Depositional and Diagenetic Sulfates of Hogwallow Flats and Yori Pass, Jezero Crater: Evaluating Preservation Potential of Environmental Indicators and Possible Biosignatures From Past Martian Surface Waters and Groundwaters

• Published in: Journal of geophysical research. Planets 2024-02, Vol.129 (2), p.n/a
• Main Authors: Benison, Kathleen C., Gill, Karena K., Sharma, Sunanda, Siljeström, Sandra, Zawaski, Mike, Bosak, Tanja, Broz, Adrian, Clark, Benton C., Cloutis, Edward, Czaja, Andrew D., Flannery, David, Fornaro, Teresa, Gómez, Felipe, Hand, Kevin, Herd, Chris D. K., Johnson, Jeffrey R., Madariaga, Juan Manuel, Madsen, Morten B., Martinez‐Frías, Jesús, Nachon, Marion, Núñez, Jorge I., Pedersen, David A. K., Randazzo, Nicholas, Shuster, David L., Simon, Justin, Steele, Andrew, Tate, Christian, Treiman, Allan, Uckert, Kyle, Williams, Amy J., Yanchilina, Anastasia
• Format: Article
• Language: English
• Subjects: Abrasion; biosignatures; cement (sedimentology); Cements; Chemical sediments; Craters; Crystals; Cutting; deposition; diagenesis; Earth; environmental indicator; Environmental indicators; fluid inclusion; fluid inclusions; Grains; groundwater; Hematite; Inclusions; Indicators; Lakes; Mars; Mars surface; Microorganisms; Minerals; Organic compounds; Outcrops; petrography; preservation; Rocks; Sand; Sandstone; Sediments; Silt; sulfate; Sulfates; Surface water
• ISSN: 2169-9097; 2169-9100; 2169-9100
• DOI: 10.1029/2023JE008155

The Mars 2020 Perseverance rover has examined and sampled sulfate‐rich clastic rocks from the Hogwallow Flats member at Hawksbill Gap and the Yori Pass member at Cape Nukshak. Both strata are located on the Jezero crater western fan front, are lithologically and stratigraphically similar, and have been assigned to the Shenandoah formation. In situ analyses demonstrate that these are fine‐grained sandstones composed of phyllosilicates, hematite, Ca‐sulfates, Fe‐Mg‐sulfates, ferric sulfates, and possibly chloride salts. Sulfate minerals are found both as depositional grains and diagenetic features, including intergranular cement and vein‐ and vug‐cements. Here, we describe the possibility of various sulfate phases to preserve potential biosignatures and the record of paleoenvironmental conditions in fluid and solid inclusions, based on findings from analog sulfate‐rich rocks on Earth. The samples collected from these outcrops, Hazeltop and Bearwallow from Hogwallow Flats, and Kukaklek from Yori Pass, should be examined for such potential biosignatures and environmental indicators upon return to Earth. Plain Language Summary Images and compositional data of Mars rocks taken by the Mars 2020 Perseverance Rover at Hogwallow Flats and Yori Pass in Jezero crater show an abundance of sulfate minerals. The goal of this study was to describe the characteristics of these rocks with close‐up views of places where these rocks were abraded to expose fresh rock surface, and to make preliminary interpretations of any preservation potential of any possible environmental and biosignature data. We found sand and silt grains with a variety of colors, some of which are sulfate minerals. We also found sulfate mineral crystals between and cross‐cutting the grains. The sulfate sand and silt grains may have originally grown as chemical sediments in past salty lakes, and the sulfate crystals found between and cross‐cutting the grains formed from past salty groundwater. Sulfate mineral grains and crystals on Earth contain fluid and solid inclusions, which are remnant water, air and other gases, other minerals, and microorganisms and organic compounds. From this knowledge of terrestrial sulfate minerals, we suggest that samples of Hogwallow Flats and Yori Pass, if returned to Earth, should be investigated for fluid and solid inclusions to be evaluated for any enclosed past Martian water, gas, minerals, and possible biosignatures. Key Points We describe sub‐mm scale observations for a