(Table T1) Phosphorus and metal concentrations of ODP Site 189-1171

A primary goal of Leg 189 was to evaluate Cenozoic changes in ocean circulation and the subsequent influence on climate variability (Exon, Kennett, Malone, et al., 2001, doi:10.2973/odp.proc.ir.189.2001; Exon et al., 2002, doi:10.1029/2002EO000176). Our approach is to use bulk sediment geochemical records to try to understand the influences of changing ocean circulation and climate on biogeochemical cycles and export production (e.g., Latimer and Filippelli, 2001, doi:10.1029/2000PA000586; 2002, doi:10.1016/S0031-0182(01)00493-X).
Site 1171 (48°S, 149°E) is located on the South Tasman Rise at a water depth of ~2150 m. Late Paleocene to late Eocene age sediments represent shallow-water silty claystones and claystones (Exon, Kennett, Malone et al., 2001, doi:10.2973/odp.proc.ir.189.2001). A 6-m section of glauconitic sandstone to siltstone is observed in the uppermost upper Eocene and is followed by a sharp lithologic change from shallow-water siliciclastics to pelagic carbonates (Exon, Kennett, Malone, et al., 2001, doi:10.2973/odp.proc.ir.189.2001). Sediments of Oligocene age to present are predominantly nannofossil ooze or chalk.
Sediment geochemistry allows us to identify changes in metal sources and terrigenous inputs using elemental data based on Fe, Al, and Ti concentrations and elemental ratios, such as Al/Ti and Fe/Ti. To assess export production, we use records of phosphorus (P) and barium (Ba) concentrations and P/metal and Ba/metal ratios, with elevated values being interpreted as higher export production.

大洋钻探计划第189航次（Leg 189）的核心目标为解析新生代海洋环流演化及其对气候变率的后续影响（Exon、Kennett、Malone等，2001，doi:10.2973/odp.proc.ir.189.2001；Exon等，2002，doi:10.1029/2002EO000176）。本研究采用沉积物全岩地球化学记录，旨在探究海洋环流与气候演化对生物地球化学循环及生物输出生产（export production）的调控作用（例如：Latimer与Filippelli，2001，doi:10.1029/2000PA000586；2002，doi:10.1016/S0031-0182(01)00493-X）。
1171站位（Site 1171，48°S，149°E）位于塔斯曼海岭（South Tasman Rise），水深约2150米。该站位晚古新世至晚始新世的沉积物为浅海相粉砂质黏土岩与黏土岩（Exon、Kennett、Malone等，2001，doi:10.2973/odp.proc.ir.189.2001）。在上始新统顶部可见一套厚度6米的海绿石砂岩（glauconitic sandstone）-粉砂岩序列，其后伴随一次由浅海硅质碎屑岩（siliciclastics）向远洋碳酸盐岩（pelagic carbonates）的显著岩性转变（Exon、Kennett、Malone等，2001，doi:10.2973/odp.proc.ir.189.2001）。渐新世至今的沉积物以颗石藻软泥（nannofossil ooze）或白垩（chalk）为主。
沉积物地球化学分析可依托铁（Fe）、铝（Al）、钛（Ti）的元素浓度及Al/Ti、Fe/Ti等元素比值，识别金属物质来源与陆源输入（terrigenous inputs）的演化特征。为评估生物输出生产强度，本研究采用磷（P）、钡（Ba）的元素浓度及P/金属、Ba/金属比值作为替代指标，其中比值升高指示更高的生物输出生产水平。