Mathematics – Logic
Scientific paper
Dec 2008
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008agufm.p53b1450b&link_type=abstract
American Geophysical Union, Fall Meeting 2008, abstract #P53B-1450
Mathematics
Logic
5410 Composition (1060, 3672), 5415 Erosion And Weathering, 5419 Hydrology And Fluvial Processes, 6225 Mars
Scientific paper
The Argyre basin is a >1500 km, well preserved impact basin in the southern highlands of Mars. The associated geologic units (USGS map I-1802-A) span the Noachian to Hesperian age of the surrounding plateau plains, making Argyre an ideal probe of compositional layering of ancient highland rocks. There are both morphologic and mineralogic indications of the past presence of water. One of the major geologic units associated with Argyre is unit Npld, interpreted as a Noachian mixture of lavas, pyroclastics, and impact breccia eroded by fluvial processes. Also, the Uzboi Vallis system can be traced to the north rim of Bond crater in north-central Argyre; many researchers have suggested that Uzboi drained a water-filled Argyre at the location where Hale and Bond craters now obscure the Argyre rim. Phyllosilicates are common alteration minerals on Earth, frequently forming during weathering and hydrothermal activity, in the presence of water. Phyllosilicates have been detected in nine 20 m/pixel resolution CRISM targeted observations of the Argyre basin. The data were corrected for illumination by dividing by the cosine of the solar incidence angle and a multiplicative correction for atmospheric gas absorption was applied. We use tetracorder, a software tool which utilizes an expert system decision methodology to analyze spectra to identify components in the spectrum, to interpret the CRISM data. In northwest Argyre a laterally extensive phyllosilicate deposit has been identified directly below a thin, pyroxene-rich Hesperian (Hpl3) cap-rock but stratigraphically above a unit of Noachian high-calcium pyroxene. Nontronite, a smectite clay that frequently forms due to the alteration of basalt or by precipitation of iron-rich hydrothermal fluids, is identified directly below the cap-rock while chlorite is identified stratigraphically below the nontronite. Nontronite is known to convert to chlorite in 1) shallow water environments, 2) where wet-dry cycling occurs or 3) in the presence of iron-rich waters. Both phyllosilicates are associated with unit Npld, as is the underlying HCP. Phyllosilicates have also been observed on the north-central Argyre rim around Hale and Bond craters, where Argyre-draining waters have been theorized, and in a ~14 km crater southwest of Hale towards the Argyre interior, in a region of probable fluvial dissection. Also, at least two high-standing knobs in the northwestern Agyre interior have a strong phyllosilicate signature. A targeted observation of one of the knobs indicates prehnite, which is known to form due to the hydrothermal alteration of mafic igneous rocks. Observations of the other phyllosilicate locations indicate the presence of chlorite and other minerals that form due to the hydrothermal alteration of ferromagnesian minerals. In all cases, these phyllosilicates are found stratigraphically above (or between) pyroxene-rich materials.
Buczkowski D.
Clark Rebecca
Murchie Scott
Seelos Frank
Team T. C.
No associations
LandOfFree
Mineralogic and morphologic signatures of Noachian water in the Argyre impact basin does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Mineralogic and morphologic signatures of Noachian water in the Argyre impact basin, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mineralogic and morphologic signatures of Noachian water in the Argyre impact basin will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1239380