Contact between layered sulfate & clay bearing strata and fluvial channel at Gale crater Latitude/longitude: 4°46'26" S, 137°23'42" E Rationale: Alteration of sulfates in bedrock associated with ancient fluvial activity Morphology and Mineralogy: Location is the contact between older layered rocks and younger fluvial channel. Sulfates & clays in layered rock What will the rover specifically do here? Use the contact to test whether the sulfates were: 1) deposited with the layered rock; 2) due to alteration during the episode of fluvial activity; or 3) from a later weathering episode. (This image was taken from the sample landing site PowerPoint presentation because is overlaps the proposed target.)

500 m Target of interest (see next slide) PSP_009149_1750 Layered rocks that should have variable composition, possibly altered by fluvial activity. This target overlaps the previously proposed Gale 8 target in location, but articulates a more specific hypothesis at a more specific site. (This image was taken from the sample landing site PowerPoint presentation because it overlaps the proposed target.)

Lower Mound - Fluvial Sediment Contact (oblique view of PSP_009149_1750 draped on HiRISE DTM; north arrow in upper right corner) 20 m Fluvial Sediment Lower Mound Strata Contact Fluvial Breccia

Target of interest From R. Milliken 4 th MSL workshop presentation (These image were taken from the sample landing site PowerPoint presentation because they overlap the proposed target.)