Opal-A in the Nakhla meteorite: A tracer of ephemeral liquid water in the Amazonian crust of Mars
Lee, M. R., MacLaren, I., Andersson, S. M. L., Kovács, A., Tomkinson, T., Mark, D. F. and Smith, C. L. Meteoritics & Planetary Science. doi: 10.1111/maps.12471 LINK