Figure F15. Interpretative summary of the lithology, morphology, and mineralogy of basement units sampled in the basement units at Site 1140. Boundaries for igneous Units 1-6 are indicated. Note that the contact between Units 1 and 2 was not recovered and has been located using downhole logging data (see "Physical Volcanology" and "Downhole Measurements"). The occurrence of plagioclase, olivine, and clinopyroxene phenocrysts is indicated as well as the presence of glassy margins. A reversal of the magnetic field occurred between the time of eruption of Units 1 and 2 (see "Paleomagnetism"). The density log (see "Downhole Measurements") and its interpretation are shown schematically to provide information about the lithology of unrecovered Cores 183-1140A-29R and 30R.