Jarosite and Alunite in Ancient Terrestrial Sedimentary Rocks: Reinterpreting Martian Depositional and Diagenetic Environmental Conditions.

ABSTRACT: Members of the alunite group are precipitated at low pH (<1 to ~4) in oxidizing environments, are unstable in circumneutral conditions, and are widespread on Mars. At Mollies Nipple in Kane County, Utah, USA, jarosite and alunite are abundant as diagenetic cements in Jurassic sandstones. This research characterizes the jarosite and alunite cements with the goal of determining their origin, and tests the hypothesis that jarosite and alunite may be more stable than the current understanding indicates is possible. Previous studies have placed the jarosite- and alunite-bearing caprock at Mollies Nipple in the Navajo Sandstone, but the presence of water-lain deposits, volcanic ash, volcanic clasts, and peloids show that it is one of the overlying Middle Jurassic units that records sea level tra

SUBMITTER: Potter-McIntyre SL 

PROVIDER: S-EPMC6160914 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature