Fig. 6
From: Origin of ocean island basalts in the West African passive margin without mantle plume involvement
Sr–Nd–Hf–Pb isotopic compositions of Cameroon volcanic line (CVL) basalts plotted with other West African passive margin intraplate basalts. a 206Pb/204Pb vs. 207Pb/204Pb; b 206Pb/204Pb vs. 208Pb/204Pb; c 87Sr/86Sr vs. 143Nd/144Nd; and d 143Nd/144Nd vs. 176Hf/177Hf. The data for Mt. Cameroon are from ref. 20. The range for mid-ocean ridge basalt (MORB) shown with broken curves was compiled with high-precision Atlantic MORB data collected between 30°N and 30°S; these data were analysed either by the double spike or Tl-addition methods and were compiled from the PetDB database (www.earthchem.org/petdb). The data for the Madeira Islands, the Canary Islands, the Atlas Mountains, the southern and northern Cape Verde islands, and the continental CVL were compiled by the GEOROC database. All the Pb isotopic data for the Canary Islands, Cape Verde, and the continental sector of the CVL were analysed either by the double spike or Tl-addition methods. Because no Pb isotopic data analysed by either the double spike or Tl-addition methods were available for the Madeira and Atlas samples, the Pb data analysed by conventional methods were compiled for samples from these regions. The solid curve is the calculated Kimberlite-source mantle composition. The 2 SD error bars are smaller than the symbols for CVL data. The source data of the compiled values are provided in ref. 66
