重建高分辨率深海环境变化:冷水竹节珊瑚无机地球化学方法

党皓文, 马小林, 杨策, 金海燕, 翦知湣

Reconstructing High-resolution Deep-sea Environmental Change: Inorganic Geochemical Proxy Methods of Cold-water Bamboo Corals

Haowen Dang, Xiaolin Ma, Ce Yang, Haiyan Jin, Zhimin Jian

图5 竹节珊瑚(Keratoisis)的硼同位素测试结果和分析 (a) 测试采样点，黄色箭头示竖向生长方向(longitudinal growth direction); (b)~(d) 依次示对应的硼(δ11B)、碳(δ13C)和氧(δ18O)同位素测试结果; (e) 竹节珊瑚δ11B (空心菱形)与冷水石珊瑚 (实心菱形)、其他海洋碳酸盐(其他标记)的比较，黑色粗实线示基于假定硼酸表观电离常数(pKB=8.78)和实测的水中硼分馏系数的海水硼酸根δ11B随pH的变化; (f) 竹节珊瑚δ11B推算的pH与海水pH的差值(ΔpH)在太平洋(方解石饱和度Ωca=0.9)和大西洋(Ωca=1.8)之间的横向比较，硼分馏系数和温度分别取αB=1.0272 (25 °C)和温度校正αB=1.0290 (3.3 °C)，绿色圆点示外围生长环、橙色方块示生长轴心样品结果;改绘自参考文献[33]

Fig.5 Boron isotope analyses and results on a bamboo coral (Keratoisis) (a) Location of samples on the skeleton, with yellow arrow showing the longitudinal growth direction; (b)~(d) The results of δ11B (B), δ13C (c) and δ18O (d) analyses; (e) The δ11B vs. pH of bamboo corals (open diamonds) and comparisons with data of cold-water scleractinian corals (filled diamonds) and other kinds of marine carbonate (other symbols), solid curve shows the δ11B of borate anion in seawater at representative deep-ocean pKB=8.78 as a function of pH based on the measured aqueous boron fractionation factor; (f) ΔpH (difference between pHapp and pHsw, pHapp: coral-δ11B calculated apparent pH, pHsw: seawater pH) for Pacific specimen (Ωcalcite=0.92) and Atlantic specimen (Ωcalcite=1.78), as calculated using αB=1.0272 (25 °C) and temperature-corrected αB=1.0290 (3.3 °C), green circles from radial thickening and orange square from the central axis; Modified after reference [33]