Miocene through Pleistocene Diatom biostratigraphy, the Antarctic margin off Wilkes Land, Integrated Ocean Drilling Program Expedition 318 rise sites

During Integrated Ocean Drilling Program (IODP) Expedition 318, six holes were drilled at three sites (U1356, U1359, and U1361) on the continental rise along the Antarctic margin off Wilkes Land. The rise sediments proved to be good paleomagnetic recorders and provided continuous magnetostratigraphic records at all three sites. Biosiliceous microfossils were present in the middle Miocene through Pleistocene sections. We applied diatom zonation of Harwood and Maruyama (1991) with published age of Coddy et al. (2008) during the expedition. Offset of diatom biostratigraphic events and geomagnetic polarity in uppermost Miocene to lowermost Pliocene section has been observed at Sites U1359 and U1361as same as in the Antarctic Peninsula (Iwai et al., 2001, Leg 178SR). This is the first attempt at direct calibration of Antarctic biostratigraphic events to the geomagnetic polarity timescale in the western Pacific sector of the Antarctic Ocean.