50th Lunar and Planetary Science Conference 2019 (LPI Contrib. No. 2132) 2050.pdf INTERPRETING AQUEOUS ALTERATION IN THE MURRAY FORMATION USING REACTIVE TRANSPORT MODELING E.M. Hausrath1, D.W. Ming2 , E.B. Rampe2, and T. Peretyazhko3 1UNLV, Las Ve- gas, NV 89154
[email protected], 2NASA Johnson Space Center, Houston, TX 77058 3Jacobs, NASA Johnson Space Center, Houston TX 77058 Introduction: Abundant evidence for liquid water Methods: Mineralogy was input into CrunchFlow exists at Gale crater, Mars [e.g. 1]. However, the char- as two layers of different compositions. The bottom acteristics of past water remain an area of active re- layer was based on CheMin measurements of Mojave search. The first exposures of the Murray formation in and Confidence Hills samples, and the top layer on Gale crater, Mars (Fig. 1) were studied with four sam- CheMin measurements of Buckskin and Telegraph ples analyzed using CheMin: Buckskin, Telegraph Peak samples, including proposed past dissolution [2]. Peak, Mojave, and Confidence Hills [2]. Analyses Both layers contained plagioclase, pyroxene, olivine, indicate differences in mineralogy and chemistry be- magnetite, fluorapatite, glass, and hisingerite; the top tween the samples which have been attributed to layer also contained cristobalite and tridymite, and the changes in pH and oxidation state of depositional and lower layer nontronite. In addition to the minerals diagenetic environments [2-6]. Recent work also sug- input, the secondary phases amorphous silica, hema- gests that hydrothermal fluids may have been present tite, ferrihydrite, jarosite, gypsum, and clinochlore based on the presence of Se, Zn, Pb, and other ele- were included based on measurements by CheMin and ments [7, 8].