Dark materials in Valles Marineris: Indications of the style of volcanism and magmatism on Mars

Journal of Geophysical Research B: Solid Earth
By: , and 

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Abstract

Rifting on the equatorial canyon system of Valles Marineris provides a unique view of the interior of the Martian crust to depths reaching 7 km, exposing several in situ bedrock units which testify to past volcanic and magmatic processes on Mars. A thick, regionally extensive deposit observed in Coprates and Juventae chasmata is interpreted on the basis of spectral reflectance, erosional morphology, and tendency for eolian mobilization to be composed of mafic glass, possibly an ancient Martian analogue of the lunar terra mantling deposits. Spectral mapping suggests that the dark floor‐covering materials in the lower canyons are derived from this unit. A series of cliffs in the Ophir Chasma wall rock is interpreted to be exposures of resistant bedrock; the spectral signature of this massive and uniform unit most closely resembles that of terrestrial mafic rocks altered to or coated by crystalline hematite. Application of computer mapping techniques to probable young volcanic materials in the central troughs yields an inferred distribution of volcanic activity consistent with the interpretation of extrusion along faults near the margins of the canyon floors. This result supports the hypothesis that the valles originated through tectonic extension.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Dark materials in Valles Marineris: Indications of the style of volcanism and magmatism on Mars
Series title Journal of Geophysical Research B: Solid Earth
DOI 10.1029/JB095iB09p14399
Volume 95
Issue B9
Year Published 1990
Language English
Publisher American Geophysical Union
Contributing office(s) Astrogeology Science Center
Description 15 p.
First page 14.399
Last page 14.413