Upper Quaternary sediment sequences east of the Great Barrier Reef are characterized by alternating siliciclastic- and carbonate-rich horizons caused by changes in the input of various sedimentary components and reflected in cores by variations in bulk carbonate content. A total of 153 measurements of bulk carbonate content were determined using the carbonate-bomb technique for late Pleistocene sediments between 0 and 23.69 meters below sea floor (mbsf) in Ocean Drilling Program Hole 1198A. Average sample resolution was 15 cm and multiple analyses were performed on each sample. Bulk carbonate content ranges from a maximum of 94 wt% at 13.63 mbsf to a minimum of 73 wt% at 14.54 mbsf. Five cyclic trends are observed that may relate to five major glacial events during the last 500 k.y. of the Quaternary.