Chaos terrain on Mars is distinctive; nothing on Earth compares to it. Chaos terrain generally consists of irregular groups of large blocks, some tens of kilometers across and a hundred or more meters high. The tilted and flat topped blocks form depressions hundreds of metres deep. A chaotic region can be recognized by a rat's nest of mesas, buttes, and hills, chopped through with valleys which in places look almost patterned. Some parts of this chaotic area have not collapsed completely—they are still formed into large mesas, so they may still contain water ice. Chaos regions formed long ago. By counting craters (more craters in any given area means an older surface) and by studying the valleys' relations with other geological features, scientists have concluded the channels formed 2.0 to 3.8 billion years ago.
26-486: Aureum Chaos is a rough, collapsed region ( chaos terrain ) in the Margaritifer Sinus quadrangle (MC-19) portion of the planet Mars at approximately 4.4° south latitude and 27° west longitude, it is also in the west of Margaritifer Terra . It is 368 km across and was named after a classical albedo feature name. The classic name came from one of the first maps of Mars drawn by Schiaparelli who has been called
52-420: A cryosphere is that an aquifer was created along with the cryosphere. As more and more ice was added resulting in a thicker cryosphere, the water in the aquifer became pressurized. When something like an impact or movement of magma broke or melted the cryosphere, floods of water under great pressure were released. However, further calculations showed that the great channels could not have been produced with just
78-420: A long time period and then something triggered it to rupture and melt suddenly. The rupturing event may have been impacts, magma movements, seismic activity, volcanic tectonic strains, increased pore pressure, or the dissociation of clathrates . A clathrate composed of carbon dioxide and methane could have explosively dissociated, thereby liquefying water-saturated sediments. A variation of this idea of
104-442: A single discharge. Later proposals advanced the notion that the geological shapes present in chaos regions could have been made by a series of over 100 flooding events. More recently, researchers have suggested ways for the formation of chaos without the need for a special triggering event. Tanja Zegers and others calculated that the simple burial of ice-rich sediments could result in the release of huge amounts of water leading to
130-414: A solid directly to a gas). Since some areas would have sublimated more than others, the upper lava cap would not be supported evenly and would crack. Cracks/troughs may have begun from sublimation and shrinkage along the edges of the lava cap. Stress from the undermining of the cap edge would have made cracks in the cap. Places with cracks would undergo more sublimation, then the cracks would widen and form
156-464: A thick atmosphere, the presence of hematite also suggests that Mars had a much thicker atmosphere at some time in the past. Tilting and erosion of Aram Chaos is also evident in satellite imagery taken of the crater. There is a possible volcanic component to the formation of outflow channels in Aram Chaos. By melting the permafrost or ground ice originally in the crater, geothermal activity may have caused
182-540: A variety places in Aureum Chaos. Clay minerals need water to form, so the area may once have contained large amounts of water. Scientists are interested in determining what parts of Mars contained water because evidence of past or present life may be found there. Aureum Chaos is one more piece of evidence that Mars once had great amounts of water. Martian chaos terrain The greatest concentrations of chaotic terrain are in
208-488: Is a heavily eroded impact crater on Mars . It lies at the eastern end of the large canyon Valles Marineris and close to Ares Vallis . Various geological processes have reduced it to a circular area of chaotic terrain . Aram Chaos takes its name from Aram, one of the classical albedo features observed by Giovanni Schiaparelli , who named it after the Biblical land of Aram . Spectroscopic observation from orbit indicates
234-524: Is the site of a volcanic flow that buried an ice-rich layer, called the Vastitas Borealis Formation (VBF). It is generally believed that the VBF is a residue from water-rich materials deposited by large floods. The VBF may have been of varied thickness and may have contained varied amounts of ice. In the thin atmosphere of Mars, this layer would have slowly disappeared by sublimation (changing from
260-446: The orbiter Mars Odyssey found gray crystalline hematite on the floor of Aram Chaos and CRISM , the spectroscope on the MRO , found hydrated sulfates, jarosite , and hematite. The floor of Aram Chaos also contains huge blocks of collapsed, or chaotic, terrain that formed when water or ice was catastrophically removed. Small, shallow outlet channels are also visible in the eastern wall of
286-511: The "Father of Mars." He called a feature "Aurea Cherso, which translates to the golden peninsula—an ancient name for Malaya. Aureum is the Latin word for gold . In chemistry, the symbol for gold is Au from gold's Latin name. In many places, the canyons of Aureum Chaos are about 1 km deep—a little more than half the depth of the Grand Canyon . But, Aureum Chaos covers an area about the size of
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#1732881199791312-495: The blocky terrain characteristic of regions of chaos. The sublimation process may have been aided by heat (geothermal flux) from magma movements. There are volcanoes, namely Elysium Montes and Hecates Tholus, nearby which most likely are surrounded by dikes , which would have heated the ground. Also, a warmer period in the past would have increased the amount of water sublimating from the ground. Chaos terrain seems to be strong evidence for large amounts of water flowing on Mars in
338-462: The compilation of these sedimentary layers, and aquifer formed beneath the surface of the crater. Following the deposition of sedimentary layers and the formation of the subsurface aquifer, a catastrophic geologic event occurred which caused the release of the subsurface aquifer and the subsequent catastrophic flooding, creating chaotic terrain within Aram Chaos. The repetition of this process led to layered terrains within Aram Chaos, including layers of
364-550: The creation of the visible outflow channels in the impact crater. High resolution MOC images of the chaotic terrains in Aram Chaos show possible volcanic features within the crater, including hills resembling volcanoes, possible magmatic intrusions within the older rock layers, and possible volcanic ash deposits on the crater floor. Not including dust and regolith common on the surface of Mars, two distinct sections of identifiable minerals have been determined to exist within Aram Chaos:
390-404: The formation of chaotic terrain. Evidence for the involvement of water has been found—minerals associated with water, such as grey, crystalline hematite and phyllosilicates, are present in chaos regions. Many explanations for the creation of chaos involve the sudden melting of giant reservoirs of ground ice. Some researchers have suggested that a frozen layer, called a cryosphere, developed over
416-417: The formation of the large river basins that are associated with most chaos terrains. The group studied Aram Chaos , a large region of chaos that probably began as a large impact crater. In their model, ice-rich material accumulated in the crater and then became covered with sediment, which prevented the ice from disappearing into the thin atmosphere. Eventually, the heat from the deep subsurface together with
442-549: The impact crater, as well as a small outflow channel connecting Aram Chaos with the Ares Valles outflow channel. Aram Chaos, as an impact crater , started its formation with the high velocity impact of an unknown smaller body on the surface of Mars. This formed the large, circular depression that originally made up the crater. This crater was then filled with sediments, likely carried by aeolian processes , that were deposited into Aram Chaos over time. Subsequently and in tandem with
468-434: The insulating qualities of the covering layer produced a thick water layer. Since dense materials tend to sink into water, the overlying rock broke under the strain. The dense, rocky cap fractured into various sized, tilted blocks. The melt water went to the top and made a channel which eroded more and more as water rushed outward. Along with water from other chaotic regions, there would have been enough erosive force to carve
494-451: The lack of a large moon. Observations of many craters have shown that many craters are mostly full of sediments—ice could be one of the sediments. Many craters appear to be very shallow, but observations of younger craters have demonstrated that impact craters start out as sort of bowl shaped; hence a crater that today looks shallow has probably been filled with sediments. Research, published by Rodriguez and others in 2005, suggested that
520-409: The large river valleys we now observe. There is ample evidence for buried deposits of ice in the form of glaciers, preserved under a thin covering of rock and dirt. It also seems that Mars has had many ice ages in which ice was deposited, then later buried. These ice ages are caused by the frequent large changes in the tilt of the planet. The tilt of the spin axis of Mars is highly variable due to
546-472: The mineral hematite. Several minerals in Aram Chaos, including the hematite sulfate minerals and water-altered silicates, suggest that a lake probably once existed within the crater at some point in time. Scientists also suggest that flood channels within Aram Chaos were carved within just weeks or months by catastrophic outflows of groundwater from beneath Aram Chaos and nearby regions. Because forming hematite requires liquid water, which cannot exist without
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#1732881199791572-575: The past. Some of the terrain is not totally broken up, so perhaps more water exists frozen inside some of the blocks. On April 1, 2010, NASA released the first images under the HiWish program in which just plain folk suggested places for HiRISE to photograph. One of the eight locations was Aureum Chaos. The first image below gives a wide view of the area. The next two images are from the HiRISE image. Aram Chaos Aram Chaos , centered at 2.6°N, 21.5°W,
598-487: The presence of the mineral hematite , likely a signature of a once aqueous environment. Aram Chaos is an impact crater on Mars measuring 280 kilometers (170 mi) in diameter. It lies in the Oxia Palus quadrangle in a region called Margaritifer Terra , and its exact coordinates on Mars are 2°36′N 21°30′W / 2.6°N 21.5°W / 2.6; -21.5 . The Thermal Emission Imaging System ( THEMIS ) on
624-666: The same locations as giant, ancient river valleys. Because so many large channels seem to originate from chaotic terrain, it is widely believed that chaos terrain is caused by water coming out the ground in the form of massive floods. Most of the chaotic terrain exists in the highlands of Mars, south of Chryse Planitia , in the Oxia Palus quadrangle , and along the Martian dichotomy . But some chaos regions can be found in Margaritifer Sinus quadrangle , Phaethontis quadrangle , and Lunae Palus quadrangle . Many different theories have been advanced for how floods of water came to be released with
650-563: The state of Alabama , almost 20 times larger than the Grand Canyon National Park . Aureum Chaos is a major canyon system and collapsed area. Large outflow channels on Mars are believed to be caused by catastrophic discharges of ground water. Many of the channels begin in chaotic terrain, where the ground has apparently collapsed. In the collapsed section, blocks of undisturbed material can be seen. The OMEGA experiment on Mars Express discovered clay minerals (phyllosilicates) in
676-486: The subsurface of Mars contains an accumulation of old craters that may be filled with water or ice. Some regions of chaos may have been produced by another means. Galaxias Chaos is different from many other chaotic regions. It does not have associated outflow channels, and it does not display a great elevation difference between it and the surrounding land area, as most of the other chaos regions. Research by Pedersen and Head, published in 2010, suggests that Galaxias Chaos
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