Template talk:Timeline Lunar Geological Timescale

Nomenclature is based on Stoffler and Ryder (2001), except that "Lower" and "Upper" have been used instead of late and early, respectively. Colors based on USGS lunar geologic maps. Ages are one set of estimates from Wilhelms (1987) [need to check this].

Lower and Upper is wrong.
An epoch is a geochronological unit of time. Geochronological units are called Early and Late Imbrian. Lower and Upper Imbrian indicates that it's a chronostratigraphic unit i.e. segments of rock. During the Early/Late Imbrian epoch the Lower/Upper Imbrian series (rock segments) were created. --Regards, Necessary Evil (talk) 23:23, 27 March 2009 (UTC)