Dark materials in Valles Marineris: Indications of the style of volcanism and magmatism on Mars
- Univ. of Arizona, Tucson (USA)
- Geological Survey, Flagstaff, AZ (USA)
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.
- OSTI ID:
- 5452756
- Report Number(s):
- CONF-9001119-; CODEN: JGREA
- Journal Information:
- Journal of Geophysical Research; (United States), Vol. 95:B9; Conference: 4. international conference on Mars, Tucson, AZ (United States), 10-13 Jan 1990; ISSN 0148-0227
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
MARS PLANET
GEOLOGY
BASEMENT ROCK
EROSION
GEOLOGIC FAULTS
MAGMA
MAPPING
MODIFICATIONS
OVERBURDEN
RIFT ZONES
SPATIAL DISTRIBUTION
TECTONICS
VOLCANISM
DISTRIBUTION
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
PLANETS
640107* - Astrophysics & Cosmology- Planetary Phenomena