NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Mars surface weathering products and spectral analogs: Palagonites and synthetic iron mineralsThere are several hypotheses regarding the formation of Martian surface fines. These surface fines are thought to be products of weathering processes occurring on Mars. Four major weathering environments of igneous rocks on Mars have been proposed; (1) impact induced hydrothermal alterations; (2) subpermafrost igneous intrusion; (3) solid-gas surface reactions; and (4) subaerial igneous intrusion over permafrost. Although one or more of these processes may be important on the Martian surface, one factor in common for all these processes is the reaction of solid or molten basalt with water (solid, liquid, or gas). These proposed processes, with the exception of solid-gas surface reactions, are transient processes. The most likely product of transient hydrothermal processes are layer silicates, zeolites, hydrous iron oxides and palagonites. The long-term instability of hydrous clay minerals under present Martian conditions has been predicted; however, the persistence of such minerals due to slow kinetics of dehydration, or entrapment in permafrost, where the activity of water is high, can not be excluded. Anhydrous oxides of iron (e.g., hematite and maghemite) are thought to be stable under present Martian surface conditions. Oxidative weathering of sulfide minerals associated with Martian basalts has been proposed. Weathering of sulfide minerals leads to a potentially acidic permafrost and the formation of Fe(3) oxides and sulfates. Weathering of basalts under acidic conditions may lead to the formation of kaolinite through metastable halloysite and metahalloysite. Kaolinite, if present, is thought to be a thermodynamically stable phase at the Martian surface. Fine materials on Mars are important in that they influence the surface spectral properties; these fines are globally distributed on Mars by the dust storms and this fraction will have the highest surface area which should act as a sink for most of the absorbed volatiles near the surface of Mars. Therefore, the objectives of this study were to: (1) examine the fine fraction mineralogy of several palagonitic materials from Hawaii; and (2) compare spectral properties of palagonites and submicron sized synthetic iron oxides with the spectral properties of the Martian surface.
Document ID
19920019774
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Golden, D. C.
(NASA Lyndon B. Johnson Space Center Houston, TX, United States)
Ming, D. W.
(NASA Lyndon B. Johnson Space Center Houston, TX, United States)
Morris, R. V.
(NASA Lyndon B. Johnson Space Center Houston, TX, United States)
Lauer, H. V., Jr.
(Lockheed Engineering and Sciences Co. Houston, TX., United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1992
Publication Information
Publication: Lunar and Planetary Inst., Workshop on the Martian Surface and Atmosphere Through Time
Subject Category
Lunar And Planetary Exploration
Accession Number
92N29017
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Document Inquiry

Available Downloads

There are no available downloads for this record.
No Preview Available