Geological Chronicle
Birkhoff is a giant lunar walled plain on the Moon's far side, in the northern hemisphere. It is a peak-ring basin: this formation has a single interior topographic ring or a discontinuous ring of peaks, with no central peak. Birkhoff dates to the Pre-Nectarian epoch, making it one of the oldest lunar basins.
The ancient impact site has been heavily eroded and reshaped by craters inside and along its rim. The rim has worn down until it is level with the irregular external terrain, while a rugged, sloping rise remains along the inner wall. Carnot borders the outer wall to the south, Rowland runs along the west rim, and Stebbins intrudes from the north. van't Hoff lies just to the northeast.
The interior includes eroded Birkhoff X along the northwest rim and Birkhoff Q on the southwest floor. A low ridge joins Q to the double-crater formation Birkhoff K and L in the east; the smaller but relatively young Birkhoff Y and Z lie in the north. The floor is flat in places and rough in others, with many tiny craterlets. An infrared spectrum of pure crystalline plagioclase has been identified on the southern floor. The International Astronomical Union adopted the crater's designation in 1970.