title: Detection of silica-rich deposits on Mars.
abstract: Mineral deposits on the martian surface can elucidate ancient environmental conditions on the planet. Opaline silica deposits (as much as 91 weight percent SiO2) have been found in association with volcanic materials by the Mars rover Spirit. The deposits are present both as light-toned soils and as bedrock. We interpret these materials to have formed under hydrothermal conditions and therefore to be strong indicators of a former aqueous environment. This discovery is important for understanding the past habitability of Mars because hydrothermal environments on Earth support thriving microbial ecosystems.
authors.affiliation: Department of Astronomy, Space Sciences Building, Cornell University, Ithaca, NY 14853, USA. squyres@astro.cornell.edu
authors.forename: S W
authors.initials: SW
authors.lastname: Squyres
authors.forename: R E
authors.initials: RE
authors.lastname: Arvidson
authors.forename: S
authors.initials: S
authors.lastname: Ruff
authors.forename: R
authors.initials: R
authors.lastname: Gellert
authors.forename: R V
authors.initials: RV
authors.lastname: Morris
authors.forename: D W
authors.initials: DW
authors.lastname: Ming
authors.forename: L
authors.initials: L
authors.lastname: Crumpler
authors.forename: J D
authors.initials: JD
authors.lastname: Farmer
authors.forename: D J Des
authors.initials: DJ
authors.lastname: Marais
authors.forename: A
authors.initials: A
authors.lastname: Yen
authors.forename: S M
authors.initials: SM
authors.lastname: McLennan
authors.forename: W
authors.initials: W
authors.lastname: Calvin
authors.forename: J F
authors.initials: JF
authors.lastname: Bell
authors.forename: B C
authors.initials: BC
authors.lastname: Clark
authors.forename: A
authors.initials: A
authors.lastname: Wang
authors.forename: T J
authors.initials: TJ
authors.lastname: McCoy
authors.forename: M E
authors.initials: ME
authors.lastname: Schmidt
authors.forename: P A
authors.initials: PA
authors.lastname: de Souza
mesh_terms: D005118:Extraterrestrial Environment; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D018535:Mars; D012822:Silicon Dioxide; D018531:Spacecraft; D014867:Water
chemical_list: C029019:opoka; D014867:Water; D012822:Silicon Dioxide