Imo Shale  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Cenozoic
 ...Paleogene
 ....Imo Shale
RTPaleocene
 Nigeria
 lower Eocene
 Benin
SNPaleocene to lower Eocene. Before 1989, also search Imo Formation AND Africa. Indexed with ages as applicable. Added to Thesaurus in 1989.