A lacustrine paleoenvironment recorded at Vera Rubin ridge, Gale crater: 1 Overview of the sedimentology and stratigraphy observed by the Mars 2 Science Laboratory Curiosity rover 3 4

The Glen Torridon (GT) region within Gale crater, Mars, occurs in contact with the southern side of Vera Rubin ridge (VRR), a well‐defined geomorphic feature that is comparatively resistant to erosion. Prior to detailed ground‐based investigation of GT, its geologic relationship with VRR was unknown. Distinct lithologic subunits within the Jura member (Murray formation), which forms the upper part of VRR, made it possible to be also identified within GT. This indicates that the strata pass across the geomorphic divide between regions. Furthermore, the cross‐bedded lower part of the overlying Knockfarril Hill member (Carolyn Shoemaker formation) also occurs within both VRR and GT. Correlation of both units demonstrates that the strata form a continuous stratigraphic succession regardless of large‐scale geomorphic expression. The lithologic change from mudstone (Jura member) to cross‐bedded sandstone (Knockfarril Hill member) heralds a significant shift in paleoenvironment from lacustrine to fluvial. The upper part of the Knockfarril Hill member consists of interbedded mudstone and sandstone that transitions to the overlying finely laminated mudstone of the Glasgow member, and a return to lacustrine deposition. In GT, the Stimson formation unconformably overlies the Glasgow member, where it demarks the southern boundary of GT. Contacts for each stratigraphic unit were defined and transferred to a high‐resolution image base to make a geologic map and cross sections perpendicular to the NE strike. Stratal dips cannot exceed 2° NW to retain the positions of stratigraphic units in the locations they are exposed throughout GT.

Hydrated carbonates indicate that the surface of Ceres is recent and dehydration is ongoing, implying a still-evolving body.

 Subaerial and subaqueous facies were identified within stratigraphy of the Hartmann's Valley and Karasburg members of the Murray formation.  Sedimentologic, stratigraphic, and geochemical evidence suggests that facies formed in a landscape capable of sustaining water.  These members extend the range of facies and environments identified within the Murray formation.

Ground-based bedding orientation measurements are critical to determine the geologic history and processes of sedimentation in Gale crater, Mars. We constrain the dip of lacustrine strata of the Blunts Point, Pettegrove Point, and Jura members of the Murray formation using a combination of regional stratigraphic correlations and bed attitude measurements from stereo Mastcam images taken by the Mars Science Laboratory Curiosity rover. In situ bed attitude measurements using a principal component analysis-based regression method reveal a wide range of dips and dip azimuths owing to a combination of high stereo errors, postdepositional deformation of strata (e.g., fracturing, rotation, and impact cratering), and different primary depositional dips. These constrain regional dips to be within several degrees of horizontal on average. Stratigraphic correlations between targets observed in the Glen Torridon trough and at the Pettegrove Point-Jura member contact of Vera Rubin ridge (VRR) constrain dips to be between 3°SE and 2°NW, consistent with nearly flat strata deposited horizontally on an equipotential surface. The Jura member is determined to be stratigraphically equivalent to the northern portion of the Glen Torridon trough. Rover-based dip magnitudes are generally significantly shallower than the orientation of VRR member contacts measured from High Resolution Imaging Science Experiment-based traces, suggesting the sedimentary strata and VRR member contacts may be discordant.Plain Language Summary The orientation of sedimentary strata is one of the most fundamental measurements of structural geology because it records information about the processes of deposition and subsequent deformation of those strata. For the last 7 years, the Curiosity rover has traversed predominantly fluviolacustrine (river-and lake-deposited) strata. Recently, the rover traversed the Vera Rubin ridge (VRR), a topographic rise within a larger collection of strata with rock exposures whose orientation can be measured using overlapping (stereo) images taken by cameras aboard the rover. By measuring the orientation of beds in stereo rover images and comparing the elevation of similar rock lithologies found along the traverse, we constrain the strata that comprise the VRR to be horizontal or only shallowly dipping. This result is consistent with the sediment that formed the VRR being deposited on a nearly horizontal surface, suggesting that at least the strata that make up the lower portion of Mount Sharp, the large sedimentary mound in Gale crater that dips more steeply outward, may not have directly contributed to its primary formation. The near-flat orientation also indicates that some portion of the VRR occurs at the same elevation as the region south of the ridge called Glen Torridon.