Named for exposures on Kamaileunu Ridge, Waianae Range, Island of Oahu. Is middle member of Waianae Volcanics. Includes Mauna Kuwale Rhyodacite Flow. Type section at Kamaileunu Ridge [21 deg 28' 42"N, 158 deg 11' 02"W, Waianae 7.5' quad] between Waianae and Makaha Valleys. Reference sections designated northeast of Puu Heleakala, between caldera boundary fault and Palehua member north of Pohakea Pass, at Puu Paheehee, and at Mauna Kuwale. Composed of olivine- and/or plagioclase-phyric tholeiitic and alkalic basalt, hawaiite, and rare ankaramite. Is 615 m thick at type section. At Mauna Kuwale reference section alkalic basalt is overlain by 1 m of icelandite airfall ash, about 59 m of icelandite block lava, 62 m of rhyodacite lava. Conformably overlies Lualualei Member (new) but locally Kamaileunu is in fault contact with Lualualei. K-Ar ages (from previous authors) range from 3.46 to 2.95 Ma.

Source: GNU records (USGS DDS-6; Menlo GNULEX).