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).