This spreadsheet will be submitted to JGR Solid Earth with a manuscrpt titled "Hydrothermal Seepage of Altered Crustal Formation Water Seaward of the Middle America Trench, Offshore Costa Rica" by Parsons et al. Keywords include Ridge flank, hydrothermal, Middle American Trench, hydrogeology, formation water, and pore water. Three short highlights include: Pore water chemical profiles reveal sediment diagenesis and seepage speeds up to 1.7 cm yr-1 resulting in a net flux of 0.1 L s-1. Crustal formation water is warm (~75ºC) and chemically altered, stemming from water-basalt reactions and diffusive exchange with pore water. This ridge-flank hydrothermal system is not hydrologically connected to the ventilated crust to the west or the trench to the east.

Data are mostly pore water chemical compositions but do include some model results using the WORM portal.