(Table A2) Geochemistry and calculated temperatures for carbonates of ocean crust@en

Sediment depth is given in mbsf. Age represents the crustal age. Carbonate powders were analysed for C and O isotopes in a Finnigan Delta XL Plus mass spectrometer, using a gas bench with A200s autosampler at the Pacific Centre for Isotopic and Geochemical Research, University of British Columbia. Helium was used to displace air in the headspace and CO2 gas was liberated using 100% phosphoric acid. The results are reported using the d notation measured in per mil relative to the VSMOW standard. After correction for fractionation, repeated analyses of NBS 18 gave an average d13C value of -5.01 ± 0.07? and d18O value of 7.23 ± 0.08 per mil, NBS 19 gave an average d13C value of 1.93 ± 0.08 per mil and d18O value of 28.74 ± 0.18 per mil. Precision was ± 0.1 per mil on 13C and ± 0.2 per mil on 18O. Strontium isotopes were measured Strontium was separated by standard cation exchange techniques (Weis et al., 2006) and measured using a Triton thermal ionization mass spectrometry at the Pacific Centre for Isotopic and Geochemical Research, University of British Columbia. The NBS 987 standard gave 87Sr/86Sr = 0.710241 ± 0.000025 (2 s.d., n= 12); the average reproducibility was ± 0.000012 (n=3).沉积物深度以海底以下米数（meters below seafloor, mbsf）计。年龄指代地壳形成年龄。碳酸粉末样品的碳、氧同位素分析在不列颠哥伦比亚大学太平洋同位素与地球化学研究中心（Pacific Centre for Isotopic and Geochemical Research）完成，采用搭载A200自动进样器（A200s autosampler）的气体样品制备台（gas bench）与Finnigan Delta XL Plus型质谱仪（Finnigan Delta XL Plus mass spectrometer）。实验流程为：以氦气置换样品顶空的空气，随后使用100%磷酸释放二氧化碳气体。分析结果采用δ标记法（δ notation）报告，测量值以相对于维也纳标准平均海洋水（Vienna Standard Mean Ocean Water, VSMOW）的千分比表示。经分馏效应校正后，对NBS 18标准物质的重复分析结果显示，其δ13C平均值为-5.01 ± 0.07?，δ18O平均值为7.23 ± 0.08‰；对NBS 19标准物质的重复分析结果显示，其δ13C平均值为1.93 ± 0.08‰，δ18O平均值为28.74 ± 0.18‰。本次分析的碳同位素（13C）精度为±0.1‰，氧同位素（18O）精度为±0.2‰。锶同位素分析流程为：先采用标准阳离子交换技术（Weis等，2006）分离样品中的锶元素，随后在不列颠哥伦比亚大学太平洋同位素与地球化学研究中心，使用Triton热电离质谱仪（Triton thermal ionization mass spectrometry）完成同位素比值测量。NBS 987标准物质的测量结果为87Sr/86Sr = 0.710241 ± 0.000025（2倍标准偏差，n=12）；平均重现性为±0.000012（n=3）。