Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Martian zeolites as a source of atmospheric methane   The origin of the martian methane is still poorly understood. A plausible
explanation is that methane could have been produced either by hydrothermal
alteration of basaltic crust or by serpentinization of ultramafic rocks
producing hydrogen and reducing crustal carbon into methane. Once formed,
methane storage on Mars is commonly associated with the presence of hidden
clathrate reservoirs. Here, we alternatively suggest that chabazite and
clinoptilolite, which belong to the family of zeolites, may form a plausible
storage reservoir of methane in the martian subsurface. Because of the
existence of many volcanic terrains, zeolites are expected to be widespread on
Mars and their Global Equivalent Layer may range up to more than $\sim$1 km,
according to the most optimistic estimates. If the martian methane present 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.

10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas