The crater was discovered by the Mariner 10 spacecraft in 1974, but was not named until 2009. It contains a large (29 × 29 km), nearly circular pit crater.[2] Multiple examples of pit craters have been observed on Mercury on the floors of impact craters, leading to the name pit-floor craters for the impact structures that host these features (see also Beckett and Picasso). Unlike impact craters, pit craters are rimless, often irregularly shaped, steep-sided, and often display no associated ejecta or lava flows.[2] These pit craters are thought to be evidence of shallow volcanic activity and may have formed when retreating magma caused an unsupported area of the surface to collapse, creating a pit. They are analogs of Earth's volcanic calderas.[2] Pit-floor craters may provide an indication of internal igneous processes where other evidence of volcanic processes is absent or ambiguous. The discovery of multiple pit-floor craters augments evidence that volcanic activity has been a widespread process in the geologic evolution of Mercury's crust.[3]
^ abc"Gibran (crater)". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program.
^ abcGillis-Davis, Jeffrey J.; Blewett, David T.; Gaskell, Robert W.; Denevi, Brett W.; Robinson, Mark S.; Strom, Robert G.; Solomon, Sean C.; Sprague, Ann L. (2009). "Pit-floor craters on Mercury: Evidence of near-surface igneous activity". Earth and Planetary Science Letters. 285 (3–4): 243–250. Bibcode:2009E&PSL.285..243G. doi:10.1016/j.epsl.2009.05.023. See unnamed feature 2.