<b>Basalts Through Time — Roy et al. (2026), Communications Earth & Environment</b>

This repository contains the supplementary data accompanying the manuscript: Roy, S., Kamber, B.S., Hayman, P.C. et al. Tectonic setting and mantle source evolution reconstructed from deep time analysis of basalt geochemistry. Commun Earth Environ (2026). https://doi.org/10.1038/s43247-026-03473-4 The study presents a global deep-time analysis of basalt CIPW normative mineralogy, tracking secular changes in basalt petrology from the Archaean to the present day. Key findings include: - Archaean continental basalts are dominantly quartz-normative (~49%), with striking compositional similarity to Phanerozoic continental flood basalts. - Normative clinopyroxene/orthopyroxene ratios argue against dominant hydrous flux-melting as a petrogenetic mechanism for Archaean basalts. - A progressive secular increase in nepheline-normative (alkali) basalts, with a pronounced step-change near the Precambrian–Phanerozoic boundary, attributed to widespread mantle hybridisation following the onset of sustained, modern-style deep subduction in the Neoproterozoic. - Two lulls in Palaeoproterozoic mafic magmatic activity are identified: the established Tectono-Magmatic Lull (~2,365–2,235 Ma) and a newly recognised lull at ~2,000 Ma. FILES INCLUDED Supplementary Data 1 — Compiled whole-rock geochemical database Supplementary Data 2 — Experimental melt compositions Supplementary Data 3 — LDA analysis outputs Supplementary Data 4 — MAGEMin fractional crystallisation model output Supplementary Information — Supplementary figures, tables, notes, and references (PDF) Python scripts for all figures are available at: https://github.com/INDeep-earth/roy-2026-basalt-normative-mineralogy