(Table 1) Bulk carbonate content of ODP Hole 194-1198A sediments, east of the Great Barrier Reef

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.

大堡礁东侧的上第四纪沉积序列以富硅质碎屑沉积层与富碳酸盐沉积层交替发育为典型特征，该沉积层序的交替变化由各类沉积组分的输入通量变化所驱动，并可通过岩芯中的全岩碳酸盐含量（bulk carbonate content）变化得到直观反映。针对大洋钻探计划（Ocean Drilling Program）1198A钻孔中海底以下0至23.69米（mbsf）的晚更新世沉积物，研究人员采用碳酸盐弹法（carbonate-bomb technique）共完成153次全岩碳酸盐含量测定。本次研究的平均样品分辨率为15厘米，且对每个样品均开展了多次平行分析。全岩碳酸盐含量的变化区间为73 wt%至94 wt%，其中最大值94 wt%出现在13.63 mbsf处，最小值73 wt%则见于14.54 mbsf处。本次研究共观测到5个沉积旋回趋势，其可能与第四纪过去50万年以来的5次重大冰期事件相关联。