PLEISTOCENE ARAGONITE CYCLES AND TRACE ELEMENT ANALYSIS OF BASINAL DRIFT DEPOSITS FROM THE INNER SEA OF THE MALDIVES

The Inner Sea of the Maldives is an isolated bank-internal basin in the Indo-Pacific with significant archival potential for climate-driven sedimentation. In this study, high-resolution bulk sediment data of drift deposits from basinal site U1467B of Expedition 359 of the International Ocean Discovery Program (IODP) were profiled via standard X-ray powder diffraction (XRD) methods for their aragonite content. Preliminary results reveal cyclic variations in aragonite content over depth and fluctuations in calcite and dolomite over a core encompassing 100 mbsf. Downcore peak intensity variations between primary carbonate minerals probably originate via episodic sea-level fluctuations whereby Maldivan carbonate platforms were overprinted by sea-level highstands. Spatial content distributions of detrital quartz and terrigenous sediments in analogue carbonate drift basins have been linked to regional glacial and interglacial periods (South Asian Monsoon). Hence, the ongoing downcore analysis of these sediments via XRD and major and trace elements via XRF and ICP-MS techniques may therefore constrain the timing and duration of mixed carbonate-siliclastic depositional successions and lend insight into the wider oceanographic paleoconditions of the Western Indo-Pacific realm.