Martian Layered Fluvial Deposits: Implications for Noachian Climate Scenarios
نویسندگان
چکیده
[1] Fluvial deposits in a basin north of Holden crater exhibiting a sinuous, anabranching pattern are of deltaic or fan origin. Channel width and meander wavelength indicate persistent flow magnitudes of about 700 m/s. If these flows were produced by quasi-periodic climate episodes involving typical terrestrial-style precipitation, the deposit required thousands to millions of years to accumulate. However, a scenario of deposition during a few short episodes of constant heavy precipitation resulting from large impacts cannot be excluded.
منابع مشابه
Glaciation in the Late Noachian Icy Highlands_ Ice accumulation, distribution, flow rates, basal melting, and top-down melting rates and patterns
Geological evidence for extensive non-polar ice deposits of Amazonian age indicates that the current cold and dry climate of Mars has persisted for several billion years. The geological record and climate history of the Noachian, the earliest period of Mars history, is less certain, but abundant evidence for fluvial channels (valley networks) and lacustrine environments (open-basin lakes) has b...
متن کاملMartian surface/near-surface water inventory: Sources, sinks, and changes with time
Today, a 34m global equivalent water layer (GEL) lies in the Martian polar-layered deposits and shallow ground ice. During the Amazonian, 3m was outgassed, and 31m was lost to space and to the surface, leaving 62m at the end of Hesperian. During the Hesperian, volcanic outgassing added 5m, 7m was lost, and 40m GEL of groundwater was added to form outflow channels, leaving 24m carryover of surfa...
متن کاملA synthesis of Martian aqueous mineralogy after 1 Mars year of observations from the Mars Reconnaissance Orbiter
[1] Martian aqueous mineral deposits have been examined and characterized using data acquired during Mars Reconnaissance Orbiter’s (MRO) primary science phase, including Compact Reconnaissance Imaging Spectrometer for Mars hyperspectral images covering the 0.4–3.9 mm wavelength range, coordinated with higher–spatial resolution HiRISE and Context Imager images. MRO’s new high-resolution measurem...
متن کاملExtensive Amazonian-aged fluvial channels on Mars: Evaluating the role of Lyot crater in their formation
Widespread Amazonian-aged fluvial channels have been mapped proximal to Lyot crater, a ~225 km diameter impact basin in the northern lowlands of Mars. Comparable in area to some Noachian/Hesperian fluvial systems, their morphology differs, being dominated by broad, shallow braided channels. Using new developments in the study of cratering, water inventory, and climate history, we assess eight d...
متن کاملCrater degradation in the Noachian highlands of Mars_ Assessing the hypothesis of regional snow and ice deposits on a cold and icy early Mars
The presence of valley networks and the highly degraded state of Noachian highland craters has led to the interpretation that Mars was once warmer and wetter. Recent climate models have suggested, however, that the extremely cold climate in the Noachian would be unlikely to support liquid water precipitation. The presence of a thicker atmosphere thermally coupled to the surface is predicted ins...
متن کامل