Data of Extremely high alkalinity due to dissolution of Mg-rich phyllosilicate in the hemipelagic sediments of the Ulleung Basin (East/Japan Sea): stable Si isotopic evidence and reactive transport modeling

The Supplementary Material includes two files: File 1 includes measure results for porewater (Table S2), leachates (Table S3) and standards (Table S4). File 2 includes (1) descriptions of the procedure of a revised sequential leaching protocol (content 1), acid-base reactions (content 2), rate expressions of transition state theory (TST) (content 3), microbial processes and rate expressions of Monod equation (content 4), contributions of marine silicate alteration (content 5), and representative Si phase of leachate (content 6). (2) Figures geochemistry of leachates and porewater (Fig. S1), saturation index of minerals and opal in simulations (Fig. S2), and comparison of NaOH leaching efficiency between our previous and modified protocols (Fig. S3). (3) Equations and values used in the modeling (Table S5), measured results of leachate from two protocols and porewater (Table S6), and Si isotopic composition of porewater references (Table S7).本补充材料包含两份文件： 文件1涵盖孔隙水（对应表S2）、浸出液（对应表S3）及标准物质（对应表S4）的测定结果。 文件2包含：(1) 修订后的连续浸提方案流程说明（内容1）、酸碱反应（内容2）、过渡态理论（Transition State Theory, TST）的速率表达式（内容3）、微生物过程及莫诺方程（Monod equation）的速率表达式（内容4）、海洋硅酸盐蚀变的贡献（内容5），以及浸出液中典型硅相的表征（内容6）；(2) 浸出液与孔隙水的地球化学特征图件（图S1）、模拟实验中矿物与蛋白石的饱和指数图（图S2），以及本研究前期与改进后浸提方案的NaOH浸提效率对比图（图S3）；(3) 建模所用的方程与参数值（表S5）、两种浸提方案下的浸出液及孔隙水实测结果（表S6），以及孔隙水参考样的硅同位素组成（表S7）。