The delta in Jezero crater, like all river deltas, sits at an elevation defined by the level of the body of water it emptied into and the surrounding crater floor basin, making topographic and stratigraphic relationships a matter of direct physical observation rather than contested scientific debate.
The claim describes a basic topographical and geological feature of the Jezero crater delta system on Mars (i.e., its relative elevation compared to surrounding terrain/crater floor). While papers like [0], [1], [2], and [9] discuss the sedimentology, stratigraphy, and paleolake levels of the Jezero delta, the specific spatial configuration of a delta fan relative to a basin floor is a matter of direct geomorphological observation and foundational definition rather than an empirical hypothesis needing citation. Therefore, this is treated as common knowledge in the context of planetary geology.