Elemental composition and chemical evolution of geologic materials in Gale crater, Mars: APXS results from Bradbury Landing to the Vera Rubin Ridge

Abstract

The Alpha Particle X-ray Spectrometer (APXS) on the Mars rover Curiosity analyzed more than 700 targets during its first 2,301 martian solar days after landing (sols; 1 sol = 24.7 h). The primary objectives of APXS investigations are to determine the elemental composition of geologic materials in Gale crater to infer the geologic and climate history, establish whether or not liquid water was stable for extended periods, constrain the geochemical conditions of ancient liquids, and deduce the provenance of sedimentary materials

Elemental Composition and Chemical Evolution of Geologic Materials in Gale Crater, Mars: APXS Results From Bradbury Landing to the Vera Rubin Ridge

“…The result is a bulk composition with same or greater TiO 2 , FeO, K 2 O, and P 2 O 5 , and depleted MnO, MgO, and CaO, which is similar to the trend observed in the Murray formation bedrock. Elements that were mobilized and removed from the bulk rock are accounted for in the closed Gale crater basin by the Mg‐ and Ca‐sulfates in veins and concretions, and in highly localized Mn‐rich features (Berger et al., 2019).…”

X‐Ray Amorphous Components in Sedimentary Rocks of Gale Crater, Mars: Evidence for Ancient Formation and Long‐Lived Aqueous Activity

“…As of sol 2300, CheMin had analyzed 12 drill hole locations within the Mount Sharp group (Achilles et al., 2020; Morris et al., 2016; Rampe, Bristow, et al., 2020; Rampe et al., 2017). Most of these rocks are fluviolacustrine mudstones and fine‐grained sandstones (e.g., Rivera‐Hernández et al., 2020) that have geochemical compositions distinct from sediments in the Bradbury group (Berger et al., 2020; Thompson et al., 2020) indicating a change in dominant sediment sources. Mount Sharp group sediment compositions are mostly fractionated, relatively SiO 2 ‐rich subalkaline basalt (Bedford et al., 2018).…”

Source‐to‐Sink Terrestrial Analogs for the Paleoenvironment of Gale Crater, Mars

“…(2018), and Berger et al. (2020). Terrestrial data sets are compiled in the supporting information text S1, and data are available from Gibson et al.…”

“…However, the nature of the sedimentary rocks higher in the strata of the Murray formation is complicated by more significant diagenetic overprints (e.g., Fraeman et al., 2020; Rampe et al., 2020) as well as diverse amorphous compositions (e.g., Achilles et al., 2020), both of which obscure geochemical signatures from subaerial weathering (Siebach & McLennan, 2018). Therefore, we only include the APXS geochemistry for the target with the highest uncorrected CIA value from the Karasburg, Sutton Island, and Blunts Point members (Berger et al., 2020), which are less impacted by these complicating factors, as well as the APXS analyses (Berger et al., 2020) and CheMin‐derived mineralogy (Bristow et al., 2018; Rampe et al., 2020) from select drill targets in these members. These members of the Murray formation were selected because they are fine‐grained in nature and lie below (Figure ) the Vera Rubin ridge (sub‐VRR) region, which is interpreted as a significantly altered diagenetic front within the Gale crater stratigraphy (e.g., Fraeman et al., 2020; Rampe et al., 2020).…”