(Table T3) Geochemical composition and age of ODP Site 181-1123 sediments

In 1998 Ocean Drilling Program Leg 181 off southwest New Zealand obtained cores from Site 1123 (41°47.2'S, 171°29.9'W; 3290 m water depth) on the Chatham Rise. Site 1123 sampled the North Chatham Sediment Drift, which is located between 169°W and 175°W at depths of 2200-4500 m (Carter, McCave, Richter, Carter, et al., 1999, doi:10.2973/odp.proc.ir.181.2000). This site is located just north of the productive surface waters associated with the Subtropical Front. The cores provide a relatively complete record of sedimentation on the Chatham Drift back to the early Miocene and beyond a stratigraphic gap into the early Oligocene. Drift sedimentation is partly indicated by modern paleoceanographic observations and by extensive microfossil reworking throughout the recovered sediment (Carter and McCave, 1994, doi:10.1029/94PA01444; Carter, McCave, Richter, Carter, et al., 1999, doi:10.2973/odp.proc.ir.181.2000).
Approximately 1000 sediment samples from the lower Oligocene, lower Miocene, middle Miocene, and upper Pleistocene have been analyzed geochemically for elemental concentrations. The stratigraphic intervals sampled at 5- to 10-cm intervals are listed in Table T1. The elemental concentrations, normalized by aluminium concentrations, provide proxies for factors such as nutrient levels, siliciclastic and volcaniclastic sediment composition, and bottom-water redox conditions. This approach was prompted by successes with Miocene and Oligocene deep-sea sediment elemental ratios obtained from the Ceara Rise in the western equatorial Atlantic (Weedon and Shackleton, 1997, doi:10.2973/odp.proc.sr.154.129.1997). The results for Ba/Al in the Pleistocene were discussed by Hall et al. (2001, doi:10.1038/35090552), and an interpretation of a selection of additional elemental ratios from all the stratigraphic intervals was provided by Weedon and Hall (2004, doi:10.1016/S0025-3227(04)00024-6). However, many components listed here, particularly the trace elements and rare earth elements, were not considered by Weedon and Hall (2004, doi:10.1016/S0025-3227(04)00024-6).