Winchcombe: An example of rapid terrestrial alteration of a <scp>CM</scp> chondrite

Winchcombe is a CM chondrite that fell in England on February 28, 2021. Its rapid retrieval was well characterized. Within two polished sections of Winchcombe, terrestrial phases were observed. Calcite and calcium sulfates found sample recovered from field March 6, 2021, halite observed months after its recovery driveway 2, These characterized by scanning electron microscopy, Raman spectroscopy, transmission microscopy. veins crosscut the fusion crust therefore postdate it. The calcite likely precipitated damp environment (sheep field) where meteorite lay for six days prior to retrieval. occur edges identified as three minerals: gypsum, bassanite, anhydrite. Given only sample's edges, including top crust, they formed fell. Sulfate precipitation attributed fall environment, resulted sulfide-derived H2S reacting with within meteorite. Halite occurs euhedral crystals surface section exclusively areas relatively enriched sodium. It produced interaction rock slice humid laboratory air over period months. sulfates, calcite, all post-date Winchcombe's entry into Earth's atmosphere showcase how rapidly falls can be terrestrially altered.