Phytolith recovery from core MD88-779

Core MD88-779 was taken during the 1988 French APSARA IV cruise in the South East Indian Ocean. The core was situated on the South Tasman Rise (47º50.690S, 146º32.750E) at a depth of 2260m. Although the core recovered was 6.7m long, only the top 2.6m were studied as preliminary investigations had indicated that this section covered the last two glacial cycles.

Analysis of the sediment identified phytoliths in the core material. This is significant as this was the first known report of phytoliths in core material this south of Australia. Phytolith material was observed sporadically down-core at the following levels; 0, 130, 140, 220 and 230 cm (approximately falling within the Holocene, 100-110 ka, and 170 ka respectively). The phytolith casts most readily identifiable were those comprising the grasses, although larger plate-like casts of trees and shrubs were observed.

岩芯MD88-779采自1988年法国APSARA IV航次于东南印度洋开展的科考作业。该岩芯布设点位位于南塔斯曼海隆（South Tasman Rise），坐标为南纬47°50.690′、东经146°32.750′，采集水深为2260米。尽管回收的岩芯总长6.7米，但仅对其顶部2.6米段开展了研究——前期预研结果显示，该段岩芯完整记录了过去两个冰期旋回。
对该岩芯沉积物的分析显示，其中存在植硅体（phytoliths）。这一发现具有重要科学意义，为已知首次在澳大利亚以南海域的海洋岩芯中发现植硅体。植硅体在岩芯剖面上的以下深度零星分布：0 cm、130 cm、140 cm、220 cm及230 cm，其对应的地质年代大致分别为全新世、10~11万年前及17万年前。其中最易识别的植硅体铸型来自禾本科植物，同时也观测到了体型更大的树木与灌木类板状植硅体铸型。