Detailed reVISIOn of geologic maps, sections, and columns of Kamo Mine area are based primarily upon the interpretation of fieldwork and drilling, both before and after the complete flooding of New Kamo Mine in November 1955. The Kamo Coal Measures (Kaiatan-Runangan), Ruatangata Sandstone (Runangan), Whangarei Limestone (Landon), and Waitakian sandstones are referred to the Te Kuiti Gronp. The Onerahi Formation of Ferrar has been re-defined as comprising a chaotic assemblage of upper Cretaceous and Eocene argillaceous rocks, and much rarer Waitakian sandstones, that now overlies the Te Kuiti Group and probably the Parahaki dacites of about Taranaki age. This formation is considered to have been emplaced locally by gravity slumping, shortly after Kaikoura faulting. Its source was probably an overthrust, nappe, piercement, or diapiric structure to the west. Kerikeri basaltic volcanism followed the formation of a terrace at about 220 ft A.S.L. (Milazzian).