Eighty-two cores of Quaternary and Quaternary/Tertiary sediments were taken by the R/V Sonne in the Exmouth and Wallaby Plateau areas off northwestern Australia in 1979. The Quaternary sediments show a systematic variation in composition with water depth which basically reflects change in the abundance and nature of certain biogenic components. These changes are mainly related to the positions of the aragonite and carbonate compensation depths, which presently lie in the region at about 800 m and between 4100 and 4800 m, respectively. The sediments form four major facies, ranging from relatively coarse carbonate sands on the continental shelf to siliceous clays on the abyssal plains. Tertiary sediments, which were penetrated in four of the cores, mainly consist of Oligocene or Miocene foraminiferal nanno oozes or chalks. A volcaniclastic sandstone containing rounded phosphatic nodules was penetrated on the eastern margin of the Wallaby Plateau and is consistent with the proposed volcanic origin of the plateau.