Figure F35. Zr/TiO₂ and Zr/Y ratios for first-order mid-ocean-ridge segments along EPR from 14°N to 19°S and Site 1256. Zr and Y data are taken from PETDB (www.petdb.org), and the plotted values are the average of segment centers. Error bars are 1. The spreading rate of each segment is calculated by the Online Ridge Spreading rate calculator (www.ldeo.columbia.edu/users/menke/plates.html). The spreading rate of Site 1256 is given by Wilson (1996). The range of latitude of each segment center is indicated by the labels underneath the x-axis, and numbers above the x-axis are the spreading rate (full rate) of each segment.