Martian zeolites as a source of atmospheric methane

Abstract

The origin of the martian methane is still poorly understood. A plausible explanation is that methane could have been produced either by hydrothermal in chabazite and clinoptilolite is directly sourced from an abiotic source in the subsurface, the destabilization of a localized layer of a few millimeters per year may be sufficient to explain the current observations. The sporadic release of methane from these zeolites requires that they also remained isolated from the atmosphere during its evolution. The methane release over the ages could be due to several mechanisms such as impacts, seismic activity or erosion. If the methane outgassing from excavated chabazite and/or clinoptilolite prevails on Mars, then the presence of these zeolites around Gale Crater could explain the variation of methane level observed by Mars Science Laboratory.

Background levels of methane in Mars’ atmosphere show strong seasonal variations

“…Regardless of the subsurface origin, methane that finds its way to surface layers over long time periods (42,43) may be expected to show seasonal variation. We consider a process that retains methane at the surface temporarily before releasing it through a process linked to the surface temperature.…”

Methane Seepage on Mars: Where to Look and Why

“…On Mars, reservoir-quality rocks within sealed traps could act as methane reservoirs, as could clathrates and zeolites (Downey, 1984 ; Chastain and Chevrier, 2007 ; Max et al, 2011 , 2013; Lasue et al, 2015 ; Mousis et al, 2016 ). Reservoirs can be either porous and permeable sedimentary rocks (like sandstone) or fractured rocks with lower intrinsic porosity (like some carbonates, basalts, and ultramafics), where the fracturing produces secondary porosity and permeability, creating storage space for gas or liquids.…”

“…Zeolites, which form by reaction of alkaline waters with volcanic rocks and ash, have been detected in numerous settings on Mars (Ruff, 2004 ; Ehlmann et al, 2009 ; Carter et al, 2013 ), and they are expected to be widespread in the martian regolith (Mousis et al, 2016 ). Carter et al ( 2013 ) concluded that most zeolites formed during the Noachian, though they also reported some in the younger lowlands (possibly related to ice-volcano interactions).…”

“…Any produced deep methane could be stored in clathrates or possibly zeolites, or trapped in impact-related structures, sealed by permafrost in the proposed thick cryosphere (Clifford et al, 2010 , 2013; Petitjean et al, 2014 ; Stuurman et al, 2016 ). Such gas could be expelled episodically when permafrost melts or sublimes, when clathrates are destabilized (by changes in temperature or pressure), or when zeolites are destabilized (perhaps by impacts, seismic activity, or erosion; Mousis et al, 2016 ).…”

Dioctahedral Phyllosilicates Versus Zeolites and Carbonates Versus Zeolites Competitions as Constraints to Understanding Early Mars Alteration Conditions

“…In addition to carbonates, zeolite formation and stability are strongly dependent on the geochemical conditions such as alkaline pH solution (Dyer, ) and are therefore a good probe to investigate the Martian environmental conditions (Ming & Gooding, ). Like clay minerals, zeolites are of prime importance, because they have a high potential for being major sinks of atmospheric gas (Ming & Gooding, ; Mousis et al, ). They can sorb and protect organic compounds and act as a catalyst for organic‐based reactions (Ming & Gooding, ; van Bekkum & Kouwenhoven, ; Venuto, ).…”