Late Quaternary paleoenvironmental change on the northeast Australian margin as evidenced in oxygen isotope stratigraphy, mineral magnetism, and sedimentology

Abstract

To investigate late Quaternary paleoclimatic and palaeoceanographic change in the sedimentary record, preserved on the Australian Continental Margin during the late Quaternary, core material was collected from Ocean Drilling Program, Leg 133, Site 819. An expanded sequence of late Quantery, rhythmically bedded, predominantly hemipelagic sediments were recovered from Hole 819A. The foraminiferal δ18O record preserved at Hole 819A suggests that the late Quaternary section is incomplete. Both benthic and planktonic δ18O stratigraphies can be traced tentatively downcore to stage 9 at about 32.5 mbsf, where a major hiatus occurs. Below 32.5 mbsf, continuous correlation can be achieved in the planktonic δ18O curve, with existing deep-sea foraminiferal oxygen istope stratigraphies from stage 14 through stage 28. The change in the nature of the records in the lower and upper parts of the sequence at Site 819 are thought to reflect perturbations by the orbital eccentricity cycle. -from Authors