K.|last2=Mouginis-Mark|first2=P. J.|date=2001-03-01|title=Slopes of Martian Volcanoes|journal=Lunar and Planetary Science Conference|url=https://ui.adsabs.harvard.edu/abs/2001LPI....32.1258K|pages=1258|bibcode=2001LPI....32.1258K}} The caldera at the summit of Elysium Mons is approximately 13.5 km in diameter.{{Cite journal|last1=Blasius|first1=Karl R.|last2=Cutts|first2=James A.|date=1981-01-01|title=Topography of Martian central volcanoes|url=https://dx.doi.org/10.1016/0019-1035%2881%2990008-7|journal=Icarus|language=en|volume=45|issue=1|pages=87–112|doi=10.1016/0019-1035(81)90008-7|bibcode=1981Icar...45...87B|issn=0019-1035}} Extending past the rim of this central caldera are at least 18 sinuous channels thought to be the remnants of collapsed lava tubes and lava channels.  

The Elysium volcanic province was first noticed as a distinct Martian region as a result of data obtained from the Mariner 9 mission, in the 1970s.{{Cite journal|last1=Williams|first1=David A.|last2=Greeley|first2=Ronald|last3=Manfredi|first3=Leon|last4=Raitala|first4=Jouko|last5=Neukum|first5=Gerhard|date=2010-06-01|title=The Circum-Hellas Volcanic Province, Mars: Assessment of wrinkle-ridged plains|url=https://www.sciencedirect.com/science/article/pii/S0012821X09006062|journal=Earth and Planetary Science Letters|series=Mars Express after 6 Years in Orbit: Mars Geology from Three-Dimensional Mapping by the High Resolution Stereo Camera (HRSC) Experiment|language=en|volume=294|issue=3|pages=492–505|doi=10.1016/j.epsl.2009.10.007|bibcode=2010E&PSL.294..492W|issn=0012-821X}}{{Cite journal|last1=McCauley|first1=J. F.|last2=Carr|first2=M. H.|last3=Cutts|first3=J. A.|last4=Hartmann|first4=W. K.|last5=Masursky|first5=Harold|last6=Milton|first6=D. J.|last7=Sharp|first7=R. P.|last8=Wilhelms|first8=D. E.|date=1972-10-01|title=Preliminary mariner 9 report on the geology of Mars|url=https://dx.doi.org/10.1016%2F0019-1035%2872%2990003-6|journal=Icarus|language=en|volume=17|issue=2|pages=289–327|doi=10.1016/0019-1035(72)90003-6|issn=0019-1035}} The Viking orbiter noted that volcanic province of Elysium experienced more diverse types of volcanism than the Tharsis volcanic region.{{Cite journal|last1=Mouginis-Mark|first1=Peter J.|last2=Wilson|first2=Lionel|last3=Head|first3=James W.|last4=Brown|first4=Steven H.|last5=Lynn Hall|first5=J.|last6=Sullivan|first6=Kathryn D.|date=1984-04-01|title=Elysium planitia, mars: Regional geology, volcanology, and evidence for volcano-ground ice interactions|url=https://doi.org/10.1007/BF00114309|journal=Earth, Moon, and Planets|language=en|volume=30|issue=2|pages=149–173|doi=10.1007/BF00114309|bibcode=1984EM&P...30..149M|s2cid=120632318|issn=1573-0794}} In 2004, ESA's Mars Express orbiter's HRSC observed the volcanoes in the region.{{Cite web|title=HRSC Bildserie #011 - Albor Tholus (Mars Express Orbit 0032); Fachrichtung Planetologie und Fernerkundung an der FU Berlin|url=http://www.planet.geo.fu-berlin.de/projekte/mars/hrsc011-AlborTholus.php|access-date=2021-02-26|website=www.planet.geo.fu-berlin.de}} The InSight Lander landed just south of the province in 2018, in Elysium Planitia, and has detected marsquakes emanating from this region.{{cite journal|last1=Horvath|first1=David G.|last2=Moitra|first2=Pranabendu|last3=Hamilton|first3=Christopher W.|last4=Craddock|first4=Robert A.|last5=Andrews-Hanna|first5=Jeffrey C.|title=Evidence for geologically recent explosive volcanism in Elysium Planitia, Mars|journal=Icarus|year=2021|volume=365|page=114499|doi=10.1016/j.icarus.2021.114499|arxiv=2011.05956|bibcode=2021Icar..36514499H|s2cid=226299879}}{{Cite journal|last1=Lognonné|first1=P.|last2=Banerdt|first2=W. B.|last3=Giardini|first3=D.|last4=Pike|first4=W. T.|last5=Christensen|first5=U.|last6=Laudet|first6=P.|last7=de Raucourt|first7=S.|last8=Zweifel|first8=P.|last9=Calcutt|first9=S.|last10=Bierwirth|first10=M.|last11=Hurst|first11=K. J.|date=2019-01-28|title=SEIS: Insight's Seismic Experiment for Internal Structure of Mars|url= |journal=Space Science Reviews|language=en|volume=215|issue=1|pages=12|doi=10.1007/s11214-018-0574-6|issn=1572-9672|pmc=6394762|pmid=30880848|bibcode=2019SSRv..215...12L}} The main science goals of the lander are to monitor the level of seismic activity occurring on Mars and to understand how Mars formed and how the planet has been evolving ever since.{{Cite web|last=mars.nasa.gov|title=Quick Facts {{!}} Mission|url=https://mars.nasa.gov/insight/mission/quick-facts|access-date=2021-11-10|website=NASA's InSight Mars Lander|language=en}}{{Cite web|last=mars.nasa.gov|title=InSight Mission Overview|url=https://mars.nasa.gov/insight/mission/overview|access-date=2021-11-10|website=NASA's InSight Mars Lander|language=en}}{{Cite journal|last1=Banerdt|first1=W. Bruce|last2=Smrekar|first2=Suzanne E.|last3=Banfield|first3=Don|last4=Giardini|first4=Domenico|last5=Golombek|first5=Matthew|last6=Johnson|first6=Catherine L.|last7=Lognonné|first7=Philippe|last8=Spiga|first8=Aymeric|last9=Spohn|first9=Tilman|last10=Perrin|first10=Clément|last11=Stähler|first11=Simon C.|date=2020|title=Initial results from the InSight mission on Mars|url=https://www.nature.com/articles/s41561-020-0544-y|journal=Nature Geoscience|language=en|volume=13|issue=3|pages=183–189|doi=10.1038/s41561-020-0544-y|bibcode=2020NatGe..13..183B|s2cid=211266334|issn=1752-0908}}

Image:Elysium THEMIS 0.5.jpg|High-resolution THEMIS daytime infrared image mosaic of Elysium from 2001 Mars Odyssey.

Image:MOLA elysium mons.jpg|MOLA maps showing the geographic context of Elysium.

Image:PIA06827 - Hecates Tholus.jpg|Hecates Tholus, as seen by THEMIS.

Image:Albor Tholus THEMIS.jpg|Albor Tholus, as seen by THEMIS.

Image:Troughs in Elysium Planitia.JPG|Troughs to the east of Albor Tholus, as seen by HiRISE under the HiWish program

Image:Troughs showing blue in Elysium Planitia.JPG|Portion of a trough (fossa) in Elysium, as seen by HiRISE under the HiWish program (blue indicates probably seasonal frost)

Image:Cerberus Fossae from Themis.JPG|A Cerberus Fossae trough, as seen from THEMIS

Image:Cerberus Fossae dark emission.JPG|Wind-blown material darkens areas around a Cerberus Fossae trough (scale bar for HiRISE image is 500 m)

Image:Cerberus Fossae with HiRISE.JPG|The Cerberus Fossae, as seen by HiRISE (scale bar is 1.0 km)

Image:Elysium Fossae.JPG|The Elysium Fossae, as seen by HiRISE (click on image to see layers)

Image:Hephaestus Fossae Two Vews.JPG|Two views of the Hephaestus Fossae, as seen by HiRISE (picture on right lies to the top (north) of other picture). Fossae often form by material moving into an underground void.

• Fossa (geology)
• Geography of Mars
• Geology of Mars
• List of quadrangles on Mars
• Volcanism on Mars

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• [http://www.google.com/mars/#lat=14.859850&lon=158.115234&zoom=4&q=Elysium%20Planitia Google Mars] - zoomable map centered on Elysium Planitia, with three main volcanoes of Elysium visible
• [http://www.google.com/mars/#lat=9.876863&lon=157.719726&zoom=8&map=infrared&q=Cerberus%20Fossae google mars - Cerebrus Fossae fissures]

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Category:Volcanoes of Mars

Category:Mountains on Mars

Category:Surface features of Mars

Category:Lava plateaus