Annotated record of the detailed examination of Mn deposits from DSDP Site 118, Leg 12 (Cores 118-17, 118-19, 118-20)

The principle objective at Site 118 was to sample a formation in the Bay of Biscay which had been tentatively ascribed to Lower Cretaceous or older sediments. However it was not clear that this corresponding seismic layer was not in fact part of an extremely irregular igneous basement structure, at least at the western end of the bay.