title: Martian fluvial conglomerates at Gale crater.
abstract: Observations by the Mars Science Laboratory Mast Camera (Mastcam) in Gale crater reveal isolated outcrops of cemented pebbles (2 to 40 millimeters in diameter) and sand grains with textures typical of fluvial sedimentary conglomerates. Rounded pebbles in the conglomerates indicate substantial fluvial abrasion. ChemCam emission spectra at one outcrop show a predominantly feldspathic composition, consistent with minimal aqueous alteration of sediments. Sediment was mobilized in ancient water flows that likely exceeded the threshold conditions (depth 0.03 to 0.9 meter, average velocity 0.20 to 0.75 meter per second) required to transport the pebbles. Climate conditions at the time sediment was transported must have differed substantially from the cold, hyper-arid modern environment to permit aqueous flows across several kilometers.
authors.affiliation: Planetary Science Institute, Tucson, AZ 85719, USA. williams@psi.edu
authors.forename: R M E
authors.initials: RM
authors.lastname: Williams
authors.forename: J P
authors.initials: JP
authors.lastname: Grotzinger
authors.forename: W E
authors.initials: WE
authors.lastname: Dietrich
authors.forename: S
authors.initials: S
authors.lastname: Gupta
authors.forename: D Y
authors.initials: DY
authors.lastname: Sumner
authors.forename: R C
authors.initials: RC
authors.lastname: Wiens
authors.forename: N
authors.initials: N
authors.lastname: Mangold
authors.forename: M C
authors.initials: MC
authors.lastname: Malin
authors.forename: K S
authors.initials: KS
authors.lastname: Edgett
authors.forename: S
authors.initials: S
authors.lastname: Maurice
authors.forename: O
authors.initials: O
authors.lastname: Forni
authors.forename: O
authors.initials: O
authors.lastname: Gasnault
authors.forename: A
authors.initials: A
authors.lastname: Ollila
authors.forename: H E
authors.initials: HE
authors.lastname: Newsom
authors.forename: G
authors.initials: G
authors.lastname: Dromart
authors.forename: M C
authors.initials: MC
authors.lastname: Palucis
authors.forename: R A
authors.initials: RA
authors.lastname: Yingst
authors.forename: R B
authors.initials: RB
authors.lastname: Anderson
authors.forename: K E
authors.initials: KE
authors.lastname: Herkenhoff
authors.forename: S
authors.initials: S
authors.lastname: Le Mouélic
authors.forename: W
authors.initials: W
authors.lastname: Goetz
authors.forename: M B
authors.initials: MB
authors.lastname: Madsen
authors.forename: A
authors.initials: A
authors.lastname: Koefoed
authors.forename: J K
authors.initials: JK
authors.lastname: Jensen
authors.forename: J C
authors.initials: JC
authors.lastname: Bridges
authors.forename: S P
authors.initials: SP
authors.lastname: Schwenzer
authors.forename: K W
authors.initials: KW
authors.lastname: Lewis
authors.forename: K M
authors.initials: KM
authors.lastname: Stack
authors.forename: D
authors.initials: D
authors.lastname: Rubin
authors.forename: L C
authors.initials: LC
authors.lastname: Kah
authors.forename: J F
authors.initials: JF
authors.lastname: Bell
authors.forename: J D
authors.initials: JD
authors.lastname: Farmer
authors.forename: R
authors.initials: R
authors.lastname: Sullivan
authors.forename: T
authors.initials: T
authors.lastname: Van Beek
authors.forename: D L
authors.initials: DL
authors.lastname: Blaney
authors.forename: O
authors.initials: O
authors.lastname: Pariser
authors.forename: R G
authors.initials: RG
authors.lastname: Deen