Assumptions about the presence of natural glasses on Mars

Abstract

Natural glasses occur not only on Earth but also in lunar rocks and in some meteorites. On geological grounds, natural glasses could be expected on the surface of Mars and their presence would have important implications for the weathering and alteration of the near‐surface layer. Ultramafic and mafic magmatism rich in iron and some volatiles appears to have been important on Mars as has been impact cratering, volcanism, and possibly hydrothermal alteration. Available data indicate that we can presume the past or present existence of volcanic basaltic glasses, impact glasses formed by thermal fusion of meteorite‐impact targets, and diaplectic (mainly maskelynite) glasses. Conditions appear unsuitable for the formation of tektites on the Martian surface, and the production of measurable amounts of fulgurite or combustion glass seems improbable. Prospects for the remote and in situ identification of Martian glasses and their subsequent weathering products are discussed and include orbital reflectance and thermal emission spectroscopic measurements and Mössbauer spectroscopy from a surface lander.

Widespread weathered glass on the surface of Mars

“…Because the glass is durable enough to form sand dunes, a signifi cant fraction of the glass must be sand sized with, at most, minor vesicle content. Glass derived from distant impacts could be consistent with these constraints (Bouška and Bell, 1993;Schultz and Mustard, 2004), but it is not clear if impact processes could produce such a large, concentrated deposit. Instead, we propose that a more plausible origin for these deposits is explosive volcanism, which may have produced extensive ash deposits across the planet (Wilson and Head, 2007).…”

Incipient hydrothermal alteration of basalts and the origin of martian soil

“…Alteration of glass on Mars is discussed by Gooding and Keil (1978), Bouska and Bell (1993) and Bell et al (2000). Gooding and Keil (1978) showed that glass would be thermodynamically unstable on the martian surface, even under current conditions.…”

Spectral properties of simulated impact glasses produced from martian soil analogue JSC Mars-1

“…Impact melts may be present on the surface of Mars both in dispersed and concentrated forms (Bouška and Bell, 1993;Lorenz, 2000;Basilevsky et al, 2000a;Schultz and Mustard, 2004).…”

“…A number of studies suggests that a large fraction of soils on Mars are erosional products of hydrothermally altered (oxidized) impact melt sheets (e.g., Newsom et al, 1980;Allen, 1982;Clifford, 1993;Morris et al, 1995Morris et al, , 2000aMorris et al, , 2001Hagerty and Newsom, 2003). However, relatively young impact glasses produced under the prevailing climatic conditions over the last billion years or so could have survived unaltered (Bouška and Bell, 1993;Lorenz, 2000;Schultz and Mustard, 2004). Impact glasses are much more likely to be found on Martian surface than on Earth due to the different exogenic conditions and slower weathering rates on Mars (Bouška and Bell, 1993;Schultz and Mustard, 2004).…”

“…However, relatively young impact glasses produced under the prevailing climatic conditions over the last billion years or so could have survived unaltered (Bouška and Bell, 1993;Lorenz, 2000;Schultz and Mustard, 2004). Impact glasses are much more likely to be found on Martian surface than on Earth due to the different exogenic conditions and slower weathering rates on Mars (Bouška and Bell, 1993;Schultz and Mustard, 2004).…”