Surface Outcrops

Formation

Oldest age

Youngest Age

Formation

Oldest Known age

Benin/Afam Clay Member

Oligocene

Plio/Pleistocene

Benin

Miocene

Recent Agbada

Eocene

Miocene

Ogwashi-Asaba

Oligocene

Eocene

Ameki

Eocene

Recent Akata

Eocene

L. Eocene

Imo Shale

Paleocene

Palaeocene

Nsukka

Maestrichtian

Maestrichtian

Ajali

Maestrichtian

Equivalent not known

Cretaceous

Campanian

Mamu

Campanian

Campanian/Maeastchtian

Nkporo Shale

Santonian

Coniacian/ Santonian

Agwu Shale

Turonian

Turonian

Eze-Aku Shale

Turonian

Albian

Asu River Group

Albian