Geological Chronicle
Mons Hadley Delta is a 17.24-kilometer-wide massif situated in the northern portion of the Montes Apenninus adjacent to Mare Imbrium. The peak rises 3.6 kilometers above the plains to its north and west. A valley lies directly north of the mountain, bordered to the northeast by the higher peak of Mons Hadley and to the west by the sinuous Rima Hadley rille.
During the Apollo 15 mission in 1971, astronauts David Scott and James Irwin explored the lower reaches of the mountain's north slope. They established sampling sites near St. George crater and Spur crater, where they recovered sample 15415, known as the Genesis Rock. An anorthosite clast within this sample is likely a piece of the Moon's primordial crust.
The mountain's name derives from the neighboring peak Mons Hadley, which honors John Hadley, the English mathematician and inventor of the octant.