A stratigraphic framework of the Jezero upper fan succession observed in an erosional window at Gnaraloo Bay, Jezero crater, Mars.;#160;

The NASA Perseverance rover has been traversing the Jezero western fan, a clastic succession on the western rim of Jezero crater, containing a series of rocks deposited between ~3.63.8 Ga that show evidence of basinward prograding fluvialdeltaic depositional conditions. The lowest stratigraphy in the Jezero fan records a transition from igneous crater floor material to distal deltaic deposits. A transition to fluviodeltaic and periodic debris flow deposition is recorded in the upper fan series: The Tenby formation sandstones are comparable to terrestrial meandering fluvial systems, planarbedded coarse sandstones of the Otis Peak member overlie the Tenby formation, and a blocky unit of boulder deposits, referred to as the Boulder Unit tops the fan. To the west and north, the upper fan overlies a carbonatebearing sandstone deposited on the crater rim: the Margin Unit. The contacts between these units have been obscured for much of the traverse, precluding detailed assessment of their stratigraphic relationships.