chasma

Below are images of some of the major chasmata of Mars. The map shows their relative locations.

Parts of the floor of Candor Chasma contains layered deposits that have been termed interior layered deposits (ILD's). These layers may have formed when the whole area was a giant lake.

Some places on Mars contain hydrated sulfate deposits. Sulfate formation involves the presence of water. The European Space Agency's Mars Express found evidence of perhaps epsomite and kieserite. Scientists want to visit these areas with robotic rovers.{{cite web|url=http://themis.asu.edu/features/candorchasma|title=Bath Salts in Candor Chasma? - Mars Odyssey Mission THEMIS|website=themis.asu.edu|access-date=5 May 2018|url-status=live|archive-url=https://web.archive.org/web/20090929231547/http://themis.asu.edu/features/candorchasma|archive-date=29 September 2009}}

Images of rocks in the canyon walls almost always show layers. Some layers appear tougher than others. In the image below of Ganges Chasma Layers, as seen by HiRISE, one can see that the upper, light-toned deposits are eroding much faster than the lower darker layers. Some cliffs on Mars show a few darker layers standing out and often breaking into large pieces; these are thought to be hard volcanic rock instead of soft ash deposits. An example of hard layers is shown below in the picture of layers in the canyon wall in Coprates, as seen by Mars Global Surveyor. Because of its closeness to the Tharsis volcanic region, the rock layers may be made of layer after layer of lava flows, probably mixed with deposits of volcanic ash that fell out of the air following big eruptions. It is likely the rock strata in the walls preserve a long geological history of Mars.{{cite web|url=http://themis.asu.edu/features/coprateschasma|title=Landslides and Debris in Coprates Chasma - Mars Odyssey Mission THEMIS|website=themis.asu.edu|access-date=5 May 2018|url-status=live|archive-url=https://web.archive.org/web/20090929232010/http://themis.asu.edu/features/coprateschasma|archive-date=29 September 2009}} Dark layers may be due to dark lava flows. The dark volcanic rock basalt is common on Mars. However, light-toned deposits may have resulted from rivers, lakes, volcanic ash, or wind blown deposits of sand or dust.{{cite web|url=http://hirise.lpl.arizona.edu/PSP_005385_1640|title=HiRISE - Light-toned Layers in Eos Chaos (PSP_005385_1640)|website=hirise.lpl.arizona.edu|access-date=5 May 2018|url-status=live|archive-url=https://web.archive.org/web/20180103072453/https://hirise.lpl.arizona.edu/PSP_005385_1640|archive-date=3 January 2018}} The Mars Rovers found light-toned rocks to contain sulfates. Probably having been formed in water, sulfate deposits are of great interest to scientists because they may contain traces of ancient life.{{cite web |url=http://hirise.lpl.arizona.edu/PSP_007430_1725 |title=Stratigraphy Exposed in Ius Chasma |date=2008-10-08}}

Hebes Chasma, a large enclosed valley, may have once held water. Hydrated minerals have been found there. It is thought that large-scale underground springs of groundwater at different times burst to the surface to form deposits called Light Toned Deposits (LTD's). Some suggest present or fossilized life forms may be found there because the deposits are relatively young.http://www.universetoday.com/2008/12/11/Groundwater May Have Played Important Role in Shaping Mars

Image:Coprates map.JPG|Map of Coprates quadrangle showing details of Valles Marineris, the largest canyon system in the solar system. Some of the canyons may have once been filled with water. The map shows the locations of a number of major Chasma.

Image:Candor Chasm in Coprates.JPG|False color image of Candor Chasma showing locations of hydrated sulfate deposits, as seen by THEMIS. Red colors show rocky places. Greens and blues show sandy, dusty areas.

Image:Melas Chasma.JPG|Melas Chasma, as seen by THEMIS. Click on image to see relationship of Melas to other features.

Image:Cliff in Candor Chasma.JPG|Cliff in Candor Chasma Plateau, as seen by THEMIS. Click on image to see relationship with other features in Coprates quadrangle.

Image:Ganges Chasma.JPG|Cliff in northern wall of Ganges Chasma, as seen by THEMIS. Click on image to see relationship with other features in the Coprates quadrangle.

Image:Ophir Chasma Wall.JPG|Ophir Chasma Wall, as seen by HiRISE.

Image:Ius Chasma.JPG|Ius Chasma, as seen by HiRISE. Click on image to see layers.

Image:Tithonium Chasma Layers.JPG|Tithonium Chasma Layers, as seen by HiRISE.

Image:Ganges Chasma Layers.JPG|Ganges Chasma Layers, as seen by HiRISE.

• {{annotated link|Geology of Mars}}

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{{Wiktionary}}

• Lists of named chasmata: [https://planetarynames.wr.usgs.gov/SearchResults?target=VENUS&featureType=Chasma,%20chasmata on Venus], [https://planetarynames.wr.usgs.gov/SearchResults?target=MARS&featureType=Chasma,%20chasmata on Mars], [https://planetarynames.wr.usgs.gov/SearchResults?target=MIMAS&featureType=Chasma,%20chasmata on Mimas], [https://planetarynames.wr.usgs.gov/SearchResults?target=TETHYS&featureType=Chasma,%20chasmata on Tethys], [https://planetarynames.wr.usgs.gov/SearchResults?target=DIONE&featureType=Chasma,%20chasmata on Diona], [https://planetarynames.wr.usgs.gov/SearchResults?target=RHEA&featureType=Chasma,%20chasmata on Rhea], [https://planetarynames.wr.usgs.gov/SearchResults?target=ARIEL&featureType=Chasma,%20chasmata on Ariel], [https://planetarynames.wr.usgs.gov/SearchResults?target=TITANIA&featureType=Chasma,%20chasmata on Titania], [https://planetarynames.wr.usgs.gov/SearchResults?target=OBERON&featureType=Chasma,%20chasmata on Oberon], [https://planetarynames.wr.usgs.gov/SearchResults?target=CHARON&featureType=Chasma,%20chasmata on Charon].

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{{Geography of Mars}}

Category:Geology of Mars

Category:Valleys and canyons on Mars

Category:Planetary geology