- Argyre Planitia
MarsGeo-Crater
caption=Topography of Argyre basin and its surroundings
name=Argyre
latitude=49.7
N_or_S=S
longitude=316.0
E_or_W=E
eponym=Argyre
diameter=1800 km
depth=5.2 kmArgyre Planitia is a plain located in the Argyre
impact basin in the southern highlands of Mars. Its name comes from a map produced byGiovanni Schiaparelli in1877 ; it refers toArgyre , a mythical island ofsilver in Greek mythology.Argyre lies between -35 and -61 deg S and 27 and 62 deg W, centered at coord|-49.7|316.0|globe:Mars. The basin is approximately 1120 miles (1800 kilometers) wide, believed to be the second-largest impact basin on Mars after
Hellas Planitia , and drops 3.2 miles (5.2 kilometers) below the surrounding plains.The basin was possibly formed by a giant impact during a
Heavy Bombardment Period of the earlySolar System , approximately 3.9 billion years ago, and may be one of the best preserved ancient impact basins from that hypothetical event. Argyre is surrounded by ruggedmassif s which form concentric and radial patterns around the basin. Several mountain ranges are present, including Charitum andNereidum Montes .Four large
Noachian epoch channels lie radial to the basin. Three of these channels (Surius Valles ,Dzígai Valles , andPalacopas Valles ) flowed into Argyre from the south and east through the rim mountains. The fourth,Uzboi Vallis , appears to have flowed out from the basin's north rim to the Chryse region and may have drained alake of melting ice within the basin. A smaller outflow channel namedNia Valles is relatively fresh-looking, and probably formed during the early Amazonian after the major fluvial and lacustrine episodes had finished.The original basin floor is buried with friable, partially deflated layered material that may be lake
sediment . No inner rings are visible, however isolated massifs within the basin may be remnants of an inner ring.This circular feature is situated at the
antipode ofUtopia Planitia .The crater Galle, located on the east rim of Argyre at 51°S, 31°W, strongly resembles a
smiley face.ee also
*
Hellas Planitia
*List of plains on Mars
*Geography of Mars External links
* [http://www.google.com/mars/#lat=-47.398349&lon=-44.648437&zoom=4&q=Argyre%20Planitia Argyre Planitia map at "Google Mars"]
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