Phaethontis quadrangle

The Electris deposits are light-toned sediments on Mars and are 100–200 m thick. Research using HiRISE images lead scientists to believe that the deposit is an accumulation of loess that initially were produced from volcanic materials in Tharsis or other volcanic centers.{{cite journal |doi=10.1016/j.icarus.2009.04.009 |title=HiRISE views enigmatic deposits in the Sirenum Fossae region of Mars |journal=Icarus |volume=205 |pages=53–63 |year=2010 |last1=Grant |first1=John A |last2=Wilson |first2=Sharon A |last3=Noe Dobrea |first3=Eldar |last4=Fergason |first4=Robin L |last5=Griffes |first5=Jennifer L |last6=Moore |first6=Jeffery M |last7=Howard |first7=Alan D |issue=1 |bibcode=2010Icar..205...53G |url=https://repository.si.edu/bitstream/handle/10088/8621/201027.pdf }} A team of researchers led by Laura Kerber found that the Electris deposits could have been formed from ash from the volcanoes Apollinaris Mons, Arsia Mons, and possibly Pavonis Mons.{{cite journal |doi=10.1016/j.icarus.2012.03.016 |title=The dispersal of pyroclasts from ancient explosive volcanoes on Mars: Implications for the friable layered deposits |journal=Icarus |volume=219 |pages=358–381 |year=2012 |last1=Kerber |first1=Laura |last2=Head |first2=James W |last3=Madeleine |first3=Jean-Baptiste |last4=Forget |first4=François |last5=Wilson |first5=Lionel |issue=1 |bibcode=2012Icar..219..358K }}

Image:Electris Depsoit.jpg|Electris Deposit, as seen by HiRISE. Electris deposit is light-toned and smooth in the image in contrast to rough materials below. Gullies are also visible.

Image:Electris Deposit Layers.jpg|Layers in light-toned Electris Deposit, as seen by HiRISE on the Mars Reconnaissance Orbiter. Gullies are visible on the left.

{{main|Martian Gullies}}

The Phaethontis quadrangle is the location of many gullies that may be due to recent flowing water. Some are found in the Gorgonum Chaos{{Cite web|url=http://hirise.lpl.arizona.edu/PSP_004071_1425|title=HiRISE | Gorgonum Chaos Mesas (PSP_004071_1425)}}{{Cite web|url=http://hirise.lpl.arizona.edu/PSP_001948_1425|title=HiRISE | Gullies on Gorgonum Chaos Mesas (PSP_001948_1425)}} and in many craters near the large craters Copernicus and Newton.{{Cite web|url=http://hirise.lpl.arizona.edu/PSP_004163_1375|title=HiRISE | Gullies in Newton Crater (PSP_004163_1375)}}U.S. department of the Interior U.S. Geological Survey, Topographic Map of the Eastern Region of Mars M 15M 0/270 2AT, 1991 Gullies occur on steep slopes, especially on the walls of craters. Gullies are believed to be relatively young because they have few, if any craters. Moreover, they lie on top of sand dunes which themselves are considered to be quite young. Usually, each gully has an alcove, channel, and apron. Some studies have found that gullies occur on slopes that face all directions,{{cite journal | last1=Edgett |first1= K. |last2= Malin |first2= M. C. |last3= Williams |first3= R. M. E. |last4= Davis |first4= S. D. |date= 2003 |title= Polar-and middle-latitude martian gullies: A view from MGS MOC after 2 Mars years in the mapping orbit |journal= Lunar Planet. Sci. |volume=34 |at=p. 1038, Abstract 1038 | url=http://www.lpi.usra.edu/meetings/lpsc2003/pdf/1038.pdf | bibcode = 2003LPI....34.1038E }} others have found that the greater number of gullies are found on poleward facing slopes, especially from 30–44° S.{{cite journal | last1 = Dickson | first1 = J | last2 = Head | first2 = J | last3 = Kreslavsky | first3 = M | title = Martian gullies in the southern mid-latitudes of Mars: Evidence for climate-controlled formation of young fluvial features based upon local and global topography | doi = 10.1016/j.icarus.2006.11.020 | url=http://www.planetary.brown.edu/pdfs/3138.pdf | date = 2007 | pages = 315–323 | volume = 188 | issue = 2 | journal = Icarus | bibcode = 2007Icar..188..315D}}

Although many ideas have been put forward to explain them,{{Cite web|url=http://www.psrd.hawaii.edu/Aug03/MartianGullies.html|title = PSRD: Gullied Slopes on Mars}} the most popular involve liquid water coming from an aquifer, from melting at the base of old glaciers, or from the melting of ice in the ground when the climate was warmer.{{cite journal | last1= Heldmann | first1= J | last2= Mellon | first2= Michael T | title= Observations of martian gullies and constraints on potential formation mechanisms | journal= Icarus | volume= 168 | issue= 2 | pages= 285–304 | date = 2004 | doi = 10.1016/j.icarus.2003.11.024 | bibcode=2004Icar..168..285H| url= https://zenodo.org/record/1259029 }}Forget, F. et al. 2006. Planet Mars Story of Another World. Praxis Publishing. Chichester, UK. Because of the good possibility that liquid water was involved with their formation and that they could be very young, scientists are excited. Maybe the gullies are where we should go to find life.

There is evidence for all three theories. Most of the gully alcove heads occur at the same level, just as one would expect of an aquifer. Various measurements and calculations show that liquid water could exist in aquifers at the usual depths where gullies begin. One variation of this model is that rising hot magma could have melted ice in the ground and caused water to flow in aquifers. Aquifers are layer that allow water to flow. They may consist of porous sandstone. The aquifer layer would be perched on top of another layer that prevents water from going down (in geological terms it would be called impermeable). Because water in an aquifer is prevented from going down, the only direction the trapped water can flow is horizontally. Eventually, water could flow out onto the surface when the aquifer reaches a break—like a crater wall. The resulting flow of water could erode the wall to create gullies.{{Cite web|url=http://www.space.com/scienceastronomy/mars_aquifer_041112.html|title = Mars Gullies Likely Formed by Underground Aquifers|website = Space.com|date = 12 November 2004}} Aquifers are quite common on Earth. A good example is "Weeping Rock" in Zion National Park, Utah.Harris, A and E. Tuttle. 1990. Geology of National Parks. Kendall/Hunt Publishing Company. Dubuque, Iowa

As for the next theory, much of the surface of Mars is covered by a thick smooth mantle that is thought to be a mixture of ice and dust.{{cite journal | last1= Malin | first1= Michael C. | last2= Edgett | first2= Kenneth S. | title= Mars Global Surveyor Mars Orbiter Camera: Interplanetary cruise through primary mission | journal= Journal of Geophysical Research | volume= 106 | issue= E10 | pages= 23429–23570 | date= 2001 | doi= 10.1029/2000JE001455 | bibcode = 2001JGR...10623429M | doi-access= free }}{{cite journal | pmid = 11473309|author1-link=John F. Mustard | last1 = Mustard | first1 = JF | date = 2001 | pages = 411–4 | issue = 6845 | last2 = Cooper | volume = 412 | first2 = CD | journal = Nature | last3 = Rifkin | first3 = MK | title = Evidence for recent climate change on Mars from the identification of youthful near-surface ground ice. | url=http://www.planetary.brown.edu/pdfs/2610.pdf | doi = 10.1038/35086515 | bibcode = 2001Natur.412..411M | s2cid = 4409161 }}{{cite journal | last1= Carr | first1= Michael H. | title= Mars Global Surveyor observations of Martian fretted terrain | journal= Journal of Geophysical Research | volume= 106 | issue= E10 | pages= 23571–23595 | date= 2001 | doi = 10.1029/2000JE001316 | bibcode=2001JGR...10623571C| s2cid= 129715420 }} This ice-rich mantle, a few yards thick, smoothes the land, but in places it has a bumpy texture, resembling the surface of a basketball. The mantle may be like a glacier and under certain conditions the ice that is mixed in the mantle could melt and flow down the slopes and make gullies.[https://web.archive.org/web/20131224133733/http://www.nbcnews.com/id/15702457 NBC News]{{cite journal | last1 = Head | first1 = J. W. | last2 = Marchant | first2 = D. R. | last3 = Kreslavsky | first3 = M. A. | title = From the Cover: Formation of gullies on Mars: Link to recent climate history and insolation microenvironments implicate surface water flow origin | journal = Proceedings of the National Academy of Sciences | volume = 105 | pages = 13258–63 | date = 2008 | doi = 10.1073/pnas.0803760105 |bibcode = 2008PNAS..10513258H | pmid=18725636 | pmc=2734344 | issue=36| doi-access = free }} Because there are few craters on this mantle, the mantle is relatively young. An excellent view of this mantle is shown below in the picture of the Ptolemaeus Crater Rim, as seen by HiRISE.{{cite journal | last1 = Christensen | first1 = PR | title = Formation of recent martian gullies through melting of extensive water-rich snow deposits. | journal = Nature | volume = 422 | issue = 6927 | pages = 45–8 | date = 2003 | pmid = 12594459 | doi = 10.1038/nature01436 |bibcode = 2003Natur.422...45C | s2cid = 4385806 }}

The ice-rich mantle may be the result of climate changes.{{Citation |last=Lovett |first=Richard A. |title=Melting Snow Created Mars Gullies, Expert Says |date=2008-03-18 |url=https://news.nationalgeographic.com/news/2008/03/080319-mars-gullies_2.html |work=National Geographic News |archive-url=https://web.archive.org/web/20091116190836/http://news.nationalgeographic.com:80/news/2008/03/080319-mars-gullies_2.html |archive-date=2009-11-16}} Changes in Mars's orbit and tilt cause significant changes in the distribution of water ice from polar regions down to latitudes equivalent to Texas. During certain climate periods water vapor leaves polar ice and enters the atmosphere. The water comes back to ground at lower latitudes as deposits of frost or snow mixed generously with dust. The atmosphere of Mars contains a great deal of fine dust particles. Water vapor will condense on the particles, then fall down to the ground due to the additional weight of the water coating. When Mars is at its greatest tilt or obliquity, up to 2 cm of ice could be removed from the summer ice cap and deposited at midlatitudes. This movement of water could last for several thousand years and create a snow layer of up to around 10 meters thick.{{cite journal | last1=Jakosky | first1=Bruce M. | last2=Carr | first2=Michael H. | title=Possible precipitation of ice at low latitudes of Mars during periods of high obliquity | journal=Nature | volume=315 | pages=559–561 | bibcode = 1985Natur.315..559J | date=1985 | doi = 10.1038/315559a0 | issue=6020| s2cid=4312172 | url=https://zenodo.org/record/1233025 }}{{cite journal | last1= Jakosky | first1= Bruce M. | last2= Henderson | first2= Bradley G. | last3= Mellon | first3= Michael T. | title= Chaotic obliquity and the nature of the Martian climate | journal= Journal of Geophysical Research | volume= 100 | issue= E1 | pages= 1579–1584 | bibcode = 1995JGR...100.1579J | date= 1995 | doi = 10.1029/94JE02801 }} When ice at the top of the mantling layer goes back into the atmosphere, it leaves behind dust, which insulating the remaining ice.{{cite news | author=MLA NASA/Jet Propulsion Laboratory |date = December 18, 2003 | title= Mars May Be Emerging From An Ice Age |work= ScienceDaily |access-date= February 19, 2009 |url= https://www.sciencedaily.com/releases/2003/12/031218075443.htm }} Measurements of altitudes and slopes of gullies support the idea that snowpacks or glaciers are associated with gullies. Steeper slopes have more shade which would preserve snow.

Higher elevations have far fewer gullies because ice would tend to sublimate more in the thin air of the higher altitude.{{cite journal | last1= Hecht | first1= M | title= Metastability of liquid water on Mars | pages= 373–386 | date= 2002 | volume= 156 | issue= 2 | doi= 10.1006/icar.2001.6794 | journal= Icarus | url= http://www.geo.brown.edu/geocourses/geo292/papers/Hecht2002.pdf | bibcode= 2002Icar..156..373H }}{{dead link|date=March 2018 |bot=InternetArchiveBot |fix-attempted=yes }}

The third theory might be possible since climate changes may be enough to simply allow ice in the ground to melt and thus form the gullies. During a warmer climate, the first few meters of ground could thaw and produce a "debris flow" similar to those on the dry and cold Greenland east coast.{{cite journal |last1=Peulvast | first1=J.P. |date= 1988 |title= Mouvements verticaux et genèse du bourrelet Est-groenlandais. dans la région de Scoresby Sund | journal=Physio Géo |volume= 18 |pages= 87–105 | language=fr }} Since the gullies occur on steep slopes only a small decrease of the shear strength of the soil particles is needed to begin the flow. Small amounts of liquid water from melted ground ice could be enough.{{cite journal | last1=Costard |first1= F. |display-authors= 4 |last2= Forget |first2= F. |last3= Mangold |first3= N. |last4= Mercier |first4= D. |last5= Peulvast |first5= J. P. |date=2001 |title= Debris Flows on Mars: Analogy with Terrestrial Periglacial Environment and Climatic Implications | journal= Lunar and Planetary Science | volume= XXXII |pages= 1534 |bibcode = 2001LPI....32.1534C | url= http://www.lpi.usra.edu/meetings/lpsc2001/pdf/1534.pdf }}http://www.spaceref.com:16090/news/viewpr.html?pid=7124{{dead link|date=March 2018 |bot=InternetArchiveBot |fix-attempted=yes }}, Calculations show that a third of a mm of runoff can be produced each day for 50 days of each Martian year, even under current conditions.{{cite journal | last1= Clow | first1= G | title= Generation of liquid water on Mars through the melting of a dusty snowpack | journal= Icarus | volume= 72 | issue= 1 | pages= 93–127 | date= 1987 | bibcode = 1987Icar...72...95C | doi = 10.1016/0019-1035(87)90123-0 }}

Image:Gorgonum in Phaethontis.JPG|Gorgonum Chaos as seen by Mars Reconnaissance Orbiter HiRISE. Image about 4 km wide.

Image:Gully in Phaethontis.jpg|Group of gullies on north wall of crater that lies west of the crater Newton (41.3047 degrees south latitude, 192.89 east longitide). Image taken with Mars Global Surveyor under the MOC Public Targeting Program.

Image:Crater wall inside Mariner Crater.JPG|Crater wall inside Mariner Crater showing a large group of gullies, as seen by HiRISE

Image:Wide view of gully on hill.JPG|CTX image of the next image showing a wide view of the area. Since the hill is isolated it would be difficult for an aquifer to develop. Rectangle shows the approximate location of the next image.

Image:Gully on mound.JPG|Gully on mound as seen by Mars Global Surveyor, under the MOC Public Targeting Program. Images of gullies on isolated peaks, like this one, are difficult to explain with the theory of water coming from aquifers because aquifers need large collecting areas.

Image:28386myglaciers.jpg|Another view of the previous gully on a mound. This one is with HiRISE, under the HiWish program. This view shows most of the apron and two old glaciers associated with it. All that is left of the glaciers are terminal moraines.

Image:Context image for gullies in crater and trough.JPG|MOLA context image for the series of three images to follow of gullies in a trough and nearby crater

File:Crater, troughs, and gullies ESP 039555 1430.jpg|Crater with gullies on the edge of a trough

Image:Gullies in trough and crater.jpg|Gullies in a trough and nearby crater, as seen by HiRISE under the HiWish program. Scale bar is 500 meters long.

Image:Gullies in crater under HiWish.JPG|Close-up of gullies in crater, as seen by HiRISE under the HiWish program At certain latitudes, gullies appear only on one wall of a crater. Here the gullies are on a north wall. This wall faces the sun more than other walls.

Image:ESP_020012gulliescropped.jpg|Gullies near Newton Crater, as seen by HiRISE, under the HiWish program. Place where there was an old glacier is labeled.

Image:20803gullies with glacier remains.jpg|Gullies with remains of a former glacier in crater in Terra Sirenum, as seen by HiRISE under HiWish program

Image:Gullies near Newton Crater.jpg|Gullies near Newton Crater, as seen by HiRISE under the HiWish Program

Image:21845gulliespatt.jpg|Close-up of gully showing multiple channels and patterned ground, as seen by HiRISE under the HiWish program

ESP 039621 1315gullies2levels.jpg|Gullies in two levels of a crater wall, as seen by HiRISE under HiWish program. Gullies at two levels suggests they were not made with an aquifer, as was first suggested. Location is Phaethontis quadrangle.

ESP 039621 1315gullies.jpg|Image of gullies with main parts labeled. The main parts of a Martian gully are alcove, channel, and apron. Since there are no craters on this gully, it is thought to be rather young. Picture was taken by HiRISE under HiWish program. Location is Phaethontis quadrangle.

ESP 039793 1385gullies.jpg|Gullies in crater, as seen by HiRISE under HiWish program. Location is Phaethontis quadrangle.

ESP 039793 1385channelsclose.jpg|Close up of gully network showing branched channels and curves; these characteristics suggest creation by a fluid. Note: this is an enlargement of a previous wide view of gullies in a crater, as seen by HiRISE under HiWish program. Location is Phaethontis quadrangle.

File:Close view of gully in Phaethontis 01.jpg|Gullies on crater wall, as seen by HiRISE under HiWish program

Sometimes other features appear near gullies. At the base of some gullies there may be depressions or curved ridges. These have been called "spatulate depressions." These depressions form after glacial ice disappears. Steep walls often develop glaciers during certain climates. When the climate changes, the ice in the glaciers sublimates in the thin Martian atmosphere. Sublimation is when a substance goes directly from a solid state to a gas state. Dry ice on Earth does this. So when the ice at the base of a steep wall sublimates, a depression results. Also, more ice from higher up will tend to flow downward. This flow will stretch the surface rocky debris thereby forming transverse crevasses. Such formations have been termed "washboard terrain" because they resemble the old fashioned washboards.jawin, E, J. Head, D. Marchant. 2018. Transient post-glacial processes on Mars: Geomorphologic evidence for a paraglacial period. Icarus: 309, 187-206 The parts of gullies and some associated features of gullies are shown below in a HiRISE images.

PSP 001842 1395gulliesglacierscracks.jpg|Wide view of crater showing gullies and other features, as seen by HiRISE

File:1842 1395depressions.jpg|Close view of crater labeled with "spatulate depression" and other features, as seen by HiRISE. Note: this is an enlargement of the previous image.

File:1842 1395washboard.jpg|Close view of crater labeled with "washboard terrain" and other features, as seen by HiRISE. Note: this is an enlargement of a previous image. The washboard terrain was formed before the gully apron since the gully apron cuts across the washboard terrain.

ESP 036995 1410tongue.jpg|Tongue-shaped glacier, as seen by HiRISE under the HiWish program. Location is Phaethontis quadrangle.

Esp 037514 1475tonguesnout.jpg|Close-up of the snouts of two glaciers from the previous image, as seen by HiRISE under the HiWish program. These are towards the bottom left of the previous image.

File:ESP 046359 1250-2pingoscale.jpg

The radial and concentric cracks visible here are common when forces penetrate a brittle layer, such as a rock thrown through a glass window. These particular fractures were probably created by something emerging from below the brittle Martian surface. Ice may have accumulated under the surface in a lens shape; thus making these cracked mounds. Ice being less dense than rock, pushed upwards on the surface and generated these spider web-like patterns. A similar process creates similar sized mounds in arctic tundra on Earth. Such features are called "pingos", an Inuit word.{{Cite web|url=http://www.uahirise.org/ESP_046359_1250|title=HiRISE | Spider Webs (ESP_046359_1250)}} Pingos would contain pure water ice; thus they could be sources of water for future colonists of Mars.

Concentric crater fill, like lobate debris aprons and lineated valley fill, is believed to be ice-rich.Levy, J. et al. 2009. Concentric crater fill in Utopia Planitia: History and interaction between glacial "brain terrain" and periglacial processes. Icarus: 202. 462-476. Based on accurate topography measures of height at different points in these craters and calculations of how deep the craters should be based on their diameters, it is thought that the craters are 80% filled with mostly ice.{{cite journal | last1 = Levy | first1 = J. | last2 = Head | first2 = J. | last3 = Marchant | first3 = D. | year = 2010 | title = Concentric Crater fill in the northern mid-latitudes of Mars: Formation process and relationships to similar landforms of glacial origin | doi = 10.1016/j.icarus.2010.03.036 | journal = Icarus | volume = 209 | issue = 2| pages = 390–404 | bibcode = 2010Icar..209..390L }}{{cite journal | last1 = Levy | first1 = J. | last2 = Head | first2 = J. | last3 = Dickson | first3 = J. | last4 = Fassett | first4 = C. | last5 = Morgan | first5 = G. | last6 = Schon | first6 = S. | year = 2010 | title = Identification of gully debris flow deposits in Protonilus Mensae, Mars: Characterization of a water-bearing, energetic gully-forming process | journal = Earth Planet. Sci. Lett. | volume = 294 | issue = 3–4| pages = 368–377 | doi=10.1016/j.epsl.2009.08.002| bibcode = 2010E&PSL.294..368L }}{{Cite web|url=http://hirise.lpl.arizona.edu/ESP_032569_2225|title=HiRISE | Ice Deposition and Loss in an Impact Crater in Utopia Basin (ESP_032569_2225)}}Garvin, J., S. Sakimoto, J. Frawley. 2003. Craters on Mars: Geometric properties from gridded MOLA topography. In: Sixth International Conference on Mars. July 20–25, 2003, Pasadena, California. Abstract 3277. That is, they hold hundreds of meters of material that probably consists of ice with a few tens of meters of surface debris.Garvin, J. et al. 2002. Global geometric properties of martian impact craters. Lunar Planet. Sci: 33. Abstract # 1255.[http://photojournal.jpl.nasa.gov/catalog/PIA09662 NASA.gov] The ice accumulated in the crater from snowfall in previous climates.Kreslavsky, M. and J. Head. 2006. Modification of impact craters in the northern planes of Mars: Implications for the Amazonian climate history. Meteorit. Planet. Sci.: 41. 1633-1646Madeleine, J. et al. 2007. Exploring the northern mid-latitude glaciation with a general circulation model. In: Seventh International Conference on Mars. Abstract 3096.{{Cite web|url=http://hirise.lpl.arizona.edu/PSP_002917_2175|title=HiRISE | Dissected Mantled Terrain (PSP_002917_2175)}} Recent modeling suggests that concentric crater fill develops over many cycles in which snow is deposited, then moves into the crater. Once inside the crater shade and dust preserve the snow. The snow changes to ice. The many concentric lines are created by the many cycles of snow accumulation. Generally snow accumulates whenever the axial tilt reaches 35 degrees.Fastook, J., J.Head. 2014. Concentric crater fill: Rates of glacial accumulation, infilling and deglaciation in the Amazonian and Noachian of Mars. 45th Lunar and Planetary Science Conference (2014) 1227.pdf

Wikiconcentric.jpg|Crater showing concentric crater fill, as seen by CTX (on Mars Reconnaissance Orbiter). Location is Phaethontis quadrangle.

Wikiconcentricclose22451.jpg|Close-up view of concentric crater fill, as seen by HiRISE under HiWish program. Note: this is an enlargement of previous image of a concentric crater. Location is Phaethontis quadrangle.

File:46622 1365contextccf.jpg|Concentric crater fill, as seen by HiRISE under HiWish program

File: ESP 046622 1365ccfclosecolor.jpg|Close, color view of concentric crater fill, as seen by HiRISE under HiWish program

File:Global Map of Martian Magnetic Anomalies PIA02059.jpg

The Mars Global Surveyor (MGS) discovered magnetic stripes in the crust of Mars, especially in the Phaethontis and Eridania quadrangles (Terra Cimmeria and Terra Sirenum).{{cite book |first=Nadine G. |last=Barlow |title=Mars: an introduction to its interior, surface and atmosphere |publisher=Cambridge University Press |location=Cambridge, UK |date=2008 |isbn=978-0-521-85226-5 }}{{cite book |author=Philippe Lognonné |author2=François Forget |author3=François Costard |title=Planet Mars: Story of Another World (Springer Praxis Books / Popular Astronomy) |publisher=Praxis |date=2007 |isbn=978-0-387-48925-4 }} The magnetometer on MGS discovered 100 km wide stripes of magnetized crust running roughly parallel for up to 2000 km. These stripes alternate in polarity with the north magnetic pole of one pointing up from the surface and the north magnetic pole of the next pointing down.{{cite book |author=Fredric W. Taylor |title=The Scientific Exploration of Mars |publisher=Cambridge University Press |location=Cambridge, UK |date=2010 |isbn=978-0-521-82956-4 }} When similar stripes were discovered on Earth in the 1960s, they were taken as evidence of plate tectonics. Researchers believe these magnetic stripes on Mars are evidence for a short, early period of plate tectonic activity. When the rocks became solid they retained the magnetism that existed at the time. A magnetic field of a planet is believed to be caused by fluid motions under the surface.{{cite journal |author=Connerney JE |display-authors=4 |author2=Acuna MH |author3=Wasilewski PJ |title=Magnetic lineations in the ancient crust of mars |journal=Science |volume=284 |issue=5415 |pages=794–8 |date=April 1999 |pmid=10221909 |doi=10.1126/science.284.5415.794 |url=http://www.astro.wisc.edu/~ewilcots/courses/astro340s04/readings/marstectonics.pdf |bibcode=1999Sci...284..794C |last4=Reme |last5=Mazelle |last6=Vignes |last7=Lin |last8=Mitchell |last9=Cloutier}}{{cite journal | last1= Langlais | first1= B. | title= Crustal magnetic field of Mars | doi= 10.1029/2003JE002048 | date= 2004 | volume= 109 | journal= Journal of Geophysical Research | issue= E2 | pages= n/a | bibcode= 2004JGRE..109.2008L |doi-access=free }}{{cite journal | last1= Connerney | first1= J. E. P. | display-authors= 4 | last2= Acuña | first2= MH | last3= Ness | first3= NF | last4= Kletetschka | first4= G | last5= Mitchell | first5= DL | last6= Lin | first6= RP | last7= Reme | first7= H | title= Tectonic implications of Mars crustal magnetism | journal= Proceedings of the National Academy of Sciences | volume= 102 | issue= 42 | pages= 14970–14975 | pmid=16217034 | date= 2005 | doi=10.1073/pnas.0507469102 | pmc=1250232 |bibcode = 2005PNAS..10214970C | doi-access= free }} However, there are some differences, between the magnetic stripes on Earth and those on Mars. The Martian stripes are wider, much more strongly magnetized, and do not appear to spread out from a middle crustal spreading zone.

Because the area containing the magnetic stripes is about 4 billion years old, it is believed that the global magnetic field probably lasted for only the first few hundred million years of Mars' life, when the temperature of the molten iron in the planet's core might have been high enough to mix it into a magnetic dynamo. There are no magnetic fields near large impact basins like Hellas. The shock of the impact may have erased the remnant magnetization in the rock. So, magnetism produced by early fluid motion in the core would not have existed after the impacts.{{cite journal | doi=10.1126/science.284.5415.790 | last1=Acuna | first1=MH | last2=Connerney | first2=JE | last3=Ness | first3=NF | last4=Lin | first4=RP | last5=Mitchell | first5=D | last6=Carlson | first6=CW | last7=McFadden | first7=J | last8=Anderson | first8=KA | last9=Reme | first9=H | last10=Mazelle | first10=C | last11=Vignes | first11=D | last12=Wasilewski | first12=P | last13=Cloutier | first13=P | title=Global distribution of crustal magnetization discovered by the Mars Global Surveyor MAG/ER Experiment | journal=Science | volume=284 | issue=5415 | pages= 790–793 | date=1999 | pmid = 10221908 |bibcode = 1999Sci...284..790A | display-authors=8 | url=https://zenodo.org/record/1231157 }}

When molten rock containing magnetic material, such as hematite (Fe₂O₃), cools and solidifies in the presence of a magnetic field, it becomes magnetized and takes on the polarity of the background field. This magnetism is lost only if the rock is subsequently heated above a particular temperature (the Curie point which is 770 °C for iron). The magnetism left in rocks is a record of the magnetic field when the rock solidified.{{Cite web|url=http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=31028&fbodylongid=645|title=ESA Science & Technology - Martian Interior}}

Image:Chloride deposits on Mars.JPG

Using data from Mars Global Surveyor, Mars Odyssey and the Mars Reconnaissance Orbiter, scientists have found widespread deposits of chloride minerals. A picture below shows some deposits within the Phaethontis quadrangle. Evidence suggests that the deposits were formed from the evaporation of mineral enriched waters. The research suggests that lakes may have been scattered over large areas of the Martian surface. Usually chlorides are the last minerals to come out of solution. Carbonates, sulfates, and silica should precipitate out ahead of them. Sulfates and silica have been found by the Mars rovers on the surface. Places with chloride minerals may have once held various life forms. Furthermore, such areas should preserve traces of ancient life.{{cite journal | last1= Osterloo | first1= M. M. | display-authors= 4 | last2= Hamilton | first2= V. E. | last3= Bandfield | first3= J. L. | last4= Glotch | first4= T. D. | last5= Baldridge | first5= A. M. | last6= Christensen | first6= P. R. | last7= Tornabene | first7= L. L. | last8= Anderson | first8= F. S. | title= Chloride-Bearing Materials in the Southern Highlands of Mars | journal= Science | volume= 319 | issue= 5870 | pages= 1651–1654 | bibcode = 2008Sci...319.1651O | date= 2008 | pmid= 18356522 | doi = 10.1126/science.1150690 | citeseerx= 10.1.1.474.3802 | s2cid= 27235249 }}

Based on chloride deposits and hydrated phyllosilicates, Alfonso Davila and others believe there is an ancient lakebed in Terra Sirenum that had an area of {{cvt|30,000|km2}} and was {{convert|200|m}} deep. Other evidence that supports this lake are normal and inverted channels like ones found in the Atacama Desert.{{cite journal | last1 = Davila | first1 = A. |display-authors=etal | year = 2011 | title = A large sedimentary basin in the Terra Sirenum region of the southern highlands of Mars | url = https://zenodo.org/record/1259043| journal = Icarus | volume = 212 | issue = 2| pages = 579–589 | doi=10.1016/j.icarus.2010.12.023| bibcode = 2011Icar..212..579D }}

The Elysium quadrangle is home to large troughs (long narrow depressions) called fossae in the geographical language used for Mars. Troughs are created when the crust is stretched until it breaks. The stretching can be due to the large weight of a nearby volcano. Fossae/pit craters are common near volcanoes in the Tharsis and Elysium system of volcanoes.Skinner, J., L. Skinner, and J. Kargel. 2007. Re-assessment of Hydrovolcanism-based Resurfacing within the Galaxias Fossae Region of Mars. Lunar and Planetary Science XXXVIII (2007)

{{Main|Fossa (geology)}}

Image:Icaria Fossae Graben.JPG|Icaria Fossae Graben, as seen by HiRISE. Click on image for a better view of Dust Devil Tracks.

Image:Sirenum Fossae Layers.JPG|Sirenum Fossae Layers, as seen by HiRISE. Scale bar is 500 meters long.

ESP 046042 1420pits.jpg|Pits in troughs, as seen by HiRISE under HiWish program

Image:25246brainseroding.jpg|Surface of crater floor showing details from image taken with HiRISE, under HiWish program. This may be a transition from one type of structure to a different, maybe due to erosion.

Image:25484hollowsclose.jpg|Close-up of surface with large hollows, as seen by HiRISE under HiWish program

File:Copernicus, Mars (THEMIS).png

The density of impact craters is used to determine the surface ages of Mars and other solar system bodies.{{Cite web|url=http://www.lpi.usra.edu/publications/slidesets/stones/|title=Stones, Wind, and Ice: A Guide to Martian Impact Craters}} The older the surface, the more craters present. Crater shapes can reveal the presence of ground ice.

File:Wikikeelertrumplerwright.pngFile:Wikihipparchus.jpgr, as seen by CTX camera (on Mars Reconnaissance Orbiter)]]FIle:Wikinansenwest.jpg, as seen by CTX camera (on Mars Reconnaissance Orbiter)]]

The area around craters may be rich in minerals. On Mars, heat from the impact melts ice in the ground. Water from the melting ice dissolves minerals, and then deposits them in cracks or faults that were produced with the impact. This process, called hydrothermal alteration, is a major way in which ore deposits are produced. The area around Martian craters may be rich in useful ores for the future colonization of Mars.{{Cite web|url=http://www.indiana.edu/~sierra/papers/2003/Patterson.html.|title = Indiana University Bloomington}}

Studies on Earth have documented that cracks are produced and that secondary minerals veins are deposited in the cracks.Osinski, G, J. Spray, and P. Lee. 2001. Impact-induced hydrothermal activity within the Haughton impact structure, arctic Canada: Generation of a transient, warm, wet oasis. Meteoritics & Planetary Science: 36. 731-745http://www.ingentaconnect.com/content/arizona/maps/2005/00000040/00000012/art00007 {{Dead link|date=February 2022}}Pirajno, F. 2000. Ore Deposits and Mantle Plumes. Kluwer Academic Publishers. Dordrecht, The Netherlands Images from satellites orbiting Mars have detected cracks near impact craters.Head, J. and J. Mustard. 2006. Breccia Dikes and Crater-Related Faults in Impact Craters on Mars: Erosion and Exposure on the Floor of a 75-km Diameter Crater at the Dichotomy Boundary. Special Issue on Role of Volatiles and Atmospheres on Martian Impact Craters Meteoritics & Planetary Science Great amounts of heat are produced during impacts. The area around a large impact may take hundreds of thousands of years to cool.Segura, T, O. Toon, A. Colaprete, K. Zahnle. 2001. Effects of Large Impacts on Mars: Implications for River Formation. American Astronomical Society, DPS meeting#33, #19.08Segura, T, O. Toon, A. Colaprete, K. Zahnle. 2002. Environmental Effects of Large Impacts on Mars. Science: 298, 1977-1980.

Many craters once contained lakes.Cabrol, N. and E. Grin. 2001. The Evolution of Lacustrine Environments on Mars: Is Mars Only Hydrologically Dormant? Icarus: 149, 291-328.Fassett, C. and J. Head. 2008. Open-basin lakes on Mars: Distribution and implications for Noachian surface and subsurface hydrology. Icarus: 198, 37-56.Fassett, C. and J. Head. 2008. Open-basin lakes on Mars: Implications of valley network lakes for the nature of Noachian hydrology. Because some crater floors show deltas, we know that water had to be present for some time. Dozens of deltas have been spotted on Mars.Wilson, J. A. Grant and A. Howard. 2013. INVENTORY OF EQUATORIAL ALLUVIAL FANS AND DELTAS ON MARS. 44th Lunar and Planetary Science Conference. Deltas form when sediment is washed in from a stream entering a quiet body of water. It takes a bit of time to form a delta, so the presence of a delta is exciting; it means water was there for a time, maybe for many years. Primitive organisms may have developed in such lakes; hence, some craters may be prime targets for the search for evidence of life on the Red Planet.Newsom H., Hagerty J., Thorsos I. 2001. Location and sampling of aqueous and hydrothermal deposits in martian impact craters. Astrobiology: 1, 71-88.

The following is a list of craters in the quadrangle. The crater's central location is of the quadrangle, craters that its central location is in another quadrangle is listed by eastern, western, northern or southern part.

¹Partly located in the quadrangle while another part is in a different quadrangle along with the crater's diameter

Linear ridge networks are found in various places on Mars in and around craters.Head, J., J. Mustard. 2006. Breccia dikes and crater-related faults in impact craters on Mars: Erosion and exposure on the floor of a crater 75 km in diameter at the dichotomy boundary, Meteorit. Planet Science: 41, 1675-1690. Ridges often appear as mostly straight segments that intersect in a lattice-like manner. They are hundreds of meters long, tens of meters high, and several meters wide. It is thought that impacts created fractures in the surface, these fractures later acted as channels for fluids. Fluids cemented the structures. With the passage of time, surrounding material was eroded away, thereby leaving hard ridges behind.

Since the ridges occur in locations with clay, these formations could serve as a marker for clay which requires water for its formation.{{cite journal | last1 = Mangold |display-authors=etal | year = 2007 | title = Mineralogy of the Nili Fossae region with OMEGA/Mars Express data: 2. Aqueous alteration of the crust | journal = J. Geophys. Res. | volume = 112| issue = E8|pages=E08S04 | doi = 10.1029/2006JE002835 | bibcode=2007JGRE..112.8S04M|s2cid=15188454 |url=https://hal.archives-ouvertes.fr/hal-00376813 | doi-access =free }}Mustard et al., 2007. Mineralogy of the Nili Fossae region with OMEGA/Mars Express data: 1. Ancient impact melt in the Isidis Basin and implications for the transition from the Noachian to Hesperian, J. Geophys. Res., 112.{{cite journal | last1 = Mustard |display-authors=etal | year = 2009 | title = Composition, Morphology, and Stratigraphy of Noachian Crust around the Isidis Basin | url =https://authors.library.caltech.edu/34913/1/2009JE003349.pdf | journal = J. Geophys. Res. | volume = 114| issue = 7|pages=E00D12 | doi = 10.1029/2009JE003349 | bibcode=2009JGRE..114.0D12M| doi-access = free }} Water here could have supported past life in these locations. Clay may also preserve fossils or other traces of past life.

ESP 034887 1490ridgesphaethontis.jpg|Linear ridge networks, as seen by HiRISE under HiWish program

ESP 034887 1490ridgesphaethontisclose.jpg|Close-up of linear ridge networks from the previous image, as seen by HiRISE under HiWish program

Sand dunes have been found in many places on Mars. The presence of dunes shows that the planet has an atmosphere with wind, for dunes require wind to pile up the sand. Most dunes on Mars are black because of the weathering of the volcanic rock basalt.{{Cite web|url=http://hirise.lpl.arizona.edu/ESP_016459_1830|title=HiRISE | Dunes and Inverted Craters in Arabia Terra (ESP_016459_1830)}}{{cite book|author=Michael H. Carr|title=The surface of Mars|url=https://books.google.com/books?id=uLHlJ6sjohwC|access-date=21 March 2011|year=2006|publisher=Cambridge University Press|isbn=978-0-521-87201-0}} Black sand can be found on Earth on Hawaii and on some tropical South Pacific islands.{{Cite web|url=https://www.desertusa.com/desert-activity/sand-dune-wind1.html|title = Sand Dunes - Phenomena of the Wind - DesertUSA}}

Sand is common on Mars due to the old age of the surface that has allowed rocks to erode into sand. Dunes on Mars have been observed to move many meters.Archived at [https://ghostarchive.org/varchive/youtube/20211205/ur_TeOs3S64 Ghostarchive]{{cbignore}} and the [https://web.archive.org/web/20151216133913/https://www.youtube.com/watch?v=ur_TeOs3S64 Wayback Machine]{{cbignore}}: {{cite web| url = https://www.youtube.com/watch?v=ur_TeOs3S64| title = Curiosity Rover Report (Dec. 15, 2015): First Visit to Martian Dunes | website=YouTube| date = 15 December 2015 }}{{cbignore}}{{Cite web|url=https://uanews.arizona.edu/story/the-flowing-sands-of-mars|title = The Flowing Sands of Mars|date = 9 May 2012}}

Some dunes move along. In this process, sand moves up the windward side and then falls down the leeward side of the dune, thus caused the dune to go toward the leeward side (or slip face).Namowitz, S., Stone, D. 1975. earth science the world we live in. American Book Company. New York.

When images are enlarged, some dunes on Mars display ripples on their surfaces.[https://www.jpl.nasa.gov/news/news.php?feature=6551 NASA.gov] These are caused by sand grains rolling and bouncing up the windward surface of a dune. The bouncing grains tend to land on the windward side of each ripple. The grains do not bounce very high so it does not take much to stop them.

ESP 046082 1380dunes.jpg|Dunes in Newton (Martian crater), as seen by HiRISE under HiWish program

46082 1380dunesbigsmallcraters.jpg|Close view of dunes in Newton Crater showing ripples on surface, as seen by HiRISE under HiWish program

Much of the Martian surface is covered with a thick ice-rich, mantle layer that has fallen from the sky a number of times in the past.{{cite journal | last1 = Hecht | first1 = M | year = 2002 | title = Metastability of water on Mars | journal = Icarus | volume = 156 | issue = 2 | pages = 373–386 | doi = 10.1006/icar.2001.6794 | bibcode = 2002Icar..156..373H }}{{cite journal | last1 = Mustard | first1 = J. | display-authors = etal | year = 2001 | title = Evidence for recent climate change on Mars from the identification of youthful near-surface ground ice | journal = Nature | volume = 412 | issue = 6845| pages = 411–414 | doi = 10.1038/35086515 | pmid = 11473309 | bibcode = 2001Natur.412..411M | s2cid = 4409161 }}{{cite journal | last1 = Pollack | first1 = J. | last2 = Colburn | first2 = D. | last3 = Flaser | first3 = F. | last4 = Kahn | first4 = R. | last5 = Carson | first5 = C. | last6 = Pidek | first6 = D. | year = 1979 | title = Properties and effects of dust suspended in the martian atmosphere | journal = J. Geophys. Res. | volume = 84 | pages = 2929–2945 | doi = 10.1029/jb084ib06p02929 | bibcode = 1979JGR....84.2929P }} In some places a number of layers are visible in the mantle.{{Cite web|url=http://www.uahirise.org/ESP_048897_2125|title=HiRISE | Layered Mantling Deposits in the Northern Mid-Latitudes (ESP_048897_2125)}}

{{Main|Latitude dependent mantle}}

Image:Tader Valles.JPG|Tader Valles, as seen by THEMIS. Smooth material in channels may be a mantle in the form of dirty snow.

Esp 037167 1445mantle.jpg|Surface showing appearance with and without mantle covering, as seen by HiRISE, under the HiWish program. Location is Terra Sirenum in Phaethontis quadrangle.

Image:Atlantis Chaos.JPG|Atlantis Chaos, within the Atlantis basin, as seen by HiRISE. Click on image to see mantle covering and possible gullies. The two images are different parts of the original image. They have different scales.

Image:Ptolemaeus Crater Rim.JPG|Ptolemaeus Crater Rim, as seen by HiRISE. Click on image to see excellent view of mantle deposit.

There is enormous evidence that water once flowed in river valleys on Mars.{{cite journal | last1 = Baker | first1 = V. | display-authors = etal | year = 2015 | title = Fluvial geomorphology on Earth-like planetary surfaces: a review | journal = Geomorphology | volume = 245 | pages = 149–182 | doi = 10.1016/j.geomorph.2015.05.002 | pmid = 29176917 | pmc = 5701759 | bibcode = 2015Geomo.245..149B }}Carr, M. 1996. in Water on Mars. Oxford Univ. Press. Images of curved channels have been seen in images from Mars spacecraft dating back to the early 1970s with the Mariner 9 orbiter.Baker, V. 1982. The Channels of Mars. Univ. of Tex. Press, Austin, TX{{cite journal | last1 = Baker | first1 = V. | last2 = Strom | first2 = R. | last3 = Gulick | first3 = V. | last4 = Kargel | first4 = J. | last5 = Komatsu | first5 = G. | last6 = Kale | first6 = V. | year = 1991 | title = Ancient oceans, ice sheets and the hydrological cycle on Mars | journal = Nature | volume = 352 | issue = 6336| pages = 589–594 | doi = 10.1038/352589a0 | bibcode = 1991Natur.352..589B | s2cid = 4321529 }}{{cite journal | last1 = Carr | first1 = M | year = 1979 | title = Formation of Martian flood features by release of water from confined aquifers | journal = J. Geophys. Res. | volume = 84 | pages = 2995–300 | doi = 10.1029/jb084ib06p02995 | bibcode = 1979JGR....84.2995C }}{{cite journal | last1 = Komar | first1 = P | year = 1979 | title = Comparisons of the hydraulics of water flows in Martian outflow channels with flows of similar scale on Earth | journal = Icarus | volume = 37 | issue = 1| pages = 156–181 | doi = 10.1016/0019-1035(79)90123-4 | bibcode = 1979Icar...37..156K }} Indeed, a study published in June 2017, calculated that the volume of water needed to carve all the channels on Mars was even larger than the proposed ocean that the planet may have had. Water was probably recycled many times from the ocean to rainfall around Mars.{{Cite web|url=http://spaceref.com/mars/how-much-water-was-needed-to-carve-valleys-on-mars.html|title = How Much Water Was Needed to Carve Valleys on Mars? - SpaceRef| date=5 June 2017 }}{{cite journal | last1 = Luo | first1 = W. | display-authors = etal | year = 2017 | title = New Martian valley network volume estimate consistent with ancient ocean and warm and wet climate | journal = Nature Communications | volume = 8 | page = 15766 | doi = 10.1038/ncomms15766 | pmid = 28580943 | pmc = 5465386 | bibcode = 2017NatCo...815766L }}

{{Main|Valley networks (Mars)}}

{{Main|Outflow channels}}

ESP 050856 1445channels.jpg|Channel, as seen by HiRISE under HiWish program. Streamlined shapes are indicated with arrows.

WikiESP 039594 1365oxbow.jpg|Oxbow lake, as seen by HiRISE under HiWish program

ESP 047149 1380channel.jpg|Channel connecting two craters, as seen by HiRISE under HiWish program

ESP 050933 1355channel.jpg|Channels, as seen by HiRISE under HiWish program

Because a thin coating of fine bright dust covers much of the surface of Mars, passing dust devils remove the bright dust and expose the underlying dark surface. Edgett, K. S., and M. C. Malin (2000), Martian dust raising and surface albedo controls: thin, dark (and sometimes bright) streaks and dust devils in MGS high-resolution images, Lunar Planet. Sci. [CDROM], XXXI, Abstract 1073. Malin, M. C., and K. S. Edgett (2001), Mars Global Surveyor Mars Orbiter Camera: Interplanetary cruise through primary mission, J. Geophys. Res., 106, 23,429–23,570. The patterns formed by the dust devil tracks change frequently; sometimes in just a few months. Fisher, J. A., M. I. Richardson, C. E. Newman, M. A. Szwast, C. Graf, S. Basu, S. P. Ewald, A. D. Toigo, and R. J. Wilson (2005), A survey of Martian dust devil activity using Mars Global Surveyor Mars Orbiter Camera images, J. Geophys. Res., 110, E03004, doi:10.1029/2003JE002165.Balme, M., and R. Greeley (2006), Dust devils on Earth and Mars, Rev. Geophys., 44, RG3003, doi:10.1029/2005RG000188.[https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA21294 NASA.gov][https://mars.nasa.gov/resources/21946/dust-devil-tracks/ NASA.gov] Dust devils have been seen from the ground and from orbiting spacecraft. Some dust devils are taller than the average tornado on Earth.{{cite web | url=https://www.foxweather.com/learn/how-tall-is-a-tornado | title=How tall is a tornado? | date=23 February 2023 }} They have even blown the dust off of the solar panels of the two Rovers on Mars, thereby greatly extending their lives.[http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20070412a.html NASA.gov]

File:ESP 057581 1340devils.jpg|Wide view of dust devil tracks, as seen by HiRISE under HiWish program

File:ESP 057581 1340devils3.jpg|Close view of dust devil tracks, as seen by HiRISE under HiWish program

Image:MarsTopoMap-PIA02031 modest.jpg|This topographic map shows volcanic peaks in white because of their great height. Near the equator, a line of three volcanoes points south to Phaethontis and three large craters-the area where there are many gullies.

Image:Phaethontis.JPG|Map of Phaethontis quadrangle. Click on to enlarge and see some crater names.

Image:Phaethontis surface.JPG|Close up image of Phaethontis surface taken with Mars Global Surveyor. Holes are thought to be caused by buried ice turning into a gas.

ESP 051252 1325pits.jpg|Pits on crater floor, as seen by HiRISE under HiWish program Pits may be formed when ice left the ground.

Image:ESP_028214_1435cratermesa.jpg|Mesa in a crater, as seen by HiRISE under HiWish program This mesa is all that remains of material that once covered a wide area, but has since been removed by erosion.

ESP 051184 1345hollows.jpg|Wide view of hollows, as seen by HiRISE under HiWish program. Hollows may be formed as ice leaves the ground.

51184 1345hollowspits.jpg|Close view of hollows, as seen by HiRISE under HiWish program

51184 1345hollows.jpg|Close view of hollows,File:ESP 084812 1440 landslide cropped.jpg

File:ESP 084812 1440 landslide cropped.jpg|Landslide, as seen by HiRISE under HiWish program The colored strip is about 1 km across.

{{div col|colwidth=30em}}

• Climate of Mars
• Concentric crater fill
• Dunes
• Electris deposits
• Fossa (geology)
• Geology of Mars
• Glaciers on Mars
• Groundwater on Mars
• HiRISE
• HiWish program
• Impact crater
• Latitude dependent mantle
• Linear ridge networks
• List of areas of chaos terrain on Mars
• List of quadrangles on Mars
• Martian chaos terrain
• Martian dichotomy
• Martian Gullies
• MOC Public Targeting Program
• Newton (Martian crater)
• Oxbow lake
• Tectonics of Mars
• Water on Mars

{{div col end}}

{{Reflist|colwidth=30em}}

{{commons category|Phaethontis quadrangle}}

• [http://www.psrd.hawaii.edu/Aug03/MartianGullies.html General review of many of the theories involving the origin of gullies.]
• {{cite journal | last1 = Dickson | first1 = J | last2 = Head | first2 = J | last3 = Kreslavsky | first3 = M | title = Martian gullies in the southern mid-latitudes of Mars: Evidence for climate-controlled formation of young fluvial features based upon local and global topography | doi = 10.1016/j.icarus.2006.11.020 | url=http://www.planetary.brown.edu/pdfs/3138.pdf | date = 2007 | pages = 315–323 | volume = 188 | issue = 2 | journal = Icarus | bibcode = 2007Icar..188..315D}} Gives a good review of the history of the discovery of gullies.
• [https://www.youtube.com/watch?v=_sUUKcZaTgA Martian Ice - Jim Secosky - 16th Annual International Mars Society Convention]

{{Mars quadrangle layout}}

{{Mars}}

{{Portal bar|Solar System}}

{{DEFAULTSORT:Phaethontis Quadrangle}}

Category:Mars